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Research on the Quality of the Soil and the Land Related to the Mining Perimeters in Valea Jiului

Research on the Quality of the Soil and the Land Related to the Mining Perimeters in Valea Jiului Revista Minelor – Mining Revue ISSN-L 1220-2053 / ISSN 2247-8590 vol. 28, issue 4 / 2022, pp. 1-13 RESEARCH ON THE QUALITY OF THE SOIL AND THE LAND RELATED TO THE MINING PERIMETERS IN VALEA JIULUI 1 2 * Liliana ROMAN , Mircea GEORGESCU University of Petroșani, Petroșani, Romania, lilianaaprilie40@yahoo.com University of Petroșani, Petroșani, Romania, mirgeorgescu@yahoo.com DOI: 10.2478/minrv-2022-0025 Abstract: In the paper, special attention is paid to the sources that lead to soil and land degradation in Valea Jiului, as these are the components of the environment that are most affected by mining activities. Three sources of pollution are analyzed: dumps, mine yards and constructions, and mining and preparation activities chemically polluting of soil. Among the environmental changes, land degradation currently has the most important consequences for human settlements and economic activities, especially through induced subsidence processes and the presence of dumps with reduced stability. The authors of the article propose their own method for establishing a Global Land Degradation Index (GLDI) affected by mining activities in a mining perimeter (mine) taking into account the entire analyzed area (in our case Valea Jiului) and make a classification (in three classes) of this index. Keywords: soil and land degradation, global land degradation index 1. Introduction In a region, such as Valea Jiului, where the coal mining and preparation activity has been carried out for an appreciable period of time, special attention must also be paid to the sources that lead to soil and land degradation in that region, because these are the components of the environment that are most affected by mining activities. In the following, an analysis will be made of the following sources of pollution: • dumps; • mine yards and constructions; • mining and preparation activities that pollute the soil chemically. 2. Dumps The underground mining activity has unwanted repercussions on the land surface by the fact that it involves the storage of relatively large amounts of mine tailings that contribute to changes in the morphology of the land, land uses and lead to the appearance of new forms of relief. Although compared to the area corresponding to the economic area of Valea Jiului (103,200ha), mining dumps, preparations, slag deposits and abandoned quarries occupy relatively small areas (402.02ha, 0.39%) the contrast between waste rock deposits (clays, marls, sandstones) and the surrounding areas, covered by forests, is an obvious one. The economic units (predominantly the mining ones), which affected the land in Valea Jiului to the greatest extent (mines and preparations, the Paroșeni thermal power plant, forestry and household activities) and which generated/generate degraded lands of various types, are reproduced in table 1 [1,2]. Mining dumps in Valea Jiului are usually located on slopes or along valleys, with or without drainage. The elevations of the storage lands generally vary between 650m in the axis of the valleys and 750m on the 0 0 slopes. The angle of inclination of the slopes varies between 6 and 35 . In some situations, the dumps were built in such a way that they block valleys without permanent water courses, forming lakes from waters originating from precipitation (fig.1). Corresponding author: Mircea Georgescu, Prof. PhD. Eng., University of Petroșani, Petroșani, Romania, contact details (University st. no. 20, Petroșani, Romania mirgeorgescu@gmail.com) 1 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 The presence of these lakes is extremely unfavorable from the point of view of the stability of the dumps. The water that seeps into the dump can cause landslides or plastic or muddy flows (such landslides and muddy flows affecting the colony of Lupeni Municipality) (fig. 2). Table 1. The economic units that affected the land in Valea Jiului - updated [3] Economic unit Name of objective Area, ha Surface area of Technical Stability influence, ha condition Dumps resulting from tailings extracted from underground and from the surface Jieț Shaft 5,70 0,40 Activate Relatively stable Lonea I 14,90 0,38 Conservative Stable Defor Valley 2,00 0,40 Conservative Relatively stable Lonea mine Defor open pit 12,65 1,05 Conservative Relatively stable Valley of Ciort 7,19 1,11 Conservative Relatively stable Valley Arsului 2,10 2,50 Conservative Stable Petrila mine 2 East 2,10 0,30 Rehabilitated Stable Jieț West open pit 14,75 1,50 Rehabilitated Stable South Petrila mine Shaft 4 3,12 0,20 Rehabilitated Stable Auxiliary Shaft 2, 3 2,50 0,20 Rehabilitated Stable PA-1 1,74 0,10 Rehabilitated Stable Run 1,74 0,10 Rehabilitated Stable Dâlja mine PA-1, PA-2 7,90 4,80 Rehabilitated Stable Refuse heap PA-3 1,20 0,20 Rehabilitated Stable Auxiliary Shaft East 1,55 0,30 Activate Relatively stable Livezeni mine PA-nr.2,3 Maleia 2,15 0,70 Rehabilitated Relatively stable Refuse heap Piscu 2,50 3,42 Rehabilitated Relatively stable Aninoasa mine South Funicular 2,73 0,34 Rehabilitated Stable Shaft 7 West (old) 9,10 7,60 Conservative Relatively stable ValleyArsului + P8,10 15,75 1,60 Activate Relatively stable Vulcan mine Hypollit 3,10 0,30 Conservative Relatively stable Shaft7West 6,30 0,80 Conservative Relatively stable Valley Lupului 2,80 0,50 Conservative Relatively stable Paroșeni mine Funicular 1,17 0,40 Conservative Relatively stable Refuse heap 1,37 - Conservative Relatively stable 2 West Ileana 14,26 0,04 Activate Relatively stable New branch Ileana 4,61 2,12 Rehabilitated Relatively stable Lupeni mine Victoria open pit 2,48 0,02 Conservative Stable New Victoria 6,69 2,62 Conservative Stable Mierleaşu 4,70 0,30 Rehabilitated Stable Bărbăteni mine Adit 0,20 - Rehabilitated Stable Old Funicular 11,00 3,00 Conservation Stable Balomir 2,18 0,60 Conservation Stable Uricani mine Shaft7Sterminos 3,12 0,60 Conservation Relatively stable New Funicular 2,00 3,00 Conservation Relatively stable Funicular 0,15 0,30 Rehabilitated Stable Valea de Brazi mine Shaft 8 0,04 0,01 Rehabilitated Stable Poiana Mare 9,60 - Rehabilitated Stable Galbena 1,10 - Rehabilitated Stable Câmpu lui Neag mine Șesul Șerbanilor 8,60 - Rehabilitated Stable Frasin 6,80 - Rehabilitated Stable 207,84 42,11 Sum (45,17%) Dumps from coal preparation plants Preparation plants Petrila 25,50 4,00 Conservation Relatively stable Livezeni 2,50 0,70 Activate Stable Coroiești 16,50 - Activate Relatively stable Lupeni 22,10 2,00 Conservation Relatively stable Uricani 0,10 - Conservation Relatively stable Total 66,70 6,70 (14,50%) 2 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 Waste dumps Petroșani 1,00 2,00 Activate Unstable Petrila 2,00 4,00 Activate Unstable Vulcan 1,50 3,00 Activate Unstable Lupeni 0,50 2,00 Activate Unstable Uricani 2,00 4,00 Activate Unstable Aninoasa 0,50 1,00 Activate Unstable Sum 7,50 16,00 (1,63%) Pot holes and ravines Petroșani forestry 5,00 1,00 Conservation Unstable Petrila forestry 7,00 1,50 Conservation Unstable Lupeni forestry 9,50 2,00 Conservation Unstable Sum 21,50 4,50 (4,67%) Slag and ash deposits from the power plant Power plant Paroșeni 20,00 - Activate Stable Sum 20,00 - (4,35%) Abandoned coal pits Cimpa open pit 9,30 0,75 Rehabilitated Stable Jieț Defor open pit 12,56 1,05 Rehabilitated Stable Jieț Vest open pit 6,41 0,50 Rehabilitated Stable Victoria Lupeni open pit 12,50 1,10 Rehabilitated Stable Uricani Sud open pit 4,37 0,30 Rehabilitated Stable Balomir open pit 5,25 0,60 Rehabilitated Stable Vineri open pit 0,87 0,10 Rehabilitated Stable Mîrșăveni open pit 2,50 - Rehabilitated Stable Câmpu lui Neag Zona E open pit 16,50 1,00 Rehabilitated Stable Câmpu lui Neag Zona A+C open pit 29,40 2,00 Rehabilitated Stable Galbena open pit 4,37 0,65 Rehabilitated Stable Jiri open pit 2,50 0,10 Rehabilitated Stable Buta open pit 0,95 - Rehabilitated Stable Sum 107,48 8,150 (23,36%) Land ruptures and gaps Petroșani 5,50 - Activate Relatively stable Petrila 4,30 - Activate Relatively stable Lupeni 15,30 - Activate Relatively stable Aninoasa 4,00 - Activate Relatively stable Sum 29,10 - (6,32%) Sum total 460,12 77,46 a b c Figure 1. Water accumulations in the area of Lupeni dumps (a), Valley Arsului-Lonea (b) and between the branches of the Petrila preparation dump (c) [4,5] 3 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 a b Figure 2. Lupeni (a) and New Uricani Funicular (b) dumps affected by erosion, landslides and uneven settlement [9]. The construction of tailing dumps was carried out with the help of funiculars or car transport (e.g. the Valley Arsului dump), thus ensuring both the transport and storage of tailings in the dump. Deposits were carried out on different alignments, and the discharge points were established according to the configuration of the land in the area of the respective alignment. To increase the storage capacity, the spilled material is generally leveled with the help of bulldozers, forming piling platforms. The platforms have widths at the lower part of 50-150m, and at the upper part of 15-50m. By leveling with the help of bulldozers, compaction is also achieved, which contributes to increasing the stability of waste heaps. A characteristic of the heaps is the fact that they are executed, as a rule, in one step, their parameters being dependent on the morphology of the land, the heights at which the funicular is mounted and the characteristics of the heaped rocks. The mentioned aspects have unfavorable repercussions on the stability of the dumps, affecting the lands in the immediate vicinity, in the area of influence. The height of the dumps varies between 3-4m and 30-40m. 0 0 0 The slope angle in the situations where plastic leaks have occurred has values of 7 -8 , but in general it is 40 - 50 . During the dumping or pushing of the waste material, a granulometric sorting takes place in the sense that the coarse material is deposited at the base of the pile, also, there is a tendency for the material to settle at angles greater than the final ones. In the case of land with a high slope, the flattening of the slope is more obvious and the material requires more room for expansion. Dumps are generally stable, and the stability reserve is above unitary. Relatively stable are those that have a small reserve of stability that can be canceled in the event of additional efforts or changes in the physical- mechanical characteristics of the piled rocks or the base ground due to the presence of water. Since the dumps are formed in a single step, due to the large difference in level the rocks tend to move from the slope, facilitating their breaking at the top where cracks and material displacements occur downstream. Because of the plasticity of the bedrock and the high height of the dump steps, crank of rocks occur in many situations. Currently (see table 1), tailing dumps from underground and surface mining (41) are active 4 (37.26ha- 18%), under conservation/rehabilitation 17 (91.51ha-44%), greened 20 (79.07ha-38%), are stable 23 (115.13ha-55%) and relatively stable 18 (92.71ha-45%). Tailings from coal preparations (5) are active 2 (19ha-28%), in conservation/rehabilitation 3 (47.7ha- 72%), is stable 1 (2.50ha-4%), with stability relative 4 (64.2ha-96%). The slag and ash deposits from the Paroșeni thermal power plant (the settling ponds) are in operation. The neighboring lands are not influenced at the moment, but the breaking of the dykes would have disastrous repercussions on them, the possibly affected surfaces being appreciable and difficult to estimate (fig.3). Figure 3. The settling pond of the Paroșeni thermal power plant [5] 4 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 The coal open pits (micro-open pits) in Valea Jiului, in most of them, have been freed from mining duties and tailings or household waste deposits have been created. All these warehouses have been closed and greened. The former Câmpu lui Neag open pit was filled with water, being currently used for recreation and sport fishing (fig. 4). Figure 4. Former open pit Câmpu lui Neag [4] The waste dumps are in operation, consisting of household waste (textile materials, paper, glass, wood scraps, metal, plastic materials, food scraps, ash, rubber, etc.), special waste from hospitals (cotton wool, diapers, dressings, paper, organic waste, plastics, etc.) and animal waste (animal carcasses, animal waste). All these deposits show a marked instability (fig. 5). Figure 5. Petrila waste dump [5] The pot holes and ravines, resulting from the location of some roads for the close removal of the woody mass, on the slope, represent approx. 5% (26ha, including potentially affected adjacent areas) of the total area of occupied and denatured land in Valea Jiului (fig. 6). Figure 6. Forest exploitation in the Jieț valley [14] 5 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 Due to the relief of Valea Jiului, most of the time the forest exploitations are located in areas with very rugged terrain where the design and location of the access roads require special caution. The construction of some roads on the slope, very close to the line of the greatest slope, on friable substrate, constituted the premise for triggering the phenomena of deep rain erosion, which had the consequence of the formation of large gullies and ravines. These formations present very steep slopes (40°- 60°) deep into the bedrock which in turn contribute to the formation of torrents during periods of heavy rainfall. Another consequence of the exploitation of the woody mass, especially if the replanting works are delayed, is that of triggering landslides (fig. 7), which, unfortunately, have not been quantified, and their assessment is difficult because they are located in hilly and mountainous areas. This danger should not be neglected even if such phenomena currently affect negligible areas of land in Valea Jiului. Figure 7. Landslides in the forest exploitation area [4] Land ruptures and gaps are in a slow evolution affecting the original uses of land and constructions in the exposed areas and represent 7% (29.1ha) of the affected land surface. Relatively stable and unstable formations will require mine development interventions to bring them to a stable state in order to reintroduce these lands into the economic circuit and landscape reintegration. Table 2 shows the current and initial uses of land in this category of sources of land damage in Valea Jiului. Table 2. Affected surfaces and changes of uses [1] Current uses Initial uses, ha Name Area, ha Forest Arable Meadow Pasture Dumps extracted from 274,54 15,00 0,50 140,54 118,50 underground, surface and coal preparation plants Slag and ash deposits 20,00 - 2,00 3,00 15,00 from the power plant (the settling ponds) Abandoned coal pits 94,18 10,00 0.50 72,30 11,38 Waste dumps 7,50 - - 4,50 3,00 Pot holes and ravines 21,50 21,50 - - - Land ruptures and gaps 29,10 - 1,50 19,20 8,40 Sum 446,82 46,50 4,50 239,54 156,28 3. Mine yards and constructions Depending on the necessary arrangements, the opening method, the technological flow from the surface and the relief of the land, the surface of these mine yards (fig.8) [9] can occupy from several hectares to several tens of hectares (table 3) [6]. 6 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 Figure 8. The mine yard (abandoned) of Lupeni preparation plant (Shaft with skip in the background) [4] Table 3. Areas occupied by mining premises and constructions No. Mining entity Used surface, m crt. Mine yard Constructions 1. Lonea mine 999.651 559.217 2. Petrila mine 283.758 76.129 3. South Petrila mine 754.196 59.946 4. Dâlja mine 276.383 129.003 5. Livezeni mine 421.550 116.115 6. Aninoasa mine 409.772 166.308 7. Paroșeni mine 456.591 68.416 8. Vulcan mine 558.398 218.003 9. Lupeni mine 1.114.726 713.628 10. Bărbăteni mine 311.305 96.174 11. Uricani mine 410.290 149.934 12. Valea de Brazi mine 165.326 36.974 13. Câmpu lui Neag mine 120.516 52.684 14. Petrila preparation plant 1.125.757 546.483 15. Livezeni preparation plant 320.592 65.138,20 16. Coroiești preparation plant 976.908 855.603 17. Lupeni preparation plant 788.335,62 557.374,83 18. Uricani preparation plant 400.267,95 146.867,70 Sum 9.336.880,57 4.614.000,73 Sum total 13.950.881,30m ᵙ 1395ha; 1,35% from the surface of Valea Jiului Other areas of land occupied by access roads, assembly platforms, warehouses, etc. it is estimated at approximately 79 ha. The general economic regression in Valea Jiului also led to a decrease in the population so that apart from the abandoned mining premises, important areas of land are occupied by other abandoned industrial premises (e.g. the GEROM premises, UPSRUEM, buildings belonging to the former Vâscoza enterprise from Lupeni etc.) as well as abandoned residential buildings (in all cities of Valea Jiului). Although there is no strict record of these lands, an approximation of their surface between 15 and 20ha can be made. An estimated calculation regarding the land surfaces in Valea Jiului that are/were occupied by anthropogenic activities directly or indirectly related to mining in this area shows that around 1900ha (1.84% of Valea Jiului surface) were affected by these activities, surface which, at a first estimate, would not be relevant, but as has been shown, the objectives, mostly inactive, on these lands leave a landscape and visual aspect much more significant than their extent. 7 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 4. Mining and preparation activities that pollute the soil chemically The soil of Valea Jiului is siliceous, with a low content of iodine and fluorine, poor in humus and therefore unfavorable for the growth of cultivated plants. These aspects have as a consequence the orientation of the population in the area towards herding and implicitly the risk of soil and stream contamination through animal droppings or their improper storage. The chemical composition of the soil includes all the known elements, although they differ from one region to another, the deficiencies or excess of mineral elements being reflected in the geographic pathology of the population. In table 4, the percentage distribution of the mineral elements in the soil on the surface of some dumps and in the one that constituted their foundation before deposition (vegetable soil) is given. Table 4. Percentage distribution of mineral elements in the soil [7] No. The mineral element MU Determined value crt. in the soil Paroșeni Vulcan Lupeni Uricani Vegetable soil 1. SiO 61,87 64,92 67,11 65,23 64,23 2. Al O 11,22 11,81 11,86 10,98 9,81 2 3 3. Fe O 3,60 3,63 3,28 3,21 3,45 2 3 4. MgO 0,93 0,92 0,90 0,78 0,71 5. CaO 0,87 0,84 0,87 0,76 0,77 6. Na O 0,99 1,05 1,11 0,91 1,07 7. K O 1,58 1,63 1,70 1,45 1,80 8. Volatile 18,94 15,20 13,28 16,68 18,16 In addition to the physical degradation processes, in Valea Jiului there are also processes of chemical degradation of the land, through pollution with heavy metals (in the areas occupied by tailings deposits and in the mining premises), with sedimentable powders transported from the dumps or other pollutants (e.g. SO ). These processes affect soil fertility, recovery being in most cases impossible. Substances that pollute the soil are organic and inorganic in nature and have negative effects on the biological activity in the soil. The possibility of soil pollution with harmful substances resulting from the mining activity is primarily related to the presence of such substances in the material stored in the dumps, which then reach the neighboring lands through precipitation. The following will present the results of the laboratory analyses, carried out in the chemistry laboratories of the University of Petroșani and the environmental laboratory of CNH Petroșani (with the S4 Pioneer Spectrometer), of the soil samples collected both from the mining premises and the surrounding areas, as well as from tailings dumps for several years (2010-2020). It should be noted that most of the data presented here were taken from works developed during this period [8, 9, 10], with the aim of obtaining a more accurate picture of the situation regarding the quality of the soil, from a chemical point of view, in Valea Jiului (table 5). Table 5. Soil chemical analyzes in the mining perimeters in Valea Jiului (multiannual average values) Value determined in the mining perimeter MAC No. Cf. Order Parameter MU Vegetable crt. Lonea Livezeni Paroșeni Vulcan Lupeni Uricani no. soil 756/1997 1. pH unit. pH 7,09 7,13 7,06 7,13 7,12 6,98 7,56 6,5-8,5 2. Arsenic (As) 5 4 4 4 3 3 2 5 3. Barium (Ba) 501 349 322 349 322 241 343 200 4. Cobalt (Co) 13 5 5 5 5 4 6 15 5. Chromium (Cr ) 186 126 112 126 127 123 125 30 6. Copper (Cu) 5 2 0 2 0 1 1,9 20 7. Fluor (F) 78 93 94 90 62 76 78 150 mg/kg 8. Manganese (Mn) 330 310 307 310 294 288 305 900 d.s. 9. Nickel (Ni) 18 16 17 16 16 14 15 20 10. Lead (Pb) 20 21 21 21 20 19 23 20 11. Sulphur (S) 347 338 327 360 343 342 310 400 12. Tin (Sn) 9 8 9 10 8 7 7 20 13. Vanadium (V) 102 101 101 101 104 98 121 50 14. Zinc (Zn) 63 47 46 47 45 44 43 100 8 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 From table 5, it can be seen that there are no exceedances of the concentrations of chemical elements (except barium, chromium and vanadium) compared to those established within the norms for less sensitive uses. The presence of certain elements, both in the composition of the soil and in that of the waste heaps in concentrations close in value, leads to the conclusion that there is no contamination of the soil caused by the chemical composition of the waste materials stored in the heaps. Although not directly related to mining activities, it should be remembered that there are also small areas of land polluted with petroleum products (in the vicinity of fuel depots) and transformer oils (in the vicinity of transformer stations). 5. Assessment of soil/land degradation In Valea Jiului, soil/land pollution has multiple causes, but mining and indirect activities related to it have a significant weight. The negative effects exerted by mining (mainly) on the soils/land in Valea Jiului are highlighted by: changes in the relief, manifested by the degradation of the landscape and displacement of households and industrial facilities from the mining areas; the occupation of some areas of land for the activity of mining, piling, coal storage, access roads etc., areas that thus become totally unusable for other purposes, for a long period of time, with effects on local communities; land degradation, through vertical and horizontal movements of the surface (induced subsidence) and the sliding of dumps and settling ponds, causing serious accidents and chemical soil pollution, which can affect its fertile properties for many years. The land surfaces in Valea Jiului that are/were occupied by human activities, directly or indirectly related to mining in this area, are valued at approx. 1900ha, which represents 1.84% of the surface of Valea Jiului, an area which, at first estimate, would not be relevant, but as it was shown, the objectives, mostly inactive, on these lands leave a much better landscape and visual aspect significantly than their extent. Among the different categories of soil pollution (organic, chemical and biological), the chemical one can be attributed the biggest blame (approx. 50%). Special attention must be paid to the role of mining activities in environmental degradation through the placement of tailings, the existence of abandoned quarries and tailing ponds, and subsidence induced by underground workings. The extent of land degradation processes through mining activities can be appreciated through a series of indicators such as: the surface occupied by quarries, tailings dumps and settling ponds, the surface affected by induced subsidence, the surface affected by soil, groundwater and vegetation pollution, the surface of land rehabilitated through greening actions or the surface of naturally grassed land. For a quantitative assessment of the negative effects induced by mining on land, in the specialized literature there are a series of assessments of the degree of land degradation by mining activities. The work of Andrei Costache [4] is noteworthy, which proposes the determination of the Land Degradation Index through mining activities (I ) by calculating some degradation indices for each objective (dump, quarry, dump instability). d.min We propose a proprietary method for establishing a Global Land Degradation Index (GLDI) affected by mining activities in a mining perimeter (mine) taking into account the entire analyzed area (in our case Valea Jiului) [3]. This is a global index because it includes several partial indices determined for each individual objective (dump, quarry, induced subsidence, area of influence, greened area, etc.), compared because the area of each objective is related to the largest area of analyzed objectives. It is also temporary because it is determined at a given moment, it being different over time with the implementation of measures to improve the technical condition of abandoned dumps and quarries and especially with the expansion of greening works on degraded lands. The proposed calculation relationship is: 𝑛𝑛 𝑚𝑚 GLDI= ∑ 𝐼𝐼 - ∑ 𝐼𝐼 (1) 𝑖𝑖 =1 𝑖𝑖 𝑗𝑗 =1 𝑗𝑗 where: I – partial indices corresponding to the objectives that cause land degradation in a mining perimeter (mine): dumps, open pits, subsidence, areas of influence for relatively stable/unstable dumps, mine yards- constructions etc. I - partial indices corresponding to the objectives that are/were reproduced in the economic circuit: the reconstruction of the landscape as it was before the degradation, finding new uses for the land, temporary development of the affected areas etc. 9 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 These partial indices take values from 0 (the value of the objective surface is zero) to 1 (the value of the objective surface is the maximum from the string of values of the entire analyzed area) and are calculated with the relation: 𝑆𝑆 I or I = (2) i j 𝑆𝑆 𝑚𝑚 where: S – the effective area of an objective in a mining perimeter (mine); ef S – the maximum area of the objective from the series of areas of these analyzed objectives in an max area. For Valea Jiului, considering the current concrete situation [11] regarding land degradation by mining and the degree of greening of these lands, it will be considered: n = 5 (dumps, open pits, subsidence, mine yards - constructions and areas of influence) and m = 1 (naturally or anthropically greened lands). For the calculation of this Index (GLDI), tables 1 and 3 were used, from which the necessary data were extracted, data which were centralized in tables 6 and 7 Table 6. GLDI calculation parameters Objective name The maximum area of an objective in Valea Jiului S , ha max Dumps 50,14 Open pits 53,72 Subsidence 15,30 Mine yards and constructions 317,41 Influence zones 40,97 Rehabilitation lands 205,30 Table 7. Land degradation index, GLDI Economic unit, Name of objective Effective area of Partial Global Land mine and objective, degradation Degradation preparation plant (S ), ha indices, I or I Index, GLDI ef i j Dumps 44,54 0,89 Open pits 21,86 0,41 1,84 Subsidence - - Lonea Mine yards and constructions 155,90 0,49 Influence zones 6,56 0,16 Rehabilitation lands 21,86 0,11 Dumps 27,60 0,55 Open pits - - 0,47 Subsidence 4,30 0,28 Petrila Mine yards and constructions 203,22 0,64 Influence zones - - Rehabilitation lands 205,30 1,00 Dumps 20,37 0,41 Open pits 6,41 0,12 0,39 Subsidence - - Petrila Sud Mine yards and constructions 25,67 0,08 Influence zones - - Rehabilitation lands 46,04 0,22 Dumps 12,58 0,25 Open pits - - 0,48 Subsidence 5,50 0,36 Dâlja Mine yards and constructions 40,54 0,13 Influence zones - - Rehabilitation lands 53,12 0,26 Dumps 6,20 0,12 Open pits - - 0,42 Subsidence - - Livezeni Mine yards and constructions 92,42 0,29 Influence zones 1,00 0,02 Rehabilitation lands 2,15 0,01 𝑚𝑚𝑚𝑚 𝑒𝑒𝑒𝑒 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 Dumps 5,23 0,10 Open pits - - Subsidence 4,00 0,26 Aninoasa 0,31 Mine yards and constructions 57,62 0,18 Influence zones 3,42 0,08 Rehabilitation lands 62,85 0,31 Dumps 34,25 0,68 Open pits - - Subsidence - - 1,76 Vulcan Mine yards and constructions 77,64 0,24 Influence zones 34,25 0,84 Rehabilitation lands - - Dumps 21,84 0,43 Open pits - - Subsidence - - 1,69 Paroșeni + Coroiești Mine yards and constructions 235,75 0,74 Influence zones 21,84 0,53 Rehabilitation lands 1,37 0,01 Dumps 1,00 50,14 Open pits 12,50 0,23 Subsidence 1,00 15,30 Lupeni 3,57 Mine yards and constructions 1,00 317,41 Influence zones 1,00 40,97 Rehabilitation lands 134,78 0,66 Dumps 4,90 0,10 Open pits - - Subsidence - - 0,01 Bărbăteni Mine yards and constructions 40,75 0,13 Influence zones - - Rehabilitation lands 45,65 0,22 Dumps 18,40 0,37 Open pits 12,99 0,24 Subsidence - - 0,85 Uricani Mine yards and constructions 110,75 0,35 Influence zones - - Rehabilitation lands 21,87 0,11 Dumps 0,19 0,01 Open pits - - Subsidence - - 0,00 Valea de Brazi Mine yards and constructions 20,23 0,07 Influence zones - - Rehabilitation lands 20,42 0,08 Dumps 28,30 0,56 Open pits 1,00 53,72 Subsidence - - 1,13 Câmpu lui Neag Mine yards and constructions 17,32 0,05 Influence zones - - Rehabilitation lands 99,34 0,48 Table 8 presents a quantitative and qualitative classification of the degree of land degradation due to mining activities, which allowed the classification of each mining perimeter (mine) in a certain category of degradation. Table 8 Classification of land degradation according to the Degradation Index, GLDI The value of IGDT The degree of land Mining perimeter (mine) degradation 0 ≤ IGDT ≤ 1,00 small Petrila, Petrila Sud, Dâlja, Livezeni, Aninoasa, Bărbăteni, Uricani, Valea de Brazi 1,01 ≤ IGDT ≤ 2,00 medium Lonea, Vulcan, Paroșeni, Câmpu lui Neag IGDT > 2,00 large Lupeni 11 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 6. Conclusions In Valea Jiului, soil / land pollution has multiple causes, but mining and indirect activities related to it have a significant weight. The paper analyzed the negative effects exerted by mining (mainly) on the soils / lands of Valea Jiului through: changes in the relief, manifested by the degradation of the landscape and displacement of households and industrial objects from the exploitation areas; the occupation of some areas of land for the activity of mining, dumping, coal storage, access roads, etc., areas that thus become totally unusable for other purposes, for a long period of time, with effects on local communities; land degradation, through vertical and horizontal movements of the surface and the sliding of dumps and settling ponds, causing serious accidents and chemical pollution of the soil, which can affect its fertile properties for many years. As shown, the land surfaces in Valea Jiului that are/were occupied by human activities, directly or indirectly related to mining in this area, are valued at approx. 1900ha, which represents 1.84% of the surface of Valea Jiului, an area which, at first estimate, would not be relevant, but as it was shown, the objectives, mostly inactive, on these lands leave a much better landscape and visual aspect significantly than their extent Among the environmental changes, land degradation currently has the most important consequences for human settlements and economic activities, especially through induced subsidence processes and the presence of tailings deposits with reduced stability. The calculation of the land degradation index caused by mining activities highlighted the fact that the most affected are the mining perimeters in the center and east of Valea Jiului, respectively Vulcan, Lupeni and Lonea, which also extend into the suburbs of Petrila settlements (Lonea colony, Cimpa), Jieț, Vulcan (north), Lupeni (east and north). In the last 10-12 years, the closure of the majority of mines in Valea Jiului and the upgrading of some major sources of pollution (e.g. the Coroiești preparation plant), have contributed to an important extent to reducing the impact of extractive activities on the environment (e.g. the significant decrease in the concentration of suspensions solids in the waters of the Jiu). However, with the development of alternative economic activities, new sources of imbalance at the local level appeared, namely tourism (through the chaotic expansion of accommodation units in the mountain area, in Straja and in Parâng) and the exploitation and primary processing of wood. These, together with agro-pastoral activities and legislative changes, lead to pollution phenomena (e.g. water pollution with wood waste and animal residues), but also to new changes in land use and vegetation. Thus, the change in the land ownership regime, grazing in the forest, uncontrolled cutting, burning of some land and pastoral pressure on the land have caused changes in the structure and composition of forests and meadows. References [1]. Biro C., 2005 Rehabilitation of lands degraded by anthropogenic activities in the Petroșani mining basin, PhD thesis, University of Petroșani (in Romanian) [2]. Georgescu, M., e.a., 2002 Evaluation of the impact of environmental pollution and socio-economic life in Valea Jiului, University of Petroșani, Grant No. 1 CNCSIS code 236 (in Romanian) [3]. Roman L., 2022 Research on the impact of the closing of the mines in Valea Jiului on the environment, PhD thesis, University of Petroșani (in Romanian) [4]. Costache A., 2020 Vulnerability of human settlements and social risks in the Petroșani Depression, Transversal Târgoviște Publishing House (in Romanian) [5]. Faur F., 2009 Development of an environmental monitoring system in Valea Jiului, PhD thesis, University of Petroșani (in Romanian) [6]. ***, 2001 Post-closure monitoring of isolated underground and surface mine constructions – S.C. I.C.P.M. S.A., Petroșani (in Romanian) 12 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 [7]. Georgescu M., e.a., 2001 Identification of pollution sources and evaluation of the degree of pollution of Valea Jiului, Grant no. 2, CNCSIS code 915, Petroșani (in Romanian) [8]. Buliga (Nălboc) I.V., 2017 The study of the impact on the environment of the pollutants generated by the mining units in the west of Valea Jiului, PhD thesis, University of Petroșani (in Romanian) [9]. Onica I., e.a., 2015 Works to develop production capacity at E.M. Lonea - Feasibility study - University of Petroșani (in Romanian) [10]. Vereș I., e.a., 2019 Development plan of E.M. Livezeni and E.M. Vulcan – Funding contract 1363/2019, University of Petroșani (in Romanian) [11]. ***, 2017-2022 Reports on the inventory and inspection of tailings dumps and settling ponds, Environmental Protection Agency, Hunedoara (in Romanian) This article is an open access article distributed under the Creative Commons BY SA 4.0 license. Authors retain all copyrights and agree to the terms of the above-mentioned CC BY SA 4.0 license. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Mining Revue de Gruyter

Research on the Quality of the Soil and the Land Related to the Mining Perimeters in Valea Jiului

Roman, Liliana; Georgescu, Mircea
Mining Revue , Volume 28 (4): 13 – Dec 1, 2022
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10.2478/minrv-2022-0025
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Abstract

Revista Minelor – Mining Revue ISSN-L 1220-2053 / ISSN 2247-8590 vol. 28, issue 4 / 2022, pp. 1-13 RESEARCH ON THE QUALITY OF THE SOIL AND THE LAND RELATED TO THE MINING PERIMETERS IN VALEA JIULUI 1 2 * Liliana ROMAN , Mircea GEORGESCU University of Petroșani, Petroșani, Romania, lilianaaprilie40@yahoo.com University of Petroșani, Petroșani, Romania, mirgeorgescu@yahoo.com DOI: 10.2478/minrv-2022-0025 Abstract: In the paper, special attention is paid to the sources that lead to soil and land degradation in Valea Jiului, as these are the components of the environment that are most affected by mining activities. Three sources of pollution are analyzed: dumps, mine yards and constructions, and mining and preparation activities chemically polluting of soil. Among the environmental changes, land degradation currently has the most important consequences for human settlements and economic activities, especially through induced subsidence processes and the presence of dumps with reduced stability. The authors of the article propose their own method for establishing a Global Land Degradation Index (GLDI) affected by mining activities in a mining perimeter (mine) taking into account the entire analyzed area (in our case Valea Jiului) and make a classification (in three classes) of this index. Keywords: soil and land degradation, global land degradation index 1. Introduction In a region, such as Valea Jiului, where the coal mining and preparation activity has been carried out for an appreciable period of time, special attention must also be paid to the sources that lead to soil and land degradation in that region, because these are the components of the environment that are most affected by mining activities. In the following, an analysis will be made of the following sources of pollution: • dumps; • mine yards and constructions; • mining and preparation activities that pollute the soil chemically. 2. Dumps The underground mining activity has unwanted repercussions on the land surface by the fact that it involves the storage of relatively large amounts of mine tailings that contribute to changes in the morphology of the land, land uses and lead to the appearance of new forms of relief. Although compared to the area corresponding to the economic area of Valea Jiului (103,200ha), mining dumps, preparations, slag deposits and abandoned quarries occupy relatively small areas (402.02ha, 0.39%) the contrast between waste rock deposits (clays, marls, sandstones) and the surrounding areas, covered by forests, is an obvious one. The economic units (predominantly the mining ones), which affected the land in Valea Jiului to the greatest extent (mines and preparations, the Paroșeni thermal power plant, forestry and household activities) and which generated/generate degraded lands of various types, are reproduced in table 1 [1,2]. Mining dumps in Valea Jiului are usually located on slopes or along valleys, with or without drainage. The elevations of the storage lands generally vary between 650m in the axis of the valleys and 750m on the 0 0 slopes. The angle of inclination of the slopes varies between 6 and 35 . In some situations, the dumps were built in such a way that they block valleys without permanent water courses, forming lakes from waters originating from precipitation (fig.1). Corresponding author: Mircea Georgescu, Prof. PhD. Eng., University of Petroșani, Petroșani, Romania, contact details (University st. no. 20, Petroșani, Romania mirgeorgescu@gmail.com) 1 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 The presence of these lakes is extremely unfavorable from the point of view of the stability of the dumps. The water that seeps into the dump can cause landslides or plastic or muddy flows (such landslides and muddy flows affecting the colony of Lupeni Municipality) (fig. 2). Table 1. The economic units that affected the land in Valea Jiului - updated [3] Economic unit Name of objective Area, ha Surface area of Technical Stability influence, ha condition Dumps resulting from tailings extracted from underground and from the surface Jieț Shaft 5,70 0,40 Activate Relatively stable Lonea I 14,90 0,38 Conservative Stable Defor Valley 2,00 0,40 Conservative Relatively stable Lonea mine Defor open pit 12,65 1,05 Conservative Relatively stable Valley of Ciort 7,19 1,11 Conservative Relatively stable Valley Arsului 2,10 2,50 Conservative Stable Petrila mine 2 East 2,10 0,30 Rehabilitated Stable Jieț West open pit 14,75 1,50 Rehabilitated Stable South Petrila mine Shaft 4 3,12 0,20 Rehabilitated Stable Auxiliary Shaft 2, 3 2,50 0,20 Rehabilitated Stable PA-1 1,74 0,10 Rehabilitated Stable Run 1,74 0,10 Rehabilitated Stable Dâlja mine PA-1, PA-2 7,90 4,80 Rehabilitated Stable Refuse heap PA-3 1,20 0,20 Rehabilitated Stable Auxiliary Shaft East 1,55 0,30 Activate Relatively stable Livezeni mine PA-nr.2,3 Maleia 2,15 0,70 Rehabilitated Relatively stable Refuse heap Piscu 2,50 3,42 Rehabilitated Relatively stable Aninoasa mine South Funicular 2,73 0,34 Rehabilitated Stable Shaft 7 West (old) 9,10 7,60 Conservative Relatively stable ValleyArsului + P8,10 15,75 1,60 Activate Relatively stable Vulcan mine Hypollit 3,10 0,30 Conservative Relatively stable Shaft7West 6,30 0,80 Conservative Relatively stable Valley Lupului 2,80 0,50 Conservative Relatively stable Paroșeni mine Funicular 1,17 0,40 Conservative Relatively stable Refuse heap 1,37 - Conservative Relatively stable 2 West Ileana 14,26 0,04 Activate Relatively stable New branch Ileana 4,61 2,12 Rehabilitated Relatively stable Lupeni mine Victoria open pit 2,48 0,02 Conservative Stable New Victoria 6,69 2,62 Conservative Stable Mierleaşu 4,70 0,30 Rehabilitated Stable Bărbăteni mine Adit 0,20 - Rehabilitated Stable Old Funicular 11,00 3,00 Conservation Stable Balomir 2,18 0,60 Conservation Stable Uricani mine Shaft7Sterminos 3,12 0,60 Conservation Relatively stable New Funicular 2,00 3,00 Conservation Relatively stable Funicular 0,15 0,30 Rehabilitated Stable Valea de Brazi mine Shaft 8 0,04 0,01 Rehabilitated Stable Poiana Mare 9,60 - Rehabilitated Stable Galbena 1,10 - Rehabilitated Stable Câmpu lui Neag mine Șesul Șerbanilor 8,60 - Rehabilitated Stable Frasin 6,80 - Rehabilitated Stable 207,84 42,11 Sum (45,17%) Dumps from coal preparation plants Preparation plants Petrila 25,50 4,00 Conservation Relatively stable Livezeni 2,50 0,70 Activate Stable Coroiești 16,50 - Activate Relatively stable Lupeni 22,10 2,00 Conservation Relatively stable Uricani 0,10 - Conservation Relatively stable Total 66,70 6,70 (14,50%) 2 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 Waste dumps Petroșani 1,00 2,00 Activate Unstable Petrila 2,00 4,00 Activate Unstable Vulcan 1,50 3,00 Activate Unstable Lupeni 0,50 2,00 Activate Unstable Uricani 2,00 4,00 Activate Unstable Aninoasa 0,50 1,00 Activate Unstable Sum 7,50 16,00 (1,63%) Pot holes and ravines Petroșani forestry 5,00 1,00 Conservation Unstable Petrila forestry 7,00 1,50 Conservation Unstable Lupeni forestry 9,50 2,00 Conservation Unstable Sum 21,50 4,50 (4,67%) Slag and ash deposits from the power plant Power plant Paroșeni 20,00 - Activate Stable Sum 20,00 - (4,35%) Abandoned coal pits Cimpa open pit 9,30 0,75 Rehabilitated Stable Jieț Defor open pit 12,56 1,05 Rehabilitated Stable Jieț Vest open pit 6,41 0,50 Rehabilitated Stable Victoria Lupeni open pit 12,50 1,10 Rehabilitated Stable Uricani Sud open pit 4,37 0,30 Rehabilitated Stable Balomir open pit 5,25 0,60 Rehabilitated Stable Vineri open pit 0,87 0,10 Rehabilitated Stable Mîrșăveni open pit 2,50 - Rehabilitated Stable Câmpu lui Neag Zona E open pit 16,50 1,00 Rehabilitated Stable Câmpu lui Neag Zona A+C open pit 29,40 2,00 Rehabilitated Stable Galbena open pit 4,37 0,65 Rehabilitated Stable Jiri open pit 2,50 0,10 Rehabilitated Stable Buta open pit 0,95 - Rehabilitated Stable Sum 107,48 8,150 (23,36%) Land ruptures and gaps Petroșani 5,50 - Activate Relatively stable Petrila 4,30 - Activate Relatively stable Lupeni 15,30 - Activate Relatively stable Aninoasa 4,00 - Activate Relatively stable Sum 29,10 - (6,32%) Sum total 460,12 77,46 a b c Figure 1. Water accumulations in the area of Lupeni dumps (a), Valley Arsului-Lonea (b) and between the branches of the Petrila preparation dump (c) [4,5] 3 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 a b Figure 2. Lupeni (a) and New Uricani Funicular (b) dumps affected by erosion, landslides and uneven settlement [9]. The construction of tailing dumps was carried out with the help of funiculars or car transport (e.g. the Valley Arsului dump), thus ensuring both the transport and storage of tailings in the dump. Deposits were carried out on different alignments, and the discharge points were established according to the configuration of the land in the area of the respective alignment. To increase the storage capacity, the spilled material is generally leveled with the help of bulldozers, forming piling platforms. The platforms have widths at the lower part of 50-150m, and at the upper part of 15-50m. By leveling with the help of bulldozers, compaction is also achieved, which contributes to increasing the stability of waste heaps. A characteristic of the heaps is the fact that they are executed, as a rule, in one step, their parameters being dependent on the morphology of the land, the heights at which the funicular is mounted and the characteristics of the heaped rocks. The mentioned aspects have unfavorable repercussions on the stability of the dumps, affecting the lands in the immediate vicinity, in the area of influence. The height of the dumps varies between 3-4m and 30-40m. 0 0 0 The slope angle in the situations where plastic leaks have occurred has values of 7 -8 , but in general it is 40 - 50 . During the dumping or pushing of the waste material, a granulometric sorting takes place in the sense that the coarse material is deposited at the base of the pile, also, there is a tendency for the material to settle at angles greater than the final ones. In the case of land with a high slope, the flattening of the slope is more obvious and the material requires more room for expansion. Dumps are generally stable, and the stability reserve is above unitary. Relatively stable are those that have a small reserve of stability that can be canceled in the event of additional efforts or changes in the physical- mechanical characteristics of the piled rocks or the base ground due to the presence of water. Since the dumps are formed in a single step, due to the large difference in level the rocks tend to move from the slope, facilitating their breaking at the top where cracks and material displacements occur downstream. Because of the plasticity of the bedrock and the high height of the dump steps, crank of rocks occur in many situations. Currently (see table 1), tailing dumps from underground and surface mining (41) are active 4 (37.26ha- 18%), under conservation/rehabilitation 17 (91.51ha-44%), greened 20 (79.07ha-38%), are stable 23 (115.13ha-55%) and relatively stable 18 (92.71ha-45%). Tailings from coal preparations (5) are active 2 (19ha-28%), in conservation/rehabilitation 3 (47.7ha- 72%), is stable 1 (2.50ha-4%), with stability relative 4 (64.2ha-96%). The slag and ash deposits from the Paroșeni thermal power plant (the settling ponds) are in operation. The neighboring lands are not influenced at the moment, but the breaking of the dykes would have disastrous repercussions on them, the possibly affected surfaces being appreciable and difficult to estimate (fig.3). Figure 3. The settling pond of the Paroșeni thermal power plant [5] 4 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 The coal open pits (micro-open pits) in Valea Jiului, in most of them, have been freed from mining duties and tailings or household waste deposits have been created. All these warehouses have been closed and greened. The former Câmpu lui Neag open pit was filled with water, being currently used for recreation and sport fishing (fig. 4). Figure 4. Former open pit Câmpu lui Neag [4] The waste dumps are in operation, consisting of household waste (textile materials, paper, glass, wood scraps, metal, plastic materials, food scraps, ash, rubber, etc.), special waste from hospitals (cotton wool, diapers, dressings, paper, organic waste, plastics, etc.) and animal waste (animal carcasses, animal waste). All these deposits show a marked instability (fig. 5). Figure 5. Petrila waste dump [5] The pot holes and ravines, resulting from the location of some roads for the close removal of the woody mass, on the slope, represent approx. 5% (26ha, including potentially affected adjacent areas) of the total area of occupied and denatured land in Valea Jiului (fig. 6). Figure 6. Forest exploitation in the Jieț valley [14] 5 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 Due to the relief of Valea Jiului, most of the time the forest exploitations are located in areas with very rugged terrain where the design and location of the access roads require special caution. The construction of some roads on the slope, very close to the line of the greatest slope, on friable substrate, constituted the premise for triggering the phenomena of deep rain erosion, which had the consequence of the formation of large gullies and ravines. These formations present very steep slopes (40°- 60°) deep into the bedrock which in turn contribute to the formation of torrents during periods of heavy rainfall. Another consequence of the exploitation of the woody mass, especially if the replanting works are delayed, is that of triggering landslides (fig. 7), which, unfortunately, have not been quantified, and their assessment is difficult because they are located in hilly and mountainous areas. This danger should not be neglected even if such phenomena currently affect negligible areas of land in Valea Jiului. Figure 7. Landslides in the forest exploitation area [4] Land ruptures and gaps are in a slow evolution affecting the original uses of land and constructions in the exposed areas and represent 7% (29.1ha) of the affected land surface. Relatively stable and unstable formations will require mine development interventions to bring them to a stable state in order to reintroduce these lands into the economic circuit and landscape reintegration. Table 2 shows the current and initial uses of land in this category of sources of land damage in Valea Jiului. Table 2. Affected surfaces and changes of uses [1] Current uses Initial uses, ha Name Area, ha Forest Arable Meadow Pasture Dumps extracted from 274,54 15,00 0,50 140,54 118,50 underground, surface and coal preparation plants Slag and ash deposits 20,00 - 2,00 3,00 15,00 from the power plant (the settling ponds) Abandoned coal pits 94,18 10,00 0.50 72,30 11,38 Waste dumps 7,50 - - 4,50 3,00 Pot holes and ravines 21,50 21,50 - - - Land ruptures and gaps 29,10 - 1,50 19,20 8,40 Sum 446,82 46,50 4,50 239,54 156,28 3. Mine yards and constructions Depending on the necessary arrangements, the opening method, the technological flow from the surface and the relief of the land, the surface of these mine yards (fig.8) [9] can occupy from several hectares to several tens of hectares (table 3) [6]. 6 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 Figure 8. The mine yard (abandoned) of Lupeni preparation plant (Shaft with skip in the background) [4] Table 3. Areas occupied by mining premises and constructions No. Mining entity Used surface, m crt. Mine yard Constructions 1. Lonea mine 999.651 559.217 2. Petrila mine 283.758 76.129 3. South Petrila mine 754.196 59.946 4. Dâlja mine 276.383 129.003 5. Livezeni mine 421.550 116.115 6. Aninoasa mine 409.772 166.308 7. Paroșeni mine 456.591 68.416 8. Vulcan mine 558.398 218.003 9. Lupeni mine 1.114.726 713.628 10. Bărbăteni mine 311.305 96.174 11. Uricani mine 410.290 149.934 12. Valea de Brazi mine 165.326 36.974 13. Câmpu lui Neag mine 120.516 52.684 14. Petrila preparation plant 1.125.757 546.483 15. Livezeni preparation plant 320.592 65.138,20 16. Coroiești preparation plant 976.908 855.603 17. Lupeni preparation plant 788.335,62 557.374,83 18. Uricani preparation plant 400.267,95 146.867,70 Sum 9.336.880,57 4.614.000,73 Sum total 13.950.881,30m ᵙ 1395ha; 1,35% from the surface of Valea Jiului Other areas of land occupied by access roads, assembly platforms, warehouses, etc. it is estimated at approximately 79 ha. The general economic regression in Valea Jiului also led to a decrease in the population so that apart from the abandoned mining premises, important areas of land are occupied by other abandoned industrial premises (e.g. the GEROM premises, UPSRUEM, buildings belonging to the former Vâscoza enterprise from Lupeni etc.) as well as abandoned residential buildings (in all cities of Valea Jiului). Although there is no strict record of these lands, an approximation of their surface between 15 and 20ha can be made. An estimated calculation regarding the land surfaces in Valea Jiului that are/were occupied by anthropogenic activities directly or indirectly related to mining in this area shows that around 1900ha (1.84% of Valea Jiului surface) were affected by these activities, surface which, at a first estimate, would not be relevant, but as has been shown, the objectives, mostly inactive, on these lands leave a landscape and visual aspect much more significant than their extent. 7 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 4. Mining and preparation activities that pollute the soil chemically The soil of Valea Jiului is siliceous, with a low content of iodine and fluorine, poor in humus and therefore unfavorable for the growth of cultivated plants. These aspects have as a consequence the orientation of the population in the area towards herding and implicitly the risk of soil and stream contamination through animal droppings or their improper storage. The chemical composition of the soil includes all the known elements, although they differ from one region to another, the deficiencies or excess of mineral elements being reflected in the geographic pathology of the population. In table 4, the percentage distribution of the mineral elements in the soil on the surface of some dumps and in the one that constituted their foundation before deposition (vegetable soil) is given. Table 4. Percentage distribution of mineral elements in the soil [7] No. The mineral element MU Determined value crt. in the soil Paroșeni Vulcan Lupeni Uricani Vegetable soil 1. SiO 61,87 64,92 67,11 65,23 64,23 2. Al O 11,22 11,81 11,86 10,98 9,81 2 3 3. Fe O 3,60 3,63 3,28 3,21 3,45 2 3 4. MgO 0,93 0,92 0,90 0,78 0,71 5. CaO 0,87 0,84 0,87 0,76 0,77 6. Na O 0,99 1,05 1,11 0,91 1,07 7. K O 1,58 1,63 1,70 1,45 1,80 8. Volatile 18,94 15,20 13,28 16,68 18,16 In addition to the physical degradation processes, in Valea Jiului there are also processes of chemical degradation of the land, through pollution with heavy metals (in the areas occupied by tailings deposits and in the mining premises), with sedimentable powders transported from the dumps or other pollutants (e.g. SO ). These processes affect soil fertility, recovery being in most cases impossible. Substances that pollute the soil are organic and inorganic in nature and have negative effects on the biological activity in the soil. The possibility of soil pollution with harmful substances resulting from the mining activity is primarily related to the presence of such substances in the material stored in the dumps, which then reach the neighboring lands through precipitation. The following will present the results of the laboratory analyses, carried out in the chemistry laboratories of the University of Petroșani and the environmental laboratory of CNH Petroșani (with the S4 Pioneer Spectrometer), of the soil samples collected both from the mining premises and the surrounding areas, as well as from tailings dumps for several years (2010-2020). It should be noted that most of the data presented here were taken from works developed during this period [8, 9, 10], with the aim of obtaining a more accurate picture of the situation regarding the quality of the soil, from a chemical point of view, in Valea Jiului (table 5). Table 5. Soil chemical analyzes in the mining perimeters in Valea Jiului (multiannual average values) Value determined in the mining perimeter MAC No. Cf. Order Parameter MU Vegetable crt. Lonea Livezeni Paroșeni Vulcan Lupeni Uricani no. soil 756/1997 1. pH unit. pH 7,09 7,13 7,06 7,13 7,12 6,98 7,56 6,5-8,5 2. Arsenic (As) 5 4 4 4 3 3 2 5 3. Barium (Ba) 501 349 322 349 322 241 343 200 4. Cobalt (Co) 13 5 5 5 5 4 6 15 5. Chromium (Cr ) 186 126 112 126 127 123 125 30 6. Copper (Cu) 5 2 0 2 0 1 1,9 20 7. Fluor (F) 78 93 94 90 62 76 78 150 mg/kg 8. Manganese (Mn) 330 310 307 310 294 288 305 900 d.s. 9. Nickel (Ni) 18 16 17 16 16 14 15 20 10. Lead (Pb) 20 21 21 21 20 19 23 20 11. Sulphur (S) 347 338 327 360 343 342 310 400 12. Tin (Sn) 9 8 9 10 8 7 7 20 13. Vanadium (V) 102 101 101 101 104 98 121 50 14. Zinc (Zn) 63 47 46 47 45 44 43 100 8 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 From table 5, it can be seen that there are no exceedances of the concentrations of chemical elements (except barium, chromium and vanadium) compared to those established within the norms for less sensitive uses. The presence of certain elements, both in the composition of the soil and in that of the waste heaps in concentrations close in value, leads to the conclusion that there is no contamination of the soil caused by the chemical composition of the waste materials stored in the heaps. Although not directly related to mining activities, it should be remembered that there are also small areas of land polluted with petroleum products (in the vicinity of fuel depots) and transformer oils (in the vicinity of transformer stations). 5. Assessment of soil/land degradation In Valea Jiului, soil/land pollution has multiple causes, but mining and indirect activities related to it have a significant weight. The negative effects exerted by mining (mainly) on the soils/land in Valea Jiului are highlighted by: changes in the relief, manifested by the degradation of the landscape and displacement of households and industrial facilities from the mining areas; the occupation of some areas of land for the activity of mining, piling, coal storage, access roads etc., areas that thus become totally unusable for other purposes, for a long period of time, with effects on local communities; land degradation, through vertical and horizontal movements of the surface (induced subsidence) and the sliding of dumps and settling ponds, causing serious accidents and chemical soil pollution, which can affect its fertile properties for many years. The land surfaces in Valea Jiului that are/were occupied by human activities, directly or indirectly related to mining in this area, are valued at approx. 1900ha, which represents 1.84% of the surface of Valea Jiului, an area which, at first estimate, would not be relevant, but as it was shown, the objectives, mostly inactive, on these lands leave a much better landscape and visual aspect significantly than their extent. Among the different categories of soil pollution (organic, chemical and biological), the chemical one can be attributed the biggest blame (approx. 50%). Special attention must be paid to the role of mining activities in environmental degradation through the placement of tailings, the existence of abandoned quarries and tailing ponds, and subsidence induced by underground workings. The extent of land degradation processes through mining activities can be appreciated through a series of indicators such as: the surface occupied by quarries, tailings dumps and settling ponds, the surface affected by induced subsidence, the surface affected by soil, groundwater and vegetation pollution, the surface of land rehabilitated through greening actions or the surface of naturally grassed land. For a quantitative assessment of the negative effects induced by mining on land, in the specialized literature there are a series of assessments of the degree of land degradation by mining activities. The work of Andrei Costache [4] is noteworthy, which proposes the determination of the Land Degradation Index through mining activities (I ) by calculating some degradation indices for each objective (dump, quarry, dump instability). d.min We propose a proprietary method for establishing a Global Land Degradation Index (GLDI) affected by mining activities in a mining perimeter (mine) taking into account the entire analyzed area (in our case Valea Jiului) [3]. This is a global index because it includes several partial indices determined for each individual objective (dump, quarry, induced subsidence, area of influence, greened area, etc.), compared because the area of each objective is related to the largest area of analyzed objectives. It is also temporary because it is determined at a given moment, it being different over time with the implementation of measures to improve the technical condition of abandoned dumps and quarries and especially with the expansion of greening works on degraded lands. The proposed calculation relationship is: 𝑛𝑛 𝑚𝑚 GLDI= ∑ 𝐼𝐼 - ∑ 𝐼𝐼 (1) 𝑖𝑖 =1 𝑖𝑖 𝑗𝑗 =1 𝑗𝑗 where: I – partial indices corresponding to the objectives that cause land degradation in a mining perimeter (mine): dumps, open pits, subsidence, areas of influence for relatively stable/unstable dumps, mine yards- constructions etc. I - partial indices corresponding to the objectives that are/were reproduced in the economic circuit: the reconstruction of the landscape as it was before the degradation, finding new uses for the land, temporary development of the affected areas etc. 9 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 These partial indices take values from 0 (the value of the objective surface is zero) to 1 (the value of the objective surface is the maximum from the string of values of the entire analyzed area) and are calculated with the relation: 𝑆𝑆 I or I = (2) i j 𝑆𝑆 𝑚𝑚 where: S – the effective area of an objective in a mining perimeter (mine); ef S – the maximum area of the objective from the series of areas of these analyzed objectives in an max area. For Valea Jiului, considering the current concrete situation [11] regarding land degradation by mining and the degree of greening of these lands, it will be considered: n = 5 (dumps, open pits, subsidence, mine yards - constructions and areas of influence) and m = 1 (naturally or anthropically greened lands). For the calculation of this Index (GLDI), tables 1 and 3 were used, from which the necessary data were extracted, data which were centralized in tables 6 and 7 Table 6. GLDI calculation parameters Objective name The maximum area of an objective in Valea Jiului S , ha max Dumps 50,14 Open pits 53,72 Subsidence 15,30 Mine yards and constructions 317,41 Influence zones 40,97 Rehabilitation lands 205,30 Table 7. Land degradation index, GLDI Economic unit, Name of objective Effective area of Partial Global Land mine and objective, degradation Degradation preparation plant (S ), ha indices, I or I Index, GLDI ef i j Dumps 44,54 0,89 Open pits 21,86 0,41 1,84 Subsidence - - Lonea Mine yards and constructions 155,90 0,49 Influence zones 6,56 0,16 Rehabilitation lands 21,86 0,11 Dumps 27,60 0,55 Open pits - - 0,47 Subsidence 4,30 0,28 Petrila Mine yards and constructions 203,22 0,64 Influence zones - - Rehabilitation lands 205,30 1,00 Dumps 20,37 0,41 Open pits 6,41 0,12 0,39 Subsidence - - Petrila Sud Mine yards and constructions 25,67 0,08 Influence zones - - Rehabilitation lands 46,04 0,22 Dumps 12,58 0,25 Open pits - - 0,48 Subsidence 5,50 0,36 Dâlja Mine yards and constructions 40,54 0,13 Influence zones - - Rehabilitation lands 53,12 0,26 Dumps 6,20 0,12 Open pits - - 0,42 Subsidence - - Livezeni Mine yards and constructions 92,42 0,29 Influence zones 1,00 0,02 Rehabilitation lands 2,15 0,01 𝑚𝑚𝑚𝑚 𝑒𝑒𝑒𝑒 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 Dumps 5,23 0,10 Open pits - - Subsidence 4,00 0,26 Aninoasa 0,31 Mine yards and constructions 57,62 0,18 Influence zones 3,42 0,08 Rehabilitation lands 62,85 0,31 Dumps 34,25 0,68 Open pits - - Subsidence - - 1,76 Vulcan Mine yards and constructions 77,64 0,24 Influence zones 34,25 0,84 Rehabilitation lands - - Dumps 21,84 0,43 Open pits - - Subsidence - - 1,69 Paroșeni + Coroiești Mine yards and constructions 235,75 0,74 Influence zones 21,84 0,53 Rehabilitation lands 1,37 0,01 Dumps 1,00 50,14 Open pits 12,50 0,23 Subsidence 1,00 15,30 Lupeni 3,57 Mine yards and constructions 1,00 317,41 Influence zones 1,00 40,97 Rehabilitation lands 134,78 0,66 Dumps 4,90 0,10 Open pits - - Subsidence - - 0,01 Bărbăteni Mine yards and constructions 40,75 0,13 Influence zones - - Rehabilitation lands 45,65 0,22 Dumps 18,40 0,37 Open pits 12,99 0,24 Subsidence - - 0,85 Uricani Mine yards and constructions 110,75 0,35 Influence zones - - Rehabilitation lands 21,87 0,11 Dumps 0,19 0,01 Open pits - - Subsidence - - 0,00 Valea de Brazi Mine yards and constructions 20,23 0,07 Influence zones - - Rehabilitation lands 20,42 0,08 Dumps 28,30 0,56 Open pits 1,00 53,72 Subsidence - - 1,13 Câmpu lui Neag Mine yards and constructions 17,32 0,05 Influence zones - - Rehabilitation lands 99,34 0,48 Table 8 presents a quantitative and qualitative classification of the degree of land degradation due to mining activities, which allowed the classification of each mining perimeter (mine) in a certain category of degradation. Table 8 Classification of land degradation according to the Degradation Index, GLDI The value of IGDT The degree of land Mining perimeter (mine) degradation 0 ≤ IGDT ≤ 1,00 small Petrila, Petrila Sud, Dâlja, Livezeni, Aninoasa, Bărbăteni, Uricani, Valea de Brazi 1,01 ≤ IGDT ≤ 2,00 medium Lonea, Vulcan, Paroșeni, Câmpu lui Neag IGDT > 2,00 large Lupeni 11 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 6. Conclusions In Valea Jiului, soil / land pollution has multiple causes, but mining and indirect activities related to it have a significant weight. The paper analyzed the negative effects exerted by mining (mainly) on the soils / lands of Valea Jiului through: changes in the relief, manifested by the degradation of the landscape and displacement of households and industrial objects from the exploitation areas; the occupation of some areas of land for the activity of mining, dumping, coal storage, access roads, etc., areas that thus become totally unusable for other purposes, for a long period of time, with effects on local communities; land degradation, through vertical and horizontal movements of the surface and the sliding of dumps and settling ponds, causing serious accidents and chemical pollution of the soil, which can affect its fertile properties for many years. As shown, the land surfaces in Valea Jiului that are/were occupied by human activities, directly or indirectly related to mining in this area, are valued at approx. 1900ha, which represents 1.84% of the surface of Valea Jiului, an area which, at first estimate, would not be relevant, but as it was shown, the objectives, mostly inactive, on these lands leave a much better landscape and visual aspect significantly than their extent Among the environmental changes, land degradation currently has the most important consequences for human settlements and economic activities, especially through induced subsidence processes and the presence of tailings deposits with reduced stability. The calculation of the land degradation index caused by mining activities highlighted the fact that the most affected are the mining perimeters in the center and east of Valea Jiului, respectively Vulcan, Lupeni and Lonea, which also extend into the suburbs of Petrila settlements (Lonea colony, Cimpa), Jieț, Vulcan (north), Lupeni (east and north). In the last 10-12 years, the closure of the majority of mines in Valea Jiului and the upgrading of some major sources of pollution (e.g. the Coroiești preparation plant), have contributed to an important extent to reducing the impact of extractive activities on the environment (e.g. the significant decrease in the concentration of suspensions solids in the waters of the Jiu). However, with the development of alternative economic activities, new sources of imbalance at the local level appeared, namely tourism (through the chaotic expansion of accommodation units in the mountain area, in Straja and in Parâng) and the exploitation and primary processing of wood. These, together with agro-pastoral activities and legislative changes, lead to pollution phenomena (e.g. water pollution with wood waste and animal residues), but also to new changes in land use and vegetation. Thus, the change in the land ownership regime, grazing in the forest, uncontrolled cutting, burning of some land and pastoral pressure on the land have caused changes in the structure and composition of forests and meadows. References [1]. Biro C., 2005 Rehabilitation of lands degraded by anthropogenic activities in the Petroșani mining basin, PhD thesis, University of Petroșani (in Romanian) [2]. Georgescu, M., e.a., 2002 Evaluation of the impact of environmental pollution and socio-economic life in Valea Jiului, University of Petroșani, Grant No. 1 CNCSIS code 236 (in Romanian) [3]. Roman L., 2022 Research on the impact of the closing of the mines in Valea Jiului on the environment, PhD thesis, University of Petroșani (in Romanian) [4]. Costache A., 2020 Vulnerability of human settlements and social risks in the Petroșani Depression, Transversal Târgoviște Publishing House (in Romanian) [5]. Faur F., 2009 Development of an environmental monitoring system in Valea Jiului, PhD thesis, University of Petroșani (in Romanian) [6]. ***, 2001 Post-closure monitoring of isolated underground and surface mine constructions – S.C. I.C.P.M. S.A., Petroșani (in Romanian) 12 Revista Minelor – Mining Revue vol. 28, issue 4 / 2022 ISSN-L 1220-2053 / ISSN 2247-8590 pp. 1-13 [7]. Georgescu M., e.a., 2001 Identification of pollution sources and evaluation of the degree of pollution of Valea Jiului, Grant no. 2, CNCSIS code 915, Petroșani (in Romanian) [8]. Buliga (Nălboc) I.V., 2017 The study of the impact on the environment of the pollutants generated by the mining units in the west of Valea Jiului, PhD thesis, University of Petroșani (in Romanian) [9]. Onica I., e.a., 2015 Works to develop production capacity at E.M. Lonea - Feasibility study - University of Petroșani (in Romanian) [10]. Vereș I., e.a., 2019 Development plan of E.M. Livezeni and E.M. Vulcan – Funding contract 1363/2019, University of Petroșani (in Romanian) [11]. ***, 2017-2022 Reports on the inventory and inspection of tailings dumps and settling ponds, Environmental Protection Agency, Hunedoara (in Romanian) This article is an open access article distributed under the Creative Commons BY SA 4.0 license. Authors retain all copyrights and agree to the terms of the above-mentioned CC BY SA 4.0 license.

Journal

Mining Revue – de Gruyter

Published: Dec 1, 2022

Keywords: soil and land degradation; global land degradation index

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