Hindawi Geofluids Volume 2018, Article ID 3564360, 16 pages https://doi.org/10.1155/2018/3564360 Research Article Effect of Coal Mining on Springs in the Yushenfu Mining Area of China Li-min Fan,1,2 Tao Li ,1,3 Maoxi Xiang,1,2 Weizhong He,1,2 Boyun Wu,1,2 Jie Peng,1,2 Yonghong Li,1,2 Cheng Li,1,2 Miao-miao Zheng,1,2 Jianping Chen,1,2 Shuai Gao,1,2 Jiangli Du,1,2 and Yiwei Ji1,2 1Key Laboratory of Mine Geological Hazards Mechanism and Control, Xi’an Shaanxi 710054, China 2Shaanxi Institute of Geo-Environment Monitoring, Xi’an, Shaanxi 710054, China 3School of Mining & Civil Engineering, Liupanshui Normal University, Liupanshui, Guizhou 553004, China Correspondence should be addressed to Tao Li; [email protected] Received 3 July 2018; Accepted 1 September 2018; Published 28 October 2018 Guest Editor: Fangtian Wang Copyright © 2018 Li-min Fan et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The main purpose of this study was to analyze the effect of coal mining on the springs in the Yushenfu mining area of China. The results of two springs and hydrological surveys conducted in 1994 and 2015 were compared to study the occurrence and evolution of springs before and after large-scale mining. The mechanism of spring evolution and ecological effects of domain evolution were analyzed by combined groundwater monitoring and evaluation of coal mining intensity. The results show that the maximum amount of single water inflow of spring with sand infiltration recharge was more than 10 L/s, the total amount of single water inflow of spring with mixed infiltration recharge was the highest, and the ecological effect of spring with loess infiltration recharge was the most significant. In the study area, 2580 springs (group) were distributed with a total flow of 4998.9428 L/s before 1994 and 376 residual springs (group) were present with a total flow of 996.392 L/s in 2015. Large-scale mining decreased the regional groundwater level, thus decreasing the amount of spring water. The high intensity of mining decreased the number of springs (group) and area of water and wetland in the study area. This directly affected the watershed ecology; the ecological degradation was significant. 1. Introduction environment [2, 3] and small-scale mining activities also cause severe damage to the ecosystem [4]. Therefore, in the Water is very important for human life, production, and eco- early stage of coal mining in Western China, some experts logical environment. Springs are the origin of water resources. realized the importance of water resources and environment The occurrence and evolution of springs determine the state in the ecologically fragile mining area [5, 6], proposed the of groundwater and surface water. Therefore, it is important concept of “water-preserved mining” [7, 8], and carried out to study the characteristics of spring water. a series of research [9–19]. Coal mining of China is moving to the west; Western The distribution characteristics and forming conditions China has become the main coal-producing area, accounting of spring in the southern edge of Mu Us Desert were analyzed for 70% of the China’s coal output. However, Western China by Wu and other researchers. Ma and other scholars classified generally lacks water resources and has a fragile ecological the influence degree of coal mining on springs and discussed environment [1]. By studying the effect of coal mining on the influence mechanism of coal mining on springs. In addi- the environment, the scientific community has already made tion, the effect of coal mining on water resources and ecolog- a conclusion: coal mining directly affects the ecological ical environment has been extensively investigated [2, 3, 20]. 2 Geofluids This study analyzed the mechanism of spring evolution produced by the infiltration of sand-covered loess ridge and in the Yushenfu mining area by comparing the evolution of hilly, and (iii) spring group produced by the infiltration of springs in the Yushenfu mining area in northwest China loess ridge and hilly. Notably, the three parts do not include around 21 years ago and combining the study of collapse the distribution area, bedrock valley geomorphology with caused by coal mining. limited infiltration, and geomorphology of the burnt zone. Because the water holding capacity of these strata is limited, 2. Materials the gush of dry season spring mainly comes from the above three parts with a high ecological significance. 2.1. General Situation of the Study Area. The study area, Yushenfu mining area, is located in Shaanxi Province of (1) Spring Produced by Aeolian Landform Infiltration. The ° China. The study area is ~7800 km2, north latitude of 38 10′ Salawusu formation is the main aquifer in the study area. ° ° ° –39 30′ and east longitude of 109 0′–110 60′ (Figure 1). No water barrier is present between the Salawusu and Mu fi The altitude of the study area is ~1200 m, the highest point Us formations, constituting a uni ed loose sand aquifer. It is 1448.7 m, and the lowest point is 932 m. Three types of geo- is generally called the aquifer of Salawusu formation. The morphology are present, namely, aeolian landform, sand- aquifer of Salawusu formation receives the atmospheric pre- fi ff covered loess ridge and hilly, and loess ridge and hilly. cipitation, condensation recharge, rapid in ltration, runo According to the meteorological observation in Yuyang Dis- in the sand layer, enrichment in the low-lying area on the trict, the annual average precipitation is 420.4 mm with the top of Jurassic, and formation of a rich water area. After ff maximum annual rainfall of 565.3 mm and the minimum the erosion of local surface runo to the aquifer, the annual rainfall of 270.8 mm. Precipitation mainly occurred descending spring is excreted and forms the spring group in July to September, accounting for 62.9% of the annual (Figure 2). Because the topography of sandy land is small, precipitation. the number of springs in this area is limited, but the total The Yushenfu mining area is in the Ordos Basin of volume is the largest. fi North China. The geological tectonic is simple. The strata (2) Spring Produced by In ltration of Sand-Covered Loess are from the old to the new: Upper Triassic Yongpoing for- Ridge and Hilly. The area of sand-covered loess ridge and ’ hilly belongs to the transition area of Mu Us Desert and mation (T3y), Yan an formation (J2y), Zhiluo formation Loess Plateau (Figure 2), and the thickness of sand layer is (J2z), Anding formation (J2a) of Middle Jurassic, Lower Cre- relatively limited. Because of the relatively low terrain com- taceous Luohe formation (K1l), Neogene Pliocene series pared with the aeolian landform area, the lateral recharge of Debao formation (N2b), Quaternary Middle Pleistocene groundwater is better owing to aeolian landform infiltration series Lishi formation (Q2l), Quaternary Upper Pleistocene and fluctuation of loess terrain, most of the groundwater is Salawusu formation (Q3s), aeolian deposit (Q4eol), and allu- exposed, and it is easy to contact with the spring spot. The vial deposit (Q4al) of Quaternary Holocene series. The main coal bearing strata are Middle Jurassic Yan’an formation. output of spring is the largest in this area, but this part of − − The main minable seam has 4 layers, of which 2 2 and 4 3 the spring is more sensitive. The instability of underlying − − of the whole area can be mined and 3 1 and 5 3 of the upper aquifer causes its attenuation; at the same time, the decline part can be mined. of groundwater level in the regional loose layer also easily The groundwater in this area is mainly supplied by makes it disappear. atmospheric water. The direction of shallow seepage flow is fi basically consistent with topographic relief. The deep seep- (3) Spring Produced by In ltration of Loess Ridge and Hilly. age flow is basically runoff from northwest to southeast. The loess layer acts as a weak permeable layer. This layer fi The buried depth of groundwater in the western desert beach has a certain in ltration capacity for precipitation, but it is fi area is generally 0~3 m, and it has gradually increased in the very limited compared with the amount of sand in ltration. fi eastern part. The buried depth of groundwater in the loess The loess has better water-holding property; long-term in l- ridge and hilly area is generally greater than 15 m. Ground- tration of water resources occurs in the stratum. After cutting water is mainly in valleys with spring in the form of emis- the loess topography, concentrated discharge of groundwater sion. Groundwater is mainly discharged in the form of occurs in the medium such as the top surface of bedrock or springs in gullies. burned rock, forming the main drainage spring spots of this type of geomorphology. 2.2. Spring Characteristics before Large-Scale Mining 2.2.2. Distribution of the Spring Group. The spring of Mu Us 2.2.1. Hydrological Background of Spring Formation. The Desert is mainly distributed in the east edge of Kuye River, stratigraphic structure of the study area successively from Tuwei River, and the upper reaches of Yuxi River, a tributary the new to the old is Q4eol (Mu Us formation), Q3 (Salawusu of Wuding River. The spring is distributed on the north-east formation), Miocene series (Lishi formation, the Loess), zonal distribution of the plane (Figure 3). The springs con- Pliocene series (Red clay), Jurassic Zhiluo formation, and verge to form Kuye River, Tuwei River, and Yuxi River.