The hydrochemical responses of underground rivers to urbanization were studied using a 25-year groundwater observation dataset and remote sensing. We found that as urbanization progresses, the mineralization degree of underground rivers gradually increases; time-series data for dominant hydrochemical indicators changed from HCO·SO-Ca·Mg during the dry season and HCO-Ca·Mg during flood season to HCO·Cl-Ca, HCO·SO-Ca, HCO-Ca, and HCO·SO-Ca·Mg. Influenced by surface precipitation input, the groundwater chemistry of underground rivers varies greatly during the dry season and the flood season. Prior to urbanization,[Mg]/[Ca] and[HCO]/[SO] molar ratios are affected by water-rock interactions, agricultural activities, and acid rain infiltration, the average values of which were 0.86 and 29.34, respectively. After urbanization, agricultural activities and the contribution from acid rain decreased gradually. During the periods 1990-1995, 1996-2010, and 2011-2015, the main sensitive geochemical cations were Ca, Mg, Na, and NH, and the main anions were HCO, HCO, and SO, and Cl. The hydrochemical response of underground rivers to urbanization was characterized by clear temporal phases.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.13227/j.hjkx.201901057 | DOI Listing |
Excavation of underground engineering structures involving deeply buried water-rich soft rocks is generally carried out using the artificial freezing method. A series of undrained uniaxial and triaxial shear and creep tests were conducted on soft rocks under different confining pressures (0, 0.2, 0.
View Article and Find Full Text PDFSci Rep
January 2025
School of Energy and Mining Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China.
For a long time, the management of surface structures such as villages and rivers affected by underground coal mining has been a popular and difficult issue in coal mining. With the further tightening of environmental protection requirements, it has become challenging for some underground coal mines that lack the conditions for filling and grouting to ensure the recovery of coal resources while controlling surface subsidence. Furthermore, many such common issues have emerged in the Yushen and Binchang mining areas of Shanxi Province, as well as in several other coalfields, severely constraining the development of coal energy and ecological environmental protection.
View Article and Find Full Text PDFHeliyon
December 2024
School of Civil and Hydraulic Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.
Small
December 2024
College of Materials Science and Engineering, Guangdong Provincial Key Laboratory of New Energy Materials Service Safety, Guangdong Research Center for Interfacial Engineering of Functional Materials, Institute of Deep Underground Sciences and Green Energy, Shenzhen University, Shenzhen, 518060, P. R. China.
The development of high-performance n-type PbTe thermoelectric (TE) modules is urgently needed to match those p-type IV-VI tellurides (i.e., PbTe, GeTe, SnTe) with high figure of merit (ZT) to obtain multi-pair TE devices for practical applications.
View Article and Find Full Text PDFSci Total Environ
December 2024
School of Geography & Environmental Science/School of Karst Science, Guizhou Normal University, Guiyang 550001, China; The State Key Laboratory Incubation Base for Karst Mountain Ecology Environment of Guizhou Province, Guiyang 550001, China; Guiyang New World School, Guiyang 550081, China.
Increases in sulphate concentrations in natural water bodies can lead to the deterioration of water quality. Human activities, such as coal mining and agricultural fertilisation, can generate sulphate, which can enter water bodies through surface runoff or underground pipelines. Owing to the widespread distribution of coal-bearing strata and an intensification of industrial and agricultural activities, the Pingzhai Reservoir is increasingly at risk of sulphate pollution.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!