Lanchu Tao , Yunhui Zhang , Xingcheng Yuan , Qingsong Chen , Jinhai Yu , Yiqi Ma , Honghao Liu , Chunlin Tu
{"title":"有采煤活动的岩溶流域多层含水层的水文过程:水化学和同位素的启示","authors":"Lanchu Tao , Yunhui Zhang , Xingcheng Yuan , Qingsong Chen , Jinhai Yu , Yiqi Ma , Honghao Liu , Chunlin Tu","doi":"10.1016/j.ejrh.2024.102016","DOIUrl":null,"url":null,"abstract":"<div><h3>Study region</h3><div>The Laochang Karst watershed (LCKW) is located in eastern Yunnan Province, southwestern China. It is the representative karst area affected by coal-mining activities in southwestern China.</div></div><div><h3>Study focus</h3><div>Identifying hydrological processes of multi-layered aquifers in karst watersheds is challenging due to complex natural and anthropogenic processes. This study attempts to clarify the hydrological conceptual model of the LCKW using hydrochemistry and D, O, Sr, S, and C isotopes.</div></div><div><h3>New hydrological insights for the region</h3><div>Surface water and multi-layered groundwater have the hydrochemical types of SO<sub>4</sub>-Ca·Mg, HCO<sub>3</sub>·SO<sub>4</sub>-Ca, and HCO<sub>3</sub>-Ca. Meteoric water and condensate were the major recharge sources. The main processes dominating hydrochemical compositions consist of sulfide oxidative dissolution, carbonate dissolution, positive cation exchange, and agricultural activities. Elevated SO<sub>4</sub><sup>2−</sup> concentration in the mine water, river water and shallow coalbed water mainly originated from the oxidation of pyrite in the coal-bearing strata of the Longtan Formation. whereas the deeper layers and groundwater away from the mines were hardly contaminated by SO<sub>4</sub><sup>2−</sup> due to the presence of aquiclude. HCO<sub>3</sub><sup>−</sup> concentrations of surface water and multi-layered groundwater were mainly derived from carbonate dissolution and soil CO<sub>2</sub>, and mine water was also influenced by atmospheric CO<sub>2</sub>. Positive cation exchange contributed to increasing Na<sup>+</sup> concentration. Agricultural activities contributed NO<sub>3</sub><sup>−</sup>, Cl<sup>−</sup>, and K<sup>+</sup> ions in aquifers, especially near large karst fallout caves. A hydrological model of multi-layered aquifers in the LCKW was built based on the above results. These findings will provide valuable guidance for understanding the hydrological processes of complex karst watersheds worldwide.</div></div>","PeriodicalId":48620,"journal":{"name":"Journal of Hydrology-Regional Studies","volume":"56 ","pages":"Article 102016"},"PeriodicalIF":4.7000,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Hydrological processes in multi-layered aquifers of a karst watershed with coal mining activity: Insights from hydrochemistry and isotopes\",\"authors\":\"Lanchu Tao , Yunhui Zhang , Xingcheng Yuan , Qingsong Chen , Jinhai Yu , Yiqi Ma , Honghao Liu , Chunlin Tu\",\"doi\":\"10.1016/j.ejrh.2024.102016\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><h3>Study region</h3><div>The Laochang Karst watershed (LCKW) is located in eastern Yunnan Province, southwestern China. It is the representative karst area affected by coal-mining activities in southwestern China.</div></div><div><h3>Study focus</h3><div>Identifying hydrological processes of multi-layered aquifers in karst watersheds is challenging due to complex natural and anthropogenic processes. This study attempts to clarify the hydrological conceptual model of the LCKW using hydrochemistry and D, O, Sr, S, and C isotopes.</div></div><div><h3>New hydrological insights for the region</h3><div>Surface water and multi-layered groundwater have the hydrochemical types of SO<sub>4</sub>-Ca·Mg, HCO<sub>3</sub>·SO<sub>4</sub>-Ca, and HCO<sub>3</sub>-Ca. Meteoric water and condensate were the major recharge sources. The main processes dominating hydrochemical compositions consist of sulfide oxidative dissolution, carbonate dissolution, positive cation exchange, and agricultural activities. Elevated SO<sub>4</sub><sup>2−</sup> concentration in the mine water, river water and shallow coalbed water mainly originated from the oxidation of pyrite in the coal-bearing strata of the Longtan Formation. whereas the deeper layers and groundwater away from the mines were hardly contaminated by SO<sub>4</sub><sup>2−</sup> due to the presence of aquiclude. HCO<sub>3</sub><sup>−</sup> concentrations of surface water and multi-layered groundwater were mainly derived from carbonate dissolution and soil CO<sub>2</sub>, and mine water was also influenced by atmospheric CO<sub>2</sub>. Positive cation exchange contributed to increasing Na<sup>+</sup> concentration. Agricultural activities contributed NO<sub>3</sub><sup>−</sup>, Cl<sup>−</sup>, and K<sup>+</sup> ions in aquifers, especially near large karst fallout caves. A hydrological model of multi-layered aquifers in the LCKW was built based on the above results. These findings will provide valuable guidance for understanding the hydrological processes of complex karst watersheds worldwide.</div></div>\",\"PeriodicalId\":48620,\"journal\":{\"name\":\"Journal of Hydrology-Regional Studies\",\"volume\":\"56 \",\"pages\":\"Article 102016\"},\"PeriodicalIF\":4.7000,\"publicationDate\":\"2024-10-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Hydrology-Regional Studies\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2214581824003653\",\"RegionNum\":2,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"WATER RESOURCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Hydrology-Regional Studies","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2214581824003653","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"WATER RESOURCES","Score":null,"Total":0}
Hydrological processes in multi-layered aquifers of a karst watershed with coal mining activity: Insights from hydrochemistry and isotopes
Study region
The Laochang Karst watershed (LCKW) is located in eastern Yunnan Province, southwestern China. It is the representative karst area affected by coal-mining activities in southwestern China.
Study focus
Identifying hydrological processes of multi-layered aquifers in karst watersheds is challenging due to complex natural and anthropogenic processes. This study attempts to clarify the hydrological conceptual model of the LCKW using hydrochemistry and D, O, Sr, S, and C isotopes.
New hydrological insights for the region
Surface water and multi-layered groundwater have the hydrochemical types of SO4-Ca·Mg, HCO3·SO4-Ca, and HCO3-Ca. Meteoric water and condensate were the major recharge sources. The main processes dominating hydrochemical compositions consist of sulfide oxidative dissolution, carbonate dissolution, positive cation exchange, and agricultural activities. Elevated SO42− concentration in the mine water, river water and shallow coalbed water mainly originated from the oxidation of pyrite in the coal-bearing strata of the Longtan Formation. whereas the deeper layers and groundwater away from the mines were hardly contaminated by SO42− due to the presence of aquiclude. HCO3− concentrations of surface water and multi-layered groundwater were mainly derived from carbonate dissolution and soil CO2, and mine water was also influenced by atmospheric CO2. Positive cation exchange contributed to increasing Na+ concentration. Agricultural activities contributed NO3−, Cl−, and K+ ions in aquifers, especially near large karst fallout caves. A hydrological model of multi-layered aquifers in the LCKW was built based on the above results. These findings will provide valuable guidance for understanding the hydrological processes of complex karst watersheds worldwide.
期刊介绍:
Journal of Hydrology: Regional Studies publishes original research papers enhancing the science of hydrology and aiming at region-specific problems, past and future conditions, analysis, review and solutions. The journal particularly welcomes research papers that deliver new insights into region-specific hydrological processes and responses to changing conditions, as well as contributions that incorporate interdisciplinarity and translational science.