Numerical simulation of groundwater in karst areas has long been restricted by the difficulty of generalizing the hydrogeological conditions of reservoirs and of determining the relevant parameters due to the anisotro...Numerical simulation of groundwater in karst areas has long been restricted by the difficulty of generalizing the hydrogeological conditions of reservoirs and of determining the relevant parameters due to the anisotropy and discontinuity of the karst water-bearing media in these areas. In this study, we used the Guang'an Longtan Coal mine in Sichuan as an example, and generalized the complex hydrogeological conditions in the reservoir area. A finite element numerical flow model was used to simulate current and future scenarios of roadway gushing at the bottom of the coal mine at pile number 1 + 700 m. The results show that the roadway section corresponding to valleys has a gushing quantity of 4323.8–4551.25 m^3/d before impoundment. Modeled water inflow after impoundment increased to 1.6 times the water inflow before impoundment, which threatens the impoundment as well as the roadway's normal operation. Therefore, roadway processing measures are needed to guarantee the safety of the impoundment and of the mining operation.展开更多
Florida＇s artesian springs receive groundwater outflows from the Floridan Aquifer System and are concentrated north of I-4 and west to the Florida Panhandle. These springs and their resulting spring runs support a un...Florida＇s artesian springs receive groundwater outflows from the Floridan Aquifer System and are concentrated north of I-4 and west to the Florida Panhandle. These springs and their resulting spring runs support a unique freshwater ecology dependent on perennial flows, constant temperature and chemistry, and high light transmissivity. Numerous observations indicate that Florida＇s springs flows are declining as a result of the increasing extraction of groundwater for human uses. North Florida＇s karst environment is especially susceptible to nitrogen pollution from agricultural and urban development. An empirical springs/aquifer water budget is needed to better understand these spring stressors. Discharge data from 393 of the state＇s 1,000＋ artesian springs are used to estimate trends in total spring discharge by decade since 1930-39. This analysis indicates that average spring flows have declined by about 32%. Large groundwater pumping centers are altering spring flows over the whole springs region. Existing groundwater pumping rates from the Floridan Aquifer in 2010 were more than 30% of average annual aquifer recharge, and allocated groundwater use in north-central Florida is nearly double current estimated uses. Based on biological research conducted in Florida springs, these flow reductions are from two to six times greater than declines known to result in significant harm to aquatic resources.展开更多
基金supported by the National Natural Science Foundation of China (41272377)
文摘Numerical simulation of groundwater in karst areas has long been restricted by the difficulty of generalizing the hydrogeological conditions of reservoirs and of determining the relevant parameters due to the anisotropy and discontinuity of the karst water-bearing media in these areas. In this study, we used the Guang'an Longtan Coal mine in Sichuan as an example, and generalized the complex hydrogeological conditions in the reservoir area. A finite element numerical flow model was used to simulate current and future scenarios of roadway gushing at the bottom of the coal mine at pile number 1 + 700 m. The results show that the roadway section corresponding to valleys has a gushing quantity of 4323.8–4551.25 m^3/d before impoundment. Modeled water inflow after impoundment increased to 1.6 times the water inflow before impoundment, which threatens the impoundment as well as the roadway's normal operation. Therefore, roadway processing measures are needed to guarantee the safety of the impoundment and of the mining operation.
文摘Florida＇s artesian springs receive groundwater outflows from the Floridan Aquifer System and are concentrated north of I-4 and west to the Florida Panhandle. These springs and their resulting spring runs support a unique freshwater ecology dependent on perennial flows, constant temperature and chemistry, and high light transmissivity. Numerous observations indicate that Florida＇s springs flows are declining as a result of the increasing extraction of groundwater for human uses. North Florida＇s karst environment is especially susceptible to nitrogen pollution from agricultural and urban development. An empirical springs/aquifer water budget is needed to better understand these spring stressors. Discharge data from 393 of the state＇s 1,000＋ artesian springs are used to estimate trends in total spring discharge by decade since 1930-39. This analysis indicates that average spring flows have declined by about 32%. Large groundwater pumping centers are altering spring flows over the whole springs region. Existing groundwater pumping rates from the Floridan Aquifer in 2010 were more than 30% of average annual aquifer recharge, and allocated groundwater use in north-central Florida is nearly double current estimated uses. Based on biological research conducted in Florida springs, these flow reductions are from two to six times greater than declines known to result in significant harm to aquatic resources.
