Environmental Effection of Groundwater Development in Xuzhou City During Rapid Urbanization
Xuzhou City is located on the most northwestern portion of Jiangsu Province, P. R. China. Karst groundwater in Ordovician and Cambrian Limestone aquifer is a main source of water supply, there are 527 wells in urban area to develop Karst groundwater, yielding up to 30.000m3 per day. After 1978, urbanization and industrialization of Xuzhou City have been going on at a greatly accelerated pace, population increased from 670,700(1978) to 1,674.200(2004).GDP from 0.65 × 108 RMB￥ to 1095.80 × 108 RMB￥ and urban area from 184Km2 to 1,038Km2(built city area from 41.3Km2 to 81.9Km2). Development volume of Karst groundwater increased year by year before operation of supply plant of surface water in 1992,from 3,852.0×104m3(1978) to 13,411.2×104m3(1991) and now also kept at 9441.0×104m3(2004). Intensive overexploitation of Karst groundwater has caused that piezometric level drawdowns continuously and area of depression cone enlarges year after year. These changes have increased of vulnerability of Karst groundwater system and have induced some environmental problems such as depletion of water resource. water quality deterioration, groundwater contamination and karst collapse. The largest buried depth of Karst groundwater is up to 100m in dry season in some areas, while 56 exhausted wells have been abandoned. Thickness change of unsaturated zone due to drawdown of piezometric level has caused the change of chemical environment to impact physical state or chemical forms of major compositions in groundwater. The content of Ca2+, Mg2+,NO3--, SO42-- and Cl- in Karst groundwater increases significantly, total hardness(CaCO3 content) rises year by year in most pumping wells and exceeds the Standard of Drinking Water of P. R. China. Point source pollution and belt-like pollution along the rivers has caused water quality deterioration. Sudden loss of buoyant support due to rapid drawdown of piezometric level has induced 7 Karst collapses to form 17 pits and has made USS10,000.000 economic loss. These problems have in fluenced the developing quality of this city.
Xuzhou City Karst groundwater vulnerability of groundwater environmental effection
XU Ai-qin LIU Xi-kun
Department of Public Health, Xuzhou Medical College.Xuzhou, Jiangsu Province.221002, P R.China Department of Water Resource Management of Xuzhou City, Xuzhou, Jiangsu Province, 221003, P R.China
国际会议
徐州
英文
85-88
2007-10-22（万方平台首次上网日期，不代表论文的发表时间）