银川平原主要水环境问题及其对策

基于野外调查、取样分析以及遥感影像等,介绍了银川平原水文地质条件及水资源利用概况,探讨了土壤盐渍化、湖泊湿地萎缩、地下水盐化、地下水超采以及土地荒漠化等水环境问题及其演化成因。结果表明：银川平原地下水主要接受渠系渗漏及灌溉入渗、大气降水入渗、平原周边地下侧向径流、洪水散失、黄河水等补给,地下水排泄方式主要是排水沟排泄、蒸发和人工开采等,大部分地区潜水埋深在3 m以内;地表水主要来源于黄河引水,水资源利用效率不高;土壤盐渍化总面积8.17×104hm2,呈逐年缩减的趋势,主要分布于银川平原北部,平原南部仅分布在邵岗东部、灵武东部秦渠和东干渠等;湖泊湿地总体呈逐渐减少趋势,主要分布在银川平原北部,永宁以北、平罗以南区域比较集中,滩涂沿黄河两岸分布;潜水总含盐量自西向东、自南向北不断增大;银川和石嘴山深层地下水超采严重,地下水降落漏斗面积已超过500 km2;沙漠化土地分布在银川平原的东西两侧;土壤盐渍化及地下水盐化主要由潜水位埋深过浅,蒸发强烈造成的。最后,提出了防治上述水环境问题的对策：进一步加强水资源管理以及地表水与地下水联合调配;提高农业水资源利用效率;完善田间工程配套,实现渠道防渗管道化;改进田间灌溉技术;严格污水排放,积极开展污水净化处理,实行污水资源化;加强对水土环境质量的系统监测。

Main Water Environmental Problem and Its Countermeasures in Yinchuan Plain

Based on field investigation,sampling analysis and remote sensing image,hydrogeological condition and water resource use in Yinchuan Plain were introduced,the current situation and genetic development of water environmental problems including soil salinization,shrinkage of lake wetland,groundwater salinization,groundwater overexploitation and land desertification were discussed.The results showed that the groundwater was supplied by ditch seepage,irrigation and rainfall infiltration,underground lateral runoff around the plain,flood loss and Yellow River water loss in Yinchuan Plain;the groundwater drained by the means of drainage ditch,evaporation and artificial exploitation;depth of phreatic water was mostly within 3 m;the surface water came from Yellow River,efficiency of water resource use was poor;the total area of saline soil was 8.17×104 hm2 with an down trend,and mainly distributed in the north of Yinchuan Plain,and partly in the south;mudflat mainly distributed in both sides of Yellow River;total salinity of phreatic water increased from west to east and from south to north;over-exploitation of deep phreatic water was serious,and the area of groundwater depression cone was more than 500 km2 in Yinchuan and Shizuishan cities;the desertification land mainly distributed in the east and west of Yinchuan Plain;the main reason of soil and groundwater salinization was the shallow buried depth of phreatic water and strong evaporation.Finally,the countermeasures,which were put forward to preventing the water environmental problems,included strengthening water resource management and coordinating the use of surface and ground water,improving field irrigation,strictly controlling sewage discharge and purifying waste water,and strengthening the monitoring of soil and water environmental quality.