渭河流域水足迹空间化及水资源评价

Spatial water footprint and water resources evaluation in Weihe River basin

基于水足迹理论,结合GIS数据空间化方法,计算分析了渭河流域栅格、行政单元、子流域3种不同尺度下的水足迹人口密度、水足迹经济效益和水资源匮乏程度。结果表明:渭河流域人均水足迹为829.67 m^3/人,陕西省的人均水足迹要小于宁夏回族自治区和甘肃省;农业耗水量最大,高值区位于流域下游西安、渭南附近,工业、生活、生态耗水的高值区均集中在西安市城区;流域平均水足迹人口密度为12.61人/万m^3,高值分布在流域东北部和南部秦岭北坡,整体呈现上游高、下游低的趋势,西安、咸阳市城区附近的人口承载能力最低;平均水足迹经济效益为49.47元/m^3,流域北部榆林市、中部宝鸡市和西安市城区边缘为高值区,水资源经济效益较高;渭河流域整体水资源匮乏度为0.71,北洛河匮乏度为0.41,水资源较为充沛,但水资源空间分布不均,各市的水资源匮乏度均大于1,城区内部水资源压力极大。城镇内部要加强居民节水意识,减少污水排放;城市周边地区应修建水库、植树造林,加强对水资源的存储。北洛河水系与秦岭北坡水资源压力较小,可适当调用以缓解核心城市水资源压力。

Based on water footprint theory and GIS method, water footprint population density, water footprint economic benefits and the degree of water resources scarcity were calculated and analyzed under three different scales. The results show that the per capita water footprint of Weihe River basin was 829.67 m3/person. The area with the highest water consumption in agriculture is located in the lower reaches of the basin, near Xi′an and Weinan city. The high value areas of industrial, domestic and ecological water consumption are all concentrated in the urban area of Xi′an city. The average water footprint population density of Weihe River basin is 12.61 person/10 000 m3, the high value is distributed in the northeast of Weihe River basin and the north slope of the Qinling mountains. The urban areas of Xi′an and Xianyang city have the lowest population carrying capacity. The average water footprint economic benefits is 49.47 yuan/m3. The values in the north of Yulin city, the urban area of Baoji city, the urban edge of Xi′an city are relatively high. The degree of water scarcity is 0.71 in Weihe River basin. BeiLuo watershed is relatively rich in water resources with 0.41 water scarcity degree. However, the water shortage degree of each city is greater than 1 because of the uneven distribution of water resources, the urban areas are under great pressure of water resources. Cities and towns should strengthen residents′ awareness of water-saving to reduce sewage discharge, surrounding areas should build reservoirs, plant trees to strengthen the storage of water. The core cities can properly transfer water from Beiluo watershed and the north of Qinling mountains to relieve the enormous pressure of water resources.