滇池流域主要农业产品水足迹空间格局及其环境影响测度

科学合理的评估农业产品水资源消耗及其环境影响对保护区域农业生产安全和水资源合理配置具有重要意义.本文以滇池流域为例,耦合水足迹和生命周期评价方法,对流域内2005—2011年主要农业产品水足迹空间格局进行分析,并对其环境影响进行测度.结果显示:滇池流域主要农作物和动物产品年平均水足迹分别为4.88×108m3·a-1和8.97×108m3·a-1,动物产品总水资源消耗大于农作物产品.动物产品水足迹的人类健康和生态系统质量总环境影响高于农作物,但资源消耗总环境影响要低于农作物,各区县产品水足迹环境影响值最大的为猪肉、水稻和玉米.各区县主要产品水足迹及其环境影响空间差异显著,嵩明县和晋宁县的产品水足迹环境影响最高,城区则较低.本文最后提出:评价一种产品对区域水资源的可持续性影响时,不仅要考虑产品耗水量也应考虑产品对水资源产生的潜在环境影响大小,应从水资源管理和生命周期角度综合考虑.水资源量少的地区,应侧重选择水资源消耗量小的产品,水量充沛地区则应选择对人类和生态产生影响小的产品.

Spatial pattern of the agricultural water footprint and its environmental impact in Lake Dianchi Basin

Scientific and reasonable assessment of water resources consumption and its environmental impact on the agricultural products is of great significance for regional agricultural production security and water resources rational allocation. By combining the water footprint and life cycle assessment methods, this paper analysed the spatial pattern of the water footprint of main agricultural products and its environmental impact in Lake Dianchi Basin from 2005 to 2011. The results show that the average water footprints of main crops and animal products were 4.88×10⁸ m³·a^-1 and 8.97×10⁸ m³·a^-1, respectively. The total water footprints of animal products were larger than those of crop productions. The environmental impacts of water footprint of animal products on human health and ecosystem quality were higher than those of crops, whereas the environmental impact on resource consumption was lower than that of crops. Pork, rice and maize had the largest environmental impact values of water footprint. The water footprints and their environmental impacts of main agricultural products for each district in Lake Dianchi Basin were significantly different. The water footprints and the relative environmental impact of agricultural products were the highest in Songming County and Jinning County and were lower in urban areas. To assess the impact of a product on regional water sustainability, water policy should be considered from the perspectives of both water resources management and life cycle environmental impact. In a water-deficient area, the products which consume less water should be chosen, whereas the products with lower environmental impact are favored in water-rich area.