九龙江流域规模化养殖环境风险评价

在GIS支持下采用养分收支平衡法对九龙江流域规模化生猪养殖的环境风险进行评价。规模化养殖污染负荷在不同类型养殖场的分配、空间分布规律以及规模化养殖的环境风险评价结果表明：规模化养猪业年产粪尿量达107万t，以小型规模化养殖场产生的污染负荷最高；整体来看，规模化生猪养殖的环境风险不大，但由于养殖场的地理分布集中，造成近郊区域规模化养殖的环境风险极高；由于过多施用化肥，中远郊规模化养殖粪尿未得到合理利用而流失。位于水系附近的养殖场对水体影响较大，根据“福建省畜禽养殖污染防治管理办法”，为减少规模化生猪养殖对九龙江水质的直接威胁，需搬迁主要支流沿岸1km范围内的规模化养猪场250个。

Environmental risk assessment of intensive animal production in Jiulong River Watershed.

With the rapid growth in the number and size of intensive livestock enterprises in China, livestock waste in a huge amount has become one of the main sources of water pollution. Environmental risk assessment of the intensive animal production in the Jiulong River Watershed was conducted with the aid of GIS and the nutrient balance method. The findings of the study of spatial distribution of pollution loads and the environmental risk assessment show that a total of 1 070 000 tons of manure is produced annually from the pig farms in the region, among which those small in scale contribute the most to the environmental pollution load. Generally speaking, the pig farms up in scale do not pose much environmental risk. However,high environmental risk is found in some suburban and exurban regions where such pig farms concentrate and produce large amounts of pig manure that cause great impact on the environment in addition to the excessive application of chemical fertilizer. Animal production units located near streams pose higher threat to the waterbodies. It is, therefore, suggested that in order to reduce their impact on water quality and urban environment,the 250 pig farms located near streams should be moved at least 1 km away from the rivers and their main tributaries.