丹江口水库新增淹没区农田土壤潜在风险评估

通过野外调查与室内模拟实验,采用综合评价指数法对丹江口水库新增淹没区农田土壤进行了潜在风险评估,结果表明:新增淹没区土壤背景总氮为0.3~3.8g/kg,平均值1.1g/kg;总磷为0.2~2.4g/kg,平均值0.8g/kg,入库支流区域土壤背景氮磷含量较高,新增淹没区的含量较低;土壤模拟淹水浸泡的溶出总氮为0.2~11.8mg/L、总磷为0.006~2.2mg/L,平均值分别为4.1,0.3mg/L.空间分布上,土壤溶出氮磷与新增淹没区土壤氮磷背景值变化相似.新增淹没区潜在风险评估等级由低到高的面积分别占整个新增淹没区总面积的3.3%、21.2%、56.9%、15.9%、2.7%,表明大部分新增淹没区处于中低风险等级,其中高风险区域主要集中在入库支流区域.

The potential risk evaluation of farmland soil from new submerged area in Danjiangkou Reservoir

Comprehensive index was used to assess the potential risk of soils from submerged area in Danjiangkou reservoir through field investigation and indoor simulation experiments. The results showed that the background content of soil total nitrogen was 0.3~3.8g/kg, and its average was 1.1g/kg. The background content of soil total phosphorus was 0.2~2.4g/kg, and its average was 0.8g/kg. The contents of nitrogen and phosphorus were mainly concentrated in Danjiangkou reservoir tributaries, and the content of new submerged area was low. The content of soil dissolved total nitrogen was 0.2~11.8mg/L, and soil dissolved total phosphorus was 0.006~2.2mg/L. The average of soil dissolved total nitrogen; total phosphorus was 4.1, 0.3mg/L, respectively. The spatial distribution of soil dissolved nitrogen, phosphorus and the background values of soil nitrogen, phosphorus was similar. The proportion that the area of the risk assessment level from low to high accounted for the entire new submerged area was 3.3%, 21.2%, 56.9%, 15.9%, and 2.7%. Most of the new submerged area was low risk level, and high risk area was mainly concentrated in the tributary area of Danjiangkou Reservoir, which was required a focus in eco-environmental governance.