新疆和田地区耕地面源污染生态风险评价

Ecological risk assessment of farmland non-point source pollution in Hotan Prefecture,Xinjiang

随着化肥、农膜等在农业生产中的过量投入,耕地面源污染的程度随之加重。选取塔里木河流域上游和田地区为研究区域,依据P-S-R框架理论,构建和田地区耕地面源污染生态风险评价指标体系,加入土壤理化数据,使用生态风险评价模型对和田地区1980年及2016年耕地面源污染状况进行生态风险评价,运用耕地生态风险模型、生态风险转移矩阵、ArcGIS分析和田地区耕地面源污染时空分异状况。研究结论表明:和田地区1980年耕地生态风险等级均为Ⅱ级或Ⅲ级,呈"中间高,两侧低"分布;2016年耕地生态风险等级上升至Ⅳ级或Ⅴ级,呈"倒W型"分布,各县耕地面源污染程度较1980年均有较大幅度的上升,其中墨玉县和于田县在2016年耕地生态风险等级达到最高的Ⅴ级,而民丰县因自身生态环境的强脆弱性,同样需要提高关注。根据面源污染"从源头治理"的原则,应切实推进和田地区耕地生态环境保护与治理,提高政府重视程度,增强技术指导,开展试点工作,改善和田地区耕地面源污染现状。

With the excessive chemical fertilizers and agricultural film put into the agricultural production,the non-point source pollution in the cultivated land has been aggravated.In this paper,the Hotan Prefecture in the lower reaches of the Tarim River Basin,Xinjiang,China is selected as the research area.Based on the PSR framework and the "input-output" principle of economics,the physicochemical data of cultivated land is added as a status indicator to construct an ecological risk assessment index system for the non-point source pollution.The spatial and temporal differentiation of the ecological risk level of cultivated land non-point source pollution in Hotan Prefecture in 1980 and 2016 is analyzed using the Arcgis software.The following conclusions are drawn from this study:The ecological risk level of the non-point source pollution in Hotan Prefecture in 2016 has been increased significantly compared with that in 1980.Particularly,the ecological risk level of the cultivated land in Moyu County and Yutian County has reached the highest V level,while Minfeng County is vulnerable due to its own ecological environment.The three counties can be used as pilots to promote non-point source pollution control.The research results can be taken as a reference for exploring the construction of non-point source pollution ecological risk assessment system,and guiding the development of differentiated non-point source pollution control according to regional characteristics.