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以黄河三角洲为研究区域,选择土壤全盐为标志,以海拔高程、地下水位、地下水矿化度、、灌溉排水状况、土壤有机质和人口密度6个土壤盐渍化主要控制性因子,采用聚类分析方法进行了土壤盐渍化原因分析;基于ArcGIS 9.3和Matlab,选择上述7个要素为评价因子,以归一化植被指数(NDVI)为生态终点,利用灰色关联度方法建立了区域土壤盐渍化的生态风险评价模型,并进行了生态风险评价。结果表明:黄河三角洲土壤盐渍化主要受自然和人为因素驱动,其中地下水位和海拔高程等自然因素是造成研究区土壤盐渍化的自然因素,土壤有机质和人口密度等是人为因素;土壤盐渍化极大和重度风险区域集中分布于黄河三角洲东南沿海区域、西北沿海、东北部的部分地区,该区域受海洋影响强烈,土壤盐渍化面积最大,占到总面积的58%以上;无风险、轻度风险和中度风险区域主要与黄河径流的距离有关,且随着距离增大而风险增加。
Taking the Yellow River Delta as the research area, six soil salinization control factors, including elevation, groundwater level, salinity, irrigation and drainage status, soil organic matter and population density, Based on ArcGIS 9.3 and Matlab, the above seven factors were selected as evaluation factors, and the NDVI was used as the ecological end point. Based on the gray relational degree method, the regional soil salinity Ecological risk assessment model, and carried out ecological risk assessment. The results show that the soil salinization in the Yellow River Delta is mainly driven by natural and man-made factors. Natural factors such as groundwater level and elevation are the natural factors causing soil salinization in the study area. Soil organic matter and population density are human factors. The areas of great and severe risk of salinization are concentrated in the southeastern coastal areas, northwestern coastal areas and northeastern parts of the Yellow River Delta. This area is strongly affected by the oceans and has the largest area of soil salinization, accounting for more than 58% of the total area. The areas of mild and moderate risk are mainly related to the runoff from the Yellow River and are at an increased risk as the distance increases.