基于GIS的慈溪市土壤侵蚀敏感性评价

A GIS-based Assessment on Soil Erosion Sensitivity in Cixi City

[目的]对影响浙江省慈溪市土壤侵蚀敏感性的各因素进行评价,为该市进行环境功能区划和各项水土保持措施工程的布局调整提供参考。[方法]借鉴土壤侵蚀流失USLE模型,选取降雨侵蚀力、土壤质地、植被覆盖和地形起伏度4因子构建土壤侵蚀敏感性评价体系,并运用GIS进行土壤侵蚀敏感性分析。[结果]慈溪市土壤侵蚀敏感性在空间格局上呈半圆环状结构分布,并且轻度敏感区面积为733.05km2,占比高达75.70%,广泛分布于平原乡镇地区;不敏感区主要分布于近海滩涂区域,极敏感、高度敏感及中度敏感区则位于南部的丘陵、山地地区。[结论]慈溪市土壤侵蚀敏感性评价结果与水土流失现状空间分布走势大致相符,为此应重视和预防水土保持工作。

[Objective] Through evaluating the impact factors of soil erosion sensitivity for the Cixi City of Zhejiang City, references for conducting the environmental functional zoning and the layout of water conservation measure were expected to be provided. [Methods] According to the USLE model, rainfall erosion force, soil texture, vegetation cover and terrain fluctuation were selected to construct sensitivity evaluation system of soil erosion. Moreover, GIS was employed to analyze soil erosion sensitivity. [Results] Results showed a semicircle structure in the spatial distribution pattern of soil erosion sensitivity in Cixi City. The area of slight sensitivity was 733.05 km2, accounting for a high percentage of 75.7%, which was widely distributed in the villages and towns of plain area. The insensitive part located in the offshore area of tidal flat. The areas of extreme sensitive, high sensitive and moderate sensitive were mainly distributed in the hill and mountain regions of the southern part of Cixi City. [Conclusion] The results of sensitivity evaluation were in accord with the spatial distribution of soil water loss, indicating that more attentions should be paid to the conservation of soil and water.