基于RUSLE和GIS技术的江门市水土流失定量监测研究

Study of water and soil quantitative monitoring based on RUSLE and GIS technology in Jiangmen City

运用水土流失方程原理,在GIS技术支持下对江门市水土流失信息进行准确提取,并分析不同植被覆盖、地形坡度和降水条件下区域水土流失规律特征。结果表明:江门市水土流失以微度为主,占区域面积的72.23%,其他强度水土流失分布均不足10%;该市年均侵蚀模数为208.46 t·km^-2·a^-1,流失量为200.65万t;随着植被覆盖度的增加侵蚀模数呈先增大后减小的趋势,特别是40%~50%植被覆盖的乔木林下,水土流失严峻;侵蚀模数与坡度呈正向相关,并且坡度在15°~25°的地带水土流失量最大;区域降水量与输沙量具有高度一致关系。

The water and soil loss information of Jiangmen City was correctly extracted by use of the principle of soil loss equation and with support of GIS technology. Analysis was made on the rule and characteristics of regional soil loss under different vegetation coverage, topographic slope and precipitation condition. The results of analysis dem. onstrate that area with slight soil loss takes up 72.23% of this region and the area with other degree of soil loss is less than 10% in Jiangmen City. The yearly average erosion modulus of Jiangmen City is 208.46t·km^-2 ·a^-1 and the amount of loss 2.006 5×10^6 t. The erosion modulus has a rise-to-fall trend with the increase of vegetation coverage. There exist serious water and soil loss under arbor with vegetation coverage of 40%~50%. The erosion modulus is positively correlated with slope. The region with a slope of 15°~25°has the maximum soil loss. Regional precipita. tion and sediment transport are highly consistent with each other .