福建省水土流失现状分析

目的]运用遥感技术监测福建省水土流失状况,为研究区的水土保持工作提供一定的科学依据。方法]利用2014年Landsat-8OLI等遥感数据,基于通用土壤流失方程(USLE)定量计算得到研究区的土壤侵蚀量,并运用GIS空间分析和数理统计的方法分析水土流失在地理空间上分布特征。结果]福建省2014年的水土流失总面积为10 939.8km2,总流失率为8.93%,其中以轻度流失为主,占总流失面积的82.3%,境内流失等级为强度及以上的区域主要集中在北部的宁德和南平、南部的漳州和西部的龙岩一带;其中22个水土流失重点县流失面积为4 786.65km2,占全省流失总面积的43.76%,平均流失率为10.54%。结论]水土流失主要发生在海拔高程为200~1 000m的区域,流失面积有8 954.35km2,占流失总面积的81.85%;坡度与水土流失关系密切,水土流失主要发生在坡度为8°~25°的区域,流失面积有69 871.71km2,占总流失面积的57.23%;容易发生水土流失的土地利用类型是裸地和林地,流失比例分别达到30.99%和9.47%。

Analysis of Soil and Water Loss in Fujian Province

Objective] Remote sensing technology was applied to monitor soil and water loss in Fujian Province, in order to provide certain scientific foundation for soil and water conservation in study area.Methods] The quantitative computation of soil erosion in the study area based on universal soil loss equation (USLE) and remote sensing data of Landsat-8 OLI at 2014 can be inspected with the GIS spatial analysis and mathematical statistic methods to get the space distribution characteristics of soil and water loss in the field.Results] The total area and rate of soil and water loss in 2014 of Fujian Province were 10 939.8 km² and 8.93%, respectively. Mild erosion played a dominant role and covered 82.3% of the erosive area. Areas having intensive erosion or more intensive level mainly concentrated in Ningde, Nanping, Zhangzhou and Longyan. The erosion area of 22 key soil erosion counties was 4 786.65 km² and the loss rate was 10.54%, accounting for 43.76% of the total erosion area in Fujian Province.Conclusion] The total 8 954.35 square kilometers erosion area mainly located at altitude of 200~1 000 m and makes up 81.85% of the total erosion area. Slope gradient was found closely associated with soil and water loss, and soil erosion primarily happens in place of 8°~25 ° slope. The loss area on that slope was 69 871.71 km², accounting for 57.23% of the total erosion area. The bare land and forest land are prone to soil erosion, 30.99% and 9.47% of the two lands were in erosion.