孟连县土壤侵蚀时空变化特征

Temporal and Spatial Variation Characteristics of Soil Erosion in Menglian County

为了评估孟连县地区土壤侵蚀状况,为当地水土流失防治和水土保持工作提供理论依据,以通用土壤流失方程(USLE)为模型,运用ArcGIS和ENVI软件,综合分析了研究区土壤侵蚀时空变化特征以及不同环境背景下的土壤侵蚀特征。结果表明,2010年孟连县土壤侵蚀相比2000年有所减轻,土壤侵蚀模数分别为104.25 t/(hm^2·a)和64.11 t/(hm^2·a),分属极强度侵蚀和强度侵蚀;从空间分布来看,孟连县2000年和2010年的土壤侵蚀格局基本是东部相对较轻,西部相对严重,均以公信乡土壤侵蚀最严重,相对较轻的是景信乡、娜允镇。在一定降水强度(800≥R≥600)下,土壤侵蚀强度总体随降水强度的升高而升高;当R>800时,土壤侵蚀强度随降水强度的升高而降低。土壤侵蚀强度随着坡度的增加而增大,侵蚀主要集中于8°~35°坡度区域。赤红壤、红壤、砖红壤的侵蚀相对严重,黄壤最轻。坡度大于15°的旱地土壤侵蚀最严重,其次为荒草地和灌木林,水田和建设用地土壤侵蚀较轻。

In order to assess the soil erosion conditions in Menglian country and provide basis for the prevention and treatment of soil erosion as well as conservation of water and soil,the spatial and temporal variation characteristics of soil erosion and soil erosion characteristics under different environmental conditions were analyzed using ArcGIS and ENVI softwares with universal soil loss equation（ USLE）model. The results showed that the soil erosion of Menglian county in 2010 had been reduced compared with that in 2000,and the soil erosion modulus were 104. 25 t/（ ha · a） and 64. 11 t/（ ha · a）respectively,belonging to very intensive erosion and intensive erosion. From the aspect of space distribution,basically,the soil erosion pattern of 2000 and 2010 were relatively not serious in eastern area and relatively serious in western area. The soil erosion in Gongxin country was the most serious in this two years,Jingxin country and Nayun town were relatively mild. Under a certain rainfall intensity（ 800 ≥R≥600）,on the whole,the intensity of soil erosion increased with the increase of rainfall intensity; when R was more than 800,the intensity of soil erosion decreased with the increase of rainfall intensity. The soil erosion intensity increased with the increase of slope,and the erosion mainly occured in 8°—35° slopearea. The erosion level of lateritic red soil,red soil and brick-red erosion were relatively serious,while the erosion level of yellow soil was the lightest one. As to upland soil with the slope more than 15°,the erosion level was the most serious,followed by grassland and shrubbery,and paddy fields and construction sites had the slightest soil erosion.