本文選題：降雨侵蝕力 + 土壤侵蝕　； 參考：《環(huán)境科學(xué)研究》2017年09期

【摘要】：為了深入認(rèn)識(shí)陜北無(wú)定河流域土壤侵蝕時(shí)空演變過(guò)程及其與降雨和植被NDVI變化的關(guān)系,采用基于RUSLE(修正通用土壤流失方程)的土壤侵蝕評(píng)估方法,開(kāi)展流域土壤侵蝕時(shí)空分布及其與降雨、植被NDVI的關(guān)系研究.結(jié)果表明:(1)2000—2014年無(wú)定河流域多年均土壤侵蝕模數(shù)為457.90 t/(km2·a),呈波動(dòng)增加過(guò)程.流域土壤侵蝕以微度侵蝕為主,占流域總面積的88.35%,其他土壤侵蝕等級(jí)面積比例隨等級(jí)升高而減少.研究時(shí)段內(nèi)除微度侵蝕面積比例減少外,其他土壤侵蝕等級(jí)面積比例均呈增加過(guò)程,并且侵蝕面積年變化速率也由微度侵蝕的0.52%降至劇烈侵蝕的0.01%.(2)無(wú)定河流域西北部土壤侵蝕程度最低,西南部其次,東南部最高,與其地貌類型及降水量沿東南—西北方向遞減有關(guān),但均反映出流域2000—2014年土壤侵蝕的增加過(guò)程.研究時(shí)段內(nèi)流域不同土壤侵蝕等級(jí)間面積及比例轉(zhuǎn)移主要由低等級(jí)土壤侵蝕類型轉(zhuǎn)為相鄰高等級(jí)土壤侵蝕類型.(3)無(wú)定河流域土壤侵蝕與降水量、侵蝕性降雨量、降雨侵蝕力呈顯著正相關(guān)(P0.01),相關(guān)系數(shù)分別為0.90、0.95和0.98,而與植被NDVI的關(guān)系不顯著.研究顯示,降雨變化尤其是侵蝕性降雨(≥12 mm/d)增加是陜北無(wú)定河流域土壤侵蝕增強(qiáng)的主要原因.
[Abstract]:In order to deeply understand the temporal and spatial evolution of soil erosion and its relationship with rainfall and vegetation NDVI changes in Wuding River basin of Northern Shaanxi, a soil erosion assessment method based on RUSLE-based modified universal soil loss equation was adopted. The temporal and spatial distribution of soil erosion and its relationship with rainfall and vegetation NDVI were studied. The results showed that the average modulus of soil erosion in Wuding River Basin from 2000 to 2014 was 457.90 t/(km2 a ~ (-1), which showed an increasing process of fluctuation. Soil erosion in the watershed was dominated by micro-erosion, accounting for 88.35% of the total area of the basin, and the proportion of other soil erosion grade areas decreased with the increase of the grade. The proportion of soil erosion grade area was increased in the period of study except for the decrease of the proportion of micro-erosion area. And the annual change rate of erosion area also decreased from 0.52% of micro-erosion to 0.01% of severe erosion. The soil erosion degree in the northwest of Wuding River Basin was the lowest, followed by the southwest and the southeast, the highest in the southwest, the highest in the southeast, and the lowest in the northwest of Wuding River Basin. It is related to the geomorphologic type and precipitation decreasing along the southeast-northwest direction, but all reflect the increasing process of soil erosion in the basin from 2000 to 2014. During the study period, the area and proportion transfer between different soil erosion grades in the basin mainly changed from low grade soil erosion type to adjacent high grade soil erosion type. 3) soil erosion and precipitation and erosive rainfall in Wuding River Basin. There was a significant positive correlation between rainfall erosivity and vegetation NDVI, and the correlation coefficient was 0.90,0.95 and 0.98, respectively, but there was no significant relationship between rainfall erosivity and vegetation NDVI. The results show that the change of rainfall, especially the increase of erosive rainfall (鈮，

本文編號(hào)：1851316