秦岭山地丹江流域土地利用变化的土壤侵蚀效应评价

发布时间：2018-10-08 20:23

【摘要】：论文采用Arc GIS 10.0及In VEST土壤保持模型,分析2000—2010年秦岭山地丹江流域土地利用类型变化特征,模拟流域不同时期不同土地利用类型土壤侵蚀及土壤保持量的变化规律,并着重探讨土地利用类型方式转变对流域土壤侵蚀的影响。结果表明:1)2000—2010年间,流域裸地大比例减少90.18%(831.06 hm~2),主要转移至水域,耕地大面积减少5 197.24 hm~2(4.11%),主要流向灌丛和城镇;坡耕地还林还草初见成效,湿地的保护与恢复成效显著。2)2000—2010年间,流域土壤侵蚀状况较为严重,整体处于中度侵蚀至强度侵蚀级别,但10 a间侵蚀状况有减缓趋势;在该研究时段内,耕地大面积转为灌丛是该流域由土地利用类型变化引起的土壤侵蚀减缓的主要原因;另外,耕地转为林地以及裸地面积的减少也起到了减轻土壤侵蚀的作用;以自然生态系统为主的林地、灌丛及草地转为耕地时,土壤侵蚀强度则会明显增加。3)生态系统土壤保持功能受多方因素共同影响;2000、2010年研究区实际土壤保持量分别为5.35×10~8、5.47×10~8t;占全区面积一半以上的林地和灌丛单位面积土壤保持量较为稳定,全区土壤保持功能有所提高。保证一定面积的林地、在人工干预下合理安排坡耕地还林还草区域的空间分布是秦岭山地丹江流域减少土壤侵蚀的必要措施,同时应注重对可利用耕地的保护。
[Abstract]:In this paper, Arc GIS 10.0 and In VEST soil conservation models were used to analyze the change characteristics of land use types in Danjiang watershed of Qinling Mountains from 2000 to 2010, and to simulate the variation of soil erosion and soil conservation in different periods of land use in Qinling Mountains. The effect of land use type change on soil erosion in watershed is discussed. The results showed that the large proportion of bare land decreased by 90.18% (831.06 hm~2) in 2000-2010, mainly transferred to water area, the large area of cultivated land decreased by 5 197.24 hm~2 (4.11%), and mainly flowed to shrubbery and towns, and the results of returning sloping farmland to forest and grass showed initial results. Between 2000 and 2010, the soil erosion in the watershed was more serious, with moderate erosion to intensity erosion, but there was a tendency to slow down the erosion in the period of 10 years. Large area of cultivated land to shrub is the main reason for the decrease of soil erosion caused by the change of land use type, in addition, the reduction of cultivated land to woodland and bare land area also plays a role in reducing soil erosion. When woodlands, shrubs and grasslands dominated by natural ecosystems are converted to cultivated land, The soil erosion intensity will increase significantly. 3) the soil conservation function of ecosystem is affected by many factors. The actual soil conservation in the study area in 2010 was 5.35 脳 10 ~ (-8) ~ (8) 脳 10 ~ (-8) t, respectively, and the soil conservation amount per unit area of forest land and shrub was relatively stable, which accounted for more than half of the total area of the study area. The function of soil conservation was improved. It is necessary to ensure a certain area of woodland and to arrange the spatial distribution of slope land for forest and grass under artificial intervention. It is necessary to reduce soil erosion in Danjiang watershed of Qinling Mountains. At the same time, attention should be paid to the protection of available arable land.
【作者单位】：西北大学城市与环境学院;
【基金】：环保部重点项目(STSN-05-27) 林业公益性行业科研专项(201304309)~~
【分类号】：S157

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