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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。
In this paper, Arc GIS 10.0 and In VEST soil conservation model were used to analyze the variation characteristics of land use types in the Danjiang River Basin in Qinling Mountains from 2000 to 2010, and to simulate the variation of soil erosion and soil conservation under different land use types in different periods of the river basin. Influence of Type Transformation on Soil Erosion in Drainage Basin. The results showed that: 1) During 2000-2010, the large proportion of bare land in the river basin decreased by 90.18% (831.06 hm ~ 2) and mainly to water area, with a large area decreasing by 5 197.24 hm ~ 2 (4.11%), mainly flowing to shrubs and towns ; Sloping arable land to forest and grass has achieved initial success, wetland protection and recovery achieved remarkable results. 2) During the period from 2000 to 2010, the soil erosion was more serious in the watershed, and the whole area was in the range of moderate erosion to intensive erosion. However, the erosion tended to slow down during the 10-year period. In the study period, In addition, the reduction of cultivated land to forest land and naked land area also played a role in reducing soil erosion. The conversion of forestland, shrub and grassland dominated by natural ecosystems to When cultivated land, soil erosion intensity will be significantly increased. 3) The soil conservation function of the ecosystem is affected by many factors; the actual soil conservation amounts in the study area in 2000 and 2010 are respectively 5.35 × 10-8 and 5.47 × 10-8 t; the unit area of forestland and shrubs, accounting for more than half of the area, Soil conservation is more stable, the whole region soil conservation has improved. To ensure a certain area of forest land, the spatial distribution of slope farmland to forest and grassland should be reasonably arranged under the artificial intervention. It is a necessary measure to reduce soil erosion in Danjiang River basin in Qinling Mountains. At the same time, the protection of available cultivated land should be emphasized.