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以丹江口水库以上的汉江流域为例,利用植被覆盖度、坡度加权的上游有效汇流面积空间分布型式和驱动-阻力耦合空间分布拟合函数2个指标,评价水蚀流域土地覆被格局土壤保持能力,并基于研究区14个子流域水文站泥沙资料进行验证。结果表明:汉江干流沿岸河谷盆地和丹江口水库周边丘陵区子流域是研究区城镇和农田的主要分布区,植被覆盖度低,距离汉江较近,当前覆被格局土壤保持能力相对较低,是河流泥沙的主要直接来源地;有效汇流面积空间分布型式和驱动-阻力耦合空间分布拟合函数能有效反映流域泥沙输出,可作为评价流域土地覆被格局土壤保持能力的指标。该评价方法基于土地覆被格局与土壤侵蚀的作用机制,简单易行,可为评价土地覆被格局土壤保持能力、土地覆被格局变化的土壤侵蚀效应提供一种简捷的途径。
Taking the Hanjiang River above Danjiangkou Reservoir as an example, the spatial distribution pattern of upstream effective catchment area and driving-resistance coupling spatial distribution fitting function of vegetation coverage and slope-weighted are used to evaluate the soil conservation ability of land cover pattern in water erosion watershed, Based on the sediment data from 14 sub-basin hydrological stations in the study area, The results show that the sub-basins along the Hanjiang River valley and the Danjiangkou reservoir are the main distribution areas of towns and farmlands in the study area. The vegetation coverage is low and close to the Han River. The current soil cover capacity of the current pattern is relatively low, The main direct source of sediment is the fitting function of space distribution type and drive-resistance coupling spatial distribution of effective confluence area, which can effectively reflect the sediment output of watershed and can be used as an index to evaluate soil retention ability of land cover pattern. Based on the mechanism of land cover pattern and soil erosion, this evaluation method is simple and easy to be implemented, which can provide a simple and convenient way to evaluate the effect of soil erosion on land cover change and land cover change.