中国东北地区侵蚀产沙尺度效应的空间分异

Spatial Patterns of Sediment Yield in Northeast China

对中国东北地区侵蚀产沙尺度效应的空间变化进行了探讨。基于气候、下垫面的一致性和流域的完整性,对整个研究区域进行了分区研究。结果表明,尺度效应同时受到地形、坡度、土地利用和地表覆盖物质等因素的影响,不同分区因素因素组合不同,其产沙模数随流域面积的变化趋势亦不相同,可以分为三类:(1)产沙模数随流域面积增大而增大;(2)产沙模数随流域面积的增大基本保持不变;(3)产沙模数随流域面积的增大而减小。基于各分区尺度效应,进行了不同标准面积下产沙模数图的校正,并使用空间插值方法,编制不同标准面积下产沙模数图。

This paper examined the spatial variation of sediment yield in Northeast China,a large area with complex geology,climate,land use history,and extensive sediment monitoring.In order to develop regional sediment yield scale relations,and to then use them to interpolate the spatial pattern of sediment yield,the area was divided into ten sub-regions of first class and fifteen sub-areas of second class.And 200 stations were used to study the scale effects of sediment yield.Three regional trends were identified：（1） a decreasing trend,with sub-regions usually located on the upper reach of river basins,such as Nenjiang sub-region on the upper reach of the Songhuajiang River basin and Xiliaohe sub-region on the upper reach of the Liaohe River basin;（2） a flat trend,with sub-regions such as the Second Songhuajiang River basin and the lower reach of Songhuajiang river basin;（3） an increasing trend,with sub-regions usually locate on the lower reach of river basins,such as lower reach of the Liaohe River basin.Using these developed relations,areally-adjusted sediment yield maps were created over the entire Northeast China with universal Kriging interpolation.