四川紫色土地区流域侵蚀产沙空间的尺度效应初探  

Effects of Spatial Scaling on the Runoff-Sediment-Yielding of the Purple Soil Region in Sichuan

作　　者：袁再健[1] 蔡强国[2] 褚英敏[3] 

机构地区：[1]河北科技大学经济管理学院,石家庄050018 [2]中国科学院地理科学与资源研究所,北京100101 [3]河北经贸大学旅游学院,石家庄050061

出　　处：《资源科学》2007年第1期160-164,共5页Resources Science

基　　金：国家自然科学基金资助项目(编号:40271075);中国科学院地理科学与资源研究所自然科学基金延伸支持领域前沿项目(编号:CXIOG-A04-10)

摘　　要：四川盆地紫色土地区水土流失非常严重,且有日益加剧的趋势,有关该地区流域侵蚀产沙的尺度问题研究还未见报道,针对这种情况,本文初步探讨了四川紫色土地区试验小区(坡面)、子流域(鹤鸣观Ⅱ号支沟)、小流域(李子口小流域)3个不同尺度的侵蚀产沙特征。发现:①在四川紫色土地区,不同的空间尺度,其侵蚀产沙特征、侵蚀类型、影响侵蚀主要因素以及泥沙沉积部位都有较大差异;②随着尺度的增大,影响侵蚀产沙的因素增多,泥沙沉积比例增大,泥沙输移比有减小的趋势;③这3个不同的空间尺度的侵蚀产沙主要取决于地表径流深(侵蚀模数与地表径流深的指数相关关系R2在0.6左右),而径流量主要由降雨量决定(径流量与降雨量的指数相关关系R2在0.4左右),该地区水沙关系密切。由于缺乏3个尺度降雨同步资料,有关四川盆地紫色土地区流域尺度转换机理以及尺度效应有待于深入研究。Soil and water loss is very serious in Sichuan Province, and it severely affects the environment of the region and increases the difficulty of agricultural cultivation in the local area. The area of the Sichuan Basin is 15.8 ×10^4km^2 and purple soil is the dominant soil type in the hilly areas of the basin. The area of soil and water loss is 7.71×10^4km^2, and the annual lost surface soils were up to 3.77 ×10^8 tons. Spatial scale is one of the major problems in the field of soil and water loss. There are no reports of the scale research on the runoff-sediment-yielding of the purple soil region in Sichuan at present. According to the aggravation status and the research status of water loss and soil erosion in the purple soil region, this paper discussed the characteristics of the erosion and sediment for three spatial scales, which are runoff plot, sub-watershed, and watershed, in the purple soil regions in Sichuan. The following conclusions were obtained： 1 ） The position of sediment deposition is different in the three scales; as the scale enlarges, the factors that affect the erosion and sediment increase, and the ratio of sediment to erosion increases too, so the sediment delivery ratio of single rain event decreases as the scale enlarges; 2） The erosion type and the main factor that affects the soil erosion are different in the three scales which are runoff plot scale, subwatershed scale and watershed scale; 3） The erosion and sediment depends on the surface runoff （the exponential relationship between the erosion modulus and the surface runoff is about 0.6） and the surface runoff depends on the rainfall （the exponential relationship between the surface runoff and the rainfall is about 0.4） in the three scales, and the relation between runoff and erosion is close in the purple soil region; 4） As the scale increases,we must consider more factors that affect the erosion in the construction of the erosion model.

关 键 词：空间尺长 坡面 子流城 小流城 侵蚀产沙特征 

分 类 号：S157[农业科学—土壤学]