影响淤地坝建设的地理要素--以黄河中游多沙粗沙区为例

Study of geographic factors that influence silt-trap dam construction:A case study in the arenaceous and coarse sand region,midstream of Yellow River

采用定性分析和定量计算、微观机理研究和宏观分析相结合的方法,对影响淤地坝建设的地理要素进行筛选,重点分析了沟壑密度、土壤侵蚀模数、农业人口密度对小流域淤地坝建设,主要是对淤地坝空间布局的影响;以黄河中游多沙粗沙区为研究对象,根据研究区域45个县(旗、市)的沟壑密度、土壤侵蚀模数、农业人口密度和淤地坝密度的基础数据,从地理学角度系统分析它们和研究区域淤地坝密度的关系,研究影响该区域淤地坝建设及布局的主要地理要素。结果表明,在黄河中游多沙粗沙区,影响淤地坝建设最主要的地理要素是农业人口密度,即人类活动的剧烈程度和淤地坝密度之间存在着直接的关系,分析结果为黄河中游多沙粗沙区淤地坝建设提供了科学依据。

Silt-trap dam is a type of proiects used for intercepting and depositing sediment in channels with serious soil erosion. Its construction is of great significance to controling soil erosion, improving ecological environment quality, realizing regional sustainable development, and insuring ecological safety in the Loess Plateau. Although much progress has been made in silt-trap dam construction since the founding of P. R. China, until now, there are still many important theoretical problems that need further study. The systematic research of the effects of geographical factors on dam system construction is insufficient and needs special attention. This paper first selected the main geographic factors that may influence silt-trap dam construction and reviewed the related previous studies, employed a methodology that combined qualitative analysis and quantitative accumulation, macroscopic research and microscopic case analysis, analyzed the influences of soil erosion modulus, channel density and rural population density on silt-trap dams construction in small watersheds. Finally, this paper selected the case study area in the arenaceous and coarse sand region, mid-stream of the Yellow River, studied the main factors that resulted in the spatial variation and restriction of silt-trap dams construction using GIS technology. The main conclusions of this study are： （1） The density of silt-trap dam is not significantly related with physical geographic factors, although the physical geographic factors represented by soil erosion modulus and channel density are important factors that need to be considered during silt-trap dam plan and construction. （2） Human geographic factors represented by rural population density have significant influence on silt-trap dam construction.