论文部分内容阅读
黄河上中游“农牧交错带”侵蚀环境形成于地质时期 ,发展于人类历史时期。现代侵蚀环境有明显的地域分异 ,环境要素的主要特征是 :①降雨量具有时间上年际的波动性和年内的集中性 ,空间上分布的不均匀性 ;②地表组成物质松散 ,以沙性物质为基调 ;③植被类型简单 ,以草本植物为主 ,覆盖度低。由侵蚀环境各要素相互作用所产生的侵蚀产沙特点是 :①侵蚀产沙类型复杂 ;②泥沙来源多样性 ;③区域产沙具有空间的不均匀性、年际的波动性和时间的集中性。农牧交错带生态环境属性难以改变 ,但是人们可以通过退耕还林还草调整人 -地关系 ,调整土地利用结构、产业结构来抑制和修复侵蚀环境
The upper and middle reaches of the Yellow River “agro-pastoral zone” erosion environment formed in the geological period, developed in the historical period of mankind. There are obvious regional differences in modern erosion environment. The main features of environmental elements are: ① The rainfall has the fluctuation in time and the concentration and spatiality in the year; ② The composition of the earth’s surface is loose, Sexual substances as the keynote; â ’¢ vegetation types are simple, mainly to herbs, low coverage. The characteristics of the erosion and sediment produced by the interaction of various elements of the erosion environment are as follows: (1) the types of erosion and sediment production are complex; (2) the diversity of sediment sources; (3) the sand production in the area has the spatial heterogeneity, interannual volatility and time concentration Sex. It is difficult to change the eco-environmental attributes in the ecotone between agriculture and animal husbandry, but one can restrain and repair the erosion environment by adjusting the man-land relations by returning farmland to forests and grasslands, adjusting the land use structure and industrial structure