黄河中游岩土侵蚀问题及防治对策探讨

黄河中游出露地层岩性主要有古生界奥陶系碳酸盐岩、石炭系和二叠系碎屑岩;中生界三叠系砂泥岩、侏罗系砂泥岩和白垩系砂泥岩;新生界古近系砂泥岩、新近系(原为第三系)红土及第四系风积黄土和现代风积沙。第四系黄土厚度大,结构松散,遇水易解体,具湿陷性,是黄河中游粗泥砂的主要物源;第四系风积沙分布于黄河中游北部,亦是黄河中游粗泥砂的主要物源。岩土侵蚀类型有五:一是风力侵蚀—风沙侵蚀;二是降雨对谷坡面的面状冲刷—坡面侵蚀;三是地表径流对谷底的侧蚀—沟谷侵蚀;四是滑塌对谷坡坡体的破坏—重力侵蚀;五是潜蚀。并对不同侵蚀类型提出了不同的防治对策。

PREVENTION AND CONTROL MEASURES FOR GROUND CORROSION OCCURRING IN THE MIDDLE REACHES OF THE YELLOW RIVER

Stratigraphic exposures in the middle streams of the Yellow River are mainly composed of carbonate rocks of the Ordovician system, elastic rocks of the Carboniferous and the Permian systems, sandy-mud rocks of the Tertiary, Jurassic, Cretaceous, and Paleogene systems, laterite of the Neogene System, eolian loess and modern aeolian sand of the Quaternary system. The Quaternary loess has a great thickness and is characterized by loose texture, easily incompact with water and collapsibility, which is the major source material of the coarse mud and sand in the middle reaches of the Yellow River, including the aeolian sand distributed in the north part of the middle reaches of the Yellow River. The erosion rock and soil are divided into 5 types, including wind erosion-sand blown erosion by wind. surfieial erosion by rainfall to the surface of valley-slope surficial erosion. lateral erosion caused by surface runoff to valley bottom; destruction of valley slope by slide-gravitational erosion; and suffosion. Based on aforementioned erosional types, different prevention measures are created in this paper.