中梁山岩溶区坡耕地土壤侵蚀^137Cs法研究

Study of Soil Erosion on Slope Farmland in the Karst Area of the Zhongliang Mountains by ^(137)Cs Technique

采用137Cs法对重庆中梁山岩溶区坡耕地进行了土壤侵蚀研究,结果表明:两个样地顶部侵蚀速率都大于10000t/(km2·a),是坡耕地土壤侵蚀最强烈的地方,坡耕地上部侵蚀速率为3000~4000t/(km2·a)左右,而在耕地下部土壤出现堆积.样地多年平均土壤侵蚀速率分别为2765,3202t/(km2·a),其均值相当云贵高原坡耕地土壤侵蚀的40.3%,三峡库区的39.9%,嘉陵江流域的54.1%,黄土高原的39.1%.土壤侵蚀绝对量不大、相对侵蚀强烈是岩溶山区的坡耕地土壤侵蚀的基本特点.

The ^137 Cs tracer method was used to investigate soil erosion on slope farmland in the karst area of the Zhongliang-mountains in Chongqing. The results showed that the erosion rate of the two research plots at the top of the slopes was the greatest, being more than 10 000 t/（km^2·a）; in the upper parts of the slope farmland the erosion rate was about 3000 to 4 000 t/（km^2·a） ; and heaping up occurred in the lower parts of slope farmland. The soil erosion rate of two slope farmland plots was 2 765 t/（km^2·a） and 3 202 t/（km^2·a）, respectively, averaging 2984 t/（km^2·a）. The average of soil erosion was only 40. 3% of slope farmland on the Yunnan-Guizhou Plateau, 39. 9% of the Three Gorges Reservoir Area, 54. 1% of the Jialing River Basin, and 39.1% of the Loess Plateau. Soil erosion on slope farmland in karst mountain areas was found to be characterized by moderate absolute erosion and strong relative erosion.