坡度和雨强对喀斯特地区坡面产流产沙的影响

摘要

利用径流小区观测法,分析了坡度和雨强对贵州喀斯特地区4种地类坡面产流产沙的影响.结果表明,随坡度的增大,各地类坡面产流产沙量并没有表现出一致增大或减小的趋势,它们在很大程度上受土地利用方式和土壤类型的制约；随最大30 min雨强(I30)的增大,坡面的产流产沙量增大.坡度为13°时,坡耕地在各地类中的产流产沙量最小,随坡度增大逐渐超过其他地类；除13°径流小区外,经济林地(梨树)在各种坡度、雨强范围内的产流产沙量均为各地类中最少；水保林地(香樟)在各种情况下的产流量虽较大,但产沙量相对较小；裸地在观测条件下的产流产沙量均较大.%Analysis of slope gradient and rainfall intensity effects on runoff and sediment generation under four types of slope land in Karst area were carried out by using the runoff plots experimental method in Guizhou province.The results showed that with the increase of slope gradient, runoff and sediment generation under different types of slope land didn't increase or decrease consistently.They were largely influenced by the way of land use and soil type. With the increase of I30, runoff and sediment generation under different types of slope land increased accordingly. When the slope gradient was 13 , the slope farmland had the least runoff and sediment generation in all types of slope land.It exceeded other types of slope land gradually with the increase of slope gradient.Except the situation that the slope gradient was 13°, runoff and sediment generation of economic forest (pear trees) kept the least in all kinds of slope and rain intensity range. Although the runoff of water conservation forest (Cinnamormum camphora) was large in all circumstances, the sediment generation was relatively small. Bare slope land had very large runoff and sediment generation in all observation conditions.