典型黄土塬区不同植物措施水土保持效应分析

基于黄土高原典型黄土塬区2014-2016年的自然降雨数据及5种植被措施(乔木、灌木、撂荒、人工种草、耕地)下的坡面产流、产沙情况的观测数据,系统分析了不同植被覆盖措施下的黄土坡地水土流失对不同类型侵蚀性降雨的响应机制,结果表明:(1)降水集中于4-10月份,其中引发水土流失的侵蚀性降雨集中于7月、8月。(2)根据最大30分钟降雨强度I30及降雨总量可将侵蚀性降雨分为5种类型,其中小雨量、小雨强类型的降雨是当地发生频率最多的侵蚀性降雨类型;降雨强度最大的Ⅴ雨型降雨侵蚀力最大,降雨量最大的Ⅰ雨型降雨侵蚀力次之,而Ⅱ雨型降雨侵蚀力最低;Ⅴ雨型在观测期内产流产沙量最大。(3)5种植被措施在不同降雨类型下均有明显的水土保持效应,在不同类型降雨下不同植物措施减沙率和减流率变化规律不同。研究结果对于黄土高原地区水土保持及资源可持续利用具有重要的指导意义。

Effects of different plant measures on soil and water conservation in typical tableland zones on the Loess Plateau

This article, based on the observations of the measured (2014-2016) rainfall data from typical loess tableland zones and slope runoff and sediment yield with five vegetation measures (arbor, shrub, woodland, artificial grass and cultivated field), systematically analyzes the effects of different types of erosive rainfall on the soil and water conservation on loess sloping land under different vegetation coverages. The results are shown as follows. (1) Most of the rainfall in the research area occurred in the period April to October, in which the erosive rainfall induced from soil erosion was concentrated in July and August. (2) Erosive rainfall can be achieved based on the maximum 30-minute rainfall intensity and total rainfall. It is divided into five types, among which the event with small rainfall and low intensity is the most frequent type, and the erosive force of the 5^th pattern is the largest, followed by the 1^st pattern with the largest rainfall, and the erosive force of the 2^nd pattern is the lowest. (3) Five types of vegetation measures show obvious soil and water conservation effect under different types of rainfall. And the changing rules of the rate of sediment reduction and the rate of reduction of flow under different rainfall conditions are different.