黄土高原坡改梯综合效益分析——以燕沟流域为例

Synthetic analyses of effects of farmland terracing on the Loess Plateau:A case study of Yangou Watershed

退耕坡地是近年来黄土高原整治生态环境和控制水土流失的关键措施,但对于如何退耕,学术界存在多种不同观点,实践方面存在多种不同模式。以延安燕沟流域坡改梯为例,利用2005年延安站的逐日气象数据和燕沟流域地貌、土壤及土地利用等资料,借助WIN-YIELD软件,对不同地形坡度条件下坡改梯在作物增产、保水减沙效益以及燕沟流域坡改梯实践效果进行模拟、对比和实证分析。结果表明:地形坡度越大,坡改梯作物增产、保水和减沙效益越显著;坡度小于5°的坡耕地可以不进行梯田改造,坡度大于15°的坡耕地应及早实施坡改梯或退耕还林(草)。

Farmland terracing is an effective measure for the improving of eco-environment and the reducing of soil and water loss on the Loess Plateau.This paper takes Yangou Watershed as a case study for research on benefits of farmland terracing. Using daily meteorological data of Yan＇an Station in 2005 and data of terrain features,soil and land use of Yangou Watershed,this research simulates and analyzes the benefits of increasing yield and soil and water conservation under different topographic conditions by the aid of WIN-YIELD software and applies an empirical analysis on the effects of farmland terracing in Yangou Watershed.The results show that the bigger the gradient of farmland,the more benefits of increasing yield and soil and water conservation.The slope farmland less than 5° should not be terraced.The slope farmland more than 15° should be terraced as early as possible.