Rainfall Collection Water-Saving Irrigation Project and Ecological Water for Small Watershed Soil Water Conservation in Semi-Arid Extremely Water Deficient Region

摘要

Henan Province, with the average annual precipitation of about 700mm, is one of water deficit provinces in China and the provincial average annual drought affected area makes up 6.4% of the national drought stricken area. How to use natural rainfall effectively is key to solving agricultural & ecological water in semi-arid & extremely water deficient regions. The paper describes the history and current status of development of rainfall collection and water saving irrigation (RC&WSI), puts forward the methods for demarcating semi-humid & extremely water deficient regions (EWDR) and discusses the necessity and feasibility of developing rainfall collection & water saving irrigation in extremely water deficient region. In the paper current ecological water consumption and ecological water demand of "the Tenth Five-year Plan Period" for small watershed soil & water conservation (S&WC)in Henan Province is calculated and three modes of rainfall collection & water saving irrigation that are suitable in Henan Province are recommended. It is concluded that developing of rainfall collection & water saving irrigation is an effective way to readjusting small watershed agricultural structure and solving ecological water demand for soil & water conservation.