Rainwater harvesting irrigation-A strategic measure for integrated rural development in the dry mountainous areas of Gansu Province, China

Abstract

The loess plateau and hilly areas of Gansu Province are one of the driest areas of China. In the past, water scarcity caused domestic water supply insecurity, low levels of agricultural production, land degradation and impoverishment of the population. For many people, rainfall is the only practicable source of water. Since 1996, the rainwater harvesting (RWH) project has been used to provide supplementary irrigation. By 2005, formerly rainfed farmland irrigated using RWH systems totaled about 80,000 ha. An approach known as "low-rate irrigation (LORI)" has been developed in which irrigation is only applied at critical periods of crop growth. Highly efficient simplified irrigation methods developed locally along with drip systems have been widely adopted. Water application is targeted at the root zone to reduce evaporation loss. With only very small amounts of irrigation, crop yield has been raised by between 22-88% and 40% on average. Furthermore, RWH enables farmers to modify their agriculture patterns according to market needs. Farmers can now grow high-value cash crops, greatly decreasing poverty levels. Simple low-cost greenhouses have also been widely replicated, further boosting household incomes. The project, outlined in this chapter, has also benefited ecological restoration and the local environment as a whole.