Models of rainwater harvesting system and their benefit evaluation in semi-arid areas

Rainwater harvesting and utilization are important for regional development in northwestern semi-arid areas. According to research and practice development over the world in recent years, this paper summarized and brought forward five models of rainwater harvesting system in semi-arid areas, that including model of rainwater collecting by courtyard for drinking of people and livestock, model of rainwater collecting by courtyard for mixed farming, model of manpower rainwater harvesting for limited water supply in farmland, model of rainwater harvesting on slope land for rebuilding of forestry and grassland, and model of rainwater harvesting by watershed for all-around use. The characteristics of rainwater harvesting system on collecting, storing and cleaning, and using methods in different models were analyzed. On the other hand, the paper also discussed the method and index of benefit evaluation for rainwater harvesting and utilization models on society, economics and ecology, these are very useful for more suitable and safe use of rainwater resources.