A rainwater resources are broad prospects for development and utilization of

 China is not a water-rich country, per capita share of cultivated land per unit area and the only possession of the world average of 1 / 4 and 3 / 4, by the United Nations as the world, one of 13 water-poor countries, coupled with combination of a very uneven distribution of water resources, disparity difference between the North and South. Entering the 90 years since the drought is worsening, the national disaster-stricken area of 27 million years, right-left hm2. Annual grain output due to drought of about 70 billion kg. Do the northwestern region, the majority of places in the 400mm annual rainfall below the inter-annual period and the uneven distribution of rainfall, mostly concentrated in June-September, and in the form of heavy rain, causing soil erosion and ineffective evaporation of rain or water irrigation, drought year with people and livestock drinking water is also difficult life of the masses poorer. However, these areas are China's important agricultural area, light and heat conditions good, for the development of cultivated land and grassland resources, has great potential, and water shortages restrict these resources advantages. Because of the topography and economic conditions, the construction of key water conservancy projects in these areas is not only large investment and long-duration work, the construction of great difficulty to bring ecological and environmental problems are numerous and difficult to solve irrigation problems. Therefore, how to take full advantage of the only potential local rainfall resources, development of a limited irrigation (irrigation critical water, life-saving water), increase crop yields, farmers and herdsmen to promote poverty alleviation, not only the local urgent need to address the issue, but also China's agricultural production, one with a strategic problem.

Since 80 years, foreign rainwater use by the rapid development, not only drier countries (such as Israel, etc.) to develop rapidly, and the number of rainy countries (such as the Southeast Asian countries) have also been developed, a number of industrial countries (such as Japan, Australia and the United States ) are actively developing the use of rainwater. China's use of rain water also has a long history, such as arid and semi-arid Loess Plateau, northwest mountain and plateau area people in the combat drought in the process of creating a lot of rainwater utilization technology, such as the construction of caverns, large-diameter wells, the Kaner and storage pond and other engineering facilities, but also improved, such as terracing and other traditional measures of in-place build rain played a big role. However, levels of productivity and technological conditions, limitations and other reasons, these measures do not fundamentally solve the rainfall and the crop water requirement are relatively concentrated period of contradictions dispersion can only be a passive drought, agricultural production has yet to get rid of "relying" situation . Since entering the 90 years, due to the worsening drought in northern, water resources become increasingly scarce, the cause of the International Rainwater Catchment under the impetus of the national importance of rainwater utilization and sustainable development of water resources research, rapid development of some provinces such as Gansu " 121 Rainwater Catchment project "," Inner Mongolia 112 Jiyujieguan project, "Ningxia" cellar build flow of water saving irrigation-type process ", as well as Shaanxi, Shanxi, Henan and Hebei provinces. These provinces rain rainwater utilization technology research applications, has made a number of achievements have resulted in an apparent economic, social and ecological benefits, showing strong vitality.

 China is a large agricultural country, the vast rural areas, the 100 million farmers, an area of great garden around their houses, as well as farm homes, villages, roads and field roads, slope, etc. There are some places for rainwater harvesting to create a favorable conditions. Because small-scale rainwater utilization project in general than were scattered, will not cause adverse environmental impacts, and help preserve the ecological environment. In accordance with national experience, the 250-500mm of rainfall in agricultural areas and efficient use of rain water zone. Advanced level of foreign water-saving agriculture also shows that for every rainfall can produce 2-2.5kg of grain. Thus, any effective than 250mm of rainfall in the area, rainwater resources can be developed, in addition to resolving domestic water, the light of local conditions to implement water-saving irrigation, so that in spring or autumn build, has a long build, with short use, change from passive to active drought and drought, which is the sustainable use of water resources in China an effective way to develop the use of broad prospects.

 Efficient use of rainwater resources in two ways

Due to our limitations, in the past the masses of the rainwater utilization is still at the spontaneous stage, fate, rain water resources, neither the scale use, not, not by the resulting economies of scale. On the one hand caused by waste water, on the other hand have long been troubled by water shortages. With the increasing scarcity of water resources, water use conflicts have been intensified, rainwater, as arid, semi-arid areas the potential resources available, causing water experts and scholars interested in, and in-depth research, achieved a number of significant results, some local Government attaches importance to and supports its development and utilization of the continuous development of the depth and breadth, so that rain water utilization and sustainable development and utilization to achieve a wide range

2.1 terracing, storing rainwater, the development of rain-fed agriculture in arid, semi-arid areas due to complex terrain, ravines and more soil is thin, poor ability to retain water and nutrients, rainfall runoff generated quickly devaluation, erosion of soil, rain and easy to drought, low and unstable crop yields. Therefore, engineering measures must be taken, the construction of a high standard terraced fields. In order to better storing rainwater, the general ditch furrow planting techniques. In this way, will be able to effectively increase soil moisture reserves, increasing the ability to withstand drought, adding the agricultural land measures, such as drought-resistant seeds, application of organic fertilizer material, soil cover film and so on, not only to increase agricultural production, and can prevent soil erosion, reduce sediment on the river hazards.

2.2 The use of garden, courtyard and rooftop rainwater harvesting for the development of courtyard economy side edge of the village farmers around their houses, generally through the rolling gardens and yard, the roof surface are mostly cement dust and the tile in order to collect rain water to create conditions. According to local rainfall, rainfall intensity and rainfall area the size of the construction of storage facilities (cellars, and ditches), flood storing rain water and store them, in addition to solve the drinking water, the water can also be used nor may limit the development of courtyard economy. Farming, aquaculture and small-scale processing industries. Practice proves that this is a mountain people, an effective way to eliminate poverty and Ben Kang. But also changed the health conditions of rural mountain areas, reduce disease, improve health

 2.3-li slope, roads, rainwater harvesting, development of irrigated field crops in general are more sloping areas. Country are accessible by paved or gravel, there are a lot of field road, these slopes, roads can be directly collected or been transformed to collect rainwater.