Study On High Effective Rainwater Use Models Of Catchment Agriculture In Semiarid Area

Based on systematical summarize the achievements of catchment agriculture research done by gansu agricultural science academy during the past 15 years. A research title of high effective rainwater use models of catchment agriculture in semiarid area has put forward for the purpose of further raise natural precipitation water use efficiency (WUE) and complete high effective rainwater use. And a embedded research on models and its theoretical foundation as well as its technique system have been carry out in semiarid area of Gansu by the ways of systematical analysis, typical research and qualitative cases analysis. Some results that have practical mean have been gained. 1. Target at the goal of raises WUE and WSE (water supply efficiency). For the purpose of open out the complex relationship that influence the increase of WUE and WSE. And take it to instruct production practices to adopt scientific skills to regulate and control the use of rainwater and to complete high effective water use, the paper has put forward and divided the high etfective rainwater use models of catchment agriculture in semiarid area into three models. The first is the rainwater impound and infiltration use models (R1IUM). This means to use measurements to impound and make rainwater infiltrate into soil for crop use on the spot. The second is rainwater enrichment and fold use model (REFUM). The mean is to use engineering measurements changing the plane shape of surface soil to enrich rainwater and use plastic film cover to harvest rainwater for crop use on the spot. The third is rainwater harvesting use model (RHUM). This means to harvest rainwater for use in deferent place.The RIIUM take rainwater??soil reservoir? crop use as the technological principal. The degree of regulated and controlled water use by man in time andspace level is low. The common character is impound and infiltration use of rainfall runoff by changing the plane shape of surface soil. Water infiltration area is the area of water use. The model further is divided into two son models. That is, soil reservoir high effective rainwater use model (SRHERUM), field film cover no-tillage evaporation prevent and soil moisture reserve model. Both the two models are the models that will play an important role in practice in the future.The REFUM take rainwater enrich and fold ?>soil reservoir store椈-crop high effective use on the spot as the technological principal. The degree of regulated and controlled water use by man enhanced gradually. The common character is to change the solid interspace shape of surface soil to build the rainwater converge section (afflux section) and crop planting section and force the runoff of converge section flow to crop planting section together with the runoff of crop plant section for crop use. The model also is further divided into three son models that can be used to instruct practice. The first is the high effective rainwater use model of using engineering measurements and film cover to harvest rainwater to plant grasses and trees on the barren hillside to resume vegetation. The second is high effective rainwater use model of using engineering measurements and film cover to harvest rainwater to irrigate farming field. The third is the high effective rainwater use model of using cover of greenhouse and lighthouse to harvest rainwater to irrigate vegetables and mushrooms that planted in the greenhouse and lighthouse. The RHUM take artificial rainwater harvesting??establishments storage椈?crop high effective use in deferent place as the technological principal. The degree of regulated and controlled water uses by man reaches the top grade. The relative output is higher because there has intensively great input. The model has two special characters, one is optimize collocation use of resources, techniques, economy, environment control and high effective management, the other is resources redistribution use. The common characters are: use man made water collecting surface harvesting rainfall runoff storing in establishments (water t...