Introduction,Adaptation and Application of Wetland-Reservoir-Subirrigation-System in Rice-based Irrigation Systems of South China

For the current irrigation and drainage systems in China,the original purposes are focused on water quantity issues more than water quality,i.e.irrigation water can be supplied during the outbreak of droughts and excessive water can be drained during the outbreak of flooding and waterlogging.However,the agricultural non-point source pollution(ANSP) are becoming more and more serious,especially in rice-based irrigation systems because of the traditional practices of flooding irrigation and excessive fertilizer application.Therefore,it is of great importance to alleviate ANSP and achieve sustainable development of agriculture through the appropriate transformation of current irrigation and drainage systems.Using the concept and idea of Wetland Reservoir Sub-Irrigation System(WRSIS) developed by researchers of Ohio State University for reference,combining the actual conditions of rice-based irrigation systems in plains and hilly areas in South China,this paper is an attempt to do research on Qingshitan Irrigation System,Guangxi and Zhanghe Irrigation System in Hubei as the sites for cleaning drainage water from paddy fields through constructed wetland and irrigation pond.