Irrigation Water Operation and Water Quality Management in Large Scale Water System

土地和水是水稻生产必不可少的资源，本研究的目的是明确灌溉用水系统的运行绩效，评价灌溉用水系统运行对流域水质管理的贡献。(1)调查了几个流域地区的灌溉用水行为，并通过多因素分析探讨了灌溉用水与几个相关因素之间的关系。(2)近年来，由于农村社区的城市化和现代化，农民对水的兴趣发生了显著的变化。对塔河流域传统小溪的各种功能进行了考察和分析。根据治水原理，从环境保护的角度对小溪的作用进行了评价。(4)对小溪水系进行了水量平衡及相关成分分析，并对水质进行了检验。小溪水系中回流的存在，提高了用水效率，但可能对小溪网点的水质产生严重影响。(5)小溪地区存在稻田和其他农作物的轮作利用，对水质状况进行了净出水分析。

Land and water are essential resources for paddy agriculture.The purposes of the study are to clarify the performances of irrigation water system operation and to evaluate the contributions of the water system operation to water quality management in river basins.(1) The practices of irrigation water use were surveyed and the relationships among the water use and several concerning factors were considered by multivariate analysis in several river basin areas.(2) There arc, recently, remarkable changing of farmers' interests in their water associations, because of urbanization and modernization in rural communities. Surveys and analyses were conducted for clarifying the change in aspects and reasons concerning on it.(3) It was tried to investigate various functions of traditional creeks in tower river basin. Based on principles of water control, the roles of creeks were evaluated from environmental conservation side.(4) The water balance and concerning components were analyzed using a complex tank model for creek water system, The water quality was also examined.The existence of return flow in the creek water system improve the efficiency of water use, but may have severe impacts on water quality in creek networks.(5) There are rotational land use of paddy and other crops in creek area.The net effluent toad analsis was conducted for evaluating the status of water quality in the area.