Analytical system on water and soil environment in paddy field areas for animal-habitat conservation

从水文、水质、土壤等方面对岛根县东部地区水田和林区的农林环境因子进行了评价。以岛根县东部稻田为研究对象，对农业地区动物习性环境进行了生物多样性与环境因子的关系评价。参数为排水渠内的水质、鱼类、水生昆虫和物理环境因子（渠宽、水深、流速、植被覆盖度和地下土壤覆盖度）。结果，调查地点共发现11种鱼类和14种水生昆虫，并用Shannon-Wiener法计算了多样性指数。阐明了水虫多样性指数受某些水质、渠道宽度和地下土壤覆盖度的影响。另一方面，针对循环灌溉水田流域污染物的质量平衡，开展了长期的水质和水文调查。结果表明，年污染物负荷的变化主要归因于水文水量（年降雨量或降雨量加灌溉水量）的变化，其净化功能与水力滞留时间有关。利用这些结果，从物质循环、水文、水质和风帆学等方面对农业和线性区环境因子进行了评价。此外，还对主要影响因素进行了量化，并评价了它们之间的相互关系，以整合基于GIS的环境分析。

Environmental factors of agricultural and forestry areas were evaluated in the light of hydrology, water quality and soils science in paddy field and forestry areas in the eastern part of Shimane prefect= and other districts. In particular for the environment for animal habits in agricultural areas, the relationship between bio-diversity and environmental factors were evaluated in a paddy-field area in the eastern part of Shimane Prefecture. The parameters were water qualities, fishes, aquatic insects, and physics' environmental factors (breadth of canal, water depth, flow velocity, vegetation coverage, and soil coverage of undersurface) in drainage canals. As a result, eleven species of fishes and fourteen species or family of aquatic insects were observed in the investigation sites and diversity indexes calculated by Shannon-Wiener method were evaluated. Then, it was clarified that the diversity indexes for aquatic insects were affected by some water qualities, breadth of canal and soil coverage of undersurface. On the other hand for the mass balance of pollutants in a paddy field watershed using a circular irrigation system, a long-term investigation on the water quality and hydrology was carried out As a result, the change in annual pollutant loads was primarily attributed to the amount of hydrological water volumes (the annual amount of rainfall or that of rainfall plus irrigation water), and the purification function was related to the hydraulic retention time. By using these results, the environmental factors in agricultural and lineally area were evaluated in the light of material cycles, hydrology, water quality and sail science. Moreover the main factors were quantified and relationships among them were evaluated in other to integrate the GIS based environmental analysis.