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

从水文、水质和土壤科学的角度，对岛根县东部等地的水田和林区的农林区环境因子进行了评价。特别是针对农业区动物习性环境，对岛根县东部水稻区生物多样性与环境因子的关系进行了评价。这些参数包括排水渠道的水质、鱼类、水生昆虫和物理环境因素(渠宽、水深、流速、植被覆盖度和下垫面土壤覆盖度)。结果表明，在调查地点共观察到鱼类11种，水生昆虫14种，并对Shannon-Wiener法计算的多样性指数进行了评价。明确了水质、渠宽和下垫面土壤盖度对水生昆虫多样性指数的影响。另一方面，对采用循环灌溉系统的水田流域污染物的质量平衡进行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取决于水文水量(年降雨量或降雨量加灌水量)，净化功能与水力滞留时间有关。利用这些结果，从物质循环、水文学、水质和帆船科学的角度对农业和线性区域的环境因子进行了评价。此外，还对主要影响因素进行了量化，并对它们之间的关系进行了评价，以集成基于地理信息系统的环境分析。

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.