GROBAL EVALUATION AND UTILIZATION OF ENVIRONMENTAL EFFECTS INCLUDED IN AGRICULTURAL WATER-USE -DEVELOPMENT OF THEIR STANDARD METHODS-

这个研究小组认为，在农村地区广泛推广的农业用水系统对环境保护是有用的。因此，该小组试图对运河和农田的环境影响进行评估，并获得1994-1996年运河和农田利用的基本指标。此外，同年还进行了利用对地观测卫星图像进行区域环境分析的尝试。结果如下：1.渠道环境影响评价及利用的基本指标。(1)水跃充气效应理论上较高。但裸射流曝气效果存在一定的理论问题。(2)如果稻田占集水流域的40%，渠道水质必须同时采用灌水期和非灌水期的L-Q方程进行估算。(3)为渠道规划提供了一种推断植物对渠道流速分布和水位变化影响的方法，以保护生态系统。农用地环境效应评价及其利用的基本指标：对稻田反硝化作用进行了定量测定，建立了评价稻田环境效应的定量指标。通过处理地球观测卫星的图像进行区域环境分析。通过处理NOAA卫星的图像，可以对全球植被进行分类，在全球范围内发现由于气候变化而导致的土地覆盖的移动和存在，并粗略地找到由于其移动和存在而导致的二氧化碳固定的数量变化。

This study group supposed that agricultual water-use systems spread widely in rural areas were useful for environmental conservation. Therefore the group tried to evaluate environmental effects of canal and farm land, and to get fundamental indexes for their utilization from 1994 to 1996. In addition, regional environment analysis by processing images from earth observation satellite was also tried in the same years.The results are as follows :1. Evaluation of environmental effects of canal and fundamental indexes for its utilization.(1) Aeration effect in hydraulic jump is theoretically high. But exposed jet flow has some theoretical problems in aeration effect.(2) If paddy field accounts for 40% of catchment basin, water quality of canal must be estimated by both L-Q eqation of irrigation period and non-irrigation period.(3) A method to infer influence of plants on velocity distribution and water level variation in canal was found for planning of canals to conserve ecosystem.2. Evaluation of environmental effects of farm land and fundamental indexes for its utilization.Quantitative measurement of denitrification in paddy field was done and Quantitative index of denitrification was found to evaluate environmental effects of paddy field.3. Regional environment analysis by processing images from earth observation satellite.By processing images from NOAA satellite, it was possible to globally classify vegetation, to globally find movement and existence of land cover due to climatic change and to roughly find quantitative change of carbon dioxide fixation due to its movement and existence.