This study aims to construct a participatory system of waterside environmental valuation. A social survey is first conducted to capture the features of subjective perception for the Geo-, Eco-, and Socio-environment at the waterside by each season and waterside section. Secondly, the relationship between items of impression and GES environment is clarified by Cramer's coefficient of contingency. Thirdly, the profile of the impression will be shown and also the image of the waterside will be obtained by applying a factor analysis to the items which constitute impression. Consequently, the hierarchical system of waterside environmental valuation will be shown.

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We investigated year-round water level fluctuations in Myoginohana floodplain, which is the largest reed wetland in Lake Kasumigaura and where there has been considerable focus on their functions such as biodiversity and water purification. As a result of having observed spatial and temporal changes of water levels in the floodplain and the lake, a series of three following mechanisms of water cycle was clarified. 1) In flood peak, the whole floodplain had same water level with the lake and the river. 2) In discharge period, when the water level in the floodplain got lower than the height of the floodplain edge, the water levels in the floodplain decreased more slowly whereas the water level of the lake fell immediately by the artificial operation of the water gate. And different reductions of water levels were observed within the floodplain caused by their topographic conditions. 3) Then if there was no longer inundation, only evapotranspiration let the water level decrease. Furthermore, water balance in each flood event was calculated to evaluate the volume of water exchange between the floodplain and the lake or the river. As the result, about 58-78% of water level rise in a flood was caused by inflow from the river. Total inflow of four floods in 2006 was estimated about 1300mm, which was same amount of average annual precipitation. Hence, it's inferred that water exchange in floods contribute to material exchange and make influence for water quality in the floodplain.

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This study investigated variability characteristics of monthly precipitation in Japan by classifying monthly precipitation data at 51 of meteorological weather stations distributed over the country. Monthly precipitation data at each of the 51 stations was transformed into non-exceedance probabilities in order to remove seasonal variations of precipitation at each station. The transformed precipitation data for the period from 1901 to 2004 was classified by applying the SOM (Self-Organizing Maps) algorithm, which algorithm enables us to compress information of high dimensional data onto 2-dimensional arrays.
Investigation of the relationships between the phase of the Pacific Decadal Oscillation (PDO) and the extracted monthly precipitation patterns indicated the negative (positive) phase of PDO is associated with the increasing (decreasing) of the appearance of high precipitation which is particularly evident at the cities in the Pacific side of eastern Japan. Moreover, Cluster analysis of the extracted precipitation patterns indicated that, since the 1977, the occurrence of countrywide high precipitation except Okinawa has decreased and the occurrence of countrywide low or severe low precipitation has increased except for Hokkaido and Okinawa. In addition, the SOM-map succeeded in visualizing the transition of the monthly precipitation pattern in the countrywide drought year from 1994 to 1995.

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The Makkink equation can estimate potential evaporation using only air temperature and sunshine duration. Therefore, it is convenient for use in developing countries where there is an insufficient amount of meteorological data. The two coefficients employed in the equation were determined to fit the estimations of the Penman equation, and the accuracy of the estimations by the Makkink equation were investigated. The results showed that the accuracy was best when the estimations were made with the coefficients which depend on each locality, and that the accuracy was further improved with the coefficients which depend on each climatological zone. The relationship between the two coefficients showed a negative correlation, which was addressed in a previous study.

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