No abstract

Habitats of aquatic creatures (fishes Oncorhynchus masou masou, Plecoglossus altivelis altivel and Cyprinus carpio, fireflies Luciola cruciata and Luciola lateralis, and frogs Anura sp) in the Natori River basin located at the middle of Miyagi prefecture were evaluated dynamically using the water temperature as one of the environmental indices. HSI (Habitat Suitability Index) and WUA (Weighted Useable Area) of aquatic creatures were quantitatively calculated from numerical map information and hydrological simulation with a heat budget model. As results, general HSI of fireflies increased but of frogs decreased by adding the factor water temperature. Migration of Plecoglossus altivelis altivel could be represented by the variation of WUA.

The water temperature in the Natori River basin located at Miyagi prefecture is evaluated combining a hydrological model and a heat budget model. This model simulates spatial and temporal distribution of temperature in March, August, and December 2003. In addition, applying this model to the climate changes that involving temperature rise, reducing precipitation, and decreasing a snowmelt, we calculated the water temperature change on these conditions. As results, we found that there is no influence to change the water temperature in rainfall, and that it has enormous influence in combining with the factors which are the temperature and sunshine durations directly related to the water temperature.

Damages of typhoon-induced storm surges would become more severe. As level flooding model is used in the past prediction of the flooded areas of storm surges, the areas and population at risk tend to be overestimated. hi the real situation, floods meet resistance of roughness on the land such as land forms, vegetations and buildings to form a slope of the penetrating water surface. In this study, storm surges and resultant floods over the land are estimated by long wave models to examine the effects of typhoon parameters, land form, and land roughness. The conditions examined are; typhoon parameters such as central pressure, propagation speed, and incident angle to the coast line; and land parameters such as slope and roughness. A systematic relationship is obtained between the flooding distance and the parameters. This result can be used to improve the accuracy of the flooded areas for the regional and global estimates.