Additional Selection of Everpotranspiration and Precipitation Measurement Points considered characteristic of catchiment, in Surface Hydrological Investigation.

Miyahara, Tomoya*; Odagawa, Shinya*; Murata, Masatoshi*

The Horonobe Underground Research Center carried out surface hydrological investigation as a part of Horonobe Underground Research Laboratory project. This report describes the examination, was additional selection of everpotranspiration and precipitation measurement points in surface hydrological investigation. In this study, characteristic analysis of catchment carried out Shimizu River catchment and divided into three catchments of Penke-Ebekorobetu River catchment. Consequently, in surrounding catchment of the Horonobe Underground Research Laboratory site, it became clear that topography is low relief and highest forest type is broadleaf tree stands. The result which examined the applicability of the Everpotranspiration calculation method, applicability of profile method and Bowen's ratio thermal balance method in broadleaf tree forest, and applicability of Penman method in pastureland were high. Moreover, three additional everpotranspiration measurement sites and three additional precipitation measurement sites is selected using these results, in surrounding catchment of the Horonobe Underground Research Laboratory site.