Simulating river discharge in a snowy region of Japan using output from a regional climate model
Snowfall amounts have fallen sharply along the eastern coast of the Sea of Japan since the mid-1980s. Toyama Prefecture, located approximately in the center of the Japan Sea region, includes high mountains of the northern Japanese Alps on three of its sides. The scarcity of meteorological observatio...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2013-07-01
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| Series: | Advances in Geosciences |
| Online Access: | http://www.adv-geosci.net/35/55/2013/adgeo-35-55-2013.pdf |
| Summary: | Snowfall amounts have fallen sharply along the eastern coast of the Sea of
Japan since the mid-1980s. Toyama Prefecture, located approximately in the
center of the Japan Sea region, includes high mountains of the northern
Japanese Alps on three of its sides. The scarcity of meteorological
observation points in mountainous areas limits the accuracy of hydrological
analysis. With the development of computing technology, a dynamical
downscaling method is widely applied into hydrological analysis. In this
study, we numerically modeled river discharge using runoff data derived by a
regional climate model (4.5-km spatial resolution) as input data to river
networks (30-arcseconds resolution) for the Toyama Prefecture. The five main
rivers in Toyama (the Oyabe, Sho, Jinzu, Joganji, and Kurobe rivers) were
selected in this study. The river basins range in area from 368 to 2720 km<sup>2</sup>. A numerical experiment using climate comparable to that at present
was conducted for the 1980s and 1990s. The results showed that seasonal
river discharge could be represented and that discharge was generally
overestimated compared with measurements, except for Oyabe River discharge,
which was always underestimated. The average correlation coefficient for
10-year average monthly mean discharge was 0.8, with correlation
coefficients ranging from 0.56 to 0.88 for all five rivers, whereas the
Nash-Sutcliffe efficiency coefficient indicated that the simulation accuracy
was insufficient. From the water budget analysis, it was possible to
speculate that the lack of accuracy of river discharge may be caused by
insufficient accuracy of precipitation simulation. |
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| ISSN: | 1680-7340 1680-7359 |