HR: 0800h
AN: H21A-0179    [Abstracts]
TI: Evaluation of Catchment Storage Volume for Moderating Flow Fluctuations
AU: * Takimoto, H
EM: takimoto@pu-toyama.ac.jp
AF: College of Technology, Toyama Prefectural University, 5180 Kurokawa, Imizu, 939-0398, Japan
AU: Horino, H
EM: horino@envi.osakafu-u.ac.jp
AF: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, 599-8531, Japan
AU: Tanakamaru, H
EM: tanakam@kobe-u.ac.jp
AF: Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657- 8501, Japan
AB: Any catchment has a storage volume to some extent as compared with a virtual catchment covered with impervious surface, e.g., glass. Such storage volume (or capacity) contributes to moderate fluctuations of discharge from the catchment. That is, any catchment has a lower peak discharge at flood and higher discharge at drought than the virtual catchment. With respect to comprehensive water management including flood prevention and effective use of water resources, it is important to evaluate the storage capacity in various catchments. In this study, the following two indices calculated by daily rainfall, discharge and evapotranspiration data: water use storage depth (WUSD) and total storage depth (TSD) are used for evaluating the catchment storage capacity. The WUSD is derived as the water storage that is performing for assuring the minimum daily flow. That is, it is the minimum storage capacity when the daily water demand rate is equal to the discharge that gives a stable water supply through the year. Meanwhile, the TSD can be obtained from the changes in storage volume in a catchment. The TDS means the maximum difference of deposited water within one year when the catchment is considered as a vessel. Taking up two forest catchments and one reclaimed farmland catchment in a snow area as case studies, those storage depths are compared. The WUSD and the TSD in the forest catchments within one year are 57-287mm and 166-444mm, respectively, while those in the reclaimed farmland catchment are about 47-159mm and 142-285mm. The results show that the forest catchments are on average more excellent for the function to ensure a stable water supply and regulate floods, although both the WUSD and the TSD in any catchment range widely depending on the climate conditions in each year, and that the amount of snow cover has a significant effect especially on the TSD.
DE: 1804 Catchment
DE: 1812 Drought
DE: 1876 Water budgets
DE: 1884 Water supply
SC: Hydrology [H]
MN: 2007 Fall Meeting