1996 Fiscal Year Final Research Report Summary
A study on the forest environment changes by long term extreme drought and headwater watersheds management measures for water conservation -A case study of Matsuyama city-
| Project/Area Number |
07456075
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
林学
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| Research Institution | KYUSHU UNIVERSITY (1996)
Ehime University (1995) |
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Principal Investigator |
OGAWA Shigeru Faculty of Agriculture, KYUSHU UNIVERSITY Professor, 農学部, 教授 (30037973)
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| Co-Investigator(Kenkyū-buntansha) |
INOUE Shouji Ehime University, College of Agriculture, Associate Professor, 農学部, 助教授 (30142342)
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| Project Period (FY) |
1995 – 1996
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| Keywords | extreme drought / forest watershed / remote sensing / moisture dynamics / discharge duration curve / watershed management / normalized difference vegetation index / headwater forest |
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| Research Abstract |
The purpose of this research is aimed at watershed management measures that would ensure proper and naturally-balanced ecosystem in the region. The results of this research were as follows :
1. In 1994 and 1995 hydrologic data of 6 dam watersheds of Shikoku, behavior of discharge duration analysis and its effects in extreme drought year and stability ratio of discharge duration were used for inference. NDVI values from 1995 satellite data were compared with that of normal year (1989) and extreme drought year (1994). In the ridge, NDVI values were low for in the drought year, but did not become low in the valley. The effects in drouht year were taken the following year from a unit slope where forest vegetation had fully recovered or not. This disparity obtained from this unit slope are useful for the management of forest.
2. Observations on the changes of soil moisture content were taken in the tentionmeters on 3 watersheds (2 fire dameged and 1 no fire dameged watersheds) at Etajima island in Seto Inland Sea. The discharge duration stablitiy was good for no fire damaged watershed in drought year. As the results of the soil moisture observations, the large water amount of infiltration into deep soil layrs or bed rock was assumed in the watershed without fire damaged.
3. From the analysis of discharge duration data on Tamagawa dam headwater watershed (Tokyo) with changes in forest vegetation, a relationship was discovered in the increase of ordinary water depth with the decrease of cuting down trees and the volume of discarge loss increases with the increase of forest vegetation.
4. The scheme in Ehime prefecture was made for forest headwater conservation adjustment method.
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