SUSTAINABLE GROUNDWATER MANAGEMENT IN KOCHI PLAIN : 1. ANALYSIS OF GROUNDWATER QUANTITY
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概要
- 論文の詳細を見る
The Konan groundwater basin in Kochi Prefecture is threatened by freshwater scarcity, especially during dry periods. The present study focuses on the critical analyses of hydrology and hydrogeology of the Konan basin to investigate the groundwater dynamics and to explore the possibility of enhanced groundwater supply on a long-term basis. The potential rainstorms are limited to relatively short periods of the year, with considerable temporal variations. The streamflow analysis revealed that the river flow is highly seasonal and varies appreciably each year, with the mean annual flow reduced to <20 m^3/s after its peak in 1993. The hydrogeologic analysis indicates that phreatic aquifers comprising alluvial sand and gravel and/or diluvial silty sand and gravel are dominant, and that the northwestern and western portions of the basin have greater potential for groundwater. Overall groundwater flow in the basin is from north to south into the Pacific Ocean. The hydraulic conductivity of the basin is characterized as high and ranges from 65 to 804 m/day, with a mean value of 229 m/day. This finding suggests high aquifer heterogeneity. The results of step-drawdown pumping tests demonstrate that though the basin is low yielding, increased groundwater withdrawals are possible. In a major part of the basin, the groundwater exhibits considerable short-term fluctuations. Groundwater levels fall substantially during dry periods, with January-February being most critical months. Considerable variations of groundwater levels in space and time over the basin indicates a wide variation of natural recharge. Apart from the rainfall infiltration, the Monobe River plays a vital role in augmenting the groundwater storage. Furthermore, the canal flows help maintain relatively high water tables over the basin and sustain flows in the intermittent rivers during dry periods. The rubber dams across the intermittent rivers and the paddy-field-irrigation also contribute significantly to the groundwater augmentation. Finally, it is concluded that the recommended measures for enhancing groundwater storage during dry periods are indispensable to ensure sustainable groundwater utilization in the Konan basin.
- 高知大学の論文
- 2002-12-25
著者
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Jha Madan
Agfe Department Indian Institute Of Technology Kharagpur
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Kamii Y
Chair Of Land Environmental Engineering Faculty Of Agriculture Kochi University
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CHIKAMORI K
Kochi University
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Chikamori K.
Kochi University
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Kamii Y.
Chair of Land Environmental Engineering, Faculty of Agriculture, Kochi University
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- Irrigation and Water Management : An Indian Perspective
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- SUSTAINABLE GROUNDWATER MANAGEMENT IN KOCHI PLAIN : 2. ANALYSIS OF WATER QUALITY AND SEAWATER INTRUSION
- SUSTAINABLE GROUNDWATER MANAGEMENT IN KOCHI PLAIN : 1. ANALYSIS OF GROUNDWATER QUANTITY