Indirect and direct recharges in a tropical forested watershed: Mule Hole, India

Marechal, Jean-Christophe and Varma, Murari RR and Riotte, Jean and Vouillamoz, Jean-Michel and Kumar, Mohan MS and Ruiz, Laurent and Sekhar, M and Braun, Jean-Jacques (2009) Indirect and direct recharges in a tropical forested watershed: Mule Hole, India. In: Journal of Hydrology, 364 (3-4). pp. 272-284.

PDF 1.pdf - Published Version Restricted to Registered users only Download (1MB) | Request a copy

Abstract

It is commonly accepted that forest plays role to modify the water cycle at the watershed scale. However, the impact of forest on aquifer recharge is still discussed: some studies indicate that infiltration is facilitated under forest while other studies suggest a decrease of recharge. This paper presents an estimate of recharge rates to groundwater in a humid forested watershed of India. Recharge estimates are based on the joint use of several methods: chloride mass balance, water table fluctuation, geophysics, groundwater chemistry and flow analysis. Two components of the recharge (direct and indirect) are estimated over 3 years of monitoring (2003-2006). The direct and localized recharges resulting from rainfall over the entire watershed surface area is estimated to 45 mm/yr while the indirect recharge occurring from the stream during flood events is estimated to 30 mm/yr for a 2 km-long stream. Calculated recharge rates, rainfall and runoff measurements are then combined in a water budget to estimate yearly evapotranspiration which ranges from 80% to 90% of the rainfall, i.e. 1050 mm/y as an average. This unexpected high value for a deciduous forest is nevertheless in agreement with the forest worldwide relationship between rainfall and evapotranspiration. The large evapotranspiration from the forest cover contributes to decrease the recharge rate which leads to a lowering of the water table. This is the reason why the stream is highly ephemeral.

Item Type:	Journal Article
Publication:	Journal of Hydrology
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Natural recharge;Chloride mass balance;Forest;Water table fluctuation;Analytical solution;Evapotranspiration.
Department/Centre:	Division of Mechanical Sciences > Civil Engineering
Date Deposited:	21 Aug 2009 10:05
Last Modified:	19 Sep 2010 05:27
URI:	http://eprints.iisc.ac.in/id/eprint/19186

Actions (login required)

View Item