Hydrological and Nutrient Budget Modelling of Surface Water of the Achankovil River, Western Ghats, India

Article type: Research Article

Authors: Prasad, M. Bala Krishna | Ramanathan, AL.

Affiliations: School of Environmental Sciences, Jawaharlal Nehru University New Delhi-110067, India

Note: [] Corresponding author. E-mail: alr0400@mail.jnu.ac.in

Abstract: An attempt has been made to develop a hydrologic and nutrient budget for Achankovil river watershed (area 1484 km^2) in Western Ghats of India. The work was carried out in the year 2002 during three seasons i.e. pre-monsoon (February), monsoon (June/July) and post-monsoon (October). The water budget was determined using the formulae dm/dt = Σ input − Σ outputs + Σ (sources − sinks). The inflow (precipitation, tributary and Achankovil river baseflow) and out-flow (evapo-transpiration and discharge from tributaries and Achankovil river) segments were measured following the standard procedure for three seasons. The result indicates that significant amount of water leaving (60.35 × 10^8m^3) the watershed to the adjoining Vembanad lake and ultimately into the ocean, which exceeds the water, entering (54.83 × 10^8m^3) the basin. The outgoing water (&cong;9%) surplus may be due to overestimation of transpiration and the lack of estimation of the water input from the intermittent streams in the present study. Nitrogen and phosphorus balances are also calculated by LOICZ-CABARET budget model. 20,976.86 &times; 10<FORMULA>^6 m mol/yr and 19,655.1 × 10^6 m mol/yr of nitrogen and phosphorus were lost or utilized within the Achankovil river basin during the study period. More detailed study on short term and variation will certainly help us in dealing with the various sources and the contribution by main stream as well as intermittent streams.

Keywords: Achankovil river, budget modelling, evapo-transpiration, base flow, nutrients

Journal: Asian Journal of Water, Environment and Pollution, vol. 3, no. 2, pp. 63-69, 2006