Assessing impacts of agricultural water interventions in the Kothapally watershed, Southern India

Author(s): Garg, K.K., L. Karlberg, J. Barron, S.P. Wani and J. Rockström
In: Hydrological Processes, online10 May 2011
Year: 2011
Type: Journal / article
Theme affiliation: Landscapes
Link to centre authors: Rockström, Johan
Full reference: Garg, K.K., L. Karlberg, J. Barron, S.P. Wani and J. Rockström (2011). Assessing impacts of agricultural water interventions in the Kothapally watershed, Southern India. Hydrological Processes, online10 May 2011. DOI: 10.1002/hyp.8138

Publication review

The paper describes a hydrological model for agricultural water intervention in a community watershed at Kothapally in India, developed through integrated management and a consortium approach.

The impacts of various soil and water management interventions in the watershed are compared to no-intervention during a 30-year simulation period by application of the calibrated and validated ARCSWAT 2005 (Version 2.1.4a) modelling tool.

Kothapally receives, on average, 800 mm rainfall in the monsoon period. 72% of total rainfall is converted as evaporation and transpiration (ET), 20% is stored by groundwater aquifer, and 8% exported as outflow from the watershed boundary in current water interventions. ET, groundwater recharge and outflow under no-intervention conditions are found to be 64, 9, and 19%, respectively. Check dams helped in storing water for groundwater recharge, which can be used for irrigation, as well minimising soil loss.

In situ water management practices improved the infiltration capacity and water holding capacity of the soil, which resulted in increased water availability by 10—30% and better crop yields compared to no-intervention. Water outflows from the developed watershed were more than halved compared to no-intervention, indicating potentially large negative downstream impacts if these systems were to be implemented on a larger scale. On the other hand, in the watershed development program, sediment loads to the streams were less than one-tenth.

It can be concluded that the hydrological impacts of large-scale implementation of agricultural water interventions are significant. They result in improved rain-fed agriculture and improved productivity and livelihood of farmers in upland areas while also addressing the issues of poverty, equity, and gender in watersheds.

There is a need for case-specific studies of such hydrological impacts along with other impacts in terms of equity, gender, sustainability, and development at the mesoscale.

Share

Stockholm Resilience Centre is a collaboration between Stockholm University and the Beijer Institute of Ecological Economics at the Royal Swedish Academy of Sciences

Stockholm Resilience Centre
Stockholm University, Kräftriket 2B
Phone: +46 8 674 70 70
info@stockholmresilience.su.se

Organisation number: 202100-3062
VAT No: SE202100306201

Intranet