HR: 0800h
AN: H11C-1274    [Abstracts]
TI: Changes in Moisture and Energy Fluxes due to Groundwater-based Irrigation in the Indian Monsoon Belt
AU: * Douglas, E M
EM: ellen.douglas@unh.edu
AF: Complex Systems Research Center, Institute for the Study of Earth Oceans and Space Morse Hall University of New Hampshire , Durham, NH 03824 United States
AU: Niyogi, D
EM: dniyogi@purdue.edu
AF: Departments of Agronomy and Earth and Atmospheric Sciences, Purdue University, West Lafayette, IN 47907 United States
AU: Frolking, S E
EM: steve.frolking@unh.edu
AF: Complex Systems Research Center, Institute for the Study of Earth Oceans and Space Morse Hall University of New Hampshire , Durham, NH 03824 United States
AU: Yeluripati, J
EM: yjbabu@eos.sr.unh.edu
AF: Complex Systems Research Center, Institute for the Study of Earth Oceans and Space Morse Hall University of New Hampshire , Durham, NH 03824 United States
AU: Pielke, R A
EM: pielke@atmos.colostate.edu
AF: Department of Atmospheric Sciences, Colorado State University, Fort Collins, CO 80523 United States
AU: Niyogi, N
EM: niveditaniyogi2002@yahoo.com
AF: Consultant, 3907 Bowhill Drive, Austin, TX 78731 United States
AU: Vorosmarty, C J
EM: charles.vorosmarty@unh.edu
AF: Complex Systems Research Center, Institute for the Study of Earth Oceans and Space Morse Hall University of New Hampshire , Durham, NH 03824 United States
AU: Mohanty, U C
EM: mohanty_uc@yahoo.com
AF: Center for Atmospheric Sciences, Indian Institute of Technology Hauz Khas, Delhi, 110016 India
AB: The Indian monsoon belt is home to a large part of the world's population and agriculture is the major land-use activity in the region. India leads the world in total irrigated land with irrigation withdrawals representing 92% of all water use. More than 50% of total irrigated area is dependent on groundwater and approximately 60% of irrigated food production depends on irrigation from groundwater. Between 1950 and 1985, surface water withdrawals for irrigation doubled, while groundwater withdrawals increased 113-fold, resulting in rapidly declining groundwater levels in as many as 15 states. An important question is whether such alteration of the hydrologic cycle simply results in a collection of localized impacts or do these alterations produce feedbacks that are significant at regional scales. In this paper we present a conceptual synthesis of the impact the agricultural activity can have on the atmosphere and regional climate through irrigation and its feedback on the atmospheric moisture flux and water cycles. Such modified atmospheric conditions could potentially lead to changes in the interannual variability in the monsoon rainfall. We found that vapor fluxes have increased by 17%, with a 7% increase in the wet season and a 55% increase in the dry season. Two-thirds of these increases were attributed to irrigation. The area-averaged change in latent heat flux across India was estimated to be 9 W m^-2. The largest increases in vapor and latent heat fluxes occurred where both cropland and irrigated lands were the predominant contemporary land cover classes. We present preliminary estimates of the role that groundwater-based irrigation plays in these increases in energy and vapor fluxes.
DE: 1807 Climate impacts
DE: 1814 Energy budgets
DE: 1834 Human impacts
DE: 1843 Land/atmosphere interactions (1218, 1631, 3322)
DE: 1880 Water management (6334)
SC: Hydrology [H]
MN: Fall Meeting 2005