Estimation of paddy water productivity (WP) using hydrological model: an experimental study |
| |
Authors: | S Govindarajan N K Ambujam K Karunakaran |
| |
Institution: | (1) Centre for Water Resources, Anna University, Chennai, 600 025, Tamil Nadu, India |
| |
Abstract: | Water productivity (WP) expresses the value or benefit derived from the use of water. A profound water productivity analysis
was carried out at experimental field at Field laboratory, Centre for Water Resources, Anna University, India, for rice crop
under different water regimes such as flooded (FL), alternative wet and dry (AWD) and saturated soil culture (SSC). The hydrological
model soil-water-atmospheric-plant (SWAP), including detailed crop growth, i.e, WOFOST (World Food Studies) model was used
to determine the required hydrological variables such as transpiration, evapotranspiration and percolation, and bio-physical
variables such as dry matter and grain yield. The observed values of crop growth from the experiment were used for the calibration
of crop growth model WOFOST. The water productivity values are determined using SWAP and SWAP–WOFOST. The four water productivity
indicators using grain yield were determined, such as water productivity of transpiration (WPT), evapotranspiration (WPET), percolation plus evapotranspiration (WPET+Q) and irrigation plus effective rainfall (WPI+ER). The highest value of water productivity was observed from the flooded treatment and lowest value from the saturated soil
culture in WPT and WPET. This study, reveals that deep groundwater level and high temperature reduces the crop yield and water productivity significantly
in the AWD and SSC treatment. This study reveals that in paddy fields 66% inflow water is recharging the groundwater. There
is good agreement between SWAP and SWAP–WOFOST water productivity indicators. |
| |
Keywords: | Richards’ s equation Transpiration Evapotranspiration Crop growth model SWAP model Field scale |
本文献已被 SpringerLink 等数据库收录! |
|