Modelling the Crop Water Requirement Using FAO-CROPWAT and Assessment of Water Resources for Sustainable Water Resource Management: A Case Study in Palakkad District of Humid Tropical Kerala, India

Abstract

Crop water requirements of crops in agro-ecological units (AEUs) of Palakkad district of humid tropical Kerala computed with CROPWAT 8.0 using the meteorological parameters.The major cultivated crops are rice, coconut, banana, arecanut, vegetables, pulses, rubber, tea, coffee, cotton etc. The total water requirement for these crops in various agro-ecological zones has been computed. Using the evapotranspiration (ET 0 ) and effective rainfall in each agro-ecological unit (AEU), a climatic water balance has been worked out. The net irrigation demand, the gross irrigation demand and irrigation interval for the various crops grown in different AEUs have been computed. The gross irrigation demand for the district is 1146 Mm 3 , in which 981 Mm 3 is from surface water and 165 Mm 3 from groundwater sources. Water balance analysis was done for the current scenario and future demand for agriculture, domestic and industrial demand. The projected future total water demands for irrigation, drinking and industrial purpose will be 3841 Mm 3 . However, the secondary data showed that utilizable water resources of Palakkad district is less and will create a deficit scenario. This deficit indicates that if the total area is brought under irrigation there will be deficit years and during such periods deficit irrigation or reduction in command area may have to be adopted. A wide spectrum of scenarios has been discussed in the paper along with the guidelines for future management of water resources.

A comprehensive review of solar‐driven desalination technologies for off‐grid greenhouses

“…After calculating the actual evapotranspiration, the total CWR is measured through the soil water balance of the system . Table summarizes different formulas suggested in the literature for calculating the CWR with their effective parameters.…”

“…104,[106][107][108] After calculating the actual evapotranspiration, the total CWR is measured through the soil water balance of the system. 59,105,[107][108][109][110][111] Table 4 summarizes different formulas suggested in the literature for calculating the CWR with their effective parameters. An example of this calculation for different crops is presented in Sawant et al 105 which shows that the reference evapotranspiration is 0.00319 to 0.00481 m 3 /d/m 2 and the total CWR is 0.001 to 0.0043 m 3 /d/m 2 .…”

Study of Runoff Farming System to Improve Dryland Cropping Index in Indonesia

“…However, the calculation of the ETP using Penman-Monteith method is the best estimate evapotranspiration recommended by FAO [22]. The potential evapotranspiration calculated using CROPWAT v.8 software [23].…”

FAO-CROPWAT Model-Based Estimation of Crop Water Need and Appraisal of Water Resources for Sustainable Water Resource Management:Pilot Study for Kollam District - Humid Tropical Region of Kerala, India

“…Details such as planting season, crop duration, depth of active root zone, canopy coverage as a percentage of spacing of various crops are based on earlier studies 2,22 . Crop coefficient values (K c ) used in our study are given in Table 2.…”

“…This data confirms that there are variations in the case of quantity of total water required for different crops within the district, and it is mainly because of the difference observed in climate parameters and existing soil types. This shows that it is indispensable to adopt scientific water management based on the need of the crop, so that higher crop yield and water productivity can be attained with optimal quantity of water, provided all other management practices are adopted 2,22,31 .…”