Publications

Javed, MA; Ahmad, SR (2020). A DECISION SUPPORT SYSTEM FOR CROP WATER REQUIREMENT ESTIMATION USING ADVANCED GEOSPATIAL TECHNIQUES. PAKISTAN JOURNAL OF AGRICULTURAL SCIENCES, 57(4), 975-985.

Abstract
It is quite challenging to assess the crop water requirement with limited time and resources on a regional scale. The study focuses on developing a spatial decision support system (SDSS) for crop water requirement and to determine the efficacy of existing irrigation systems by utilizing advanced geo-spatial techniques. Selected region was Punjab province of Pakistan that covers a total area of 105227 sq.km . Reflectance based crop coefficient approach was used forcrop water requirement estimation. Various metrological, climatic, geographical vector layers and statistical data of irrigation supply along with satellite imageries were used for monitoring the crop health on 8-days periodic intervals for the summer (Khalif) season in the year 2018. For accurate quantification and mapping of crop water requirement, Landsat, MODIS and SPOT imageries were processed for crop classification, top of the atmosphere radiation calculation and actual and reference measurements, respectively. Reference evapotranspiration (ETo) was calculated using Penman method leading to provide water demand and consumption by further calculations in each irrigation circle. The results show that the regions lying at the tail of the canal command area (CCA) facing higher water deficit. In addition, irrigation circles facing insufficient irrigation water supplies (upper and lower Jhelum canal, Pothoar region) also demonstrating higher crop water deficits. Comparing southern with northern parts of the province high water deficits observed in images in the year 2018, reflecting these regions are relatively hotter and receive less average precipitation. Similarly, high water deficit observed at northeast of the Punjab due to insufficient irrigation water supply. The results have been validated by comparing the water demand with the irrigation supply in each CCA, which provides the water being utilized other than irrigation sources to satisfy crop water needs. This study is quite effective in water budget estimation and mitigation of water scarcity issues.

DOI:
10.21162/PAKJAS/20.9482

ISSN:
0552-9034