Estimation of Crop Water Productivity (CWP) of Wheat crop in Mirpur Khas District using Landsat Imagery

Water scarcity is a significant global challenge, particularly in agrarian countries like Pakistan, where 80% of freshwater resources are dedicated to agriculture. As an arid and semi-arid region, Pakistan needs to adopt efficient irrigation practices to ensure sustainable water use. This study calculates Crop Water Productivity (CWP) to identify the most feasible irrigation methods, using the Mirpur Khas (MPK) District in Sindh, Pakistan, as the study area. Wheat, a crucial crop in Pakistan, was selected for analysis during the Rabi season (November to April), which spans 160 days. By employing processed Landsat 8 imagery and the EEFlux model, based on the METRIC (Mapping ET at high Resolution with Internalized Calibration) approach, this study estimated the actual evapotranspiration (ETa) and CWP for the wheat crop. The results revealed that the ETa averaged 296.26 mm throughout the growing season, with the highest ETa values observed during the crop development stage (approximately 152 mm), indicating increased water requirements during midseason. The calculated CWP was 1.17 kg/m³, significantly higher than Pakistan's national average of 0.80 kg/m³, suggesting that the wheat crop in MPK is utilizing water more efficiently. These findings emphasize the potential of advanced remote sensing techniques and models like EEFlux to enhance water use assessments in agriculture, enabling more sustainable management of water resources. The method used in this study is both time-efficient and resource-efficient, offering a viable alternative to traditional methods that require extensive human resources. The method is quite feasible and can be applied to different areas with various crops. This study demonstrates that adopting technological advancements in water resource management can significantly improve irrigation practices, making it a crucial step toward sustainable agriculture in water-scarce regions like Pakistan.