Multi-spectral remote sensing for current irrigated area mapping of the Rift Valley Lakes Basin in Ethiopia

Abstract

The study was conducted in the Rift Valley Basin in 2020–2022, with the objective of evaluating the newly developed techniques for irrigated area mapping of spatially large areas and assessing the current irrigated area in the basin. Methods used for irrigated area mapping are imagery analysis using the NDVI and EVI methods and land use classification. All results were verified with ground-truthing data using the sample locations selected. A 10 m × 10 m spatial resolution image derived from the European Space Agency Sentinel-2 satellite was used to create a time series spanning 2020, 2021, and 2022. Irrigated area maps from all three techniques were obtained and evaluated. Metric indicators were used to evaluate the performance of the irrigated area mapping techniques, the mean overall accuracy was 0.82, with a kappa coefficient of 0.76 and an F1-score of 0.86 with the highest and lowest overall accuracy observed in 2020 (0.86) and 2022 (0.76), respectively. Coefficient of determination was used to quantify the correlation of geospatial information and the multispectral remote sensing data analysis results maps agreed with irrigated area mapping with respect to ground truthing with R2 mean value of 0.87 which suggests a strong agreement. HIGHLIGHTS No previous study has been done for the basin.; The study will have an impact on managing water resources, strategic water allocation planning and climate change mitigation options.; Appropriate references are used.;

Keywords

• analysis
• evaluation
• image
• irrigated
• mapping