Using Remote Sensing Techniques to Monitor the Changes in AL-Habbaniya Lake, West of Iraq

Abstract

     Lakes and other water bodies change over time and are influenced by natural and anthropogenic processes during the hydrological cycle. One method for monitoring those factors is remote sensing, which collects digital information about objects or regions remotely and is useful for a wide range of tasks. It is a powerful reminder that data is focused on changes in the Earth’s surface, rather than being opposed to the traditional methods. Al-Habbaniya Lake, a vital reservoir west of Baghdad, mainly serves three functions: flood control, supplying ecosystem services, and irrigation. Recently, the lake’s surface area has significantly fallen due to drought, slow water flow in the Euphrates River, and delayed maintenance, influencing its agricultural, recreational, and natural functions. The focal point of this study is to monitor changes in Al-Habbaniya Lake in western Iraq using remote sensing techniques over approximately 34 years, 1988, 2002, and 2022, using Landsat satellite images. The methods employed are atmospheric correction, image masking, maximum-likelihood supervised classification, and identification of land cover change using ENVI 5.3. The strengths of this study are: (i) multi-temporal analysis through the use of Landsat images, (ii) atmospheric correction, which reduces the uncertainty of the data due to atmospheric effects, (iii) binary masking, which maximizes the accuracy of the lake area, and (iv) maximum likelihood classification, which maximizes the analysis of the pixels. Results showed that the water category decreased from 362.94 km² (95.02%) in 1988 to the lowest point in 2002 at 103.03 km² (26.97%), and then rose to 189.20 km² (49.53%) in 2022. The soil class rose from 0.58 km² (0.15%) in 1988 to 201.63 km² (52.79%) in 2002, then decreased from 2002 to 2022 to 98.48km² (25.78%). In the case of vegetation, the area grew from 18.45 km² (4.83%) in 1988 to 77.31 km² (20.24%) in 2002, and finally expanded to 94.30 km² (24.69%) in 2022. Results of the change detection showed that in 1988-2002, 48.71% of the study area was changing from water to land. Conversely, 2002-2022 showed some recovery in ecology, with 11.51% of the study area recovering to water, from bare soil. Generally, the work showed that between 1988 and 2002, water loss was enormous, and only partially recovered in the following decades, providing valuable information for water management of a critical ecosystem.