Modeling and monitoring surface water dynamics in the context of climate changes using remote sensing data and techniques: case of Ain Zada Dam (North-East Algeria)

The manuscript discusses the problem of water scarcity engendered by climate change impact through our test area, the Ain Zada Dam (North-East Algeria). The latter has witnessed a noticeable water-level decrease during the last years. Therefore, the status of the water surface is in a critical condition and the dam is in need of continuous follow-up survey. The present paper aims to model the spatiotemporal changes of the Ain Zada Dam’s water surface in the period 2015–2018 using remote sensing. To reach this end, NDWI (Normalized Difference Water Index) algorithm, which is a reference for water body extraction techniques on Sentinel-2 Satellite, is used for detecting spatiotemporal changes of the dam under study. The results obtained showed that the use of the NDWI provides an accurate water body mapping in the region for the time-series Sentinel-2 images, with an average overall accuracy of 98.57%. Also, the findings demonstrated that the dam’s surface area has steadily decreased between 2015 and 2018, where the dam has lost about two thirds of its water surface area, which corresponds to about 77% of the water size since the 2015 winter. These major repercussions are due mainly to the climate change and human factors that have affected the water supply as well. Considering that water shortage is one of the biggest future environmental issues in Algeria, the findings of the present study should be taken into account vis-à-vis any future potential development in the area, and they could be further enhanced or complemented by future research on the environmental impact of water shortage, which is relevant to the Algerian context.