Sustainability of water bodies of northern Egyptian Lakes: Case studies, Burrulus and Manzalla Lakes

Abstract

Change detection in the land use and land cover (LU and LC, respectively) is known as one of the most important indicators of global and regional environmental sustainability. Also, change detection in LULC is one of the most important and sound environmental management tools for sustainable development. In this paper, the maximum likelihood supervised classification is applied to subsets of the Landsat TM, ETM+, and OLI/TIRS images to monitor changes in the Burullus Lake and Manzala Lake. Burullus Lake is the second largest of the Egyptian northern lakes along the Mediterranean coast. Five classes are detected including seawater, lake water, sandbar and urban, floating vegetation, and agriculture. ERDAS IMAGINE and ArcGIS software are used in this study for processing of the images and managing the database of each image. The results show that the lake water area decreased by 38.01% (10,882.5 ha), while floating vegetation area increased mostly by the same amount during the period from 1990 to 2015. This increase in floating vegetation is due to the discharge of agricultural and municipal wastes in the lake without adequate treatment. The seawater has minor changes during the period of study. Other classes show remarkable changes over the time from 1990 to 2015. Manzala Lake is the largest natural lake in Egypt; it is located between longitudes 31°45′ and 32°22′E and latitudes 31°00′ and 31°35′N. Six classes are detected including seawater, lake water (water bodies), floating vegetation, islands, sandbar and urban, and agriculture. ERDAS IMAGINE and ArcGIS software are used in this study for processing of the images and managing the database of each image. The results show that the water bodies of the lake decreased by 57.06% (47,419.1 ha), while floating vegetation and island area increased mostly by the same amount during the period from 1984 to 2015. This increase in floating vegetation is due to the discharge of agricultural and municipal wastes in the lake without adequate treatment. The seawater has minor changes during the period of study. Other classes show remarkable changes over the time from 1984 to 2015. The future prediction was conducted using the annual rate of change over the next 15 years; the results from this prediction showed that the water bodies of the lake will be reduced by 84.67% (70,363.85 ha), and this decrease leads to a negative impact on fisheries and the environment. The results of this study shall help decision-makers to take the necessary measures to reduce the environmental risk and maintain the lake in order to sustain the lake water area against further reduction.