Northern coastal lakes in the Nile Delta of Egypt have an ecosystem of distinctive nature. While customary acknowledged as environmentally rich water bodies, these lakes are alleviating the non-favorable polluting effect of development activities before reaching the Mediterranean Sea. Moreover, climate change challenges are adding more important role to coastal lakes to act as natural adaptive measure that effectively buffer potential sea level rise or any unprecedented events. Therefore, efforts are needed to maintain sustainable system for coastal lakes in face of continuously altering conditions. The main goal of this research study is to investigate vulnerability of coastal lake systems in facing climate changes, with reference to the water quality status. As a key indicator of healthy ecological structure, acceptable quality condition would ensure beneficial uses and, consequently, socioeconomic well-being in served watershed. With the existing challenges of development processes, this research considers the hypothesis of regarding the climate change phenomenon as potentially having positive impact in improving certain water quality problems. Through a case study application in Lake Burullus, located in the northern coast of Egypt; this research study addresses one of the main water quality problems defined, which is the declining salinity level, and entailed deteriorating aquatic ecosystem and fish population. Projection for changes in salinity concentrations is based on changes in inflow/outflow salinity budget with predicted change in climate. Results show that climate change will improve water salinity within the lake under consideration by year 2150. However, meeting target levels would still require supplementary measures. Finally, this research proposes management plan with applicable adaptation measures for Lake Burullus. This research also sets basis for future research continuation while considering factors from coastal side and served watershed side, simultaneously. This research sheds some light, through Lake Burullus case study, on management measures for coastal lakes to be considered by decision makers.

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Progressive anthropogenic intrusion and increasing water demand necessitate frequent water quality monitoring for sustainability management. Unlike laborious, time consuming field-based measurements, remote sensing-based water quality retrieval proved promising to overcome difficulties with temporal and spatial coverage. However, remotely estimated water quality parameters are mostly related to visibility characteristic and optically active property of water. This study presents results of an investigated approach to derive oxygen-related water quality parameter, namely Dissolved Oxygen (DO), in a shallow inland water body from satellite imagery. The approach deduces DO levels based on interrelated optical properties that dictate oxygen consumption and release in waters. Comparative analysis of multiple regression algorithms was carried out, using various combinations of parameters; namely, Turbidity, Total Suspended Solids (TSS), Chlorophyll-a, and Temperature. To cover the wide range of conditions that is experienced by Edku coastal lake, ground truth measurements covering the four seasons were used with corresponding satellite imageries. While results show successful statistically significant correlation in certain combinations considered, yet optimal results were concluded with Turbidity and natural logarithm of temperature. The algorithm model was developed with summer and fall data (R2 0.79), then validated with winter and spring data (R2 0.67). Retrieved DO concentrations highlighted the variability in pollution degree and zonation nature within that coastal lake, as related to boundary interactions and irregularity in flow dynamics within. The approach presented in this study encourages expanded applications with space-based earth observation products for exploring non-detectable water quality parameters that are interlinked with optically active properties in water.

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