The text describes a study on the impacts of climate change on the carbon dioxide (CO2) sink capacity of the Wadi El-Rayan Lakes in Egypt. The lakes are two man-made lakes in the hyper-arid Western Desert, formed by diverting agricultural wastewater in 1973 and 1980. The study uses a hydrodynamic model to simulate the lakes’ water levels, temperature, and salinity under different climate scenarios (RCP 2.6 and 8.5) from 2020 to 2050. The model is validated using data from 2014.
The study estimates the potential changes in the lakes’ CO2 sink capacity by simulating the solubility of CO2 in water at different temperatures and salinities. The results show that the lakes’ CO2 sink capacity will decrease under both scenarios, with the largest decrease expected in the Upper Lake. The study also examines the impact of climate change on the lakes’ water column capacity and total capacity to dissolve CO2 from the atmosphere.
The study uses four assumptions to simplify the estimation of CO2 sink capacity: 1) the waterbody is divided into water columns, 2) temperature and salinity distribution is homogenous along the water column, 3) CO2 solubility is a function of surface cell values, and 4) the CO2 sink capacity is a function of the solubility and water volume.
The study uses ArcGIS and OriginLab software for spatial data processing and statistical analysis. The results show that the changes in the lakes’ CO2 sink capacity will depend on the season, location, and time. The Upper Lake has a higher CO2 sink capacity than the Lower Lake, and the largest decrease in sink capacity is expected in the Lower Lake under RCP 8.5.
Overall, the study provides an estimate of the impacts of climate change on the CO2 sink capacity of the Wadi El-Rayan Lakes, which can be used to inform management and conservation efforts to mitigate the effects of climate change on these lakes.