oa Hydrodynamic Modelling of the Northeastern Qatar Coast for Assessment of Sensitive Ecosystems under Anthropogenic and Natural Stressors

The Northeastern Qatari coast is comprised of diverse and sensitive flora and fauna such as seagrass meadows, turtles, algae, and coral reefs/patches that tolerate harsh environmental conditions. In the near future, this area may see a rise in anthropogenic activity in the form of coastal development projects, which will add to the existing natural stresses, such as high temperature, high salinity and low rates of precipitation. Therefore, there is a need to characterize the area and assess the potential impacts that these anthropogenic activities may have on the region. Eco-hydrological models are theoretical, mathematical representations of natural systems, made to help understand their functionalities under physical forcing. Site-specific data, hydrodynamic models, and ecological and physical phenomena are combined to build a functional ecosystem model that mimics real environments. These models can then be used to predict the impacts of anthropogenic and natural stressors on real systems. There are two main types of Eco-hydrological models: analytic and computational. Analytic models are usually less complex since they have an analytical solutions, and are used to represent simple or abstract systems with well-known behaviors. Alternatively, computational models are considered to be more ecologically sensible, as they can be used to solve complex systems that require the use of numerical techniques. The results of the computational model can vary between different numerical techniques or modeling software, resulting in uncertainty and variability that should be estimated. Given the complex nature of the environmental system in the Northeastern Qatari coast, numerical solutions using modeling software are developed to establish an adequate representation. There are three main modeling programs that have been used for the development of Ecological Response Models in Qatar (SWAN, GEMSS, and TELEMAC-2D). GEMSS provides a set of hydrodynamic, transportation and water quality modules allowing for the development of an integrated Eco-hydrological model according to the needs of each modeling application, which makes it the most appropriate software to use in this study. The aim of this study is to develop hydrodynamic and sediment transport models for a stretch of the Jabal Fuwairat Coastline in Qatar, using GEMSS and bathymetric LIDAR data processed with ArcGIS. The hydrodynamic model (HDM), which will be calibrated and tested using field data, simulates the spatial and temporal dynamics of the water, while the sediment transport model (STM) identifies, under present or simulated scenarios, the fate of the suspended sediments in the studied coastal zone. The STM provides data about sediment typologies, suspended particulate matter and currents that are near the seafloor (shear stress). The developed models will be tested using potential scenarios of future anthropogenic activities forecasted to take place in the area. The results will show the effects on water and sediment behavior, and provide a scientific basis for key stakeholders to make decisions with respect to the management of the considered coastal zone. It also provides a tool/framework that can be utilized in future hydrodynamic studies along other areas of the Qatari coastal zone. Furthermore, the outcomes are fundamental to developing a complete and accurate Eco-hydrological model. Keywords: Hydrodynamic Model, Sediment Transport Model, Anthropogenic stressors, coastal dynamics, GEMSS, ArcMap, LIDAR.