P. Pourteimouri1*, G.H.P Campmans1, D.W. Poppema1 , K.W. Wijnberg1 , S.J.M.H Hulscher1
1 University of Twente, Water Engineering and Management
Coastal urbanization is rapidly developing in many countries around the world. Rapid urbanization in coastal zones has the potential to affect the local airflow patterns. The impact of airflow variations on coastal dunes are still not fully known. In meteorology, the atmospheric boundary layer (ABL) can be defined as the lowest portion of the atmosphere that is directly influenced by the presence of the Earth’s surface. The airflow characteristics in the ABL are strongly dependent on the underlying roughness elements such as buildings, structures, trees and vegetation. Therefore, the resulting airflow perturbations due to urbanization impact the surrounding environment and the adjacent aeolian dunefield. There have been relatively few studies addressing the geomorphological impact of urbanization on aeolian dune dynamics. Hernández-Calvento et al. (2014) implemented an urban airflow model into a geomorphological context and investigated the human-induced changes in aeolian landforms using aerial photographs and LiDAR surveying. Smith et al. (2017) numerically illustrated the direct impact of successive stages of urbanization on aeolian dunefield dynamics. To the best of the authors’ knowledge, this study is the first of its kind investigating the effect of different construction patterns on dunefield behaviour. The main objective of this project is to understand the effect of the buildings and their configuration, including geometry, orientation, spacing as well as their distance to the dunefield on aeolian sediment transport.
In recent years, the application of computational fluid dynamics (CFD) to study a wide variety of processes in the atmospheric boundary layer (ABL) has progressively increased. In this project, an opensource CFD modeling software, OpenFOAM, in combination with a sediment transport model will be deployed for the simulation of the airflow over urbanized environment and to investigate the morphodynamics of the aeolian dune systems. First, the model will be validated with the field measurements from Poppema et al (2019) who experimentally studies the impact of built environment on the morphological development of the beach-dune system in the Sand Engine along the coast of South Holland (Figure 1). Then, the model will be utilized to investigate the effect of different building patterns along the coast on the aeolian sediment transport and the dunes migration.
Figure 1 Study site (Sand Engine).
Hernández-Calvento, L., Jackson, D. W. T., Medina, R., Hernández-Cordero, A. I., Cruz, N., & Requejo, S. (2014). Downwind effects on an arid dunefield from an evolving urbanised area. Aeolian research, 15, 301-309.
Poppema, D.W., Wijnberg, K.M., Mulder, J.P.M. & Hulscher, S.J.M.H (2019). Scale experiments on Aeolian deposition patterns around buildings on the beach. Abstract for NCK days 2019.
Smith, A. B., Jackson, D. W., Cooper, J. A. G., & Hernández‐Calvento, L. (2017). Quantifying the role of urbanization on airflow perturbations and dunefield evolution. Earth's Future, 5(5), 520-539