Quantifying the role of urbanization on airflow perturbations and dunefield evolution

Abstract

Rapid urban development has been widespread in many arid regions of the world during the Anthropocene. Such development has the potential to affect, and be affected by, local and regional dunefield dynamics. While urban design often includes consideration of the wind regime, the potential impact of construction on the surrounding environment is seldom considered and remains poorly understood. In this study, regional airflow modeling during successive stages of urbanization at Maspalomas, Gran Canaria, Spain, indicates significant and progressive flow perturbations that have altered the adjacent dunefield. Significant modifications to the boundary layer velocity, mean wind directionality, turbulence intensity, and sediment flux potential are attributed to the extension of the evolving urban geometry into the internal boundary layer. Two distinct process/response zones were identified: (1) the urban shadow zone where widespread dune stabilization is attributed to the sheltering effect of the urban area on surface wind velocity; and (2) the acceleration zone where airflow is deflected away from the urbanized area, causing an increase in sediment transport potential and surface erosion. Consistent coherent turbulent structures were identified at landform and dunefield scales: counter-rotating vortices develop in the lee-side flow of dune crests and shedding off the buildings on the downwind edge of the urban area. This study illustrates the direct geomorphic impact of urbanization on aeolian dunefield dynamics, a relationship that has received little previous attention. The study provides a template for investigations of the potential impact of urbanization in arid zones.

Geomorphological changes in an arid transgressive coastal dune field due to natural processes and human impacts

“…For this reason, the dunes move from northeast to southwest. Aeolian dynamics have been altered due to tourism development (Hernández‐Calvento et al ., ; Smith et al ., ). The buildings built on the adjacent El Inglés high terrace, a sedimentary terrace that is above the dunefield, increased the wind speed notably, and values increased between 30 and 35% in the area close to the southern end of the terrace.…”

Morphometric analysis of slipface processes of an aeolian dune: Implications for grain‐flow dynamics

“…This dune field was chosen because of the arid climate, where the annual precipitation is <100 mm year À1 (Marzol, 1987), resulting in sparse vegetation, and regular aeolian activity, thus making it a suitable field site for dune morphodynamic studies. Observations were collected on 8 December 2014, during the winter season when the eastern and north-eastern winds are the strongest and have the most influence on dune migration (Hernandez et al, 2002;Jackson et al, 2013b;Hernandez et al, 2014;Smith et al, 2017b).…”

Effects of artificial light on flowering of foredune vegetation

“…This study demonstrates the existence of a new form of impact that produced by artificial lighting, which has not been considered in these aeolian systems previously. This new impact adds to the significant impacts on the functioning of the aeolian dynamics and vegetation produced directly by the construction of a holiday resort in this system (Hern andez-Calvento et al 2014, Smith et al 2017, Hern andez-Cordero et al 2018.…”

“…The Maspalomas dunefield.-The transgressive dunefield of Maspalomas, at 360.9 ha, is located in the south of the island of Gran Canaria (Canary Islands, Spain; Fig. 1 The climate is arid, with an average annual rainfall of 81 mm, but with large annual and interannual rainfall variability, and an average annual temperature of 21°C (Hern andez Calvento 2006, Smith et al 2017.…”

“…The climate is arid, with an average annual rainfall of 81 mm, but with large annual and interannual rainfall variability, and an average annual temperature of 21°C (Hernández Calvento , Smith et al. ).…”