Impact of port development on the northern Yucatan Peninsula coastline

Abstract

Development of port infrastructure for small-scale fisheries started in the late 1960s and increased in the 1980s along the northern Yucatan Peninsula. These ports mainly consist of a pair of jetties that significantly interrupt littoral transport. Hence, they are responsible for coastal erosion in this region, which has been exacerbated by urbanization in coastal areas. Here, satellite imagery, Unmanned Aerial Vehicle flights, and high-resolution GPS beach surveys were employed to investigate seasonal to multi-annual impacts of ports on the coastline. Shoreline positions prior to the construction of the ports are compared with the current location using satellite imagery for 7 ports along the Yucatan coast. Accretion (erosion) rates averaged 8 m yr −1 and affected approximately 1.5 (2.5 km) updrift (downdrift), respectively. To investigate seasonal variability, a beach monitoring program was conducted along one of the ports (Sisal) between May 2019–April 2020. Field observations show that seasonal variations of wave conditions, associated with sea breeze and winter storms (anticyclonic cold fronts known as Nortes), modulate beach response. Analysis of beach transects show yearly net accretion (erosion) in subaerial and intertidal beach volume updrift (downdrift) of the port in the order of 76.0 (−60.4) m3/m. Moreover, during the period of study four Reef Ball™ breakwaters were deployed on the downdrift side and a beach nourishment of approximately 860 m3 took place to mitigate beach erosion. Field observations suggest that the annual erosion rate decreased from −60.4 m3/m to an accretion of 3.5 and 4.4 m3/m in the two transects located immediately behind the structures installed in May 2019. The current results highlight the need for sand bypassing at ports as a way of mitigating beach erosion in their vicinity. Previous studies conducted at other locations experiencing the same problem suggest that the re-design of the port’s layout might reduce downdrift effects and dredging costs.