Abstract
This paper aims to study the environmental impact of the human inference on the coastal zone of Sarum area, Red Sea coast, Saudi Arabia. In the past, the study area was occupied by coastal lagoons that were connected with the sea with several inlets. Change detection technique based on multi-date satellite images in the last 44 years indicated the occurrence of environmental changes accompanied the construction of the main asphaltic road of the Red Sea that separated some coastal lagoons at the studied area from the Red Sea. Field investigation and litho-and bio-facies distribution indicated the existence of six lateral facies types: gypsum, microbial mats, halite, Quaternary coral reef terrace, bioclasts, and siliciclastic sand sheets. The lateral distribution of these facies is related to the following changes: (1) disconnection between the coastal lagoons and the sea, (2) extensive contraction of the coastal lagoons and formation of saline ponds, (3) exposure of the submerged Quaternary coral reef terrace, (4) increasing of the salinity of the ponds up to 270%, and (5) deposition of the evaporitic facies types (gypsum and halite) over intertidal and subtidal marine carbonates. Based on the above-mentioned criteria, the human activity leads to environmental changes in the Sarum area from coastal lagoons dominated with carbonate deposits into hypersaline ponds dominated with evaporitic deposits.