The Impact of Climate Change/Variability on the Southern Zone of the Sudanese Red Sea Coast with Emphasis on Key Habitats

Abstract

This research was carried out in a study area that extends from Suakin to the south along the coastal region just north of the Eritrean border in a shape of a buffer which extends up to 2 Km inside the Red Sea and 20 Km inland which was extended to include Toker Delta. The study objectives were to assess the impacts of climate change/variability on the Southern Zone of the Sudanese Red Sea coast through the assessment of the impact of climate change/variability on key habitats (coral reef, sea- grass, mangrove and salt marches), on land cover, on fisheries, chlorophyll-a and Nutrients distributions concentrations, on current and future impacts of climate change on ecotourism and the sea level rise on the study area and its impacts on potable water reservoirs in Toker Delta. The primary data used for this study included metreological data (1984-2013), oceanographic data (1984-2013), ground water wells data for Toker Delta and sets of satellite data from different sources (Landsat imageries, Chlorophyll-a data, Shuttle Radar Topography Mission data and Google Earth high resolution data) the secondary data included samples from ground water wells for Toker Delta dated 2004 which was chemically analyzed. Several methods to assess the trend of climate variability were followed. The statistical analysis for the rainfall, temperature, relative humidity monthly means anomalies, frequency and speed of the wind was performed and land cover change detection methods using remote sensing and GIS techniques for the key habitats and inundation model, using projected sea level rises of 0.4 meters and 0.82 meter by 2030 and 2100 respectively were adopted. Inverse Distance Weighting (IDW) interpolation tool was used to illustrate seawater intrusion using chemical indictors. The results of this research (based on metrological data) revealed that there was climate variability that has relationship with chlorophyll-a concentration and the nutrient distribution varies over a wide range of time and space scales. Total land cover changes trend in the study area (1972-2013) manifests the increase of the area occupied by coral reef (1.6%), Salt Marshes (2.1%) Sand beaches (4.41%) Sea-grass (2.8%), Trees Open with Sparse Shrubs (1.9%) built-up land increased (urban expansion) by (7.5%) and mangrove (-1.06%) decreased and Sand unconsolidated materials (-39.4%) of the total class. The findings of the study anticipated that climate change will aggravate the inundation in the mediumterm (2030) and long-term (2100) periods and the expected inundation (caused by the sea level rise) by 2030 showed that sand and unconsolidated materials, inundation will beV equivalent to (1%), coral reefs (2.2%), mangroves (0.88%), salt marches (0.89%) and sea grasses(0.6%), and even the Urban Area will be affected (0.5%). The inundation by 2100 showed that sand and unconsolidated materials inundation would be equivalent to (6.35%), as well as important marine habitat such as coral reefs (4.03%), mangroves (9.9%), salt marches (8.1%) and sea grasses (11.9%). Urban Area is expected to be affected by (56.8%) and sand beaches (10.4%) which are important as sea habitat and their loss adversely affects eco-tourism. The research concluded that the global climate change\ variability adversely affects the ability of coastal ecosystems to cope with its stresses: such as increasing maximum temperatures, more variable rainfall, variable wind direction and speed and rising sea levels all - on different timescales and adversely affect the coastal key habitat (sea-grass, mangrove, coral reef, fisheries and salt marches) that plays a crucial role in the region's marine ecosystems. The research recommends taking a set of measures for proper management for key habitat with emphasis on the expected effects of climate change, and great emphasis on improving the sources of ground data related to metrology, ground water and oceanographic data.