Identification of global hotspots for salinity vulnerability

Abstract

Global food security is challenged by lack of fresh water availability and increasing salinity. Water and soil salinity have increased during the last few decades and are projected to increase in the future which will adversely effect the food security. Effect of climate change will exacerbate the situation. Previous researches have predominantly focused on the impact of either soil or water salinity on agriculture and food security. An assessment of combined impact of soil and water salinity at global scale is required. We have considered global datasets on soil and water salinity to locate areas with higher impact of salinity and combined indicators on climate, water availability, source of irrigation, cropping pattern, soil characteristics and level of salinity to identify regions with higher vulnerability to salinization. The impact of salinity on crop (wheat, rice and maize) yield was considered to produce a primary estimate of potential loss of food production. Combining soil and water salinity data indicate that currently the southeast and southwest coast of USA, southern part of Africa, southeast regions of Australia and coastal regions of Bangladesh are mostly impacted by salinity.  The MENA region, sub-saharan regions, large parts of Australia, southern Europe, southwestern coast of USA, eastern China, as well as the coast of Vietnam, GCC states, the eastern part of Indonesia, northern parts of India, coastal regions of Bangladesh and southeastern regions of Africa are identified as vulnerable regions for increasing salinity. The potential crop yield loss due to salinity is highest for Maize and lowest for Wheat.  Global cropping pattern shows that rice and maize are being cultivated more in salinity vulnerable areas than wheat, even though wheat is the most saline tolerant of the three. Identification of saline hotspot areas and regions vulnerable to increasing salinity will assist in development location specific of policies, regulation and adaptation strategies to counter the adverse impact of salinity in the future. More in depth analysis on Ganges-Brahmaputra-Meghna (GBM), Mekong and Nile delta will be carried out for regional verification of salinity hotspot and vulnerable location identification.