ALBERT

Description: Information on aquifer thickness is one of the crucial inputs to numerical groundwater flow models, especially in the coastal areas that are threatened by increasing salt water intrusion leading to declining fresh groundwater resources. Since aquifer thickness data is missing in many parts of the world we designed a methodology to estimate it on global scale using state of the art datasets. We estimated the aquifer thickness by combining global topographical (Weatherhall et al., 2015, doi:10.1002/2015EA000107), lithological (Hartmann et. al, 2012, doi:10.1029/2012GC004370), soil thickness (Pelletier et al., 2016, doi:10.1002/2015MS000526) and sediment thickness from the global PCR-GLOBWB model (de Graaf et. al, 2015, doi:10.5194/hess-19-823-2015) to find the position and slope of the bedrock formation that are overlaid by unconsolidated sediments forming the aquifer system. The dataset includes the estimates of aquifer thickness at the coastline for each cross-section together with corresponding "anchor points" (last point with known thickness from Pelletier et. al, 2016). With this information it is possible to create 2D cross-sectional groundwater flow coupled with salt transport models to estimate the fresh groundwater resources in coastal areas. More attention should be paid to the composition of unconsolidated sediment aquifers in terms of low permeable layers that can play a large role in the distribution of fresh and saline groundwater.