New paper: No evidence found of large scale groundwater depletion in major African aquifers

A new paper has been published by the GroFutures team as part of a Special Issue “Remote Sensing of Groundwater from River Basin to Global Scales”

Key Points : –

  • GRACE (Gravity Recovery and Climate Experiment) satellite can be used to estimate changes in water storage on time resolution of 1 month and a spatial resolution of about 450 x 450 km.
  • GRACE can be used to estimate groundwater storage changes where it is the dominant water mass. It is therefore useful in many areas of Sub-Saharan Africa where there are relatively few direct groundwater level measurements.
  • The paper focuses on the major sedimentary aquifers basins, where the majority of Africa’s groundwater resources are to be found. Away from these basins, groundwater storage is 1-2 orders of magnitude less.
  • There is no evidence of continuous long-term declining trends of Total Water Storage (mostly groundwater) in any of the major sedimentary aquifers, which indicates that none are stressed by current abstraction rateshowever it is important to stress that local scale depletion may be occurring but is beyond the resolution of GRACE to detect.

There are also some interesting findings in regard to the combination of GRACE and Land Surface Modelling and how well (or not) they represent groundwater recharge processes in the different basins.

Read the full paper here:

Bonsor, H.C.; Shamsudduha, M.; Marchant, B.P.; MacDonald, A.M.; Taylor, R.G. Seasonal and Decadal Groundwater Changes in African Sedimentary Aquifers Estimated Using GRACE Products and LSMs. Remote Sens. 201810, 904.

photo: Well for cattle, Songho, Mali, Credit: Emeline Hassenforder. Well for cattle and domestic use. , Songho, Mali.