Global Water Availability Assessment Model (GWAVA)
GWAVA predicts the impacts of humans on future water availability, water quality and damage to river ecosystems. It operates at monthly or daily timescale and from large basins to global geographic scales. GWAVA has been applied to global, continental and basin scales across Europe, Africa and Asia for more than 20 years by scientists and water practitioners to: (1) predict water resource availability and water quality; (2) assess the impacts of climate and socio-economic changes; and (3) understand anthropogenic influences and their effects.
GWAVA is a hydrology model used to study changing water resource availability, quality and other impacts driven by human influences. It uses Fortran code that can be run on multiple operating systems from individual PCs to high-performace computers. A GWAVA-GUI version of the model provides a basic GWAVA model with a graphical user interface (GUI). GWAVA combines locally sourced data with global datasets. A sequence of processes represents interactions between environmental and human water systems, including: (i) surface water and subsurface flow representation; (ii) natural features (eg. lakes, wetlands and glaciers), as well as human interventions such as reservoirs and long-distance transfers; (iii) water demands from household supply, irrigation, livestock and industry; (iv) water quality assessment; and (v) environmental flows assessment. GWAVA can be run at spatial scales from basins (5 arc minutes) to global (30 arc minutes) and temporal scales from daily to monthly. It has an autocalibration routine for streamflow with a choice of efficiency metrics.
Version 1.0 of the GWAVA model was developed by UKCEH in the late 1990's. The model is regularly updated and new versions released when significant changes occur. The GWAVA-GUI version was released in February 2021.
GWAVA has broadly similar capabilities to other models such as WaterGap or VIC, but brings a combination of advantages including: (1) it is a large scale water resources model with particular emphasis on anthropogenic influences; (2) it has the unique option to include small scale interventions; (3) it has unique applicability to data scarce regions: data requirements are kept to a minimum and are mostly available from publicly available datasets.
GWAVA was developed by UKCEH with research partners who ensured that specific processes are suitably represented in the model: British Geological Survey (groundwater processes); Indian Institute of Science and National Institute of Hydrology India (small scale intervention in India); Leeds University (cropping model); Finnish Environment Institute SYKE (diffuse pollution); Institute of Water and Flood Management and Centre for Environmental and Geographic Information Services in Bangladesh (snowmelt and glacial melt); Warsaw University (e-Flows); plus others.
GWAVA-GUI is open access: available to use at no cost for non-commerical users by request to the model owner.
Development of GWAVA was funded by: UKRI-NERC National Capability (including LTS-ODA); EU Horizon 2020; UKRI-NERC research project grants.
GWAVA is used by UKCEH, UK and international researchers, including PhD students. It is also used to train water practioners in India.