DOWN2EARTH functions on the premise that current modeling frameworks for assessing the impacts of climate on water storage at or near the land surface (and associated crop growth) are inadequate for dryland environments. Drylands pose many modeling challenges including the spatial and temporal variability in rainfall (1), very high potential evapotranspiration relative to input rainfall (2), high transmission losses below ephemeral stream channels (3) leading to focused recharge to groundwater aquifers (4), and low but significant rates of diffuse recharge.
Additionally, there are challenges of water scarcity and food insecurity within rural (agro-pastoralist) communities in the HAD region that are driven by spatiotemporal variability in seasonal rainfall. Currently, most analysis and forecasting of water scarcity and food insecurity is based only on rainfall downscaled from climate models, which is subsequently analyzed in various impact contexts.
The DOWN2EARTH Model Development Team will be working to create a simpler set of models that support decision making at multiple levels in society. In this project, we will:
1) develop a regional, dryland-relevant hydrological model designed for multiple simulations and simplifed output describing water storage as a function of climate
2) an agent-based model designed to investigate emergent behaviors between climate and human society, in response to climatic and policy forcing
3) Analysis of seasonal climate forecasts in terms of hydrological fluxes and storage
4) Exploration of future climate projections and their impact on water and livelihoods