Decision Support Tools to Communicate Hydrologic Anomalies and Impacts

Abstract:

Anomalous hydrologic events, from flooding at the individual stream level to large-scale drought, need to be taken into account in decision-making for both civil works and military contexts. Floods can affect mobility operations, humanitarian assistance and disaster response, and power generation. Droughts can impact food security and fresh water availability, which when coupled with social, political, and economic stressors can affect national security interests. To address the need for predictive information tools around hydrologic anomalies, two decision support platforms have been developed at the US Army Corps of Engineers Engineer Research and Development Center (USACE ERDC). The Water Security Indicator Tool platform presents results of the Water Security Indicator Model (WSIM), which was developed by ISciences, LLC. WSIM provides a gridded global forecast of relative water surpluses and deficits, scaled to the “normal” seasonal blue water availability of each given grid cell. The ERDC-developed portal adds social vulnerability and population density data layers to gauge impact, and aggregates cells into geographic regions to provide at-a-glance estimations of regional anomalies. Forecasts in WSIM are monthly with up to nine months lead time.

The Streamflow Prediction Tool (SPT) provides up to two-week forecasts of stream flows worldwide. Flows are computed using the Routing Application for Parallel Computation of Discharge (RAPID) hydrologic model, and can be configured to use atmospheric input parameters from various sources. Results are displayed in a geospatial portal with return period “warning flags” used to distinguish stream reach with predicted flooding. This provides finer scale, both spatially and temporally, information than is computed by WSIM. Together, the two portals enable decision-making around hydrologic anomalies for both short term logistical and tactical planning, and longer-term preparedness and strategy.