Hydrological Forecasting for Early Warning
It is a well-established fact that early warning for food insecurity risks allows for early mitigation and disaster preparedness efforts to take place ahead of a food crisis. Drought is one factor that can lead to reduced food crop production and thereby put fragile food systems at risk, particularly in some areas throughout southern Africa that are already vulnerable to food insecurity due to the high frequency of these devastating droughts. NASA Harvest partners from various academic and government institutions recently published research on the use of hydrological monitoring and forecasting products as tools for drought prediction and by extension, early warning tools for susceptible regions in southern Africa. The resulting paper, “Improving early warning of drought-driven food insecurity in southern Africa using operational hydrological monitoring and forecasting products,” was published in the journal Natural Hazards and Earth System Sciences and included contributions from experts at: the University of California, Santa Barbara, Climate Hazards Center (UCSB CHC), the Science Applications International Corporation (SAIC), NASA Goddard Space Flight Center (NASA GSFC), the University of Maryland Earth System Science Interdisciplinary Center (UMD-ESSIC), the Famine Early Warning Systems Network (FEWS NET), the U.S. Geological Survey, Earth Resources Observation and Science Center (USGS), the Department of Earth and Planetary Sciences at John Hopkins University (EPS-JHU), the U.S. Agency for International Development (USAID), the Southern Africa Development Community Climate Services Center (SADC), and the University of Maryland Department of Geographical Sciences (UMD-GEOG).
Percentage of income share held by the lowest 10 % and 20 % income population in the southern Africa countries (data source: the World Bank's World Development Indicators).
With such a large group of knowledgeable scientists collaborating on this work, there is no shortage of expertise when it comes to applying the most relevant data to inform food security efforts. They explain that early warning before the harvest season (beginning in April) and before the lean season (beginning in November) is absolutely vital to food insecurity mitigation activities should a potential drought be of concern. Hydrologic monitoring and forecasting can provide consistent updates on critical variables that contribute to crop yields, such as root-zone soil moisture which is essentially an estimate of the water that is available to plants. Forecasting the root-zone soil moisture is done by combining estimates of the degree of wetness of the soil at the time of forecast release and with climate forecasts for the next several months in future.
This study used NHyFAS implementation to monitor root-zone soil moisture and forecasting products.
In this study, the team looked at the performance of root zone soil moisture products based on NASA’s Hydrological Forecasting and Analysis System (NHyFAS) for identifying droughts and forecasting crop yield in southern Africa. Results of this research showed that the NHyFAS products can “effectively support food insecurity early warning” for the southern Africa regions explored in the study. The results also show that the NHyFAS products could have predicted severe drought, such as in 2015-16, as early as a month ahead of drought occurrences and can skillfully forecast crop yield up to an year before the typical start of the lean season in the region. Additionally, because frameworks similar to NHyFAS could be used to provide root-zone soil moisture monitoring and forecasting products over any number of regions across the globe, this case study also demonstrated that food insecurity early warning could be supported globally by its implementation in other regions.
Read the full publication in National Hazards and Earth System Sciences to learn more.