NASA releases new global maps mapping groundwater, soil wetness

New satellite-based, weekly global maps of soil moisture and groundwater wetness conditions were developed by US space agency National Aeronautics and Space Administration (NASA) and the University of Nebraska-Lincoln (UNL) on March 31, 2020.

Groundwater and soil moisture — which depicts wetness in soil — are crucial for irrigation and crop growth.

The need to constantly monitor groundwater and soil moisture is important since both act as useful indicators for predicting drought conditions.

Data, however, on ground-based observations is limited.

The need for global maps was important as there was limited availability of drought maps, according to hydrologist and project lead Matt Rodell of NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

“This will help to deal with the global crisis beforehand,” he added.

One of the goals of the new global maps is to make the same consistent product available in all parts of the world, especially in countries that do not have any groundwater-monitoring infrastructure.

The maps are distributed online by the National Drought Mitigation Center at UNL to support global drought monitoring.

“The weekly availability of soil moisture and groundwater data help built complete picture of drought,” said professor Brian Wardlow, director for the Center for Advanced Land Management Information Technologies at UNL.

The weekly availability of data on these indicators would also help the agricultural sector in getting a boost.

The data would help in managing the selection of appropriate agricultural crops and predicting yields.

Data available from NASA and German Research Center for Geosciences’ Gravity Recovery and Climate Experiment Follow On (GRACE-FO) satellites was used to derive these global maps.

The satellite-based observations of changes in water distribution were integrated with other data within a computer model that simulated water and energy cycles.

The model then produced — among other outputs — time-varying maps of the distribution of water at three depths: Surface soil moisture, root zone soil moisture (roughly the top three feet of soil) and shallow groundwater.

The maps have a resolution of up to 8.5 miles, providing continuous data on moisture and groundwater conditions across the landscape.

The development and support of drought monitoring using Gravity Recovery and Climate Experiment Follow-On global maps and other tools in west Asia, north Africa, south Asia and India was being done by the UNL.

The scientific community believes data available through this project would fill existing gaps in understanding the full picture of wet and dry conditions that can lead to drought.

The global maps are freely available to users through the drought centre’s data portal.

These tools are absolutely critical to helping us address and offset some of the impacts anticipated, whether it is from population growth, climate change or just increased water consumption in general.