Satellite data plays a crucial role in hydrology by providing valuable information about various aspects of the Earth’s water cycle, including precipitation, surface water bodies, soil moisture, and even…groundwater!
Here are some ways in which Earth Observation data contributes to hydrology:
- Precipitation Monitoring: Satellite data, such as that from NASA’s Global Precipitation Measurement (GPM) mission, provides estimates of precipitation with unprecedented accuracy. GPM data covers over 90% of the Earth’s surface every three hours, contributing significantly to our understanding of global precipitation patterns and supporting weather forecasting models.
- Surface Water Monitoring: According to a study published in the Journal of Hydrology, satellite observations have shown a 10% increase in global inland water bodies’ surface area over the past three decades, indicating the importance of satellite data in monitoring changes in surface water resources worldwide.
- Soil Moisture Monitoring: The European Space Agency’s Soil Moisture and Ocean Salinity (SMOS) satellite mission has been instrumental in providing global soil moisture data since its launch in 2009. SMOS data has been used in various studies to monitor soil moisture variations, contributing to improved agricultural practices and water resource management.
- Groundwater Exploration: Research by the United States Geological Survey (USGS) has shown that satellite-based measurements of ground subsidence due to groundwater depletion have helped identify regions experiencing significant aquifer stress. For instance, in the Central Valley of California, satellite observations have revealed subsidence rates exceeding 20 inches per year in some areas.
- Snow Cover Monitoring: Satellite observations from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) have shown a decreasing trend in Northern Hemisphere snow cover extent over the past few decades, with significant implications for water resource management, particularly in regions dependent on snowmelt for freshwater supply.
- Evapotranspiration Estimation: According to a study published in Remote Sensing of Environment, satellite-based estimates of evapotranspiration have been found to closely match ground-based measurements, demonstrating the reliability of satellite data in quantifying water loss from terrestrial ecosystems.
- Water Quality Monitoring: The European Space Agency’s Sentinel-2 satellite mission, equipped with multispectral sensors, has been used to monitor water quality parameters in inland and coastal waters. Studies have shown that Sentinel-2 data can accurately detect changes in water quality, supporting efforts to monitor and manage aquatic ecosystems.
- Flood Mapping and Monitoring: Satellite data, including that from the Copernicus Emergency Management Service, has been instrumental in providing near real-time flood mapping and monitoring during extreme events. For instance, during the 2019 Midwest floods in the United States, satellite imagery helped emergency responders identify affected areas and assess the extent of flooding.
These examples extracted from BWI‘s day-to-day research and development highlight the significant contributions of satellite data to hydrology, supporting various aspects of water resource management, disaster preparedness, and environmental monitoring.
