A global dataset of average specific yield for soils.

Area of Science:

• Hydrology
• Soil Science
• Earth System Science

Background:

• Specific yield (Sy) is crucial for groundwater simulations but lacks reliable global datasets.
• Inaccurate Sy values are a major source of error in hydrological models.
• Existing Sy data is often localized or lacks textural information.

Purpose of the Study:

• To develop a comprehensive global dataset of gridded average specific yield (GASY) for various soil textures.
• To provide a reliable Sy dataset for improving groundwater modeling and resource assessment.
• To address the critical lack of global Sy data for Earth system models.

Main Methods:

• Utilized a trilinear graph approach relating Sy to soil textures.
• Integrated data from Global Soil Dataset for Earth System Models, SoilGrids, and Harmonized World Soil Database.
• Developed gridded average specific yield (GASY) values for diverse soil types.

Main Results:

• Validated the GASY dataset against laboratory and field-derived Sy values across scales.
• Demonstrated that GASY effectively represents average specific yield for different soil textures.
• Identified a depth limitation (~2m) due to soil texture data constraints.

Conclusions:

• The GASY dataset offers a reliable and globally applicable resource for groundwater studies.
• It enhances the accuracy of groundwater dynamics modeling and resource distribution understanding.
• The dataset aids in climate change impact assessments on water resources and supports future research into deeper soil profiles.