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United States Department of Agriculture

Agricultural Research Service

South Fork Experimental Watershed
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The South Fork Watershed of the Iowa River is the United States site for the Joint Experiment for Crop Assessment and Monitoring (JECAM). The goal of JECAM is to develop international standards and a "global system of systems" for agricultural research by sharing data, methods, and results from different cropping systems throughout the world. Read more at

The South Fork Watershed is situated in a four-county area in Iowa which is dominated by a corn-soybean crop rotation. Ongoing scientific investigations include measuring the impact of conservation practices on water quality, modeling the watershed using the Soil Water Assessment Tool (SWAT), collecting calibration/validation data for large-scale surface soil moisture remote sensing products, and evaluating water/energy/CO2 land surface flux models.

The South Fork experimental watershed participated in the IFloodS experiment which studied precipitation estimation using high resolution radar. This was a preparatory experiment for the Global Precipitation Measurement (GPM) mission. The network also provides validation data for the Soil Moisture Active Passive (SMAP) mission which launched on January 31, 2015.

Explore maps and data for the South Fork Watershed by accessing the Interactive Data Interface:

  • The Hydrology map shows the locations of 20 soil moisture monitoring stations, overlaying 86 watershed subbasins with localized precipitation estimates.
  • The Crops map contains 13 years of land cover classification data and a slider to switch between them.

Interactive Data Interface

Last Modified: 11/22/2016
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