Equipping conservation practitioners with quantitative estimations of sediment and P reduction from BMPs

Date: 
Jul 2023

Issue

Water bodies worldwide are facing increasing pollution from sediment and phosphorus (P), threatening aquatic ecosystems and water quality. This environmental issue poses significant challenges to sustainable water resource management and necessitates effective solutions to mitigate its impacts. Numerous water quality models, tools, and estimators are available for predicting P loss from agricultural fields and watersheds. Many of these approaches can be challenging and complex to use, requiring specialized knowledge and expertise for proper implementation. This can be a challenge for conservation planners, who could benefit from applying these approaches to prioritize best management practices to address sediment and P in agricultural landscapes.

The Daily Erosion Project (DEP) and the Agricultural Conservation Planning Framework (ACPF) are two tools that simplify the complexities of required inputs and outputs in soil erosion and conservation planning. Tailored for the Midwest region of the U.S. and harnessing the power of a process model, the DEP offers a user-friendly approach for daily soil erosion estimation. ACPF uses geographic information systems and geospatial data to identify critical sources areas to target conservation practices and locates opportunities for their placement.

Objective

To address the duality of these two approaches and to provide stakeholders with needed quantitative information and certainty, researchers plan to harness the quantitative and computational prowess of DEP and the accessibility and planning strength of ACPF into a singular, integrated tool for conservation practitioners. The primary goal of this research is to develop an easy-to-use tool that would utilize quantitative sediment and P loss outputs from DEP in ACPF to: (i) simulate, identify and prioritize areas of high erosion and P transport potential; (ii) characterize potential BMP placement; and (iii) quantify potential sediment and phosphorus reduction and costs at different scales, from field to the small catchment level.

Approach

The project will employ a multi-faceted approach to achieve its objectives:

  • Assess the various approaches and tools that can be used in Watershed Erosion Prediction Project (WEPP) for simulating sediment and P transport for adaptation into the tool.
  • Develop an independent, downscaled DEP model to simulate sediment and P loss potential of fields or small catchments using high-resolution field data.
  • Incorporate the downscaled DEP sediment and P model into the ACPF Financial and Nutrient Reduction Tool (ACPF FiNRT) framework to produce sediment and P reductions and costs for BMP scenarios for fields and small catchments.

Project Updates

Note: Project reports published on the INRC website are often revised from researchers' original reports to increase consistency.

January 2024

Over the past six months, our team has been diligently working on the two primary objectives of our grant. Under Objective 1, we analyzed various WEPP tools and spreadsheet load estimators for estimating sediment and phosphorus transport. This phase also included selecting experimental fields and small watersheds with existing nutrient data, vital for testing our modeling approaches. In achieving Objective 2, we developed the first version of the "OFEtool", a GIS tool that downscales Daily Erosion Project (DEP) hillslope soil loss estimations from the HUC12 watershed level to a detailed field and pixel level (3x3 m). This tool is key in estimating sediment with greater resolution for our project's next stages. We've tested OFEtool in multiple HUC12 watersheds in Iowa and randomly chosen one for publication. Currently, we're also working on drafting a manuscript about OFEtool for the 'Earth Surface Processes and Landforms' journal, focusing on the special issue “Advances in Soil Erosion and Soil Conservation”.

Other Activities

2 Presentations

Presentation to the Iowa Nutrient Reduction Science Team (08/02/2023) titled "A GIS-based WEPP modeling approach to locate and quantify vulnerable fields prone to hillslope soil loss" Presentation at the ISU GIS day (11/15/2023) titled "Integrating Daily Erosion Project outputs into the ACPF Toolbox: A strategy to locate vulnerable fields and prioritize BMPs in agricultural landscapes"

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