2013 Annual Report
1a.Objectives (from AD-416):
1. Define end-user requirements for the GIS-based RUSLE2 interface and establish evaluation criteria for the final product.
2. Establish clear objectives and guidelines for use and development of the tool based on input from key agency partners.
3. Identify and evaluate existing methodologies for using high-resolution DEMs to calculate slope length and steepness, as well as determine the most appropriate aggregation of soil loss calculations across a field landscape.
4. Develop a working prototype of a GIS-based RUSLE2 template.
5. Optimize the current RUSLE2 application to handle multiple calculations.
6. Provide demonstrations for GIS-based RUSLE2 template to SWCDs statewide.
7. Provide training and support for statewide use of the GIS-based RUSLE2 template.
1b.Approach (from AD-416):
Develop a summary report of end-user requirements and agency objectives based on stakeholder meetings and interviews. Prepare a list of final evaluation criteria for the GIS-based RUSLE2 template. Prepare a report on most appropriate methodology for using DEMs to interact with RUSLE2 and most appropriate application of RUSLE2 soil loss calculation across a field landscape. Document functional requirements for a GIS-based tool for statewide application. Evaluate slope length and steepness algorithms for applying LiDAR-derived DEMs to RUSLE2 model. Prepare a beta version of GIS-based RUSLE2 for stakeholder evaluation and obtain feedback on the proposed tool. Proivde trainings for beta users on operation of GIS-based RUSLE2 template and and develop a written survey tool for stakeholder evaluation as a precursor to a summary report of stakeholder evaluation results. Prepare an enhanced GIS-based RUSLE2 template based on end-user experiences and requirements.
High-resolution Digital Evaluation Models (DEMs) were used to calculate slope length and steepness and link these to the most appropriate aggregation of soil loss calculations across a field landscape. Linkage of the DEMs with the Geographic Information System (GIS)-base forms the foundation for the optimization of the Revised Universal Soil Loss Equation, Version 2 (RUSLE2) model to estimate erosion at the landscape scale. This has led to the development of a soil loss calculator applicable to the landscape scale and has been evaluated by district level soil and water personnel. This system will be available to the state personnel for use in estimating soil loss from different landscapes and management practices using the high-resolution digital elevation maps for Iowa.