Code optimization for two-dimensional distributed soil loss modeling

Central Iowa-based small business, Agren, in collaboration with the ARS Sedimentation Laboratory and the University of Tennessee, has developed two GIS-based soil loss modeling tools. Each tool combines remotely-sensed, high-resolution digital elevation models (LiDAR) and newly developed hydrologic algorithms with long standing soil-loss modeling principles. The results to date are two-dimensional, distributed (grid-based) soil loss models for sheet and rill erosion and ephemeral gully erosion. However, with flow networks that may approach one-million cells on one to three-meter raster spacing, runtimes for a single rasterized field take several hours. The models are not practical to deploy at a large scale for localized conservation planning.The proposed Phase I work plan will determine the technical feasibility of optimizing the SoilLossCalculator code set to meet user requirements in a web-based system. In order to be commercially viable, the model needs to process an entire field and return a result to the user in under one-minute, requiring the execution time to be reduced by about 400 times. Research questions that will be explored include:Where within the model infrastructure are opportunities for significant speed increases?What alterations to the code set can be proposed as possible options for further optimization?What approximate decrease in execution time may be realized by each proposed change?What are the estimated time and resource requirements for each proposed code modification?The proposed project expands the research and development of models for distributed erosion modeling, which are substantial scientific improvements over existing soil loss modeling tools. Moreover, if successful, these efforts will make the concepts of precision conservation a practical reality for land managers. Conservation practitioners will be able to quickly and easily target appropriate management practices to landscape positions that contribute the most significant sediment loads and evaluate which practice alternatives provide the most environmental benefit.If optimization efforts prove successful, Agren intends to incorporate both the SoilLossCalculator and ephemeral gully calculator models into their commercially-available suite of conservation planning tools. Agren provides access to the conservation planning tools through a web-based, Software as a Service model. Subscribers pick and choose from a suite of conservation practice planning tools to create a package that best suits their local needs. Agren & #39;s target markets include both public sector conservation planning agencies and private sector audiences such as engineering firms, land improvement contractors, and agricultural retailers.