This webinar explores the ways USAID and NASA are working with partners to use water data for improved climate resilience. NASA Science Coordination Office Water Security Lead Chinmay Deval moderates a panel discussion with water experts from across the SERVIR global network.
The growing size and frequency of wildfires in the Western US has pressed a sense of urgency on the Forest Service, other land management agencies and many municipalities on developing fuel management and post-fire mitigation plans. With fuel management practices there is a risk that the management process itself (e.g. thinning and prescribed fire) might lead to more long term erosion compared to doing nothing and gambling that the forest will not be burned by a wildfire. After a wildfire occurs, managers must balance the risk of post-fire erosion with the expense required to protect the soil from an extreme event with an agricultural or wood-based mulch. In the Tahoe basin, we have been using a site-specific, process-based erosion model, WEPPcloud, to identify landscape positions that are most susceptible to erosion by thinning operations or under post-fire wildfire conditions. The WEPPcloud model was used to evaluate the probability of erosion under current undisturbed conditions, various timber harvesting scenarios, prescribed fire, and post-wildfire conditions. The distribution of soil burn severity for future wildfires was simulated using a trained geostatistical approach based on historic regional wildfires. Using WEPPcloud and a newly developed post-processing R shiny app, PI-VAT, which allows prioritization and targeting analysis across multiple watersheds and multiple treatment scenarios, we map the specific hillslopes that are most sensitive to disturbance and provide an optimization approach to guide managers and land use planners in selecting the areas which provide the greatest reduction in sediment load through erosion mitigation activities. Using various statistical analyses, we identify the key soil, vegetative, topographic, and climatic factors that best describe the distributed soil erosion potential following fuel management throughout the basin. Through this analysis we provide recommendations to guide future fuel management based on measurable landscape characteristics. We analyzed sensitive landscape characteristics such as slope length, soil steepness, soil depth, and mean annual precipitation, among other variables, and their effects on soil erosion. Results are displayed in a variety of interactive graphs, tables and descriptive text which aid managers in interpretation. The WEPPcloud analysis and interpretation with the PI-VAT tool was applied to the Lake Tahoe basin to assess the key soil and landscape characteristics driving soil erosion in the basin. Of particular interest to managers in the basin was the sensitivity between soil erosion and slope steepness. The analysis revealed slope steepness, slope length, and annual precipitation drive much of the variability and suggest spatially explicit timber harvest recommendations based on these factors would minimize the risk of erosion following timber harvest for fuel management. These tools provide managers with access to complex result into easy-to-use information for decision making.
The Water Erosion Prediction Project (WEPP) model is a process-based computer simulation model that has been widely used in research and by land managers to predict runoff and soil erosion from both agricultural and forested areas. While the model can produce accurate predictions with proper input data and minimal calibration, its usability has been limited by data accessibility and processing, and model setup. WEPPcloud is a free online interface developed mainly for forest applications that allows users to run WEPP without explicit knowledge of GIS and computer programming or even the area being modeled. All input files for the WEPP model are either automatically created from freely available databases or are used directly from an extensive WEPP database stored locally on the server. WEPPcloud also includes algorithms to simulate phosphorus yield based on simple static phosphorus concentrations in surface runoff, subsurface lateral flow, baseflow, and particulate phosphorus concentration attached to sediment. Recently, the WEPPcloud capabilities have been used in various applications to aid land managers with making decisions about pre- and post-fire fuel management and soil erosion. We will specifically present results from a basin-wide modeling effort in the Lake Tahoe Basin (Figure 1) where we compared several management scenarios (uniform high, moderate, and low severity, uniform thinning, simulated wildfire under current climate and future climate conditions) to current management conditions based on historic weather data. Similarly, we will demonstrate the applicability of the WEPPcloud interface to two municipal watersheds in Portland and Seattle, respectively. All hydrologic simulations were conducted online with the WEPPcloud interface. Minimum calibration was performed on watersheds using data from a USGS gauging station and calibrated parameters were applied uniformly to all modeled watersheds. All results are for individual hillslopes, channels, and at each watershed outlet. Average annual surface runoff, lateral flow, baseflow, sediment detachment, deposition, and yield, and total phosphorus, soluble reactive phosphorus, and particulate phosphorus are displayed both in tabular (as a text file) and visual (as a shapefile) format for each individual watershed or for multiple watersheds combined. Managers can further use these results to sort and select hillslopes that are generating more runoff and erosion based on specific hillslope attributes such as slope steepness or soil or management type for each simulation scenario. Lastly, we will discuss advantages and disadvantages of using online interfaces for hydrologic modeling and forest management.
In this video, I walk you through downloading a WEPPcloud project to a windows machine using Wepppy Win Bootstrap. wepppy-win-bootstrap provides two approaches to download the WEPPcloud runs. One approach uses Wget in the windows batch script and the other approach uses python script.
Since the development and availability of GIS-based software and satellite imagery, there has been a vision that watershed managers would have near-real-time, three-dimensional hydrologic and soil erosion models that could easily assess impacts of watershed management decisions at high spatial resolutions across multiple scales. Our research team has made significant advances to address this challenging problem especially in the forest environment. The technology and data retrieval and access has dramatically improved to the point where it is possible to provide useful, near-real-time, geospatial decision support for watershed managers. This talk describes an online watershed model called WEPPcloud, widely used by the Forest Service and one of the FSWEPP suite of watershed tools, which is based fundamentally on a process-based hydrologic, soil erosion model (WEPP, Water Erosion Prediction Project). WEPPcloud is driven by discoverable, data-rich geospatial mapping products (e.g. soils, topography, satellite-based vegetation characteristics) and management libraries. It accesses daily grid-based historical and future projected climatic data to provide a comprehensive spatially and temporally explicit assessment of the impacts of management decisions on hydrologic response and sediment transport. Currently, WEPPcloud can be applied throughout the continental US, and beta versions are available for Australia and Europe. We will demonstrate this tools’ development and application to guide pre-fire fuel management and post-fire mitigation, flood risk for communities where drinking water supplies and water resources are vulnerable to wildfire. We will discuss the ongoing limitations, challenges and opportunities towards more fully incorporating geospatial hydrologic and soil erosion models into watershed management decisions.