Satellite-derived potential evapotranspiration for distributed hydrologic runoff modeling in Midwestern basins

The historical lack of distributed input data has been a key factor in hindering the use of distributed hydrologic models for operational streamflow prediction by the National Weather Service (NWS), which currently relies primarily on lumped models. Satellite remote sensing has held the promise of providing the needed spatial variables for hydrologic applications for some time, and currently sufficient data from sensors such as the Moderate Resolution Imaging Spectro-radiometer (MODIS) have amassed such that robust modeling applications testing is now possible. The goal of this study is to test the use of satellite-derived potential evapotranspiration (PET) estimates, computed using 13 MODIS observations and the Priestly Taylor formula (MODIS-PET), as input in the NWS Hydrology Laboratory Research Distributed Hydrologic Model (HL-RDHM). Daily PET grids at 4km resolution are generated for 13 watersheds in the upper Mississippi River basin. Precipitation data are obtained from the Climate Prediction Center\u27s (CPC) Climatology-Calibrated Precipitation Analysis (CCPA). Application of the MODIS-PET is compared to model results using the PET grids that are provided as a default in the HL-RDHM. The default PET grids are based on historical ground-based evaporation measurements and are spatially and temporally less variable than the MODIS-PET. Model results are evaluated for the May 1 through September 30 period for eight years using observed evapotranspiration (ET) adjacent to two watersheds and daily discharge observations for all watersheds. Results indicate that even with the more physically realistic MODIS-PET input, simulated basin discharge at the outlet shows little to no improvement compared to the default PET simulations. The simulated basin mean ET results exhibit mixed results when analyzing the MODIS-PET simulations against the default PET simulations. Calibrating several model parameters substantially improves simulated discharge for both MODIS-PET and default PET simulations; however, the range of improvement for simulated streamflow among individual basins varies between the two different PET data sources, and simulated discharge errors can often be directly related to simulated ET errors

Spatializing the Soil-Ecological Factorial: Data Driven Integrated Land Management Tools

Soils form the dynamic interface of many processes key to the function of terrestrial ecosystems. Many soil properties both influence and are influenced by activity of flora and fauna. Interactions between soils, biota, and climate determine the potential ecosystem services that a given unique ecological site (ES) can support, and how resilient a site is to various pressures and disturbances. Soil data are needed to fully understand how these factors interact, but because this data is difficult to obtain, existing soil maps are sometimes not detailed enough to fully explore relationships. Environmental raster GIS data layers were used to increase the detail of maps by representing soil forming factors and associated ecological pedomemory legacies important to understanding ecological potential. This dissertation presents methods and tools to help create these new soil maps at appropriate resolution and theme for field scale assessment of ecological sites that enable land managers to plan and implement appropriate management decisions.;USDA-NRCS soil surveys were disaggregated to higher resolution maps using a semi-automated expert training routine to implement a random forest classification model. This transformed soil map polygons of variable thematic and spatial resolution (soil map unit concepts) to a consistent 30-meter raster grid of unified theme (soil taxa). Disaggregated maps (DM) showed highly variable accuracy (25--75% overall validation accuracy) that mirrored that of the original soil surveys evaluated in Arizona (AZ) and West Virginia (WV). However, disaggregated maps expressed the soil data at a much more detailed spatial scale with a more interpretable legend. The WV surveys exhibited much lower accuracy than the AZ survey evaluated. This lower accuracy in WV is likely due to the forested setting and highly dissected landscape, two factors that create more intrinsic soil variability that is harder to explain with spatial covariates.;Ecological site descriptions (ESD) document soil-ecosystem groups that produce unique amounts and types of biological constituents and respond similarly to disturbance and environmental variation. ESD are linked to soil map unit components in USDA-NRCS soil surveys and are used as the basis for land management planning on rangelands and forestlands. The component level connection makes DM a good way to spatialize ESD because both are spatially represented at the same thematic level, whereas conventional soil maps have polygons that often have multiple components linked to a delineation.;However, in the evaluation of mapping ESD via DM, the DM turned out not to document the key difference in spodic soil properties that distinguished the important ecotone between northern hardwood and alpine red spruce conifer ESDs in Pocahontas and Randolph counties, WV. So, to adjust, spodic soil properties were mapped directly using digital soil mapping approaches. A strong spatial model of spodic soil morphology presence was developed from a random forest probability model and showed correspondence to red spruce and hemlock occurrences in local historic land deed witness trees from records between 1752 and 1899. From this result, areas with spodic soil properties were assumed to be associated with historic red spruce communities, although 68% of those areas in the WV study area are currently under hardwood cover. This would seem to indicate that hardwoods have encroached on the historic extent of spruce, which is consistent with other recent studies. O-horizon thickness was also observed to be one cm thicker for every 10% greater importance value of red spruce or hemlock versus that of hardwood species at field sites. From these observations, it was calculated conservatively that at least 3.74-6.62 Tg of C have likely been lost from red spruce influenced ecological sites in WV due to historic disturbance related conversions of forest to hardwood composition. These results highlight the value of working within a soil-ecological factorial framework (e.g. an ESD) to contextualize land management options and potential derived services or negative consequences of each available action