Location: Hydrology and Remote Sensing Laboratory
Project Number: 8042-13610-029-33-I
Project Type: Interagency Reimbursable Agreement
Start Date: Aug 15, 2018
End Date: Aug 14, 2023
1. Remote detection and functional assessments for wetlands; 2. Improved representation of denitrification processes in SWAT; 3. Application of InVEST modeling; 4. Comprehensive analyses of wetland water budget data; 5. Topographic openness for mapping surface flow patterns.
Objective 1: The goal of this study is to refine a framework and approach applicable on a regional basis that can be used throughout the coterminous U.S. (lower 48 states). We will further develop an existing functional assessment approach. Our development will extend the applicability of the existing approach to regional or national levels. The developed approach will be tested in the Mid-Atlantic Region (MIAR) as regional pilot. Objective 2: Use of topographic metrics is increasing due to their capacity to represent geophysical characteristics over the landscape. Those metrics developed by CEAP-Wetland teams have successfully represented key landscape parameters (e.g., denitrification potential and soil organic carbons) that are not easily obtainable without intensive labor. Spatialized landscape parameters gained from topographic metrics are highly useful for a hydrologic model since a model tends to set uniform characteristics for all areas due to limited observations. ARS will apply spatialized denitrification potential information into a hydrologic model, Soil and Water Assessment Tool (SWAT). SWAT has been used by CEAP-Wetland teams to quantify the aggregate impacts of wetlands on upstream water budget and downstream flow. However, this model oversimplifies denitrification potential. For example, all areas have the same denitrification potential regardless of soil characteristics. ARS will modify SWAT to represent varying denitrification potential for individual locations. Then, spatialized denitrification potential from topographic metrics will be employed to parameterize a modified SWAT. The simulations will be calibrated and validated using available remotely sensed data and in-situ observations. Objective 3: CEAP-Wetland teams have worked on developing GIS platform to run InVEST modeling. This tool will allow wetland scientists and conservationist to readily assess wetland carbon storage functions at the regional scale. However, carbon storage and sequestration parameters in InVEST are limited to representing wetland function in the CEAP-MIAR study sites. The hydroperiod of a wetland exerts great impacts on wetland carbon budget, but all wetlands are assumed to have the same value for carbon parameters regardless of hydroperiod. Over multiple years, in-field data have been collected from several wetlands and those data include soil carbon budget for different wetland types. Thus, in-situ data can be incorporated into InVEST model to better characterize wetland carbon function for this region. Objective 4: Wetland water budget database have been developed as one of objectives for the CEAP-MIAR group since 2015. Using those data, the CEAP-Wetland team successfully demonstrated the impacts of subsurface soil characteristics on surface-groundwater interactions within a wetland . Comprehensive analyses of wetland water budget data can provide the answers to multiple research questions with respect to wetlands.