Table of contentsDevelopment of a Geospatial Approach for Assessing Groundwater Connectivity for Land Planning Activities www.ruralgis.org Understanding groundwater connectivity dynamics is important for: Project Goals Model Selection Criteria Numerical Groundwater Model: MODFLOW MODFLOW: Conservation of Fluid Mass MODFLOW Grid Analysis Data Requirements & Assumptions Case Studies: Yakima River, Wapato, Washington Nisqually River, Yelm, Washington Slide 11 Slide 12 Site Location and Surface Hydrology Surficial Geology Slide 15 Slide 16 Data Collection and Model Development Data Collection and Model Development Slide 19 2-Dimensional Perspective of Groundwater Flow Direction within Unconfined Aquifer Slide 21 3-Dimensional Perspective of Predicted Flow Paths Limitations Strength of modeling approach: Slide 25 Acknowledgements References Groundwater Modeling System processes Policy case study: Shorelands and Associated Wetlands Considering all the factors ‘Grey Areas’ Associated Wetland assessment using MODFLOW Case Study 1: Yelm, Thurston County, WA Designated SMA Streams Area of Interest and Local Wetlands FEMA extents and NWI Wetlands Slide 38 Are these ‘Associated Wetland’? MODFLOW Modeling Objectives Data Collection Public Data Resources Define Conceptual Model Boundaries Area of Interest - Yelm Geologic Stratigraphy Well Locations Hydrogeologic Cross-Section Slide 49 Hydrogeologic Interpretation: Aquifers Geologic Unit Representation within the model Model Construction Water Table Elevations Boundary Conditions & Assumptions Results: Projected Groundwater Flow Paths Pathline Direction Conclusions Strengths & Limitations of Approach Slide 59 Regional Stratigraphy SMP Example: Yakima County– Current & Proposed Streams Slide 62 Determination of Wetland Hydraulic Connectivity…Why? Why model? Numerical Groundwater Model |