Date of Award

2020

Document Type

Open Access Dissertation

Degree Name

Doctor of Philosophy in Forest Science (PhD)

Administrative Home Department

College of Forest Resources and Environmental Science

Advisor 1

Ann L. Maclean

Committee Member 1

Curtis B. Edson

Committee Member 2

Joseph W. Wagenbrenner

Committee Member 3

Sinan A. Abood

Abstract

A riparian area is a zone of interaction between aquatic and terrestrial ecosystems. Delineating accurate riparian management zones (RMZs), often utilized in Best Management Practices (BMPs) for wetlands and stream protection, is important. The Riparian Buffer Delineation Model (RBDM) has been used extensively for accurate RMZs delineation. Utilizing the validated RBDM generates additional questions about riparian area form and function, which will ideally lead to an improved understanding of the ecological process within these zones. This study aims to determine how geomorphic landforms and their associated landscape characteristics influence riparian areas in terms of shape and complexity, whether sampling methods of the RBDM (ground distance vs. horizontal distance) along the water course impact the extent and complexity of the riparian area, and how spatial resolution of DEM influence riparian area delineation using different sampling methods.

Based on the geomorphology of Province 212 (Laurentian Mixed Forest Province, or LMF Province), the portion located in Minnesota are chosen as the study site. In Chapter 2, sample watersheds and the 50-year flood heights are categorized by landform types, and new stream data are generated using the Arc Hydro tools. By integrating these data with other inputs, both basic and inclusive riparian areas on each landform are generated using the RBDM. Extent parameters and complexity indicators, such as edge density, total edge and mean shape index, of the buffers are calculated using Patch Analyst and analyzed for each landform type. The results provide an analytical perspective of the RMZs’ delineation and geomorphic landforms do impact the size and shape of riparian areas. In Chapter 3, a new sampling approach is introduced- equal interval ground distance. This method compared to the traditional approach of using planar coordinates (horizontal distance) for sampling is incorporated in the RBDM via a Python script. A comparison between the two sampling methods is conducted for each landform type using 1, 5, and 10-meter DEMs. The results indicate the ground distance sampling method delineates more accurate riparian buffer boundaries with 1-meter DEMS. However, the boundary differences when using 5 and 10-meter DEMs are negligible.

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