First Advisor

Yangdong Pan

Date of Award

2025

Document Type

Project

Degree Name

Master of Environmental Management (MEM)

Department

Environmental Science and Management

Language

English

Subjects

Stream ecology -- Monitoring -- Methodology, Water quality management -- Oregon, Riparian restoration -- Oregon, Oregon -- Environmental conditions

Abstract

In the Pacific Northwest, rising stream temperatures threaten the survival of cold-water species, such as salmonids. The Oregon Department of Environmental Quality (DEQ) regulates stream temperature statewide through Total Maximum Daily Loads (TMDLs). To do this, the DEQ uses stream shade as a surrogate measurement for heat, as stream shade and stream temperature have a well-known strong relationship. This project focused on developing effective shade modeling and monitoring methods that increase the pace and scale of temperature TMDL implementation and tracking in Oregon. Stream shade can be measured in the field and modeled with computer models such as HeatSource, which require canopy height data. DEQ sources this data from airborne LiDAR or hand digitization of aerial photography. However, LiDAR canopy height data is not available in a large portion of the state and can be outdated depending on the location. Additionally, hand digitization of canopy height is time consuming and not practical on a large, repeatable scale. An organization, Planet Labs, developed a proprietary model that provides statewide canopy height estimates at higher temporal frequency and lower cost than LiDAR. This study evaluated the usage of canopy height data derived from satellite imagery for modeling effective shade with the HeatSource model in comparison to LiDAR derived effective shade. The performance of the effective shade values derived from satellite image canopy height data varied across land (Spearman’s Rank Correlation Coefficient (ρ) = 0.57). The highest correspondence was in forested areas (ρ = 0.75) and the lowest in agricultural areas (ρ = 0.15). Canopy structure was the driver behind this pattern, as homogeneous canopy structures had higher correspondence between satellite image and LiDAR derived effective shade, while heterogeneous canopy structures had lower correspondence. Additional field research is needed to evaluate the correspondence between field measured and satellite image derived effective shade because equipment failure precluded the direct comparison. For increasing the pace and scale of field measurements of effective shade, the DEQ plans to add an additional field method, hemispherical photography, which captures 360-degree canopy images to measure and document shade, alongside the current effective shade method, the solar pathfinder. This study evaluated the correspondence between the two field methods. The results of this study show that the two effective shade field methods produced comparable results in streams with moderate to high shade coverage. The DEQ will move forward with adopting hemispherical photography as an approved field method. By improving shade modeling and monitoring processes, this project seeks to aid in accelerating riparian restoration efforts and improve water quality management across Oregon.

Rights

Copyright 2025 Ella Wagner. In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).

Comments

A project report submitted in partial fulfillment of the requirements for the degree of Master of Environmental Management.

Persistent Identifier

https://archives.pdx.edu/ds/psu/44329

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