Assessing the Impacts of Climate Change, Urbanization, and Filter Strips on Water Quality Using SWAT

Precipitation changes and urban growth are two factors altering the state of water quality. Changes in precipitation will alter the amount and timing of flows, and the corresponding sediment and nutrient dynamics. Meanwhile, densification associated with urban growth will create more impervious surfaces which will alter sediment and nutrient loadings. Land and water managers rely on models to develop possible future scenarios and devise management responses to these projected changes. We use the Soil and Water Assessment Tool (SWAT) to assess potential changes in stream flow, sediment, and nutrient loads in two urbanizing watersheds in Northwest Oregon, USA. We evaluate the spatial patterns climate change and urban growth will have on water, sediment and nutrient yields. We identify critical source areas (CSAs) for each basin and investigate how implementation of vegetative filter strips (VFS) could ameliorate the effects of these changes. Our findings suggest that: 1) Water yield is tightly coupled to precipitation. 2) Large increases in wintertime precipitation provide enough sub-surface storage to increase summertime water yields despite a moderate decrease in summer precipitation. 3) Expansion of urban areas increases surface runoff and has mixed effects on sediment and nutrients. 4) Implementation of VFS reduces pollutant loads helping overall watershed health. This research demonstrates the usefulness of SWAT in facilitating informed land and water management decisions

Where Do Mount Baker Snoqualmie National Forest Visitors Go and Which Roads Do They Use To Get There? An Analysis of the Spatial Data from the 2013 Sustainable Roads Workshops

This report provides an overview of the key patterns that emerged from the spatial analyses of the destination and route data collected during the 2013 Sustainable Roads workshops on the Mount Baker Snoqualmie (MBS) National Forest. We excluded the pilot workshop data from the analyses because a somewhat different process was used to collect the mapped data. The data used in the analysis was collected from 262 participants in eight workshops (Bellingham, Sedro-Woolley, Darrington, Monroe, Everett, Seattle, Issaquah, Enumclaw). During the workshops, participants mapped up to eight destinations of importance to them, and in most cases, also mapped the routes they took to each destination. For each destination and its associated route, participants also provided the following information. Name of the place Why the destination is especially important What activities or work the participant does there How often the participant visits the place in a typical year What type of transportation the participant uses to get there Of the 262 participants, 252 provided useable data for destinations and 246 provided useable data for roads. The dataset used in the spatial analysis contained 1733 records for destinations and 1609 records for roads. We entered the worksheet data for the destination and road mapping exercise into an Excel spreadsheet. The activities associated with each destination were grouped into eight categories (camping/relaxation, collecting/harvesting, hiking, motorized recreation, observation, sociocultural, strenuous recreation, and winter recreation). Although most people listed no more than two activities for a location, some people listed up to six different activities for certain destinations. The description of why a participant visited a particular location was similarly classified as a set of eight different values. Given the way the question was posed, many of the reasons workshop participants gave for visiting a particular place mirrored the activities in which they participated. The spatial analysis team created map data from a roads dataset provided by MBS National Forest. The routes in the dataset were converted to lines broken at all intersections. Since the lines marked on the maps did not necessary begin or end at intersections, the digitized lines were broken at the beginning and ending vertices for analysis. Segments of state highways (SR 542, 20, 2, etc.) that were marked by participants were removed from the dataset prior to analysis. Marked county roads were retained for analysis to provide context for routes taken to certain popular destinations (e.g., Cascade River Road). All data were checked for quality by someone who did not create the map data

Water Supply, Demand, and Quality Indicators for Assessing the Spatial Distribution of Water Resource Vulnerability in the Columbia River Basin

We investigated water resource vulnerability in the US portion of the Columbia River basin (CRB) using multiple indicators representing water supply, water demand, and water quality. Based on the US county scale, spatial analysis was conducted using various biophysical and socio-economic indicators that control water vulnerability. Water supply vulnerability and water demand vulnerability exhibited a similar spatial clustering of hotspots in areas where agricultural lands and variability of precipitation were high but dam storage capacity was low. The hotspots of water quality vulnerability were clustered around the main stem of the Columbia River where major population and agricultural centres are located. This multiple equal weight indicator approach confirmed that different drivers were associated with different vulnerability maps in the sub-basins of the CRB. Water quality variables are more important than water supply and water demand variables in the Willamette River basin, whereas water supply and demand variables are more important than water quality variables in the Upper Snake and Upper Columbia River basins. This result suggests that current water resources management and practices drive much of the vulnerability within the study area. The analysis suggests the need for increased coordination of water management across multiple levels of water governance to reduce water resource vulnerability in the CRB and a potentially different weighting scheme that explicitly takes into account the input of various water stakeholders

Engaging Stakeholders in Ecosystem Service Assessment Under Climate Change and Urban Development Scenarios

This presentation focuses on how scientists can engage stakeholders in ecosystem service assessment

Water Supply, Demand, and Quality Indicators for Assessing the Spatial Distribution of Water Resource Vulnerability in the Columbia River Basin

We investigated water resource vulnerability in the US portion of the Columbia River basin (CRB) using multiple indicators representing water supply, water demand, and water quality. Based on the US county scale, spatial analysis was conducted using various biophysical and socio-economic indicators that control water vulnerability. Water supply vulnerability and water demand vulnerability exhibited a similar spatial clustering of hotspots in areas where agricultural lands and variability of precipitation were high but dam storage capacity was low. The hotspots of water quality vulnerability were clustered around the main stem of the Columbia River where major population and agricultural centres are located. This multiple equal weight indicator approach confirmed that different drivers were associated with different vulnerability maps in the sub-basins of the CRB. Water quality variables are more important than water supply and water demand variables in the Willamette River basin, whereas water supply and demand variables are more important than water quality variables in the Upper Snake and Upper Columbia River basins. This result suggests that current water resources management and practices drive much of the vulnerability within the study area. The analysis suggests the need for increased coordination of water management across multiple levels of water governance to reduce water resource vulnerability in the CRB and a potentially different weighting scheme that explicitly takes into account the input of various water stakeholders