Development of standardized watershed assessment tools and techniques for Alberta

Transcription

1 Development of standardized watershed assessment tools and techniques for Alberta GeoAlberta Presentation September 25, 2013 Gillian Holloway, PhD

2 Watershed Assessment In Alberta The Alberta Water for Life Strategy (AWFLS; GoA 2008) recognized the fundamental importance of water to all aspects of: i) to human health and quality of life, ii) to long-term economic sustainability and prosperity, iii) to ecological integrity in Alberta The AWFLS had several goals including: i) maintenance of healthy aquatic ecosystems; ii) a secure supply of drinking water; iii) a secure supply of water for a sustainable economy Photo by C. Simmons

3 Watershed Assessment In Alberta A key player in AWFLS are the Watershed Planning and Advisory Councils (WPAC s) WPACs provide guidance to the government on the management of water and watershed health Watershed assessment reports are a major tools used by WPAC s, which: 1) report on the current ecological state of the watersheds 2) identify major threats and potential problems to water quality, water supply, and biodiversity.

4 Watershed Assessment In Alberta The GoA has developed general guidance documents for watershed assessment They provide general recommendations on environmental indicators to measure and monitor for watershed conditions

5 Indicator: An indicator is a measureable (quantitative) or descriptive (qualitative) variable that can be used to evaluate, or describe spatial and/or temporal trends over repeated intervals Name of Indicator Indicator Type Indicators Modeled in Report Criterion 1. Conservation of Biological Diversity Road Density Pressure Δ Seismic Line, Pipeline, Power Line & Δ Pressure Railroad Density Large Patches of Natural Vegetation Condition Δ Stream Connectivity Pressure Δ Fish Community* Condition Amphibian Community* Condition Macroinvertebrate Community* Condition Wetland Condition and/or Rate of Loss* Condition Criterion 2. Maintenance of Surface Water Quality Stream Crossing Density Pressure Δ Surface Water Quality Condition Δ Point Source Contamination Pressure Δ Sediment Quality* Condition Criterion 3. Maintenance of Ecologically Significant Water Levels & Flows River Water Flow Pressure Δ Potential Surface Water Use Pressure Δ Criterion 4. Maintenance of Groundwater Quality and Quantity Potential Groundwater Use Pressure Δ Groundwater Quality* Condition Criterion 5. Maintenance of Watershed integrity Human Population Growth Pressure Δ Human Land Use Pressure Δ Land Conversion *Aspirational indicators Pressure (Trend) Δ

6 Watershed Assessment Tools The recommended indicators can be split into 3 categories: 1) The easy wins - those which are readily measurable with currently existing and (freely?) available data 2) The long slogs those for which the information exists in multiple, non-standardized databases, often collected with different methodologies 3) The dreamer s list aspirational indicators for which neither the data, or often the scientific methods exists From Alberta Environment 2008

7 Examples of the easy-win list Intact Landscapes Road Density Linear Feature Density Agricultural lands Urban development Industrial development Water-well density Stream Crossing Density Stream Connectivity Human Population Growth **All can be calculated from standardize and/or (freely?)-available spatial data layer including Alberta Base Features layers (including roads, pipelines, seismic lines, industrial facilities), ABMI Human footprint layer, census data and spatial boundaries

8 Indicator Reporting Beyond selection of the indicators to monitor, each WPAC must develop a understandable and scientificallydefensible framework The method of summary needs to flexible, able to be tailored to the individual needs and human-land uses existing within different watersheds. In order to make the watershed assessment process must be transparent and repeatable, a set of standardized tools and reporting strategies is needed (Alberta Environment 2008a, Davies and Hanley 2010).

9 Scale of Assessment Indicators must be summarized using a spatial methodology which allows for direct comparisons of across localized areas This is a crucial step the unit of analysis will: i) influence the ecological patterns detected; ii) thresholds or targets; iii) the data sources that can be practically measured and/or monitored.

10 Scale, Scale, Scale

11 Watershed Analysis Watersheds are a flexible, commonly used and recommended unit of analysis

12 Stream Stahler Order

13 Rating Indicators Indicators are evaluated and rated relative to: i) thresholds ii) targets Iii) guidelines iv) historical reference condition Allow for direction comparison of individual watershed units relative to each other Given a strong foundation of scientific research, we recommend using thresholds for many indicators

14 Table 2. Thresholds used to differentiate Pressure Indicator Risk Rating Categories. Indicator Intact Landscapes Road Density km/km 2 Unit % aerial coverage of watershed with intact habitat patches High Risk Moderate Risk Low Risk Negligible Risk <30% >30 50% >50 75% >75% 0.87 >0.5 to 0.87 >0.1 to to 0.10 All Linear Feature Density Erosion Risk Indicator km/km 2 >3 >1.2 to 3 >0.6 to to 0.6 km/km 2 >1.5 >0.6 to 1.5 >0.3 to to 0.3

15 Linear Features Density in a) Headwaters of the Oldman

16 Linear Features Density in b) Athabasca Watershed

17 Intact Landscape Create a Human Footprint layer, then subtracted (delete) all these polygons the overall watershed boundary to create an intact vegetation layer.

18 Intact Landscapes in a) Headwaters of the Oldman

19 Intact Landscapes in b) Athabasca Watershed

20 Standardize and automate the easy win list Standardize and automate the easy win list create ArcGIS toolbox or QGIS tools This allow s individual WPAC s to spend time and funds on critical indicators on the long-slog list

21 Calculate Watershed Road Density Input Feature Class Output Feature Class Oldman Road Density Indicator.shp Watershed Summary File Oldman 4 th Order Watershed.shp Calculate Road Density (km/km2) for each subwatershed Toolbox uses the Alberta Base Features layer for roads to calculated road density in km/km2 to each summary unit (subwatersheds), then ranks each subwatershed as Very Low, Low, Medium or High based on the user-input threshold breakpoints. Threshold Breakpoints 0.1; 0.5; 0.87

22 Application and Use of Indicators These models are important tools to guide future planning and local stewardship They identify areas that are currently at high risk due to human-land use stressor Also, identify areas that appear to be in good ecological condition. *BLTR = Bull Trout *CTTR = Cutthroat Trout

23 Questions? Fiera Biological Consulting Ltd (Fiera) Oldman Watershed Headwaters Indicator Project Final Report (Version ). Edmonton, Alberta To be published in October 2013 at: ( Available at