Watershed Data Collection and Analysis

Transcription

1 Watershed Data Collection and Analysis Chris Keithley Department of Forestry and Fire Protection October, 2006

2 Why Collect Data for a Watershed Assessment? Environmental data is needed to both evaluate the condition of your watershed and to examine the environmental issues that the watershed group is most concerned with. Data collection is often done by citizen groups, consultants, and government agencies depending on the complexity of the topic and the technical background of the watershed group members.

3 Data Considerations The type and method of data collection will ultimately determine the data analysis methods that are possible. Data collection can include the following: qualitative, quantitative, spatial, and non-spatial. The temporal and spatial scales of the environmental processes under investigation should be considered when considering the design of a data collection effort or the limitations of existing databases.

4 Sources of Data and Information for Watershed Assessments Most watershed assessments will need to review the availability of existing environmental data as the first step in the data collection effort. See handout for a listing of useful web sites for watershed data.

5 Watershed Data Catalogs Purpose : Provide broad access to reports, maps, photos, and environmental data that are specific to your watershed. A data catalog supports: Education of watershed issues Enhances understanding of watershed condition Supports planning and decision making Centralized source for data distribution

6 Watershed Information Model wim.shastacollege.edu/ The mission of WIM is to allow anyone with an interest in watershed management Access to the best science education on local natural resources.

7 Napa Watershed Information Web Site Napa Watershed Information Web Site

8 Klamath Resources Information System

9 Data Display and Analysis Stream Temperature Example

10 Data Table For Air and Stream Temperature YEAR MONTH DAY AMIN AMAX AAVG WMIN WMAX WAVG

11 Maximum Stream Temperature (MWAT) in Noyo and Big River

12 MWAT Thresholds and Standards Temperature ( C ) Descriptions Temperature (F) 26 Upper end of range of acute thresholds (considered lethal to 78.8 salmonids) Lower end of range of acute thresholds (considered lethal to 75.2 salmonids) Steelhead growth reduced 20% from maximum (Sullivan and 66.2 others, 2000).MWAT metric USEPA (1977) growth MWAT for rainbow trout Coho growth reduced 20% from maximum (Sullivan and others, 2000), MWAT metric 18 USEPA (1977) growth MWAT for coho Steelhead growth reduced 10% from maximum NMFS MWAT threshold Welsh and others (2001) MWAT threshold for coho 62.1 presence/absence in the Mattole 16 Oregon Dept. of Environmental Quality Standard for salmonids 60.8 (equivalent MWAT calculated from 7-day max.) 15 EPA Region 10 Recommended MWAT Threshold for Coldwater Salmonid Rearing 14.8 Coho growth reduced 10% from maximum (Sullivan and others, ), MWAT metric 14.6 Upper end of preferred rearing range of coho Washington Dept. of Ecology standard (equivalent MWAT 57.7 calculated from annual max.) Upper end of preferred rearing range for steelhead. 55.4

13 Graph of Maximum Daily Stream Temperatures Stream Temperature NF Casper Ck June, Water Temperature (celcius) Days of the month

14 Histogram Caspar Creek Stream Temperature June - September, 2002 Frequency Water Temperature in Celcius

15 Stream Temperature Data on James Creek Stream Temperature Data on James Creek Temperature ( C) Maximum Instantaneous Temperature C 07/17/ :00 1-Jul Jun Jun-05 1-Jun-05 9-Oct Sep Sep-05 9-Sep Aug Aug Aug Jul Jul Jul-05

16 Water Temperature Metrics Water Temperature Metrics 7-Day Moving Average of Daily Maxima for James Creek tributary to NF Big River, 2005 MWAT C 7/17/ :00 1-Jul Jun Jun-05 1-Jun-05 9-Oct Sep Sep-05 9-Sep Aug Aug Aug Jul Jul Jul-05 Temperature ( C)

17 Plotting Stream Temperature Against Air Temperature (Correlation = ) Daily Stream Temperature Daily Air Temperature

18 Characteristics of Correlation Coefficients Correlation coefficients measure the strength of association Between two continuous variables. Negative No Correlation Positive

19 Correlation Can Take on Many Different Forms. Source: Statistical Methods In Water Resources (2002).

20 GIS and Map Making Basics GIS combines the spatial features that exist on a map with a relational database that stores the data that describes each feature. The spatial features can be represented in either a raster or a vector format. A basic understanding of cartography can greatly improve the usefulness of maps that are made with GIS software. See handout for a listing of useful web sites for watershed data.

21 GIS and Spatial Data Analysis GIS also provides data analysis tools that can be used to describe watershed characteristics. The types of analysis range from descriptive techniques (i.e. data summaries) to highly quantitative models of environmental processes. The following section provides examples of GIS data and analysis for assessing: vegetation, channel gradient, peak flow, and fire.

22 Vegetation Map for Ten Mile, Noyo, Big River and Albion Watersheds

23 Vegetation Data Summary by Planning Watersheds

24 Using GIS to Calculate Stream Order

25 Box and Whiskers Plot of Channel Gradient Channel Gradient QUART_1 Min QUART_2 Max QUART_ Stream Order

26 Relationship of Stream Order to Channel Characteristics Stream Order Average Width (m) Average Depth (m) Average Cross- Sectional Area (m2)

27 Tools for GIS and Watershed Analysis There are many different types of models evaluate watershed conditions and environmental processes. Many of these have some type of GIS component to them. The following slides provide a few examples. Visit the CWAM web site for a more comprehensive listing of watershed models ( Examples include: Delta Q Peak flow model EPA Basins Water quality-based models USGS StreamStats Hydrologic flow

28 Peak Flow Model Delta Q Delta Q is a GIS based model that can be used to estimate changes in peak flow that result from timber harvesting. Peak flow recovery was calculated using the following equation: Where: D(Q) = total change in flow in the watershed being modeled d(q) = change in runoff in absolute or percentage terms for each activity type i = polygon identification number m = total number of affected polygons x(i)= years since harvesting activity in area i n = number of years to full hydrologic recovery

29 Results of Peak Flow Analysis

30 Predicted Changes in Peak Flow Along the South Fork Noyo River

31 See CDF-FRAP web site for vegetation, fire, and fuels data:

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33 Little understory to provide ladder to main canopy Canopy height Crown base height

34 Dense understory provides ladder to main canopy. Effective CBH is the CBH of the understory. Canopy height Crown base height