delineating watersheds
DESCRIPTION
Learn how to delineate a watershed.TRANSCRIPT
Terrain Modeling:
How to delineate a watershed using a printed topographical map
See NRCS handout: How to Read a Topographic Map and Delineate a Watershed
Mark the outlet (circle); Mark the high points adjacent to the stream or lake (“x’s”)
Starting at the circle , draw a line connecting the “x's" along one side of the waterbody . This line should always cross the contours at right angles (i.e. it should be perpendicular to each contour line it crosses).
Practice Exercises; Watershed & Lakeshed Delineation
Follow the steps just discussed:
•Mark the outlet•Mark the high points adjacent to the water body•Connect the marks; always cross a contour line at right angle (perpendicular).
Delineating Exercise 1
Start with a “lakeshed”; the land area contributing (draining) to a lake.
The lake is Four Point Lake in Cass County, near Hackensack, Minnesota
ADD OUTLET
MARK HIGH POINTS NEAR LAKE
CONNECT THE MARKS
Delineating Exercise 2
A watershed of a stream.
The small stream south of the Kadunce River, near Covill (just north of Grand Marais) in Cook County.
ADD OUTLET
MARK HIGH POINTS NEAR StREAM
CONNECT THE MARKS
Remember contour lines often point up stream; so near outlet make sure you don’t include other near by very small streams
Lab 11
Terrain AnalysisBrush Valley Creek
Data, Instructions,& Videos on FR website
Brush Valley Creek, Houston Country, MN
Lab 11Two .pdf maps to turn in via WebVista
Pay careful attention to where you create your output files
Watch the File Names
Write them down as you create them
3D Analyst
Hillshade
Viewshed
1. Fill2. Flow Direction3. Flow Accumulation4. Snap Pour Point5. Watershed
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