X hits on this document

PDF document

Parameter Sensitivity in Hydrologic Modeling - page 80 / 163

394 views

0 shares

0 downloads

0 comments

80 / 163

can be calculated automatically. A longest flow path is also digitized from the DRG and its length calculated by the GIS.

Table 4.2 outlines the results of Area 1, Area 2, and Area 3 from digitization.

(mi2)

(mi)

(mi)

Slope (%)

0.55

3.42

1.79

1.27

0.52

3.24

1.57

1.32

1.68

6.57

3.28

1.47

1.65

6.50

3.09

1.44

8.85

14.75

6.63

0.77

8.87

15.53

6.58

0.78

Table 4.2: On-Screen Digitizing Results

Longest Perimeter Flow Path

Area

Watershed Area 1

Area 2

Area 3

No Hwy/ Hwy No Hwy Hwy No Hwy Hwy No Hwy Hwy

4.4

CASE III: AUTOMATED METHODS USING A DEM

Case III is divided into two parts. The first part describes using ArcView GIS 3.2 and CRWR-PrePro to delineate the watersheds and extract watershed parameters using two different spatial resolution DEMs. The second part explores using the Watershed Modeling System (WMS) to also delineate the watersheds and extract watershed parameters at the same two spatial resolutions as with ArcView GIS 3.2.

The most widely available grid DEMs in the US are distributed by the USGS and are of 7.5 minute resolution (same coverage as a standard USGS 7.5 minute map series quadrangle), with a grid spacing of 30 x 30 meters. These

70

Document info
Document views394
Page views394
Page last viewedTue Dec 06 18:16:38 UTC 2016
Pages163
Paragraphs3546
Words25756

Comments