CE 394K.2  Surface Water Hydrology     Homework 1: Fluxes, Flows and Volumes

Spring 2005

 

1.  We are working with the flow data for five streamflow gaging stations as shown below.   The 15 min flows for Jan 1 through Jan 10,  2005 are given the file 15minflow.xls for all of the stations, except for the Blanco River at Wimberley Texas.  Go to http://water.usgs.gov, select Realtime, download the 15 min flow data for this period, for the missing station (Site No. 08171000) and add it to the spreadsheet.   Make a plot of the discharge at the five stations for this period.

 

2.   At a daily time interval, calculate the cumulative volume (acre-ft), incremental volume (acre-ft) and the daily mean discharge (cfs) for each gage for the period of record.   1 acre = 43,560 ft2

 

 

 

3.  The USGS area given below is the total drainage area above each gage site and the Sub Area is the incremental drainage area for each of the five subwatersheds draining to to the stream gages.   1 square mile = 640 acres.

 

Site No

Name

USGS Area

Sub Area

Wshed

 

 

 (Sq. Miles)

 (Sq. Miles)

 

8171000

Blanco River at Wimberley Tx

355

355

1

8171300

Blanco River nr Kyle Tx

412

57

2

8172400

Plum Creek at Lockhart Tx

112

112

3

8170500

San Marcos R at San Marcos Tx

49

49

4

8172000

San Marcos R at Luling Tx

838

377

5

 

Calculate the runoff in mm/day occurring in each subwatershed for the period of record (i.e. the daily value of runoff coming from the subwatershed into the stream system for each day, Jan 1 through Jan 10).