IBW Discharge Analysis

Introduction

In order to characterize the flows within the Indian Bend Wash, I have written some Matlab codes that make processing of Maricopa County Flood Control District Gauge data.

Matlab codes

See this page for the Matlab codes and simple explanations of what they do

FCDMC Water level Sensors along the IBW

Name	Number	Beginning of record	T_R_S	Lat	Long	Elevation	Jurisdiction	Location
IBW @ Indian Bend Rd.	4613	3/27/1992	2N-4E-11	33 32 00	111 54 53	1071	Scottsdale	On Indian Bend Wash just S. of Indian bend Rd.
IBW @ Indian School	4618	11/26/1997	2N-4E-23	33 29 28	111 54 20	1235	Scottsdale	Indian School Rd. at Hayden Road
IBW @ Interceptor	4623	4/21/1994	2N-4E-12	33 31 57	111 53 55	1071	Scottsdale	1/4 mi. SW of Pima Rd. & Indian Bend Rd.
IBW @ McDonald Dr.	4628	11/25/1997	2N-4E-11	33 31 15	111 54 08	1265	Scottsdale	McDonald Drive at Hayden Road
IBW @ McKellips Rd.	4603	5/21/1985	1N-4E-11	33 26 58	111 54 58	1187	Scottsdale	On Indian Bend Wash 1/4 mi. South of McKellips
IBW @ Shea Blvd.	4693	6/9/1998	3N-4E-29	33 34 56	111 58 08	1350	Phoenix	Shea Blvd. At 52nd Street
IBW @ Sweetwater	4643	12/27/1990	3N-3E-13	33 36 15	112 00 18	1400	Phoenix	1/2 mi. E of 32nd St. and Sweetwater Ave.

Here is a map from the Flood Control District that shows where some of these are.

The data come from the ALERT Pages: http://156.42.96.39/showflow.html

Longitudinal Analysis

From north to south, it looks like it is 4643, 4693, 4613, 4623, 4628, 4618, 4603
So, I took a small storm seen by all of them: The Valentine's Flood of 2003 (4/14/03 12:00:00 to 4/17/2003 24:00:00).
I used the findrange.m and getvolumesimple.m codes to window out that range and to calculate the volume of flow in the event at each station.

4643 IBW @ Sweetwater

4693 IBW @ Shea

4613 IBW @ Indian Bend

4623 IBW @ Interceptor

4628 IBW @ McDonald

4618 IBW @ Indian School

4603 IBW @ McKellips Rd.

Summmary

As is evident from this simple study of a small flow event, not all gages are activated in these events. I don't think that it is a problem of lag, given the 3 day window. These gages with no flow must not be located in places where they get runoff from these kinds of events?

Furthermore, perhaps one can conclude that the effect of urbanization is such that the expected downstream increase in discharge does not occur because of alterations in hydrologic flow paths and/or transmission loss (i.e., if you accept a connection between the three non-zero gages in this event).

The problem I have at the moment is that I don't know what the basic spatial relationship between the gages is beyond this N-S comparison.

Ramón Arrowsmith
Last modified May 28, 2003.