Using Remote Sensing to Estimate Water Resources from Glacial Melt Prof. Kenneth L. Verosub Dept of Geology University of California, Davis,

Santiago and its mountains

Rivers of Central Chile

Glacial and Snow Melt

Rivers and glaciers

Rio Cruces discharge record

Center of Volume Sierra Nevada (Calif.)

Spring Fraction of Runoff Sierra Nevada (Calif.)

Basic Hypothesis: Riverflows can be measured using only geospatial imagery.

River Gauge

Rating Curve

An Alternate Approach Measure the width

River Profile Use width to determine height from topographic profile. An Alternate Approach (con’t)

Q = v A v = c (RS) 1/2 Basic flow equation: where Q is discharge, v is velocity and A is area Chezy equation: where c is a constant, R is hydraulic radius and S is the slope of the channel. Hydraulic radius is the area divided by the wetted perimeter.

c = (1/n) R 1/6 Q = (1/n) A R 2/3 S 1/2 Manning Chezy equation: Manning equation: where n is the roughness coefficient. Note: A, R, and S can be determined from detailed topography or a DEM, and n can be estimated visually.

GeoEye-1 5 spectral bands 40 cm resolution (visible) Commercial

GeoEye: Coliseum in Rome

GeoEye: Kansas City Airport

Obtain topographic maps or DEMs (at low flow) from stereo image pairs, SRTM and/or Lidar. Determine topographic profile and slope for target site. Calculate other geometric parameters from width vs. depth relationship. Use Manning-Chezy Equation (and others) to calculate discharge as a function of width. Use regular imagery to determine flows at other dates/times. Basic Methodology

Width vs. Depth

Area (A) Perimeter Hydraulic Radius (R) Mean Depth (Ym) Width (W) vs. Depth Numerical integration of to obtain for any given depth.

Half-width vs. Depth

Q = (1/n) A R 0.67 S 0.5 Q = 7.1 A Y m 0.67 S 0.33 Q = 7.22 W 1.02 Y m 1.74 S 0.33 Q = 4.62 W 1.17 Y m 1.57 S 0.34 Bjerklie et al. equation: Dingman and Sharma equation: Manning (Bjerklie) equation: Manning Chezy equation:

Mississippi at Thebes

Width vs. Discharge Curve

6/25/ /27/2003 6/01/2007 3/8/2009 3/18/2006 a 6/4/2010 Cosumnes at Michigan Bar (CA) – Chronological

6/25/ /27/2003 6/01/2007 3/8/2009 3/18/2006 a 6/4/2010 Cosumnes at Michigan Bar (CA) – Sequential

6/4/ /25/ /27/ /01/ /8/ /18/ a Cosumnes at Michigan Bar (CA) – Sequential (II)

a Cosumnes at Michigan Bar (CA) – Match-ups

Increase spatial resolution of current monitoring efforts. Application – Monitoring Rivers

April 2011 precipitation

Measuring flows on the Mississippi River

Increase spatial resolution of current monitoring efforts. Determine flows for critical times for sites where gauging stations have been lost or abandoned. Application – Monitoring Rivers

Gauging stations are few and far between

Increase spatial resolution of current monitoring efforts. Determine flows for critical times for sites where gauging stations have been lost or abandoned. Obtain new flow data from physically inaccessible areas, such as high mountains and deserts. Obtain new flow data from restricted areas, such as military bases and wilderness areas. Application – Monitoring Rivers

Mountain runoff is poorly understood.

Increase spatial resolution of current monitoring efforts. Determine flows for critical times for sites where gauging stations have been lost or abandoned. Obtain new flow data from physically inaccessible areas, such as high mountains and deserts. Obtain new flow data from restricted areas, such as military bases and wilderness areas. Combine with Lidar for total “state of the river” analysis. Application – Monitoring Rivers

“State of the River” Murray-Darling Basin, Australia

“State of the River” Murray-Darling Basin Commission website

“State of the River” Yellowstone River Basin Lidar

“State of the River” Yellowstone River Lidar corridor

Application to Chile

Gauging stations in Bio Bio province

Period of dicharge record.

Gracias.