Combining GIS and GPS to Improve Our Understanding of the

Spatial Distribution ofSnow Water Equivalence

Todd AckermanTodd AckermanTyler EricksonTyler Erickson

Mark W. WilliamsMark W. Williams

Institute of Arctic and Alpine ResearchInstitute of Arctic and Alpine ResearchUniversity of ColoradoUniversity of Colorado

Boulder, ColoradoBoulder, Colorado

Overview

Research goalsResearch goals Site descriptionSite description Data collectionData collection AnalysisAnalysis

Why study snow?

75% of annual water supply in the western US75% of annual water supply in the western US Catastrophic floodingCatastrophic flooding

Problems in Snow Hydrology

In western US, SWE is measured once every In western US, SWE is measured once every 1,800 square miles1,800 square miles

Scaling: point measurements of SWE to Scaling: point measurements of SWE to regional and global scalesregional and global scales

Research Goals

Detailed data set for snow hydrologyDetailed data set for snow hydrology Improvement of methods for estimating SWE Improvement of methods for estimating SWE

in alpine basinsin alpine basins Relationship of SWE to landscape typeRelationship of SWE to landscape type

GIS

PlatformsPlatforms ArcInfo 7.0.2 Workstation for SolarisArcInfo 7.0.2 Workstation for Solaris ArcInfo 8.1 Desktop and Workstation for ArcInfo 8.1 Desktop and Workstation for

Windows NT Windows NT ExtensionsExtensions

Spatial AnalystSpatial Analyst Geostatistical Analyst Geostatistical Analyst

Green Lakes Valley

3,575 to 4,000 m3,575 to 4,000 m 1,000 mm of1,000 mm of

precipitationprecipitation 80% as snow80% as snow UNESCO BiosphereUNESCO Biosphere

ReserveReserve LTER network siteLTER network site

Surrounding Area

Access

25 km roundtrip25 km roundtrip Tundra labTundra lab

Field Methods

Snow ProbesSnow Probes Snow PitsSnow Pits DEMDEM LandcoverLandcover GPSGPS

Field Methods

Snow ProbesSnow Probes Snow PitsSnow Pits DEMDEM LandcoverLandcover GPSGPS

Field Methods

Snow ProbesSnow Probes Snow PitsSnow Pits DEMDEM LandcoverLandcover GPSGPS

Field Methods

Snow ProbesSnow Probes Snow PitsSnow Pits DEMDEM LandcoverLandcover GPSGPS

Field Methods

Snow ProbesSnow Probes Snow PitsSnow Pits DEMDEM LandcoverLandcover GPSGPS

GPSComparison

0

1

2

3

Trimble Garmin

we

igh

t (kg

)

$0

$2,000

$4,000

$6,000

$8,000

$10,000

$12,000

Trimble Garmin

pu

rch

ase

co

st

TrimbleTrimblePro XRPro XR

GarminGarminGPS-III PlusGPS-III Plus

GPSComparison

Snow Depth Measurements

Kriging

Geostatistical AnalystGeostatistical Analyst Useful, flexible toolUseful, flexible tool

CaveatsCaveats StationarityStationarity Lower boundLower bound

constraintconstraint

KrigingResults

Correlation of Snow Depth with Landscape Type

Measured Points Interpolated Points

Summary

GIS technology allows us to conduct better GIS technology allows us to conduct better snow surveys, and to analyze the resultssnow surveys, and to analyze the results

GPS: lighter, cheaper, happierGPS: lighter, cheaper, happier Kriging can be used to scale up the point Kriging can be used to scale up the point

measurement, but is currently a black box measurement, but is currently a black box operation.operation.

Acknowledgements

Students, field staff (especially Tim Bardsley), Matt Students, field staff (especially Tim Bardsley), Matt Tomaszewski, and volunteers who have helped with the Tomaszewski, and volunteers who have helped with the snow surveys over the years.snow surveys over the years.

NSF EAR-9526875 (Hydrology)NSF EAR-9526875 (Hydrology) Army Research Office grant DAAH04-96-1-0033Army Research Office grant DAAH04-96-1-0033 NASA-EOSNASA-EOS Mountain Research Station of INSTAAR andMountain Research Station of INSTAAR and

CU-BoulderCU-Boulder Ongoing maintenance and data access is funded by the Ongoing maintenance and data access is funded by the

NSF grants DEB 92-11776 and DEB 98-10218NSF grants DEB 92-11776 and DEB 98-10218

Further Information

Niwot LTER (Niwot LTER (http://culter.colorado.eduhttp://culter.colorado.edu)) INSTAAR (INSTAAR (http://ekman.colorado.eduhttp://ekman.colorado.edu)) TundraCam (TundraCam (http://tundracam.colorado.eduhttp://tundracam.colorado.edu))