Fractional snow cover estimation in the complex alpine-forested areas using MODIS and Landsat...
-
Upload
marilyn-kelley -
Category
Documents
-
view
217 -
download
0
Transcript of Fractional snow cover estimation in the complex alpine-forested areas using MODIS and Landsat...
Fractional snow cover Fractional snow cover estimation estimation in the complex alpine-forested in the complex alpine-forested areas using MODIS and areas using MODIS and LandsatLandsat
Elzbieta Czyzowska – Wisniewski
research conducted under guidance ofDr. K. Hirschboeck
Why do we have to study winter precipitation Why do we have to study winter precipitation and snow cover in the Southwest USAand snow cover in the Southwest USA
- winter precipitation and snow cover supply - winter precipitation and snow cover supply up to up to 90%90% of annual precipitation; of annual precipitation;
- winter precipitation and snow cover - winter precipitation and snow cover is is very sensitive very sensitive to global climate change;to global climate change;
- estimation of - estimation of snow water equivalent (SWE)snow water equivalent (SWE) based based on on instrumental data – remote sensing data complement instrumental data – remote sensing data complement sparse ground datasparse ground data;;
- estimation of snow cover and SWE is needed for better - estimation of snow cover and SWE is needed for better understanding understanding of spatial and temporal variationof spatial and temporal variation of these elements of these elements
in the decadal and century time scales;in the decadal and century time scales;
30 m
30 m
30 m
30 m
Ground Satellite
Remote sensing – introduction
30 m
30 m
30 m
30 m
30 m
30 m
30 m
30 m
Ground Satellite
Present day snow classification
< snow > non snow
snow
non snow
nonsnow
snow
30 m
30 m52
52
bandTMbandTM
bandTMbandTMNDSI
52
52
bandTMbandTM
bandTMbandTMNDSI
Normalized Difference Snow IndexNormalized Difference Snow Index
Snow detection – current methods: NDSI
Ikonos as a source information
for snow cover monitoring
30 m
30 m
Landsat
Ikonos
1 m
4 m
snow
52
52
bandTMbandTM
bandTMbandTMNDSI
52
52
bandTMbandTM
bandTMbandTMNDSI
how much of the pixel is covered by snow ?
Ikonos as a source information
for snow cover monitoring
30 m
Landsat
Ikonos
1 m
1 Landsat pixel (30m) = 900 Ikonos pixels (1m);1 MODIS pixel (500m) = 278 Landsat pixels = 250 000 Ikonos
forest
road
water
housefresh snow
old snow
metamorphosed snow
% snow cover
Ikonos
Landsat TM/ETM+ classification map
snow
snow
MODIS Terra/Aqua
snow
10 m DEM
ModisFSC
snow
GIS
snow
ANN1
/ 4
/4
ANN2
A –LandsatFSC development B – ModisFSC development C – Verification
Ikonos classification map
30 m DEM
ANN1 training
ANN2training
LandsatFSC
snow
MODIS, Landsat NDSI
NOHRSC, SNOTEL
- panchromatic - visible - near infrared - shortwave infrared - thermalLegend:
ANN2
parameters
ANN1
parameters
Landsat and MODIS fractional snow cover
IIa. Comparison of fractional snow area distribution with snow maps produced by: MODIS NDSI;Landsat NDSI; NOAA; SNOTEL;
Ikonos
Landsat ETM+
snow
snow
MODIS Terra & Aqua
snow
DEM
Fractional snow cover in mountain areas
IV. SWE at 1st April (1972 – 2007)
snow
IIb. Weekly and annual MODISfractional snow cover distribution;
19721980
snow2006
ModelsIIIa. Spatial and temporal changes of SWE based on MODIS fractional snow cover;
Model
19721980
snow2006
ANN&
GIS
V. Reconstruction of SWE and snow days (1400 – 2007);
snow
I. Neural network based fractional snow cover estimator
Future plans: 2005 - 2008