230
Multiscale Hydrologic Remote Sensing: Perspectives and Applications
East Rim Divide, Granite Creek, Gross Ventre Summit, Gunsight Pass, Lewis Lake
Divide, Philips Bench, Snake River Station, Thumb Divide, Togwotee Pass, and
Two Ocean Plateau. Further information about these stations may be obtained from
NRCS (http://www.wcc.nrcs.usda.gov/snotel/Wyoming/wyoming.html). The data
used from these stations for snowmelt runoff modeling included daily time series
of average air temperature and precipitation depth, together with accumulated precipitation and SWE to assist in determining a snow-covered area for years prior to
availability of satellite snow cover data.
The USGS (http://waterdata.usgs.gov/id/nwis/current/?type=flow?) NWIS was
used to obtain daily average stream flow data for model testing purposes. Historical
stream flow data were taken from gage number 13022500, labeled “Snake River AB
Reservoir NR Alpine WY,” which lies in the Upper Snake River Basin. Stream flow
at this gage is modulated significantly both within and between years by storage in the
Jackson Lake Reservoir, which is recorded by the USBR Hydromet network (http://
www.usbr.gov/pn-bin/arcread.pl?station=JCK). “Natural” or unregulated daily average stream flow at the USGS gage site was recovered by adding the daily change in
volumetric reservoir storage at the Jackson Lake divided by the time step (1 day),
expressed in cubic meters per second, to the measured flow rate.
Snow-covered area data were obtained from the Terra satellite’s MODIS 8-day L3
global 500-m grid composite SCA products (MOD10A2) available from the NSIDC
(see Hall et al. 2006). Ninety-six remotely sensed images were used, covering the
period from February to August for the years 2003–2006. The snow cover images
were processed in the Geographic Information System (GIS) ArcGIS software package to extract the basin area, delineate the basin zones used in the SRM, and then
calculate the fraction of SCA within each elevation zone.
10.4.3 BaSin chaRacteRiSticS
The snowmelt runoff modeling carried out in this work was applied to a basin located
in western Wyoming, in the United States, shown in Figure 10.4. It serves as the
headwaters of the Snake River and drains across the Snake River Plain of southern
Idaho and represents an important water resource for agriculture, and power generation, in-stream fish requirements, as well as municipal, commercial, and industrial
uses. The basin is designated by USGS Hydrologic Unit Codes 17040101, 02, and
03, known as the Snake Headwaters, Gross Ventre, and Greys-Hobock, respectively
(Seaber et al. 1987). It drains an area of 8894 km 2 (3465 mi 2 ) and spans an elevation
range of 1737–4194 m above mean sea level (amsl; 5799–13,760 ft). This basin was
selected because it supplies the South Fork of the Snake River, which accounts for
more than one-third of the total annual volume of flow across the Snake River Plain.
To run SRM, a basin must be divided into one or more elevation zones. In the
present case, the parent basin ranged from 1737 to 4194 m amsl, an elevation span of
2457 m. For modeling purposes, the basin was subdivided into five elevation zones
of 500-m each. Figure 10.5 shows the basin and the area occupied by each elevation
zone.
Table 10.2 shows for each elevation zone the elevation range, the zone area, the
hypsometric mean elevation (i.e., the area-weighted average zone elevation), and
Multiscale Hydrologic Remote Sensing: Perspectives and Applications
East Rim Divide, Granite Creek, Gross Ventre Summit, Gunsight Pass, Lewis Lake
Divide, Philips Bench, Snake River Station, Thumb Divide, Togwotee Pass, and
Two Ocean Plateau. Further information about these stations may be obtained from
NRCS (http://www.wcc.nrcs.usda.gov/snotel/Wyoming/wyoming.html). The data
used from these stations for snowmelt runoff modeling included daily time series
of average air temperature and precipitation depth, together with accumulated precipitation and SWE to assist in determining a snow-covered area for years prior to
availability of satellite snow cover data.
The USGS (http://waterdata.usgs.gov/id/nwis/current/?type=flow?) NWIS was
used to obtain daily average stream flow data for model testing purposes. Historical
stream flow data were taken from gage number 13022500, labeled “Snake River AB
Reservoir NR Alpine WY,” which lies in the Upper Snake River Basin. Stream flow
at this gage is modulated significantly both within and between years by storage in the
Jackson Lake Reservoir, which is recorded by the USBR Hydromet network (http://
www.usbr.gov/pn-bin/arcread.pl?station=JCK). “Natural” or unregulated daily average stream flow at the USGS gage site was recovered by adding the daily change in
volumetric reservoir storage at the Jackson Lake divided by the time step (1 day),
expressed in cubic meters per second, to the measured flow rate.
Snow-covered area data were obtained from the Terra satellite’s MODIS 8-day L3
global 500-m grid composite SCA products (MOD10A2) available from the NSIDC
(see Hall et al. 2006). Ninety-six remotely sensed images were used, covering the
period from February to August for the years 2003–2006. The snow cover images
were processed in the Geographic Information System (GIS) ArcGIS software package to extract the basin area, delineate the basin zones used in the SRM, and then
calculate the fraction of SCA within each elevation zone.
10.4.3 BaSin chaRacteRiSticS
The snowmelt runoff modeling carried out in this work was applied to a basin located
in western Wyoming, in the United States, shown in Figure 10.4. It serves as the
headwaters of the Snake River and drains across the Snake River Plain of southern
Idaho and represents an important water resource for agriculture, and power generation, in-stream fish requirements, as well as municipal, commercial, and industrial
uses. The basin is designated by USGS Hydrologic Unit Codes 17040101, 02, and
03, known as the Snake Headwaters, Gross Ventre, and Greys-Hobock, respectively
(Seaber et al. 1987). It drains an area of 8894 km 2 (3465 mi 2 ) and spans an elevation
range of 1737–4194 m above mean sea level (amsl; 5799–13,760 ft). This basin was
selected because it supplies the South Fork of the Snake River, which accounts for
more than one-third of the total annual volume of flow across the Snake River Plain.
To run SRM, a basin must be divided into one or more elevation zones. In the
present case, the parent basin ranged from 1737 to 4194 m amsl, an elevation span of
2457 m. For modeling purposes, the basin was subdivided into five elevation zones
of 500-m each. Figure 10.5 shows the basin and the area occupied by each elevation
zone.
Table 10.2 shows for each elevation zone the elevation range, the zone area, the
hypsometric mean elevation (i.e., the area-weighted average zone elevation), and