This study analyzed changes in lakes on the Tibetan Plateau between 2000 and 2011 using Landsat and SRTM data. Over 50 lakes were identified, with 9 lakes in 2000 and 10 lakes in 2011 larger than 50 square km selected for further analysis. The total area change was calculated for these lakes over the two time periods. Elevation was analyzed for individual lakes greater than 50 square km, and volume change was estimated for the largest lake, Selin Co, by summing the elevation differences multiplied by pixel areas.

1. Background
STUDY AREA
High Tibetan Plateau (HTP) has
thousands of lakes and are the origins
of major river systems to the South.
Consists of more than 50 lakes within
the study area.
Selin Co is the second largest
saltwater lake in HTP and is located in
the central Tibetan Plateau (88.5–
89.4E, 31.5–32.1N) with a surface
area of >1830 sq. km.

2. Background
DATA
LANDSAT ETM+ for 2000 SRTM3 in 2000 LANDSAT TM for 2011
Cloud Cover: 1% Date: 2000/10/7 Shuttle Radar Topography Mission (SRTM)Cover: 1%
Cloud Date: 2011/8/27
Product: ETM+ L1T Date: Feb. 2000 Product: TM L1T
Bands: 8 Resolution: 90m Bands: 7
Bands: 1

3. Methodology
• No Geometric Correction
Image Correction
• Cos(t) Module for Atomspheric
Correction
Water Body Detection
Lake Selection
Area Calculation
Elevation Calculation
Volume Calculation

4. Methodology
Image Correction
Water Body Detection
• Greater than 1 sq. km Lakes Selected
Lake Selection
• 61 Lakes in 2000
• 53 Lakes in 2011
Area Calculation • Greater than 50 sq. km Lakes Selected
• 9 Lakes in 2000
• 10 Lakes in 2011
Elevation Calculation
Volume Calculation

5. Methodology
Image Correction
Water Body Detection
• Greater than 1 sq. km Lakes Selected
Lake Selection
• 61 Lakes in 2000
• 53 Lakes in 2011
• Total Change in Area in 2 Study Years.
Area Calculation • Greater than 50 sq. km Lakes Selected
• 9 Lakes in 2000
• 10 Lakes in 2011
Elevation Calculation
Volume Calculation

6. Methodology
Image Correction
Water Body Detection
Lake Selection
• Total Change in Area in 2 Study Years.
Area Calculation
• Done only for Lakes greater than 50
Elevation Calculation sq. km.
• Analyzed Mean and Standard
Volume Calculation Deviation for each Lake greater than
50 sq. km. (Extraction by Mask,
Import/Export, Histo)

7. Methodology
Image Correction
Water Body Detection
Lake Selection
Area Calculation
• Done only for Lakes greater than 50
Elevation Calculation sq. km.
• Done only for Selin Co Lake.
• Analyzed Mean and Standard
Volume Calculation • Box Plot for Accuracy Assessment
Deviation for each Lake greater than
50 sq. km. (Extraction by
• SUM[(Mean Elevation - Changed Pixel Elevation) * Pixel
Mask, Import/Export, Histo)
2011
Area ]
2011

8. Methodology
Image Correction
Water Body Detection
Lake Selection
Area Calculation
Elevation Calculation
• Done only for Selin Co Lake.
Volume Calculation • Box Plot for Accuracy Assessment
• SUM[(Mean Elevation 2011 - Changed Pixel Elevation) * Pixel
Area ]
2011