Soil Moisture Mapping of Drought in Texas

By Johnny Sullivan

Transcript

1. Soil Moisture Mapping of Drought in Texas Presentation by: Johnny Sullivan Center for Research in Water Resources University of Texas at Austin Texas GIS Forum October 4th, 2012
2. Texas Is Getting Drier Source: Bates et al. 2008 (IPCC Report, “Climate Change and Water”)
3. Drought of 2011 § 2011: driest and hottest year in Texas’ history § Lake Travis evaporation losses > Austin supply § $7.6 billion in agricultural losses http://whinesisters.com/wp-content/uploads/2011/09/Lake-Travis-Drought-5.jpg
4. Analyzing Drought http://www.laketravis.org/wp-content/uploads/2010/01/LakeTravis_Texas.jpg http://www.cc.gatech.edu/cpl/projects/graphcuttextures/data/interaction/LittleRiver.jpg
5. Project Goal Create a map, available online and updated in real-time, showing the extent of drought in Texas based on soil moisture content
6. Soil Moisture Parameters Available Water Storage Current Water Storage
7. NLDAS § National Land Data Assimilation System § Current Water Storage § kg/m2, for 0-100 cm § 1/8th degree quads
8. Geoprocessing Model
9. Soil Moisture Map
11. § Process convoluted, difficult § Could be scripted § Converted using THREDDS § Not efficient: - Download entire model output for timestep - Separate Texas and soil moisture
12. New NLDAS Web Service §  Specify: §  start/end dates (1979-2012) §  location (either lat/long or NLDAS grid point) §  Returns hourly soil moisture data for top 100 cm §  Nearly 290,000 data points §  Every hour from 1979 to 2012
13. NLDAS Grid Points over Texas (centroids of output quads) 1979 2012 2011 Drought 27 cm … wet or dry?
14. Relative Frequency Curve
15. Cumulative Frequency Curve Current Value = 27.5 cm ~ 60th Percentile
16. Collecting Water Data Globally (GRACE) Gravity Anomaly of Texas, 2002 – 2012 In 2011, we lost 100 Km3 of water or 70 Lake Travis’s Normal Reservoir Storage in Texas, 2002 – 2012
17. Calculating the Water Balance for Texas Water Volume Equivalent Water Storage Soil Moisture 9 km3 100 km3 25 km3
18. Moving Forward § Automation of soil moisture mapping § Access data rods for all of Texas § Further statistical analysis to determine historical significance of current soil moisture values § Integration with mapping and emergency planning/management systems (GEMSS)
19. Soil Moisture Mapping of Drought in Texas Presentation by: Johnny Sullivan Center for Research in Water Resources University of Texas at Austin Texas GIS Forum October 4th, 2012