Global Drought Monitoring Using PERSIANN & SPI

1. 2011 NASA Drought Monitoring Workshop April 11-12, Silver Spring, MD, USA Global Drought Monitoring Using PERSIANN & SPI Peyman Daneshkar Arasteh Assistant Prof. of IKIU, IR Visiting Prof. of UCI, USA pdaneshk@uci.edu

2. Presentation Outlines • Importance of Drought Monitoring • SPI as a Drought Index • Water Resources Management • PERSIANN Data • Results • Further Works

3. Importance of Drought Monitoring Precipitation Spatial and Temporal Variations More Water Consumption Global Warming (Climate Change) Population Growth Change in Precipitation Amount And its Type (Meteorological Drought) Less Extra Water Available More Pressure on Water Resources Specially Groundwater Change in River Flow Change in Groundwater Recharge Hydrological and Groundwater Drought Socio-Economic Fragility More Poverty and Hunger in Developing Countries and Less economic stability in Developed Countries and LESS ENVIRONMENTAL SUSTAINABILITY

4. Standard Precipitation Index (SPI) • To manage drought three steps are required: • Monitoring (i.e. Definition of Drought Indices, Drought Severity, Magnitude and Duration Identification) • Policy Making (Action Plan) • Action (Coping with drought) McKee TB, Doesken NJ, Kleist J. 1993. The Relationship of Drought Frequency and Duration to Time Scales. Proceedings of the Eighth Conference on Applied Climatology. American Meteorological Society: Boston; 179–184.

5. SPI as a drought index SPI magnitude shows severity of drought but its time step indicate the depth ofdrought effects on water resources and the environment: 1-month SPI is being used to determine the effects of drought on short term conditions of water stress, soil water deficiency and rainfed agriculture 3-month SPI is being applied for investigating the seasonal effects of drought specially on river discharge and it is applicable in low flow management in hydro structures such as hydro power stations, agricultural water diversions as well as agricultural production 6/12-month SPI is being used in reservoir management and ground water impact assessment to drought in small to mid size aquifer 24/48-month SPI is being used to monitor groundwater drought in large scale aquifers

6. Human Activities (Population Growth, Water Pollution, …) Climate Change (Droughts, Floods, …) Water Resources (Supplies) Water Resources (Supplies) Water Requirements (Demands) Water Requirements (Demands) Re-Balance Balance Water Resources Management Big Challenge Water Resources Management New Challenge Supplies Demands Water Resources Management In Global and Basin Scales Precipitation is the main SUPPLY Balance PERSIANN is a tool to estimate this supply

7. PERSIANN Data Set Access and Method of Precipitation Estimation Sorooshian et al. (2005), Available on: http://chrs.web.uci.edu/research/satellite_precipitation/activities00.html http://chrs.web.uci.edu/

8. Data Set: PERSIANN • Spatial Coverage: -50 to 50 degrees Latitudes • Spatial Resolution: 0.25 degree • Duration: March 2000 to December 2009 • Time step: Monthly • Change time step of PERSIANN from daily to monthly time step • Calculating SPI with different time steps (1, 3, 6, 12 and 24 months) • Mapping drought

9. Evaluation PERSIANN Capability in Drought Monitoring To show PERSIANN potentials in drought monitoring especially in groundwater drought a research carried out in an aquifer in South Caspian Sea region. It showed that there is a relatively reasonable relationship between PERSIANN 12-month SPI and annual groundwater unit hydrograph (GHU) fluctuations. ANOVA Table GHU = -0.75+1.66 SPI, R2 = 0.56

15. Groundwater Drought In Small Aquifers and local scales Rainfed Agriculture And Meteorological Drought Irrigated Agriculture And Hydrological Drought Groundwater Drought in Large Aquifers and Regional Scales Reservoir operation

16. Conclusion Further Works • Results showed that in most regions which populations are concentrated a degree of drought has been experienced and a pressure on groundwater has been exerted during the last decade. • PERSIANN 0.25 degree spatial resolution showed its capability to be a suitable bed for drought monitoring due to its resolution and also for its near real time global coverage. • PERSIANN-CCS data set with spatial resolution of 0.04 degree is the other alternative that can be used with more spatial accuracy • Comparing other remotely sensed drought indices such as EVI and ground based hydrological observations in basin scale can evaluate the results of this study • Joining to other drought monitoring activities which are carrying out by other institutions is appreciated

17. Thank you