What Does GRACE Contribute To The Drought Monitoring: A Case Study In Turkey

Okay Ahi G., Jın S.

27th International Union of Geodesy and Geophysics (IUGG) General Assembly, Montreal, Canada, 8 - 18 July 2019, pp.1-2

  • Publication Type: Conference Paper / Summary Text
  • City: Montreal
  • Country: Canada
  • Page Numbers: pp.1-2
  • Hacettepe University Affiliated: Yes


One of the mostly investigated application areas in gravimetry missions e.g. GRACE (Gravity

Recovery and Climate Experiment) is drought monitoring from the hydrological perspective.

When studying drought monitoring, scientific questions concerns primarily observed drought

periods, spatial distribution of the drought, long-term mass change, impact on terrestrial water

storage (TWS) variations and possible causes of the drought. Recently, NASA finds drought in

the Eastern Mediterranean worst of past 900 years. Thus, it has been critical to study an eventual

drought events in a Mediterranean climate region which has not been much investigated with

satellite technics. GRACE Level 3 (Release05-RL05) monthly land mass data of the Centre for

Space Research (CSR) processing center covering the period from April 2002 to January 2016,

Global Land Data Assimilation System (GLDAS: MOS, NOAH, VIC), and Tropical Rainfall

Measuring Mission (TRMM-3B43) models and drought indices such as self-calibrating Palmer

Drought Severity (SCPDSI), El Niño–Southern Oscillation (ENSO), and North Atlantic

Oscillation (NAO) are used to reply above-mentioned scientific questions in Turkey as study

area. We found that GRACE results reveal drought periods by a significant decrease in the TWS

signal. The spatial distribution of the drought is primarily conducted by the precipitation

patterns. Turkey observe a decreasing annual trend of TWS with 1 cm/yr. GRACE is more

sensitive to meteorological drought and can predict a possible drought event 9 months before

compared to traditional studies. One possible reason of the drought in Turkey seems to be

related with the La Nina effect from the climatic perspective.