An Analysis of Spatial and Temporal Dimension of Drought Vulnerability in Turkey Using the Standardized Precipitation Index

Abstract

Drought has become a recurrent phenomenon in Turkey in the last few decades. Significant drought conditions were observed during years of late 1980s and the trend continued in the late 1990s. The country's agricultural sector and water resources have been under severe constraints from the recurrent droughts. In this study, spatial and temporal dimensions of meteorological droughts in Turkey have been investigated from vulnerability concept. The Standardized Precipitation Index (SPI) method was used to detail geographical variations in the drought vulnerability based on frequency and severity of drought events at multiple time steps. Critical (threshold) rainfall values were derived for each station at multiple-time steps in varying drought categories to determine least amount of rainfall required to avoid from drought initiation. The study found that drought vulnerability portrays a very diverse but consistent picture with varying time steps. At regional scale, south-eastern and eastern Anatolia are characterized with moderate droughts at shorter time steps, while the occurrence of severe droughts at shorter time steps is observed at non-coastal parts of the country. A similar picture was observed with very severe droughts. The critical (threshold) values exhibited rising numbers during the growing season at 3-month step in the South-eastern Anatolia, which might have significant consequences considering presence of large irrigation projects underdevelopment in the region. In general, rainfall amounts required for non-drought conditions decrease from the coastal parts toward the interiors with increasing time steps.

Investigating the presumed causal links between drought and dzud in Mongolia

“…The standardised precipitation index (SPI) documents anomalous and extreme precipitation and drought events (McKee et al 1993;Sonmez et al 2005;Sternberg et al 2009). Using [30 years meteorological data, the SPI gives a numeric value to precipitation surplus or deficiency; this enables drought monitoring at different time scales and facilitates comparison across regions and varied climatic zones.…”

“…The SPI identifies positive/negative anomalies from zero that give a probability indication of event severity; a result of -1 reflects moderate drought, -1.5 severe drought and\-2 extreme conditions. With event probability based on a 100 year scale, an extreme drought would be expected to occur 2.3 times per century (Sonmez et al 2005). As the data record in this study is 45 years, drought frequency is extrapolated rather than a reflection of long-term (unavailable) data.…”

A Methodology for the Vulnerability Analysis of the Climate Change in the Oromia Region, Ethiopia

“…Drought is considered as the time period when the SPI is negative and it is classified on the basis of its duration. The meteorological drought is a period of at least one month of negative SPI, the agricultural drought is at least a three months period of negative SPI, while the hydrologic drought has a length of at least six months of negative SPI (Sönmez et al 2005).…”

Study of water stress and droughts with indicators using daily data on the Bani river (Niger basin, Mali)

“…This choice is due to the availability of precipitation data and the non-availability of temperature and PET data for the selected stations within the region on a daily time scale. This indicator has also been frequently used in different parts of the world (Wu et al, 2001;Giddings et al, 2005;Sönmez et al, 2005) with better spatial representation than any other common indicator, for example, the Palmer drought severity index (LloydHughes and Saunders, 2002). It is also very practical because of its normalization as drought occurrence thus being associated to a return period.…”