Advantages And Disadvantages Of Droughts

Introduction

Increased temperature due to global warming has a severe effect on the water cycle over land [1]. Global warming will, for example, result in an increase of the frequency and severity of droughts [2]. Drought is a major natural hazard, and is of interest because it is one of the main causes of agricultural, economic and environmental damage. For example: the number of people affected by drought in European countries increased over the last three decades by 20%. Recent droughts in Europe include the persistent drought of 1989–1993 and the severe drought of 2003. The drought of 2003 only affected about 100 million people, resulting in a cost of damage of circa 8.7 billion Euros [3]. Management of drought is required to reduce the vulnerability of the affected systems, so the effects of droughts may be mitigated. However, it is very difficult to determine the characteristics for droughts. For this reason, much effort is needed for developing techniques for drought analysis and monitoring [4].

Until now, many studies of dryness

So far, the two most used methods are the standardized precipitation index (SPI) and the Palmer drought severity index (PDSI) [4]. The main advantage of SPI is its simplicity whereas the main disadvantage is the use of only one meteorological parameter for describing the water deficit [6]. The PDSI is calculated from a water-balance model driven by monthly temperature data and precipitation. The simplicity of the PDSI makes it an attractive tool in drought assessments, but the method is not comparable between diverse climatological regions and may give wrong impressions in the context of climate change [7]. Recent research also indicated that previously reported increases in global drought by the PDSI are overestimated because it uses a simplified model of PET, and thus incorrectly responds to global warming