Estimating the meteorological based drought indicators to better manage its negative impact

Abstract: Drought is generally defined as a high moisture deficit below some expected levels but beyond this summarized definition, drought is a complex event compared to many other natural phenomena. Without a clear definition, nor a clear entry or termination, the drought phenomenon is very specific and highly region climate dependent. Defining this phenomenon by regions or quantifying it, is a very complex issue because of many alternative definitions by diverse authors. Despite the diversity on defining it, drought is a severe natural hazard that can be manageable. Viewed as a natural hazard, drought can be managed during its occurrence by alleviating and repairing the damages and by anticipating strategies and funds. Before planning the strategies, there is a need for a better known of the drought phenomenon in a given area. Knowing as well as possible of the regional drought indicators would provide an objective picture for quantification and analysis of drought. There are more than 100 drought indicators developed by diverse authors but the importance stands on the selection of the proper indicators that presents most of the risk for the area under the study. Accepting that there is no a unique accepted drought indicator but the indicators need to be developed for a specific context, in a specific area, some important drought indicators and widely used are meteorological indicators, mainly precipitation based indicators as the main driver of drought phenomenon. Some of the main drought indices based on precipitation are the Standardized Precipitation Index (SPI), Rainfall Deciles (RD), Palmer Drought Severity Index (PDSI), etc. Besides the above indicators there is some soil moisture indicators considered as a very relevant in drought analyses but the soil measurements is not always possible because of the lack of soil monitoring.

In this study were perform detailed analyses of the above drought indicators by using the proper meteorological parameter thresholds. The derived results may be used to better manage the drought phenomenon in order to convert it in a manageable natural hazard and mitigating its negative impacts.

Keywords: local drought, precipitation index, moisture, extreme drought