The aim of this paper is to investigate characteristics of meteorological and agricultural droughts and their trends in Iran, as well as several subregions with different climate conditions from 1980 to 2013. The Standardized Precipitation Index (SPI) and Standardized Soil Moisture Index (SSI) are used as the primary indicators of meteorological and agricultural droughts, respectively. This stu...

in order to avoid drought effects, it is essential to detect and monitor the spatial andtemporal changes of the phenomenon. in general, drought indices are made use of toachieve the goals. the main aim followed in this paper is to introduce and assess a newdrought index termed mrdi. mrdi (modified reconnaissance drought index) is thencompared with modified standardized precipitation index (mspi...

although precipitation is the most important factor which effects rangeland production, but there is little information on the relationship between production and the interactions of climatic factors and specially drought indices. .in this research, the relation between production and climatic factors of rainfall, temperature, evapo- transpiration, and as well as drought indices of standardized...

In order to have effective agricultural production the impacts of drought must be mitigated. An important aspect of mitigating the impacts of drought is an effective method of forecasting future drought events. In this study, three methods of forecasting short-term drought for short lead times are explored in the Awash River Basin of Ethiopia. The Standardized Precipitation Index (SPI) was the ...

Drought is a major problematic phenomenon mostly for semi-arid areas of Iran. During drought periods, reduction in vegetation levels causes such problems as soil erosion, surface runoff, flood risk, etc. Therefore, the assessment of drought effects on plant covers is the most important issue. This research was conducted in 2015 using the extracted vegetation indices from Moderate Resolution Ima...

The evaluation of the meteorological drought is fundamental for management water resource. One most used indices to evaluate standardized precipitation index (SPI) due its practicality and in a variety time scales, however, this uses as only variable, depending on deviations values. This important when evaluating SPI, because some ecosystems close equatorial zone, there are very warm periods wi...

drought is a natural hazard that have in arid and semiarid areas more frequency. so the study and identify synoptic patterns affecting this phenomenon seems to be necessary. by using peripheral circulation approach, drought periods during the 30-year (2011-1982) in the six synoptic stations provinces of kerman, yazd and isfahan, which have a long-term cooperative period were calculated with usi...

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