drought is a natural hazard that has significant impact on economic, agricultural, environmental, and social aspects. in the present study details analysis of rainfall data has been carried out for the years 1981-2011. standard precipitation index (spi) has been used to evaluate the precipitation deficit in the karun watershed of iran. the results indicated that 1981-82,82-83,83-84,84-85,88-89,...

comparability analyses are performed to investigate similarities/differences of the standard precipitation index (spi) and the reconnaissance drought index (rdi), respectively, utilizing precipitation and ratio of precipitation over potential evapotranspiration (et0). data are from six synoptic stations in south khorasan province in iran.at the first for calculating spi, the elevation-precipita...

Comparability analyses are performed to investigate similarities/differences of the standard precipitation index (SPI) and the reconnaissance drought index (RDI), respectively, utilizing precipitation and ratio of precipitation over potential evapotranspiration (ET0). Data are from six synoptic stations in south Khorasan province in Iran.At the first for calculating SPI, the elevation-precipita...

Comparability analyses are performed to investigate similarities/differences of the standard precipitation index (SPI) and the reconnaissance drought index (RDI), respectively, utilizing precipitation and ratio of precipitation over potential evapotranspiration (ET0). Data are from six synoptic stations in south Khorasan province in Iran.At the first for calculating SPI, the elevation-precipita...

Droughts are one of the most damaging climatic phenomena, and the most complex natural hazard  which affects the economy, agriculture, public health and environment in large areas. The aim of this study is to compare drought indicators derived from tropical rainfall measuring mission (TRMM) data in the south of Iran. Also the TRMM rainfall was considered, so as to investigate changes in the rai...

Meteorological drought monitoring is important for drought early warning and disaster prevention. Regional meteorological drought can be evaluated and analyzed with standardized precipitation index (SPI). Two main processing schemes are frequently adopted: (1) mean of all SPI calculated from precipitation at individual stations (SPI-mean); and (2) SPI calculated from all-station averaged precip...

The effect of the length of record on the standardized precipitation index (SPI) calculation was investigated by examining correlation coefficients, the index of agreement, and the consistency of dry/wet event categories between SPI values derived from different precipitation record lengths. The effect was also illustrated by comparing SPI values derived from different lengths of record in some...

iran is located in dry belt of the earth and always involved with drought in different sections. drought has already caused many losses to natural plant cover, agriculture and human society. for drought monitoring, we can use some drought indecies. in this research, the standard index of annual precipitation)siap),sandardized precipitation index (spi) and palmer drought severity index (pdsi) we...

Drought is a natural hazard that has significant impact on economic, agricultural, environmental, and social aspects. In the present study details analysis of rainfall data has been carried out for the years 1981-2011. Standard precipitation index (SPI) has been used to evaluate the precipitation deficit in the Karun watershed of Iran. The results indicated that 1981-82,82-83,83-84,84-85,88-89,...