The authors propose a new climatic drought index: the standardized precipitation evapotranspiration index (SPEI). The SPEI is based on precipitation and temperature data, and it has the advantage of combining multiscalar character with the capacity to include the effects of temperature variability on drought assessment. The procedure to calculate the index is detailed and involves a climatic wa...

drought stress is one of the most important dangers for increasing the yield and good production of crops in iran and the world. to evaluate the genetic diversity of rapeseed genotypes, identifying the drought resistance indices and drought tolerant genotypes, 16 genotypes were tested in a randomized complete block design (rcbd) with three replications and two different water regimes (irrigated...

in order to evaluation the effect of drought stress on germination indices and early seedling growth of medicinal herb dill (anethum graveolens l), an experiment was conducted in the agricultural laboratory of urmia payam noor university in 2015 as a randomized complete block design with four replications. treatments were five levels of drought stress (0, -1, -2, -3 and -4 bar induced by polyet...

In the dry Swiss Rhone Valley, Scots pine forests have experienced increased mortality in recent years. It has commonly been assumed that drought events and bark beetles fostered the decline, however, whether bark beetle outbreaks increased in recent years and whether they can be linked to drought stress or increasing temperature has never been studied. In our study, we correlated time series o...

Six meteorological drought indices including percent of normal (PN), standardized precipitation index (SPI), China-Z index (CZI), modified CZI (MCZI), Z-Score (Z), the aridity index of E. de Martonne (I) are compared and evaluated for assessing spatio-temporal dynamics of droughts in six climatic regions in Iran. Results indicated that by consideration of the advantages and disadvantages of the...

In this study, to improve the efficiency of the original Palmer Drought Severity Index (PDSI_original), we coupled the Soil and Water Assessment tool (SWAT) and PDSI_original to construct a drought index called PDSI_SWAT. The constructed PDSI_SWAT is applied in the Wei River Basin (WRB) of China during 1960–2012. The comparison of the PDSI_SWAT with four other commonly used drought indices reve...

This study was conducted to evaluate antioxidant enzyme activities in four caprifig varieties under drought stress and subsequent rewatering in order to screen drought tolerance. Leaf relative water content and membrane stability index significantly reduced under drought stress. ‘Shah Anjir’ and ‘Khormaei’ were able to preserve the highest relative water content and membrane stability index lev...

Drought affects natural environment of an area when it persists for a longer period. So, drought forecasting plays an important role in the planning and management of natural resources and water resource systems of a river basin. During last decade neural networks have shown great ability in modeling and forecasting nonlinear and non-stationary time series. This paper compares linear stochastic...