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 monitoring is a fundamental component of drought risk management. it is normally performed using various drought indices that are effectively continuous functions of rainfall and other hydrometeorological variables. in many instances, drought indices are used for monitoring purposes. geostatistical methods allow the interpolation of spatially referenced data and the prediction of values...

altogether 20 groundwater samples were collected around the lakan pb and zn mine in iran. samples were analyzed for 8 constituents including fe, pb, hg, mn, zn, cn, so4 and cl using standard method. the results show that the average concentrations of constituents were 0.01, 0.60, 0.10, 0.01, 0.40, 35, 0.01 and 5.95 mg/kg for fe, mn, pb, zn, hg, so4, cn and cl, respectively. the computed contami...

Numerical experiments with the global model of the European Centre for Medium-Range Weather Forecasts (ECMWF) were devoted to the sensitivity of the modelled evaporation and precipitation to the vegetation Leaf Area Index (LAI). The temporally static LAI-distribution was replaced with a seasonally varying LAI, derived from Normalized Difference Vegetation Index (NDVI) archives. The seasonality ...

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 southern shores of caspian sea is subjected to several atmospheric factors due to its geographical position. north atlantic oscillation(nao) one of the effective phenomenon's affects the most part of hemisphere included caspian sea. in this research negative and positive phases of nao considered with variability of temperature and precipitation of southern shores of caspian sea in a 30...

Random fluctuations in temperature and precipitation have substantial impacts on agricultural output. However, the contribution of these changing configurations in weather to total factor productivity (TFP) growth has not been addressed explicitly in econometric analyses. Thus, the key objective of this study is to quantify and to investigate the role of changing weather patterns in explaining ...

abstract variation of climatic elements could be estimated by standard deviation, coefficients of variation and so on. in iranian climatological literature, variations of climatic elements have main attention during last decades. meanwhile worldwide climatologist desired to study the characteristics of variations as well as the distribution of frequency average of these elements. in this paper,...

We introduce an objective definition for onset and withdrawal of the South Asian summer monsoon (SASM), based on the large-scale atmospheric moisture budget. The change point (CHP) index allows precise characterization of the different stages and timescales of the large-scale SASM and is highly correlated with the local operational index, the monsoon onset over Kerala. The CHP-based onset and w...