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...

Introduction Conclusions References

Precipitation is very important to the formation of runoff, and studying of runoff variation and its response to precipitation has practical significance to sustainable utilization of water resources. The study used Mann-Kendall test, anomaly accumulation method, and precipitation elasticity of runoff method to analyze the changes in the relation of precipitation and runoff and the contribution...

Meteorological stations usually contain some missing data for different reasons.There are several traditional methods for completing data, among them bivariate and multivariate linear and non-linear correlation analysis, double mass curve, ratio and difference methods, moving average and probability density functions are commonly used. In this paper a blended model comprising the bivariate expo...

[1] Auroral substorms are the result of a complex process involving coupling between the solar wind, magnetosphere and ionosphere. In this study, the objective is to understand the processes that precede what is perhaps the most fundamental aspect, the brightening of a preexisting arc at onset. The notion that this brightening provides an indicator of substorm onset remains one of the few aspec...

Precipitation, in meteorology, is defined as any product, liquid or solid, of atmospheric water vapor that is accumulated onto the earth’s surface. Water, and thus precipitation, has a major impact on our daily livelihood. As such, the uncertainty of both the future occurrence and amount of precipitation can have a negative impact on many sectors of our economy, especially agriculture. There is...

Background: Mature landfill leachate is a complicated mixture which is resistant to biological treatment processes. The treatment of mature landfill leachate by struvite precipitation and Fenton oxidation was the main objective of the current research. Methods: Struvite with the phosphate/ammonia/magnesium molar ratio of 1/1/1.05 was considered during all experiments. Five initial pHs of 3, 4, ...