نتایج جستجو برای: standard precipitation index spi
تعداد نتایج: 941481 فیلتر نتایج به سال:
Drought is a natural and climatic phenomenon that occurs in world wide areas every year and occurrence becomes an inevitable issue. This phenomenon is impaired in ecosystem. Arid rangeland ecosystems are a significant part of our land that is brittle systems that climatic changes are useful to simply unfounded destruction. Therefore, drought identifying and monitoring valid descriptive statisti...
We examined the relationship between satellite measurements of solar-induced chlorophyll fluorescence (SIF) and several meteorological drought indices, including the multi-time-scale standard precipitation index (SPI) and the Palmer drought severity index (PDSI), to evaluate the potential of using SIF to monitor and assess drought. We found significant positive relationships between SIF and dro...
Precipitation is the only water supply and most important factor affecting vegetation growth on the slopes of semi-arid Loess Plateau of China. Based on precipitation data from 7 synoptic stations in the study area over the period 1957-2012, the trends of precipitation and standardized precipitation index (SPI) were analyzed by using linear regression, Mann-Kendall, and Spearman's Rho tests at ...
The present paper focused on the analysis of drought in the Heihe River basin based on daily precipitation data observed at 13 weather stations covered from 1961 to 2010. The spatial and temporal variation of drought was estimated by means of the Standardized Precipitation Index (SPI), linear regression analysis and inverse distance weighted analysis. The SPI series on 1-month, 3-month, 6-month...
This paper presents a new index to determine meteorological drought conditions, the Drought Exceedance Probability Index (DEPI), derived from monthly precipitation time series. Its formulation is simple and undemanding in terms of baseline information requirements. makes DEPI suitable for routine application any climate, similar well-known Standardized Precipitation (SPI). The based on calculat...
drought detecting is a necessary aspect of drought risk management. it is generally performed usingdifferent drought indices that are effectively continuous functions of rainfall and other hydro- meteorologicalvariables. a number of drought indices have been introduced and used in various countries to date. in thecurrent research, four meteorological drought indices including the standardized p...
Drought is an unpredictable hydrological phenomenon, and climate change has made it difficult to predict analyze droughts. Nyala city airport metrological station rainfall records from 1943 2017 (75 years) were investigated. Four statistical drought indices used; the standardized precipitation index (SPI), anomaly (RAI), decile percent (RDI), normal (PNI). The study analyzes, assesses, compares...
hydrological drought analysis using sdi index in halilrud basin of iran abstract nowadays, drought is considered as damaging environmental phenomenon which affects natural resources and social communities. therefore it will be an important issues that magnitude and effects of these phenomena to be considered. to do this we used l-moment method for regional homogeneity testing. the streamflow dr...
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...
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