نتایج جستجو برای: drought index

تعداد نتایج: 424034  

Journal: :جغرافیا و مخاطرات محیطی 0

1. introduction a drought is a prolonged period of water deficit and usually occurs when an area does not receive significant precipitation for a sustained period of time, say several months (chen, kuo, & yu, 2009; linsely, kohlerm, & paulhus, 1959). the effects of drought often accumulate slowly over a considerable period of time that may linger for several years even after the termination of dr...

2016
Nina Nikolova Pavol Nejedlík Milan Lapin

Atmospheric drought in lowlands in Slovakia is analyzed on the bases of Standardised Precipitation Index (SPI) and Standardised Precipitation Evapotranspiration Index (SPEI). This paper gives information about the dynamic, intensity, seasonal and territorial differences in occurrence of drought with various intensity: mild (near to normal), moderate, severe and extreme for the period 1961–2011....

2011
Mevlüt AKÇURA Sait ÇERI

The main objective of this research was to evaluate fourteen oat (Avena sativa L.) landraces and cultivars for drought tolerance using several indices. The trials were conducted both under rain-fed and irrigated conditions for three growing seasons (2001–2004) in two locations in the Central Anatolian Region of Turkey. Biplot analysis based on the Spearman’s rank correlation matrix revealed tha...

Investigating the trend of changes in drought as one of the natural disasters is essential. For this purpose, in the present study, the trend of changes in standardized precipitation-evapotranspiration drought index (SPEI) for the synoptic stations of Kerman province was evaluated for the years 1990 to 2018. The change trend of the SPEI time series was evaluated using two both Mann-Kendall and ...

Journal: :پژوهش های جغرافیای طبیعی 0
حمید زارع ابیانه وحید یزدانی خلیل اژدری

quantitative measurement of meteorological drought, z score(z), rainfall anomaly (rai), standard precipitation (spi) indices and percent of normal precipitation (pnpi) based upon seasonal and annual rainfall data of the 15 meteorological stations of meteorological in hamedan province were used. also, in studying influences of drought on agriculture relative yield index of wheat was used. the re...

Journal: :crop breeding journal 2012
m. pouresmaeil r. khavari-nejad j. mozafari f. najafi f. moradi

drought is a major limiting factor for agricultural production in most parts of the world and landraces areimportant genetic resources for crop improvement in dry areas. during the 2007-2008 cropping season, 23 chickpea (cicer arietinum l.) genotypes consisting of 21 kabuli chickpea landraces provided by the national plant gene bank of iran and two known commercial varieties (hashem and arman) ...

2016
Jinwei Dong Xiangming Xiao Pradeep Wagle Geli Zhang Yuting Zhou Cui Jin Margaret S. Torn Tilden P. Meyers Andrew E. Suyker Junbang Wang Huimin Yan Chandrashekhar Biradar

Comparison of four EVI-based models for estimating gross primary production of maize and soybean croplands and tallgrass prairie under severe drought" (2015). a b s t r a c t a r t i c l e i n f o Keywords: Gross primary production (GPP) Drought Light use efficiency (LUE) Vegetation Photosynthesis Model (VPM) Temperature and Greenness (TG) model Greenness and Radiation (GR) model Vegetation Ind...

Journal: :پژوهش های حبوبات ایران 0
مسلم فتحی محمدرضا بی همتا ناصر مجنون حسینی علی اکبر شاه نجات بوشهری هادی محمدعلی پوریامچی

in order to study and determine the most effective traits, drought tolerance indices and identify tolerant genotypes in terminal drought stress on the cowpea, an experiment was carried out based on an augment design in two separate conditions in the karaj farm, faculty of agriculture, tehran university in 2009. drought stress was imposed by cutting irrigation after flowering against normal irri...

Extended Abstract Introduction and Objective: Due to the water resources limitation required for agriculture in Iran, providing effective methods to reduce the negative effects of drought on crop yield is one of the important studies to plant breeding. Drought tolerance in crops is very important. By using different cultivars of crops that are able to produce relatively good yield in drought s...

2012
André Kost Peter Läderach Myles Fisher Simon Cook Lorena Gómez

This paper discusses a methodology to model precipitation indices and premium prices for index-based drought insurance for smallholders. Spatial basis risk, which is borne by the insured, is a problem, especially in variable topography. Also, site-specific drought risk needs to be estimated accurately in order to offer effective insurance cover and ensure financial sustainability of the insuran...

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