نتایج جستجو برای: drought index

تعداد نتایج: 424034  

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...

2013
Zengchao Hao Amir AghaKouchak

Defining droughts based on a single variable/index (e.g., precipitation, soil moisture, or runoff) may not be sufficient for reliable risk assessment and decision-making. In this paper, a multivariate, multiindex droughtmodeling approach is proposed using the concept of copulas. The proposed model, named Multivariate Standardized Drought Index (MSDI), probabilist ically combines the Standardize...

2010
M. Ebrahimi A. A. Matkan

Rainfall, soil moisture, increasing temperature and changes in vegetation cover are the most important parameters effecting drought. Therefore, analysis of vegetation fraction and soil spectral signature, especially in red and infra red bands, are essential in drought estimation using remote sensing. In this study, Modified Perpendicular Drought Index (MPDI), which uses Vegetation Fraction (VF)...

2013
Linglin Zeng Linglin ZENG Jie SHAN Daxiang Xiang

Various drought monitoring models have been developed from different perspectives, as drought is impacted by various factors (precipitation, evaporation, runoff) and usually reflected in various aspects (vegetation condition, temperature). Cloud not only plays an important role in the earth's energy balance and climate change, but also directly impacts the regional precipitation and evaporation...

2006
Peter T. Soule

The impacts of severe droughts on human activities, terrestrial ecosystems, and hydrologic systems are wide ranging and easily discernible. Because these impacts are felt at different times by water users, various forms of drought are recognized (e.g. agricultural, hydrological). The purpose of this study is to examine spatial patterns of drought in the contiguous United States on a seasonal ba...

2015
Hi-Ryong Byun Donald A. Wilhite HI-RYONG BYUN DONALD A. WILHITE

Common weaknesses of current drought indexes were analyzed. First, most of the current indexes are not precise enough in detecting the onset, end, and accumulated stress of drought. Second, they do not effectively take into account the aggravating effects of runoff and evapotranspiration, which build up with time. Third, they have a limited usefulness in monitoring ongoing drought because they ...

2008
Marcelo de A. Silva John L. Jifon Jorge A.G. Da Silva Vivek Sharma

Use of physiological parameters as fast tools to screen for drought tolerance in sugarcane: Drought is one of the major limitations to plant productivity worldwide. Identifying suitable screening tools and quantifiable traits would facilitate the crop improvement process for drought tolerance. In the present study, we evaluated the ability of four relatively physiological parameters (variable-t...

In this research, the possibility of applying selection index of ideal genotype (SIIG) technique for identify tolerate genotypes using the different drought tolerance indices be amended. The experiment was conducted as split plot based on randomized complete block design with three replications at the experimental farm of agricultural research institute and natural resources, Yazd, Iran in 2011...

Journal: :international journal of advanced biological and biomedical research 2013
ezatollah farshadfar mohammad mehdi poursiahbidi seyed mehdi safavi

one of the possible ways to ensure future food needs of an increasing world population involves the better water use through the development of crop varieties which need less water and are more tolerant to drought. in order to study the response of twenty landraces of bread wheat to drought stress, an experiment was conducted in a randomized complete block design with three replications under t...

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