نتایج جستجو برای: drought duration

تعداد نتایج: 234998  

Journal: :آب و خاک 0
حسین انصاری کامران داوری سیدحسین ثنائی نژاد

abstract drought is a natural creeping event that starts due to lower moisture compared to normal condition. this phenomenon impacts all aspects of human activities. however there is neither any detailed definition nor a general and proper index for drought monitoring. in this study, fuzzy logic has been applied to deal with inherent uncertainties of the real world data. we presented a fuzzy mo...

Journal: :Journal of Geophysical Research: Atmospheres 2014

2011
D. A. Wilhite

Drought is a naturally occurring event that is associated with virtually all climatic regions. Given its slow onset and other characteristics, including its spatial dimensions and duration, impacts are difficult to assess and have been, historically, poorly documented. These impacts are strongly influenced by a society’s exposure to the hazard and the vulnerability of that society to the hazard...

2014
Amin Zargar Rehan Sadiq Bahman Naser Faisal I. Khan

Drought is a stochastic natural hazard that is instigated by intense and persistent shortage of precipitation. Following an initial meteorological phenomenon, subsequent impacts are realized on agriculture and hydrology. Among the natural hazards, droughts possess certain unique features; in addition to delayed effects, droughts vary by multiple dynamic dimensions including severity and duratio...

Journal: :Remote Sensing 2015
Binbin He Zhanmang Liao Xingwen Quan Xing Li Junjie Hu

Existing drought indices have been widely used to monitor meteorological drought and agricultural drought; however, few of them are focus on drought monitoring for grassland regions. This study presented a new drought index, the Grassland Drought Index (GDI), for monitoring drought conditions in global grassland regions. These regions are vital for the environment and human society but suscepti...

Journal: :Zeitschrift fur Naturforschung. C, Journal of biosciences 2008
Tuğçe Kalefetoğlu Macar Yasemin Ekmekçi

The effect of drought on the chickpea variety ILC 3279 was investigated at the vegetative stage. After 20 days from sowing, the plants subjected to drought stress for 3, 5 and 7 days imposed by withholding water were permitted to recover by rewatering for 2 days after 3, 5 and 7 days of drought. Shoot elongation, leaf production, fresh and dry biomass reduced while MDA and proline accumulation ...

2007
T. C. SHARMA

The important elements of a drought phenomenon are the longest duration and the largest severity for a desired return period. These elements form a basis for designing water storage systems to cope with droughts. At times, a third element, drought intensity, is also used and is defined as the ratio of severity to duration. The commonly available statistics for the causative drought variables su...

Journal: :جغرافیا و مخاطرات محیطی 0
پرویز رضائی محمود روشنی سیده مهشید امیرآبادیزاده

1. introduction droughts are long-term phenomena that can affect large areas and cause severe downturn in economic and social activities. recognizing this phenomenon, its features and properties, knowledge of facilities, capabilities and talents of areas and providing short and long term solutions leads to the effort of the surface water resource managers to prepare for drought mitigation. the ...

2006
WARREN B. WHITE ALEXANDER GERSHUNOV JEFFREY ANNIS

The Dustbowl Era drought in the 1930s was the principal Midwest drought of the twentieth century, occurring primarily in late spring–summer [April–August (AMJJA)] when 70% of annual rainfall normally occurred. Another major Midwest drought occurred in the 1950s but primarily in fall–early winter [September–December (SOND)] when normal rainfall was 1/2 as much. Optimized canonical correlation an...

بایزیدی, مطلب, شاهدی, کاکا , کریمی, مهشید,

  Drought is known as an environmental phenomenon which leads to socio- economic and environmental issues. Therefore its analysis is crucial for proper management and planning of water resources . The Karkheh River basin is one of the important water resources in Iran and that is located in western Iran. Current paper tries to take one step ahead toward scientific and practical drought manageme...

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