نتایج جستجو برای: drought severity

تعداد نتایج: 183107  

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...

Journal: :Journal of Japan Society of Hydrology and Water Resources 1990

2014
RAFAEL M. NAVARRO-CERRILLO RAÚL SÁNCHEZ-SALGUERO RUBÉN D. MANZANEDO

To assess if tree age may modulate the main climatic drivers of radial growth, two relict Pinus nigra subsp. salzmannii populations (María, most xeric site; Mágina, least xeric site) were sampled in southern Spain near the limits of the species range. Tree-ring width residual chronologies for two age groups (mature trees, age ≤ 100 years (minimum 40 years); old trees, age > 100 years) were buil...

The purpose of this study is analyzing the trend of drought characteristics in Hamedan Province In this regard, the corrected standardized precipitation index (SPImod) was calculated based on the monthly precipitation data from 11 synoptic and rain gauge stations during the period of 1985-2013. Drought characteristics, including severity, duration and interarrival time were defined and extracte...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2010
Connie A Woodhouse David M Meko Glen M MacDonald Dave W Stahle Edward R Cook

A key feature of anticipated 21st century droughts in Southwest North America is the concurrence of elevated temperatures and increased aridity. Instrumental records and paleoclimatic evidence for past prolonged drought in the Southwest that coincide with elevated temperatures can be assessed to provide insights on temperature-drought relations and to develop worst-case scenarios for the future...

2017
Saran Aadhar Vimal Mishra

Drought in South Asia affect food and water security and pose challenges for millions of people. For policy-making, planning, and management of water resources at sub-basin or administrative levels, high-resolution datasets of precipitation and air temperature are required in near-real time. We develop a high-resolution (0.05°) bias-corrected precipitation and temperature data that can be used ...

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 ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید چمران اهواز - دانشکده مهندسی علوم آب 1393

drought is transient phenomenon , slow , repetitive and integral part of the climate of each region. drought begins with a substantial reduction in precipitation over the long-term average rainfall and over time, reduced soil moisture and surface and ground water resources will continue to decrease. this phenomenon is the most important in bakhtegan basin because of its importance in strategic ...

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...

2011
Michael Michaelian Edward H Hogg Ronald J Hall Eric Arsenault

Drought-induced, regional-scale dieback of forests has emerged as a global concern that is expected to escalate under model projections of climate change. Since 2000, drought of unusual severity, extent, and duration has affected large areas of western North America, leading to regional-scale dieback of forests in the southwestern US. We report on drought impacts on forests in a region farther ...

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