نتایج جستجو برای: are significantly more than those after river water drought

تعداد نتایج: 7742932  

2014
Fei Ma Ting Ting Xu Ming Fei Ji Chang Ming Zhao

To predict the ecological consequences of climate change for a widely distributed tree species, it is essential to develop a deep understanding of the ecophysiological responses of populations from contrasting climates to varied soil water availabilities. In the present study, we focused on Pinus tabuliformis, one of the most economically and ecologically important tree species in China. In a g...

2012
Richard A. Wildman Noelani A. Forde

The water of the Colorado River of the southwestern United States (U.S.) is presently used beyond its reliable supply, and the flow of this river is forecast to decrease significantly due to climate change. A recent interim report of the Colorado River Basin Water Supply and Demand Study is the first acknowledgment of these facts by U.S. federal water managers. In light of this new stance, we e...

Journal: :پژوهش های علوم و فناوری چوب و جنگل 0

poplars are classified as fast-growing and slightly water tolerant species which will be weakened with decreased growth in extreme moisture or drought lands. the plantation of these species in agricultural lands and at the edge of rivers and water canals has currenthy an important role in both economical and social development of rural regions. the purpose of this study was to investigate and c...

Sistan has recently confronted to periodic drought and water scarcity that destroyed vital resources especially vegetation. Information about reaction of the vegetation species to drought is necessary for protecting and biological restoring this ecosystem, so density of Tamarix aphylla, Salix babylonica and Eucalyptus were investigated using quadrates 50m × 50 m during wet (1366-1376) and droug...

Journal: :پژوهش های زراعی ایران 0
کمال حاج محمدنیا قالی باف یحیی سلاح ورزی

drought and salinity are the most important limiting factors of plant growth and development in many regions of the world. in this regard, using of species that are able to have higher production in this condition is a suitable strategy. in order to study the effect of drought and salinity stresses on morphophysiological properties of kallar grass (leptochloa fusca l. kunth), a factorial experi...

2009
A. K. Gilgen N. Buchmann

Water is an important resource for plant life. Since climate scenarios for Switzerland predict an average reduction of 20% in summer precipitation until 2070, understanding ecosystem responses to water shortage, e.g. in terms of plant productivity, is of major concern. Thus, we tested the effects of simulated summer drought on three managed grasslands along an altitudinal gradient in Switzerlan...

Journal: :تحقیقات اقتصاد و توسعه کشاورزی ایران 0
اعظم رضایی دانشجو/دانشگاه تربیت مدرس سید ابوالقاسم مرتضوی استاد/دانشگاه تربیت مدرس غلامرضا پیکانی استاد/دانشگاه تهران

the agriculture sector is the largest water consumer in arid and semi-arid areas. so water scarcity has an important effect on this section. drought as one of the most important factors in making crisis in zayanderud river basin (zrb) has a deep effect on the agriculture sector. this study evaluates the drought effects on irrigation land and farmers profit on the east of zrb by using spi and cb...

2016
Farshid Vahedifard

There is a crucial need to improve our understanding of the potential threats of extreme events, such as the ongoing California drought, on critical geotechnical infrastructure and take subsequent actions in a timely manner to adapt our infrastructure. The need is more pronounced for levees because their functionality to protect limited water resources and dry land is more critical during droug...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه کاشان - دانشکده علوم انسانی 1390

increasing academic and professional language demands around the world are not a deniable fact. the purpose of this study was to investigate english language needs and communication needs of the chemistry students at master and ph.d. levels at the iranian universities. in this research, different methods were used including un-structured interview, structured interview, and two sets of question...

2004
W. L. Nieuwoudt R. M. Armitage

[1] Statistical analyses (discriminant, logit, and principal components) of water transfers in the Lower Orange River showed that water rights were transferred to farmers with the highest return per unit of water applied, those producing table grapes, and with highpotential arable ‘‘outer land’’ without water rights. Only unused water (sleeper right) was transferred, while water saved (through ...

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