نتایج جستجو برای: volumetric soil moisture

تعداد نتایج: 228697  

Journal: :پژوهش آب در کشاورزی 0
مهدی شرفا دانشیار پردیس کشاورزی دانشگاه تهران، علوم خاک. مجتبی مهدوی کرمشاهلو دانشجوی کارشناسی ارشد دانشگاه تهران، پردیس کشاورزی و منابع طبیعی دانشگاه تهران. منوچهر گرجی دانشیار پردیس کشاورزی دانشگاه تهران، علوم خاک.

iran as an arid and semi-arid country always faces with the problem of soil water shortage due to insufficient precipitation and, especially in light soils, low water holding capacity and high deep percolation. therefore, researchers have tried to use new methods for increasing this capacity to keep the water in the root zone and increase the amount of plant available water and water use effici...

2004
Dennis D. Baldocchi Liukang Xu Nancy Kiang

Savannas and open grasslands often co-exist in semi-arid regions. Questions that remain unanswered and are of interest to biometeorologists include: how do these contrasting landscapes affect the exchanges of energy on seasonal and annual time scales; and, do biophysical constraints imposed by water supply and water demand affect whether the land is occupied by open grasslands or savanna? To ad...

2013
Yingying Chen Kun Yang Jun Qin Long Zhao Wenjun Tang Menglei Han

[1] A multi-scale soil moisture and temperature monitoring network, consisting of 55 soil moisture and temperature measurement stations, has been established in central Tibetan Plateau (TP). In this study, the station-averaged surface soil moisture data from the network are used to evaluate four soil moisture products retrieved from the Advanced Microwave Scanning Radiometer-Earth Observing Sys...

2016
Cécile Pellet Christin Hilbich Antoine Marmy Christian Hauck

In regions affected by seasonal and permanently frozen conditions soil moisture influences the thermal regime of the ground as well as its ice content, which is one of the main factors controlling the sensitivity of mountain permafrost to climate changes. In this study, several well established soil moisture monitoring techniques were combined with data from geophysical measurements to assess t...

2012
S. Bircher N. Skou K. H. Jensen J. P. Walker

The Soil Moisture and Ocean Salinity Mission (SMOS) acquires surface soil moisture data of global coverage every three days. Product validation for a range of climate and environmental conditions across continents is a crucial step. For this purpose, a soil moisture and soil temperature sensor network was established in the Skjern River Catchment, Denmark. The objectives of this article are to ...

Journal: :Remote Sensing 2017
Alexandre Roy Peter Toose Chris Derksen Tracy L. Rowlandson Aaron A. Berg Juha Lemmetyinen Alain Royer Erica Tetlock Warren Helgason Oliver Sonnentag

Passive microwave measurements from space are known to be sensitive to the freeze/thaw (F/T) state of the land surface. These measurements are at a coarse spatial resolution (~15–50 km) and the spatial variability of the microwave emissions within a pixel can have important effects on the interpretation of the signal. An L-band ground-based microwave radiometer campaign was conducted in the Can...

2015
Y. Yu W. Wei L. D. Chen F. Y. Jia L. Yang H. D. Zhang T. J. Feng

Soil moisture plays a key role in vegetation restoration and ecosystem stability in arid and semiarid regions. The response of soil moisture to rainfall pulses is an important hydrological process, which is strongly influenced by land use during the implementation of vegetation restoration. In this study, vertical soil moisture variations of woodland (Pinus tabulaeformis), native grassland (Sti...

2008
Thierry Pellarin Jean-Christophe Calvet Wolfgang Wagner

This paper investigates the ERS Scatterometer soil moisture products precision over a half-degree region in Southwestern France. Based on a high resolution soil moisture simulation (1km2) validated at the local scale, the ERS-scat product is assessed at its own resolution (about 50x50 km2). The study points out the suitable quality of the surface soil moisture product (root mean square error eq...

Journal: :Plant physiology 1976
B B Patil R De

Daily transpiration rate was decreased by low soil moisture, phenylmercuric acetate (PMA) in combination with kaolinite, Mobileaf (a filmforming wax emulsion manufactured by the Mobil Oil Co.), PMA alone, and kaolinite alone in this order. At high soil moisture, dry matter was decreased by PMA but was increased by Mobileaf and by PMA + kaolinite combination. At low soil moisture, dry matter was...

2010
Feifei Pan Christa D. Peters-Lidard Anthony W. King

Soil particle size distribution PSD i.e., clay, silt, sand, and rock contents information is one of critical factors for understanding water cycle since it affects almost all of water cycle processes, e.g., drainage, runoff, soil moisture, evaporation, and evapotranspiration. With information about soil PSD, we can estimate almost all soil hydraulic properties e.g., saturated soil moisture, fie...

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