نتایج جستجو برای: maintain soil moisture

تعداد نتایج: 317372  

2008
Enrique R. Vivoni Mekonnen Gebremichael Christopher J. Watts Rajat Bindlish Thomas J. Jackson

Comparisons to ground-based surface soil moisture estimates are necessary to evaluate the capability of remote sensors to determine soil moisture and its spatiotemporal variability. Soil moisture can be especially variable in regions of complex terrain which exhibit large variations in vegetation, soil properties and hydrologic conditions. The objective of this study is to evaluate the spatiote...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده کشاورزی 1389

چکیده توان بالقوه تجاری سلولازها و کاربردهای گوناگون آن ها در بسیاری از صنایع انگیزه ای قوی برای تحقیق در این زمینه طی چند دهه گذشته بوده است. با توجه به کاربردهای فراوان این آنزیم در صنایع غذایی? در این پژوهش تصمیم به جداسازی ریزسازواره های تولید کننده سلولاز از خاک درختان انار، انگور، خرمالو و گردو حیاط دانشکده کشاورزی تربیت مدرس، گرفته شد. در این بین خاک درخت خرمالو به دلیل دارا بودن تعداد ...

2017
Juha M. Alatalo Annika K. Jägerbrand Jaanis Juhanson Anders Michelsen Peter Ľuptáčik

High-altitude and alpine areas are predicted to experience rapid and substantial increases in future temperature, which may have serious impacts on soil carbon, nutrient and soil fauna. Here we report the impact of 20 years of experimental warming on soil properties and soil mites in three contrasting plant communities in alpine/subarctic Sweden. Long-term warming decreased juvenile oribatid mi...

2010
Ram L. Ray Jennifer M. Jacobs

The combined effect of soil moisture in unsaturated soil layers and pore-water pressure in saturated soil layers is critical to predict landslides. An improved infinite slope stability model, that directly includes unsaturated zone soil moisture and groundwater, is derived and used to analyze the factor of safety’s sensitivity to unsaturated zone soil moisture. This sensitivity, the change in t...

2002
William L. Crosson Charles A. Laymon Ramarao Inguva Marius P. Schamschula

A key state variable in land surface–atmosphere interactions is soil moisture, which affects surface energy fluxes, runoff and the radiation balance. Soil moisture modelling relies on parameter estimates that are inadequately measured at the necessarily fine model scales. Hence, model soil moisture estimates are imperfect and often drift away from reality through simulation time. Because of its...

2003
Wenge Ni-Meister Paul R. Houser

Current models for seasonal climate prediction are limited due to poor initialization of the land surface soil moisture states. Passive microwave remote sensing provides quantitative information on soil moisture in a thin near-surface soil layer at large scale. This information can be integrated with a land surface process model through data assimilation to give better prediction of the near su...

Journal: :Remote Sensing 2009
Tarendra Lakhankar Hosni Ghedira Marouane Temimi Manajit Sengupta Reza Khanbilvardi Reginald A. Blake

Satellite remote sensing observations have the potential for efficient and reliable mapping of spatial soil moisture distributions. However, soil moisture retrievals from microwave remote sensing techniques are typically complex due to inherent difficulty in characterizing the interactions among land surface parameters that contribute to the retrieval process. Therefore, adequate physical mathe...

2004
ROLF H. REICHLE RANDAL D. KOSTER JIARUI DONG AARON A. BERG

Three independent surface soil moisture datasets for the period 1979–87 are compared: 1) global retrievals from the Scanning Multichannel Microwave Radiometer (SMMR), 2) global soil moisture derived from observed meteorological forcing using the NASA Catchment Land Surface Model, and 3) ground-based measurements in Eurasia and North America from the Global Soil Moisture Data Bank. Time-average ...

2006
Wenge Ni-Meister Paul R. Houser Jeffrey P. Walker

[1] Climate model prediction skill is currently limited in response to poor land surface soil moisture state initialization. However, initial soil moisture state prediction skill can potentially be enhanced by the assimilation of remotely sensed near-surface soil moisture data in off-line simulation. This study is one of the first to evaluate such potential using actual remote sensing data toge...

2011
Julien Minet Patrick Bogaert Marnik Vanclooster Sébastien Lambot

Ground penetrating radar (GPR) is an efficient method for soil moisture mapping at the field scale, bridging the scale gap between small-scale invasive sensors and large-scale remote sensing instruments. Nevertheless, commonly-used GPR approaches for soil moisture characterization suffer from several limitations and the determination of the uncertainties in GPR soil moisture sensing has been po...

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