نتایج جستجو برای: soil moisture

تعداد نتایج: 205538  

1999
MARK Z. JACOBSON

This paper examines the effects of soil moisture initialization in a coupled air quality–meteorological model on temperature profiles, wind speeds, and pollutant concentrations. Three simulations, each with different initial soil moisture fields, were run. In the baseline simulation, predicted temperatures, wind speeds, and gas/aerosol pollutant concentrations accurately matched observations. I...

Journal: :Remote Sensing 2016
Tiexi Chen Tim R. McVicar Guojie Wang Xing Chen Richard de Jeu Yi Y. Liu Hong Shen Fangmin Zhang Albertus Johannes Dolman

To improve the understanding of water–vegetation relationships, direct comparative studies assessing the utility of satellite remotely sensed soil moisture, gridded precipitation products, and land surface model output are needed. A case study was investigated for a water-limited, lateral inflow receiving area in northeastern Australia during December 2008 to May 2009. In January 2009, monthly ...

2012
Xiaofei An Minzan Li Lihua Zheng Yumeng Liu Yajing Zhang

The measurement and control of soil moisture are the key technologies of precision agriculture. In order to real-time detect soil moisture content faster and more accurately, a portable soil moisture sensor based on NIR spectroscopy was developed. With the sixty soil samples collected from a winter jujube orchard, a linear regression model was established. The determination coefficients of the ...

2016
Lingyuan Yang Petrutza C. Caragea Matthew J. Helmers Robert Horton Brian L. Steward

This dissertation describes efforts to overcome the challenges in designing in situ soil moisture observation network. The surface soil moisture data collected at two spatial scales in a working field in Iowa throughout the growing seasons in 2004 to 2008 were used to describe the spatio-temporal characteristics of soil moisture at field scale. The rank stability analysis was used to identify t...

2011
M. Zribi A. Chahbi M. Shabou Z. Lili-Chabaane

The present paper proposes a method for the evaluation of soil evaporation, using soil moisture estimations based on radar satellite measurements. We present firstly an approach for the estimation and monitoring of soil moisture in a semi-arid region in North Africa, using ENVISAT ASAR images, over two types of vegetation covers. The first mapping process is dedicated solely to the monitoring o...

Journal: :Remote Sensing 2015
Huihui Feng Yuanbo Liu Guiping Wu

In-situ soil moisture was widely used to validate and calibrate the satellite-retrieved data of different footprints. However, it contained unavoidable uncertainty when used as spatial representative. This paper examined the uncertainty in pixel-wise soil moisture designed for satellite validation in the HiWATER project. Two in-situ data sets were used for the examination, which were carefully ...

2004
Xi Chen Qi Hu

Soil hydrological processes play an important role in land-atmosphere system. In most climate models, these processes are described by soil moisture variations in the first 2 m of soil resulting from precipitation, evaporation, and transpiration. Groundwater effects on soil moisture variations and surface evaporation are either neglected or not explicitly treated. Although groundwater may have ...

2012
F. E. Moyano N. Vasilyeva L. Bouckaert

Soil moisture is of primary importance for predicting the evolution of soil carbon stocks and fluxes, both because it strongly controls organic matter decomposition and because it is predicted to change at global scales in the following decades. However, the soil functions used to model the heterotrophic respiration response to moisture have limited empirical support and introduce an uncertaint...

2010
Claire Gruhier Yann Kerr Thierry Pellarin Patricia de Rosnay Manuela Grippa

Soil moisture is one of the most important variable that in uences the soil-vegetation-atmosphere uxes. However, due to its high temporal and spatial variability, it is dif cult to provide accurate quantitative information on soil moisture at regional and global scales. Different approaches exist, but remote sensing is the more appropriated to measure soil moisture values and its variations. It...

2008
Niko E.C Verhoest Hans Lievens Wolfgang Wagner Jesús Álvarez-Mozos M. Susan Moran Francesco Mattia

Synthetic Aperture Radar has shown its large potential for retrieving soil moisture maps at regional scales. However, since the backscattered signal is determined by several surface characteristics, the retrieval of soil moisture is an ill-posed problem when using single configuration imagery. Unless accurate surface roughness parameter values are available, retrieving soil moisture from radar ...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید