Search results for " time lag"

showing 3 items of 3 documents

Estimation of the time lag occurring between vegetation indices and aridity indices in a Sicilian semi-arid catchment

2009

The evolution of drought phenomena in a Sicilian semi-arid catchment has been analyzed processing both remote sensing images and climatic data for the period 1985-2000. The remote sensing dataset includes Landsat TM and ETM+ multispectral images, while the climatic dataset includes monthly rainfall and air temperature. The results have been specifically discussed for areas where it is possible to neglect agricultural activities and vegetation growth is only influenced by natural forcing. The main outcome of this study is the quantification of the time lag between the remote sensing retrieved vegetation indices and the aridity indices (AIs) calculated from climatic data. Moreover the obtaine…

Atmospheric Sciencegeography.geographical_feature_categoryvegetation indices aridity indices drought time series time lagApplied MathematicsMultispectral imageSettore ICAR/02 - Costruzioni Idrauliche E Marittime E IdrologiaDrainage basinVegetationForcing (mathematics)Aridlanguage.human_languageGeographyRemote sensing (archaeology)ClimatologylanguageAridity indexComputers in Earth SciencesSicilianGeneral Environmental Science
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On the Use of the Eddy Covariance Latent Heat Flux and Sap Flow Transpiration for the Validation of a Surface Energy Balance Model

2018

Actual evapotranspiration is assessed via surface energy balance at an hourly rate. However, a robust estimation of daily evapotranspiration from hourly values is required. Outcomes of surface energy balance are frequently determined via measures of eddy covariance latent heat flux. Surface energy balance can be applied on images acquired at different times and spatial resolutions. In addition, hourly actual evapotranspiration needs to be integrated at a daily rate for operational uses. Questions arise whether the validation of surface energy balance models can benefit from complementary in situ measures of latent heat flux and sap flow transpiration. Here, validation was driven by image ac…

CanopyAcquisition time; Flux tower; Heat dissipation technique; Spatial resolution; Time lag; Earth and Planetary Sciences (all)010504 meteorology & atmospheric sciencesScienceAcquisition time; Flux tower; Heat dissipation technique; Spatial resolution; Time lag; Earth and Planetary Sciences0208 environmental biotechnologyEnergy balanceEddy covariance02 engineering and technologyAtmospheric sciences01 natural sciencestime lagFlux (metallurgy)Latent heatEvapotranspirationSettore AGR/08 - Idraulica Agraria E Sistemazioni Idraulico-Forestaliflux tower; heat dissipation technique; time lag; spatial resolution; acquisition timeacquisition timeImage resolutionspatial resolution0105 earth and related environmental sciencesTranspirationSettore ICAR/02 - Costruzioni Idrauliche E Marittime E IdrologiaQ020801 environmental engineeringEarth and Planetary Sciencesheat dissipation techniqueGeneral Earth and Planetary SciencesEnvironmental scienceEarth and Planetary Sciences (all)Settore ICAR/06 - Topografia E Cartografiaflux towerRemote Sensing
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Timing in methods for studying psychosocial factors at work

2014

In the present chapter we focus on time lags in panel studies investigating psychosocial factors and stressor-strain relationships. First, a framework of theoretical reasons for choosing specific time lags is provided, which is based on the work by Frese and Zapf (Methodological issues in the study of work stress: objective vs. subjective measurement of work stress and the question of longitudinal studies. In: Cooper CL, Payne R (eds) Causes, coping and consequences of stress at work. Wiley, Chichester, pp 375–411, 1988). Although this theoretical framework provides a clear rationale for time intervals, researchers are frequently mistaken using it to derive appropriate time lags. Second, an…

Coping (psychology)Asia pacificWork stressstressor-strain relationshipsSpecific timetaxonomy on time lagsAsia pacific regionPsychologypsychosocial factorstime lagsPsychosocialSocial psychologyCognitive psychology
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