WorldWideScience

Sample records for modeling moisture movement

  1. Modeling studies of gas movement and moisture migration at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Tsang, Y.W.; Pruess, K. [Lawrence Berkeley Lab., CA (United States)

    1991-06-01

    Modeling studies on moisture redistribution processes that are mediated by gas phase flow and diffusion have been carried out. The problem addressed is the effect of a lowered humidity of the soil gas at the land surface on moisture removal from Yucca Mountain, the potential site for a high-level nuclear waste repository. At the land surface, humid formation gas contacts much drier atmospheric air. Near this contact, the humidity of the soil gas may be considerably lower than at greater depth, where the authors expect equilibrium with the liquid phase and close to 100% humidity. The lower relative humidity of the soil gas may be modeled by imposing, at the land surface, an additional negative capillary suction corresponding to vapor pressure lowering according to Kelvin`s Equation, thus providing a driving force for the upward movement of moisture in both the vapor and liquid phases. Sensitivity studies show that moisture removal from Yucca Mountain arising from the lowered-relative-humidity boundary condition is controlled by vapor diffusion. There is much experimental evidence in the soil literature that diffusion of vapor is enhanced due to pore-level phase change effects by a few orders of magnitude. Modeling results presented here will account for this enhancement in vapor diffusion.

  2. Nonisothermal moisture movement in wood

    Institute of Scientific and Technical Information of China (English)

    LI Xianjun; ZHANG Biguang; LI Wenjun; LI Yanjun

    2006-01-01

    In order to analyze the effect of temperature gradient on moisture movement during highly intensive drying,such as microwave-vacuum drying,the profile of the temperature and moisture content in sealed wood whose opposite faces were subjected to temperature gradient for a short time was measured.The ratio of the moisture content (MC) gradient to the temperature gradient (dM/dT) was calculated and the factors influencing moisture movement under nonisothermal conditions were discussed.The results indicate that moisture moved in wood from the warm surface to the cold one even if opposite faces of the sealed wood assembly were exposed continuously to different but constant temperatures for a short period.The moisture content on the cold surface was higher than that on the warm surface.The moisture content gradient opposite to the temperature gradient was established,and the dM/dT was below 0.9%/℃.The temperature in the sample and the distance from the hot surface of the sample was strongly linearly correlated.With an increase in temperature,initial moisture content and experimental time,the dM/dT was significantly increased.

  3. Numerical Simulation of Moisture Movement in Unsaturated Expansive Soil Slope Suffering Permeation

    Institute of Scientific and Technical Information of China (English)

    Chen Shanxiong; Yu Song; Liu Zhiguo; Xu Haibin

    2005-01-01

    This study develops a way of analyzing moisture movement in unsaturated expansive soil slope. The basic equations and the integrated finite difference method for moisture movement in unsaturated soils are briefly described, and the calculation code MFUS2 has been developed. The moisture movements in unsaturated expansive soil slopes suffering precipitation were simulated numerically. The simulation results show that expansion or contraction must be taken into account in an analysis model. A simplified equivalent model for calculating rainwater infiltration into expansive soil slopes has been developed. The simplified equivalent model divides the soil slope into two layers according to the extent of weathering of the soil mass at depth. Layer Ⅰ is intensively weathered and moisture can be fully evaporated or rapidly absorbed. The moisture movement parameters take into account the greater soil permeability caused by fissures. Layer Ⅱ is unweathered and the soil is basically undisturbed. The moisture movement parameters of homogeneous soils are applicable. The moisture movements in unsaturated expansive soil slopes suffering precipitation were simulated numerically using the simplified equivalent model. The simulation results show that the moisture movement in the expansive soil slope under rainfall permeation mainly takes place in the extensively weathered layer Ⅰ, which closely simulates the real situation.

  4. MOISTURE MOVEMENT (WICKING) WITHIN GYPSUM WALLBOARD

    Science.gov (United States)

    Gypsum wallboard with repeated or prolonged exposure to water or excess moisture can lose its structural integrity and provide a growth medium for biological contaminants. Poorly sealed buildings, leaking or failed plumbing systems, or improperly constructed HVAC systems can all ...

  5. Moisture movements in render on brick wall

    DEFF Research Database (Denmark)

    Hansen, Kurt Kielsgaard; Munch, Thomas Astrup; Thorsen, Peter Schjørmann

    2003-01-01

    A three-layer render on brick wall used for building facades is studied in the laboratory. The vertical render surface is held in contact with water for 24 hours simulating driving rain while it is measured with non-destructive X-ray equipment every hour in order to follow the moisture front...... through the render and into the brick. The test specimen is placed between the source and the detector. The test specimens are all scanned before they are exposed to water. In that way the loss of counts from the dry scan to the wet scan qualitatively shows the presence of water. The results show nearly...... no penetration of water through the render and into the brick, and the results are independent of the start condition of the test specimens. Also drying experiments are performed. The results show a small difference in the rate of drying, in favour of the bricks without render....

  6. Misrepresentation and amendment of soil moisture in conceptual hydrological modelling

    Science.gov (United States)

    Zhuo, Lu; Han, Dawei

    2016-04-01

    Although many conceptual models are very effective in simulating river runoff, their soil moisture schemes are generally not realistic in comparison with the reality (i.e., getting the right answers for the wrong reasons). This study reveals two significant misrepresentations in those models through a case study using the Xinanjiang model which is representative of many well-known conceptual hydrological models. The first is the setting of the upper limit of its soil moisture at the field capacity, due to the 'holding excess runoff' concept (i.e., runoff begins on repletion of its storage to the field capacity). The second is neglect of capillary rise of water movement. A new scheme is therefore proposed to overcome those two issues. The amended model is as effective as its original form in flow modelling, but represents more logically realistic soil water processes. The purpose of the study is to enable the hydrological model to get the right answers for the right reasons. Therefore, the new model structure has a better capability in potentially assimilating soil moisture observations to enhance its real-time flood forecasting accuracy. The new scheme is evaluated in the Pontiac catchment of the USA through a comparison with satellite observed soil moisture. The correlation between the XAJ and the observed soil moisture is enhanced significantly from 0.64 to 0.70. In addition, a new soil moisture term called SMDS (Soil Moisture Deficit to Saturation) is proposed to complement the conventional SMD (Soil Moisture Deficit).

  7. Modeling soil moisture memory in savanna ecosystems

    Science.gov (United States)

    Gou, S.; Miller, G. R.

    2011-12-01

    Antecedent soil conditions create an ecosystem's "memory" of past rainfall events. Such soil moisture memory effects may be observed over a range of timescales, from daily to yearly, and lead to feedbacks between hydrological and ecosystem processes. In this study, we modeled the soil moisture memory effect on savanna ecosystems in California, Arizona, and Africa, using a system dynamics model created to simulate the ecohydrological processes at the plot-scale. The model was carefully calibrated using soil moisture and evapotranspiration data collected at three study sites. The model was then used to simulate scenarios with various initial soil moisture conditions and antecedent precipitation regimes, in order to study the soil moisture memory effects on the evapotranspiration of understory and overstory species. Based on the model results, soil texture and antecedent precipitation regime impact the redistribution of water within soil layers, potentially causing deeper soil layers to influence the ecosystem for a longer time. Of all the study areas modeled, soil moisture memory of California savanna ecosystem site is replenished and dries out most rapidly. Thus soil moisture memory could not maintain the high rate evapotranspiration for more than a few days without incoming rainfall event. On the contrary, soil moisture memory of Arizona savanna ecosystem site lasts the longest time. The plants with different root depths respond to different memory effects; shallow-rooted species mainly respond to the soil moisture memory in the shallow soil. The growing season of grass is largely depended on the soil moisture memory of the top 25cm soil layer. Grass transpiration is sensitive to the antecedent precipitation events within daily to weekly timescale. Deep-rooted plants have different responses since these species can access to the deeper soil moisture memory with longer time duration Soil moisture memory does not have obvious impacts on the phenology of woody plants

  8. Sources of Sahelian-Sudan moisture: Insights from a moisture-tracing atmospheric model

    Science.gov (United States)

    Salih, Abubakr A. M.; Zhang, Qiong; Pausata, Francesco S. R.; Tjernström, Michael

    2016-07-01

    The summer rainfall across Sahelian-Sudan is one of the main sources of water for agriculture, human, and animal needs. However, the rainfall is characterized by large interannual variability, which has attracted extensive scientific efforts to understand it. This study attempts to identify the source regions that contribute to the Sahelian-Sudan moisture budget during July through September. We have used an atmospheric general circulation model with an embedded moisture-tracing module (Community Atmosphere Model version 3), forced by observed (1979-2013) sea-surface temperatures. The result suggests that about 40% of the moisture comes with the moisture flow associated with the seasonal migration of the Intertropical Convergence Zone (ITCZ) and originates from Guinea Coast, central Africa, and the Western Sahel. The Mediterranean Sea, Arabian Peninsula, and South Indian Ocean regions account for 10.2%, 8.1%, and 6.4%, respectively. Local evaporation and the rest of the globe supply the region with 20.3% and 13.2%, respectively. We also compared the result from this study to a previous analysis that used the Lagrangian model FLEXPART forced by ERA-Interim. The two approaches differ when comparing individual regions, but are in better agreement when neighboring regions of similar atmospheric flow features are grouped together. Interannual variability with the rainfall over the region is highly correlated with contributions from regions that are associated with the ITCZ movement, which is in turn linked to the Atlantic Multidecadal Oscillation. Our result is expected to provide insights for the effort on seasonal forecasting of the rainy season over Sahelian Sudan.

  9. Modelling group dynamic animal movement

    DEFF Research Database (Denmark)

    Langrock, Roland; Hopcraft, J. Grant C.; Blackwell, Paul G.

    2014-01-01

    Group dynamic movement is a fundamental aspect of many species' movements. The need to adequately model individuals' interactions with other group members has been recognised, particularly in order to differentiate the role of social forces in individual movement from environmental factors. However......, to date, practical statistical methods which can include group dynamics in animal movement models have been lacking. We consider a flexible modelling framework that distinguishes a group-level model, describing the movement of the group's centre, and an individual-level model, such that each individual...... makes its movement decisions relative to the group centroid. The basic idea is framed within the flexible class of hidden Markov models, extending previous work on modelling animal movement by means of multi-state random walks. While in simulation experiments parameter estimators exhibit some bias...

  10. CFD modelling of moisture interactions between air and constructions

    DEFF Research Database (Denmark)

    Mortensen, Lone Hedegaard; Woloszyn, Monika; Hohota, Raluca;

    2005-01-01

    There is a strong demand for accurate moisture modelling since moisture poses a risk for both the constructions and the indoor climate. Thus, in this investigation there is special focus on moisture modelling. The paper describes a new model based on a CFD tool that is enhanced to include both de...

  11. Should we use a simple or complex model for moisture recycling and atmospheric moisture tracking?

    NARCIS (Netherlands)

    Ent, van der R.J.; Tuinenburg, O.A.; Knoche, H.R.; Kunstmann, H.; Savenije, H.H.G.

    2013-01-01

    This paper compares state-of-the-art atmospheric moisture tracking models. Such models are typically used to study the water component of coupled land and atmosphere models, in particular quantifying moisture recycling and the source-sink relations between evaporation and precipitation. There are se

  12. Should we use a simple or complex model for moisture recycling and atmospheric moisture tracking?

    NARCIS (Netherlands)

    Van der Ent, R.J.; Tuinenburg, O.A.; Knoche, H.R.; Kunstmann, H.; Savenije, H.H.G.

    2013-01-01

    This paper compares three state-of-the-art atmospheric moisture tracking models. Such models are typically used to study the water component of coupled land and atmosphere models, in particular quantifying moisture recycling and the source-sink relations between evaporation and precipitation. Howeve

  13. Should we use a simple or complex model for moisture recycling and atmospherix moisture tracking?

    NARCIS (Netherlands)

    Van der Ent, R.J.; Tuinenburg, O.A.; Knoche, H.R.; Kunstmann, H.; Savenije, H.H.G.

    2013-01-01

    This paper compares state-of-the-art atmospheric moisture tracking models. Such models are typically used to study the water component of coupled land and atmosphere models, in particular quantifying moisture recycling and the source-sink relations between evaporation and precipitation. There are se

  14. CFD modelling of moisture interactions between air and constructions

    DEFF Research Database (Denmark)

    Mortensen, Lone Hedegaard; Woloszyn, Monika; Hohota, Raluca

    2005-01-01

    There is a strong demand for accurate moisture modelling since moisture poses a risk for both the constructions and the indoor climate. Thus, in this investigation there is special focus on moisture modelling. The paper describes a new model based on a CFD tool that is enhanced to include both...... detailed modelling of airflows in rooms and heat and moisture transfer in walls by applying them as fluid walls. In a 3D configuration the impact of different boundary conditions are investigated and the results are discussed. The changes of boundary conditions that are studied are velocity, moisture...

  15. Modelling heat and moisture transfer in buildings. Applications to indoor thermal and moisture control

    Energy Technology Data Exchange (ETDEWEB)

    Lu Xiaoshu

    2002-07-01

    The objective of this thesis is to firstly develop a mathematical model for predicting heat and moisture transfer in buildings exposed to outdoor climatic conditions presented as temperature, relative humidity, solar radiation and wind velocity. Secondly, the heat and moisture transfer model is used to theoretically study the possibilities of controlling indoor thermal and moisture levels into an allowable range by means of heating indoor air and ventilating outdoor air. Starting from an extensive literature, it is indicated that less attention has been devoted to the topic that is similar to this thesis work. The reviewed literature has been classified into different categories in a consistent and systematic way. In modelling heat and moisture transfer in a building, the building structure is split into two components: building indoor air and building envelopes, most of which are porous media. The heat and moisture transfer equations are based on the fundamental thermodynamic relations. Darcy's law, Fick's law and Fourier's law are used in describing the transfer equations. The resultant nonlinear system of partial differential equations is discretised by using the finite element method or the finite difference method. The time marching scheme, Crank-Nicolson scheme, is adopted to advance the solution in time. The final solution provides transient distributions of thermal, moisture content and gaseous pressure for the envelopes as well as the transient thermal and moisture content for indoor air. The model program, named as HMTB, is validated with the real test houses. HMTB has a highly flexibility: It has been used to simulate the multiphase drying process of a porous medium. It has been adopted to predict transient thermal and moisture contents for buildings, transient indoor moisture generation rates and condensation potential on the wall surfaces. In studying the applications of indoor thermal and moisture control, HMTB has been applied to

  16. Monitoring soil moisture through assimilation of active microwave remote sensing observation into a hydrologic model

    Science.gov (United States)

    Liu, Qian; Zhao, Yingshi

    2015-08-01

    Soil moisture can be estimated from point measurements, hydrologic models, and remote sensing. Many researches indicated that the most promising approach for soil moisture is the integration of remote sensing surface soil moisture data and computational modeling. Although many researches were conducted using passive microwave remote sensing data in soil moisture assimilation with coarse spatial resolution, few researches were carried out using active microwave remote sensing observation. This research developed and tested an operational approach of assimilation for soil moisture prediction using active microwave remote sensing data ASAR (Advanced Synthetic Aperture Radar) in Heihe Watershed. The assimilation was based on ensemble Kalman filter (EnKF), a forward radiative transfer model and the Distributed Hydrology Soil Vegetation Model (DHSVM). The forward radiative transfer model, as a semi-empirical backscattering model, was used to eliminate the effect of surface roughness and vegetation cover on the backscatter coefficient. The impact of topography on soil water movement and the vertical and lateral exchange of soil water were considered. We conducted experiments to assimilate active microwave remote sensing data (ASAR) observation into a hydrologic model at two field sites, which had different underlying conditions. The soil moisture ground-truth data were collected through the field Time Domain Reflectometry (TDR) tools, and were used to assess the assimilation method. The temporal evolution of soil moisture measured at point-based monitoring locations were compared with EnKF based model predictions. The results indicated that the estimate of soil moisture was improved through assimilation with ASAR observation and the soil moisture based on data assimilation can be monitored in moderate spatial resolution.

  17. Numerical Investigation of a Moisture Evaporation Model in Building Materials

    CERN Document Server

    Amirkhanov, I V; Pavlish, M; Puzynina, T P; Puzynin, I V; Sarhadov, I

    2005-01-01

    The properties of a model of moisture evaporation in a porous building material of a rectangular form proposed in [1] are investigated. Algorithms of solving a nonlinear diffusion equation with initial and boundary conditions simulating the dynamic distribution of moisture concentration, calculation of coefficients of a polynomial describing transport of moisture with usage of experimental measurement of moisture concentration in a sample are developed and investigated. Research on the properties of the model is carried out depending on the degree of the polynomial, a set of its coefficients, and the quantity of the used experimental data.

  18. Assimilating soil moisture into an Earth System Model

    Science.gov (United States)

    Stacke, Tobias; Hagemann, Stefan

    2017-04-01

    Several modelling studies reported potential impacts of soil moisture anomalies on regional climate. In particular for short prediction periods, perturbations of the soil moisture state may result in significant alteration of surface temperature in the following season. However, it is not clear yet whether or not soil moisture anomalies affect climate also on larger temporal and spatial scales. In an earlier study, we showed that soil moisture anomalies can persist for several seasons in the deeper soil layers of a land surface model. Additionally, those anomalies can influence root zone moisture, in particular during explicitly dry or wet periods. Thus, one prerequisite for predictability, namely the existence of long term memory, is evident for simulated soil moisture and might be exploited to improve climate predictions. The second prerequisite is the sensitivity of the climate system to soil moisture. In order to investigate this sensitivity for decadal simulations, we implemented a soil moisture assimilation scheme into the Max-Planck Institute for Meteorology's Earth System Model (MPI-ESM). The assimilation scheme is based on a simple nudging algorithm and updates the surface soil moisture state once per day. In our experiments, the MPI-ESM is used which includes model components for the interactive simulation of atmosphere, land and ocean. Artificial assimilation data is created from a control simulation to nudge the MPI-ESM towards predominantly dry and wet states. First analyses are focused on the impact of the assimilation on land surface variables and reveal distinct differences in the long-term mean values between wet and dry state simulations. Precipitation, evapotranspiration and runoff are larger in the wet state compared to the dry state, resulting in an increased moisture transport from the land to atmosphere and ocean. Consequently, surface temperatures are lower in the wet state simulations by more than one Kelvin. In terms of spatial pattern

  19. A model for hydraulic redistribution incorporating coupled soil-root moisture transport

    Directory of Open Access Journals (Sweden)

    G. G. Amenu

    2007-10-01

    Full Text Available One of the adaptive strategies of vegetation, particularly in water limited ecosystems, is the development of deep roots and the use of hydraulic redistribution which enables them to make optimal use of resources available throughout the soil column. Hydraulic redistribution refers to roots acting as a preferential pathway for the movement of water from wet to dry soil layers driven by the moisture gradient – be it from the shallow to deep layers or vice versa. This occurs during the nighttime while during the daytime moisture movement is driven to fulfill the transpiration demand at the canopy. In this study, we develop a model to investigate the effect of hydraulic redistribution by deep roots on the terrestrial climatology. Sierra Nevada eco-region is chosen as the study site which has wet winters and dry summers. Hydraulic redistribution enables the movement of moisture from the upper soil layers to deeper zones during the wet months and this moisture is then available to meet the transpiration demand during the late dry season. It results in significant alteration of the profiles of soil moisture and water uptake as well as increase in the canopy transpiration, carbon assimilation, and the associated water-use-efficiency during the dry summer season. This also makes the presence of roots in deeper soil layers much more important than their proportional abundance would otherwise dictate. Comparison with observations of latent heat from a flux tower demonstrates improved predictability and provides validation of the model results. Hydraulic redistribution serves as a mechanism for the interaction between the variability of deep layer soil-moisture and the land-surface climatology and could have significant implications for seasonal and sub-seasonal climate prediction.

  20. A model for hydraulic redistribution incorporating coupled soil-root moisture transport

    Directory of Open Access Journals (Sweden)

    G. G. Amenu

    2008-01-01

    Full Text Available One of the adaptive strategies of vegetation, particularly in water limited ecosystems, is the development of deep roots and the use of hydraulic redistribution which enables them to make optimal use of resources available throughout the soil column. Hydraulic redistribution refers to roots acting as a preferential pathway for the movement of water from wet to dry soil layers driven by the moisture gradient – be it from the shallow to deep layers or vice versa. This occurs during the nighttime while during the daytime moisture movement is driven to fulfill the transpiration demand at the canopy. In this study, we develop a model to investigate the effect of hydraulic redistribution by deep roots on the terrestrial climatology. Sierra Nevada eco-region is chosen as the study site which has wet winters and dry summers. Hydraulic redistribution enables the movement of moisture from the upper soil layers to deeper zones during the wet months and this moisture is then available to meet the transpiration demand during the late dry season. It results in significant alteration of the profiles of soil moisture and water uptake as well as increase in the canopy transpiration, carbon assimilation, and the associated water-use-efficiency during the dry summer season. This also makes the presence of roots in deeper soil layers much more important than their proportional abundance would otherwise dictate. Comparison with observations of latent heat from a flux tower demonstrates improved predictability and provides validation of the model results. Hydraulic redistribution serves as a mechanism for the interaction between the variability of deep layer soil-moisture and the land-surface climatology and could have significant implications for seasonal and sub-seasonal climate prediction.

  1. Moisture Absorption Model of Composites Considering Water Temperature Effect

    Directory of Open Access Journals (Sweden)

    HUI Li

    2016-11-01

    Full Text Available The influence of water temperature on composite moisture absorption parameters was investigated in temperature-controlled water bath. Experiments of carbon fiber/bismaleimide resin composites immersed in water of 60℃, 70℃and 80℃ were developed respectively. According to the moisture content-time curves obtained from the experimental results, the diffusion coefficient and the balanced moisture content of the composites immersed in different water temperature could be calculated. What's more, the effect of water temperature on the diffusion coefficient and the balanced moisture content were discussed too. According to the Arrhenius equation and the law of Fick, a moisture absorption model was proposed to simulate the hygroscopic behaviour of the composite laminates immersed in different water temperature which can predict the absorption rate of water of the composites immersed in distilled water of 95℃ at any time precisely and can calculate how long it will take to reach the specific absorption rate.

  2. Should we use a simple or complex model for moisture recycling and atmospheric moisture tracking?

    Directory of Open Access Journals (Sweden)

    R. J. van der Ent

    2013-05-01

    Full Text Available This paper compares three state-of-the-art atmospheric moisture tracking models. Such models are typically used to study the water component of coupled land and atmosphere models, in particular quantifying moisture recycling and the source-sink relations between evaporation and precipitation. However, there are several atmospheric moisture tracking methods being used in the literature, and depending on the level of aggregation, the assumptions made and the level of detail, the performance of these methods may differ substantially. In this paper, we compare three methods. The RCM-tag method uses highly accurate 3-D water tracking (including phase transitions directly within a regional climate model (online, while the other two methods (WAM and 3D-T use a posteriori (offline water vapour tracking. The original version of WAM makes use of the well-mixed assumption, while 3D-T is a multi-layer model. The a posteriori models are faster and more flexible, but less accurate than online moisture tracking with RCM-tag. In order to evaluate the accuracy of the a posteriori models, we tagged evaporated water from Lake Volta in West Africa and traced it to where it precipitates. It is found that the strong wind shear in West Africa is the main cause of errors in the a posteriori models. The number of vertical layers and the initial release height of tagged water in the model are found to have the most significant influences on the results. With this knowledge small improvements were made to the a posteriori models. It appeared that expanding WAM to a 2 layer model, or a lower release height in 3D-T, led to significantly better results. Finally, we introduced a simple metric to assess wind shear globally and give recommendations about when to use which model. The "best" method, however, very much depends on the spatial extent of the research question as well as the available computational power.

  3. Remote Sensing Derived Fire Frequency, Soil Moisture and Ecosystem Productivity Explain Regional Movements in Emu over Australia.

    Directory of Open Access Journals (Sweden)

    Nima Madani

    Full Text Available Species distribution modeling has been widely used in studying habitat relationships and for conservation purposes. However, neglecting ecological knowledge about species, e.g. their seasonal movements, and ignoring the proper environmental factors that can explain key elements for species survival (shelter, food and water increase model uncertainty. This study exemplifies how these ecological gaps in species distribution modeling can be addressed by modeling the distribution of the emu (Dromaius novaehollandiae in Australia. Emus cover a large area during the austral winter. However, their habitat shrinks during the summer months. We show evidence of emu summer habitat shrinkage due to higher fire frequency, and low water and food availability in northern regions. Our findings indicate that emus prefer areas with higher vegetation productivity and low fire recurrence, while their distribution is linked to an optimal intermediate (~0.12 m3 m(-3 soil moisture range. We propose that the application of three geospatial data products derived from satellite remote sensing, namely fire frequency, ecosystem productivity, and soil water content, provides an effective representation of emu general habitat requirements, and substantially improves species distribution modeling and representation of the species' ecological habitat niche across Australia.

  4. Monitoring moisture movements in building materials using x-ray attenuation

    DEFF Research Database (Denmark)

    Pease, Bradley Justin; Scheffler, Gregor A.; Janssen, Hans

    2012-01-01

    X-ray attenuation measurements are commonly used as a non-destructive method to monitor internal concentration changes of moisture (i.e., moisture content) and other chemical compounds in porous building materials. The technique provides direct measurements of moisture content changes through ana...

  5. Evaluation of the Effective Moisture Penetration Depth Model for Estimating Moisture Buffering in Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Woods, J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Winkler, J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Christensen, D. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2013-01-01

    This study examines the effective moisture penetration depth (EMPD) model, and its suitability for building simulations. The EMPD model is a compromise between the simple, inaccurate effective capacitance approach and the complex, yet accurate, finite-difference approach. Two formulations of the EMPD model were examined, including the model used in the EnergyPlus building simulation software. An error in the EMPD model we uncovered was fixed with the release of EnergyPlus version 7.2, and the EMPD model in earlier versions of EnergyPlus should not be used.

  6. Analog modeling of transient moisture flow in unsaturated soil

    NARCIS (Netherlands)

    Wind, G.P.

    1979-01-01

    Hydraulic and electronic analog models are developed for the simulation of moisture flow and accumulation in unsaturated soil. The analog models are compared with numerical models and checked with field observations. Application of soil physical knowledge on a soil technological problem by means of

  7. Should we use a simple or complex model for moisture recycling and atmospheric moisture tracking?

    Science.gov (United States)

    van der Ent, R. J.; Tuinenburg, O. A.; Knoche, H.-R.; Kunstmann, H.; Savenije, H. H. G.

    2013-12-01

    This paper compares state-of-the-art atmospheric moisture tracking models. Such models are typically used to study the water component of coupled land and atmosphere models, in particular quantifying moisture recycling and the source-sink relations between evaporation and precipitation. There are several atmospheric moisture tracking methods in use. However, depending on the level of aggregation, the assumptions made and the level of detail, the performance of these methods may differ substantially. In this paper, we compare three methods. The RCM-tag method uses highly accurate 3-D water tracking (including phase transitions) directly within a regional climate model (online), while the other two methods (WAM and 3D-T) use a posteriori (offline) water vapour tracking. The original version of WAM is a single-layer model, while 3D-T is a multi-layer model, but both make use the "well-mixed" assumption for evaporation and precipitation. The a posteriori models are faster and more flexible, but less accurate than online moisture tracking with RCM-tag. In order to evaluate the accuracy of the a posteriori models, we tagged evaporated water from Lake Volta in West Africa and traced it to where it precipitates. It is found that the strong wind shear in West Africa is the main cause of errors in the a posteriori models. The number of vertical layers and the initial release height of tagged water in the model are found to have the most significant influences on the results. With this knowledge small improvements have been made to the a posteriori models. It appeared that expanding WAM to a 2-layer model, or a lower release height in 3D-T, led to significantly better results. Finally, we introduced a simple metric to assess wind shear globally and give recommendations about when to use which model. The "best" method, however, very much depends on the research question, the spatial extent under investigation, as well as the available computational power.

  8. Water Transport Models of Moisture Absorption and Sweat Discharge Yarns

    Institute of Scientific and Technical Information of China (English)

    WANG Fa-ming; ZHOU Xiao-hong; WANG Shan-yuan

    2008-01-01

    An important property of moisture absorption and sweat discharge yams is their water transport property. In the paper, two water transport models of moisture absorption and sweat discharge yams were developed to investigate the influence factors on their wicking rate. In parallel Column Pores Model, wicking rate is determined by the equivalent capillary radius R and length of the capillary tube L. In Pellets Accumulation Model, wicking rate is decided by the capillary radius r and length of the fiber unit assemble L0.

  9. A Model For Non-Fickian Moisture Transfer In Wood

    DEFF Research Database (Denmark)

    Krabbenhøft, Kristian; Damkilde, Lars

    2004-01-01

    A model for non-Fickian moisture transfer in wood is presented. The model considers the transfer of water vapour separate from the transfer of bound water. These two components are linked by an equation describing the sorption on the cell wall level. Hereby, a formulation capable of describing...

  10. A Model For Non-Fickian Moisture Transfer In Wood

    DEFF Research Database (Denmark)

    Krabbenhøft, Kristian; Damkilde, Lars

    2004-01-01

    A model for non-Fickian moisture transfer in wood is presented. The model considers the transfer of water vapour separate from the transfer of bound water. These two components are linked by an equation describing the sorption on the cell wall level. Hereby, a formulation capable of describing kn...

  11. Physically plausible prescription of land surface model soil moisture

    Science.gov (United States)

    Hauser, Mathias; Orth, René; Thiery, Wim; Seneviratne, Sonia

    2016-04-01

    Land surface hydrology is an important control of surface weather and climate, especially under extreme dry or wet conditions where it can amplify heat waves or floods, respectively. Prescribing soil moisture in land surface models is a valuable technique to investigate this link between hydrology and climate. It has been used for example to assess the influence of soil moisture on temperature variability, mean and extremes (Seneviratne et al. 2006, 2013, Lorenz et al., 2015). However, perturbing the soil moisture content artificially can lead to a violation of the energy and water balances. Here we present a new method for prescribing soil moisture which ensures water and energy balance closure by using only water from runoff and a reservoir term. If water is available, the method prevents soil moisture decrease below climatological values. Results from simulations with the Community Land Model (CLM) indicate that our new method allows to avoid soil moisture deficits in many regions of the world. We show the influence of the irrigation-supported soil moisture content on mean and extreme temperatures and contrast our findings with that of earlier studies. Additionally, we will assess how long into the 21st century the new method will be able to maintain present-day climatological soil moisture levels for different regions. Lorenz, R., Argüeso, D., Donat, M.G., Pitman, A.J., den Hurk, B.V., Berg, A., Lawrence, D.M., Chéruy, F., Ducharne, A., Hagemann, S. and Meier, A., 2015. Influence of land-atmosphere feedbacks on temperature and precipitation extremes in the GLACE-CMIP5 ensemble. Journal of Geophysical Research: Atmospheres. Seneviratne, S.I., Lüthi, D., Litschi, M. and Schär, C., 2006. Land-atmosphere coupling and climate change in Europe. Nature, 443(7108), pp.205-209. Seneviratne, S.I., Wilhelm, M., Stanelle, T., Hurk, B., Hagemann, S., Berg, A., Cheruy, F., Higgins, M.E., Meier, A., Brovkin, V. and Claussen, M., 2013. Impact of soil moisture

  12. The spatial distribution and movement of the spring soil moisture in the hinter land of Junggar Basin

    Science.gov (United States)

    Zhao, Congju; Lei, Jiaqiang; Wang, Xueqin; Jiang, Jin

    2003-07-01

    The exploitation of resources and an increase in civil engineering projects in the Junggar Basin has caused major environmental disturbance to the fragile desert eco-system. It is a serious problem that attracts global attention on how to restore and reconstruct the stable natural eco-system. Understanding soil moisture content and lateral water movement in arid areas, at a shallow depth, is of practical importance. On the one hand, lateral flow can be expected to reduce the groundwater recharge rate. On the other hand, it may result in a strong variability of water resources over short distances, thus affecting the distribution and composition of the vegetal cover. The eolian soil moisture condition is the primary factor that affects desert plant-cover in the hinter land of Junggar Basin, especially in spring (from March to May). With neutron probe, through field calibration, the soil moisture changes in different terrain parts, which are the crest, slope, the foot of the natural and disturbed dunes and the interdune land were measured. The data shows that the spatial distribution of the soil moisture in spring is closely related to the sun radiation, the depth of snow in winter, landscape position, the depth of soil, plant cover condition (cover-degree, plant species), and human impact. The data also provides scientific information and instruction for restoring and reconstructing the eco-system that has been damaged by engineering disturbance.

  13. Implications of complete watershed soil moisture measurements to hydrologic modeling

    Science.gov (United States)

    Engman, E. T.; Jackson, T. J.; Schmugge, T. J.

    1983-01-01

    A series of six microwave data collection flights for measuring soil moisture were made over a small 7.8 square kilometer watershed in southwestern Minnesota. These flights were made to provide 100 percent coverage of the basin at a 400 m resolution. In addition, three flight lines were flown at preselected areas to provide a sample of data at a higher resolution of 60 m. The low level flights provide considerably more information on soil moisture variability. The results are discussed in terms of reproducibility, spatial variability and temporal variability, and their implications for hydrologic modeling.

  14. Model Based Control of Moisture Sorption in a Historical Interior

    Directory of Open Access Journals (Sweden)

    P. Zítek

    2005-01-01

    Full Text Available This paper deals with a novel scheme for microclimate control in historical exhibition rooms, inhibiting moisture sorption phenomena that are inadmissible from the preventive conservation point of view. The impact of air humidity is the most significant harmful exposure for a great deal of the cultural heritage deposited in remote historical buildings. Leaving the interior temperature to run almost its spontaneous yearly cycle, the proposed non-linear model-based control protects exhibits from harmful variations in moisture content by compensating the temperature drifts with an adequate adjustment of the air humidity. Already implemented in a medieval interior since 1999, the proposed microclimate control has proved capable of permanently maintaining constant a desirable moisture content in organic or porous materials in the interior of a building. 

  15. Soil Type, Soil Moisture, and Field Slope Influence the Horizontal Movement of Salmonella enterica and Citrobacter freundii from Floodwater through Soil.

    Science.gov (United States)

    Callahan, Mary Theresa; Micallef, Shirley A; Buchanan, Robert L

    2017-01-01

    Pathogens in soil are readily mobilized by infiltrating water to travel downward through the soil. However, limited data are available on the horizontal movement of pathogens across a field. This study used a model system to evaluate the influence of soil type, initial soil moisture content, and field slope on the movement of Salmonella enterica serovar Newport across a horizontal plane of soil under flooding conditions. Three soil types of varying clay content were moistened to 40, 60, or 80% of their maximum water-holding capacities and flooded with water containing 6 log CFU/ml Salmonella Newport and Citrobacter freundii , the latter being evaluated as a potential surrogate for S. enterica in future field trials. A two-phase linear regression was used to analyze the microbial populations recovered from soil with increasing distance from the flood. This model reflected the presence of lag distances followed by a quantifiable linear decrease in the population of bacteria as a function of the distance from the site of flooding. The magnitude of the lag distance was significantly affected by the soil type, but this was not attributable to the soil clay content. The rate of the linear decline with distance from the flood zone was affected by soil type, initial soil moisture content, and soil incline. As the initial soil moisture content increased, the rate of decline in recovery decreased, indicating greater bacterial transport through soils. When flooding was simulated at the bottom of the soil incline, the rate of decline in recovery was much greater than when flooding was simulated at the top of the incline. There was no significant difference in recovery between Salmonella Newport and C. freundii , indicating that C. freundii may be a suitable surrogate for Salmonella Newport in future field studies.

  16. Moisture evaluation by dynamic thermography data modeling

    Science.gov (United States)

    Bison, Paolo G.; Grinzato, Ermanno G.; Marinetti, Sergio

    1994-03-01

    This paper discusses the design of a nondestructive method for in situ detection of moistened areas in buildings and the evaluation of the water content in porous materials by thermographic analysis. The use of heat transfer model to interpret data allows to improve the measurement accuracy taking into account the actual boundary conditions. The relative increase of computation time is balanced by the additional advantage to optimize the testing procedure of different objects simulating the heat transfer. Experimental results on bricks used in building for restoration activities, are discussed. The water content measured in different hygrometric conditions is compared with known values. A correction on the absorptivity coefficient dependent on water content is introduced.

  17. Water movement in building walls: interfaces influence on the moisture flux

    Science.gov (United States)

    Delgado, J. M. P. Q.; de Freitas, V. P.; Guimarães, A. S.

    2016-11-01

    Most building elements are a composite of different material layers; however the majority of the works presented in literature were developed for multi-layered elements with perfect contact interface, without resistance. Experimental results presented in literature showed that a considerable hydraulic resistance could be created by the imperfect contact between two porous building materials. Moisture transport in multi-layered building elements can deviate from the moisture transport found for the combination of the single material elements, so the assumption of perfect hydraulic contact could lead to significant errors in predicting the moisture transport. This work presents an experimental campaign and a critical analysis of water absorption in samples of two different building materials (clay brick and autoclaved aerated concrete) with and without joints at different positions (heights) and different contact configurations (natural contact and air space between layers). The results show that when the moisture reaches the interface there is a slowing of the wetting process due to the interfaces hygric resistance. The interfaces hygric resistance, in the AAC samples, is only observed for the joint located from a distance of 2 cm of the wetting plane. The penetration coefficient of the two building materials analysed is very different. Finally, the evolution of the distribution of liquid in the porous medium was analysed in terms of the Boltzmann transform method and anomalous diffusion equation.

  18. Investigation of Microclimate by CFD Modeling of Moisture Interactions between Air and Constructions

    DEFF Research Database (Denmark)

    Mortensen, Lone Hedegaard; Woloszyn, Monika; Rode, Carsten;

    2007-01-01

    There is a strong demand for accurate moisture modeling since moisture poses a risk for both the constructions and the indoor climate. This investigation has special focus on moisture modeling. The paper describes a new model based on a CFD tool enhanced to include both detailed modeling of airfl...

  19. A modelling study of moisture redistribution by thin cirrus clouds

    Directory of Open Access Journals (Sweden)

    T. Dinh

    2014-05-01

    Full Text Available A high resolution 2-dimensional numerical model is used to study the moisture redistribution following homogeneous ice nucleation induced by Kelvin waves in the tropical tropopause layer (TTL. We compare results for dry/moist initial conditions, and three levels of complexity for the representation of cloud processes: full bin microphysics and radiative effects of the ice, ditto but without radiative effects, and instantaneous removal of moisture in excess of saturation upon nucleation. Cloud evolution and the profiles of moisture redistribution are found to be sensitive to initial conditions and cloud processes. Ice sedimentation leads to a downward flux of water. On the other hand, the cloud radiative heating induces upward advection of the cloudy air. This results in an upward flux of water vapour if the cloudy air is moister (or drier than the environment, which is typically when the environment is subsaturated (or supersaturated. The numerical results show that only a small fraction (less than 25% of the cloud experiences nucleation. Sedimentation and reevaporation are important, and hydrated layers in observation may be as good an indicator as dehydrated layers for the occurrence of thin cirrus clouds. The calculation with instantaneous removal of condensates misses the hydration by construction, but also underestimates dehydration due to lack of moisture removal from sedimenting particles below the nucleation level, and due to nucleation before reaching the minimum saturation mixing ratio. The sensitivity to initial conditions and cloud processes suggests that it is difficult to reach generic, quantitative conclusions regarding the role of thin cirrus clouds for the moisture distribution in the TTL and stratosphere.

  20. Reliability-Based Modeling of Moisture and Load-Duration Effects

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Svensson, Staffan

    2005-01-01

    and moisture processes. Permanent and snow load sand moisture variations are considered and stochastic models are formulated in accordance with the load models in the Danish structural codes. A damage accumulation model based on fracture mechanics that accounts for both load duration and moisture effects...

  1. Potential for Remotely Sensed Soil Moisture Data in Hydrologic Modeling

    Science.gov (United States)

    Engman, Edwin T.

    1997-01-01

    Many hydrologic processes display a unique signature that is detectable with microwave remote sensing. These signatures are in the form of the spatial and temporal distributions of surface soil moisture and portray the spatial heterogeneity of hydrologic processes and properties that one encounters in drainage basins. The hydrologic processes that may be detected include ground water recharge and discharge zones, storm runoff contributing areas, regions of potential and less than potential ET, and information about the hydrologic properties of soils and heterogeneity of hydrologic parameters. Microwave remote sensing has the potential to detect these signatures within a basin in the form of volumetric soil moisture measurements in the top few cm. These signatures should provide information on how and where to apply soil physical parameters in distributed and lumped parameter models and how to subdivide drainage basins into hydrologically similar sub-basins.

  2. Modelling larval movement data from individual bioassays.

    Science.gov (United States)

    McLellan, Chris R; Worton, Bruce J; Deasy, William; Birch, A Nicholas E

    2015-05-01

    We consider modelling the movements of larvae using individual bioassays in which data are collected at a high-frequency rate of five observations per second. The aim is to characterize the behaviour of the larvae when exposed to attractant and repellent compounds. Mixtures of diffusion processes, as well as Hidden Markov models, are proposed as models of larval movement. These models account for directed and localized movements, and successfully distinguish between the behaviour of larvae exposed to attractant and repellent compounds. A simulation study illustrates the advantage of using a Hidden Markov model rather than a simpler mixture model. Practical aspects of model estimation and inference are considered on extensive data collected in a study of novel approaches for the management of cabbage root fly.

  3. Assimilation of neural network soil moisture in land surface models

    Science.gov (United States)

    Rodriguez-Fernandez, Nemesio; de Rosnay, Patricia; Albergel, Clement; Aires, Filipe; Prigent, Catherine; Kerr, Yann; Richaume, Philippe; Muñoz-Sabater, Joaquin; Drusch, Matthias

    2017-04-01

    In this study a set of land surface data assimilation (DA) experiments making use of satellite derived soil moisture (SM) are presented. These experiments have two objectives: (1) to test the information content of satellite remote sensing of soil moisture for numerical weather prediction (NWP) models, and (2) to test a simplified assimilation of these data through the use of a Neural Network (NN) retrieval. Advanced Scatterometer (ASCAT) and Soil Moisture and Ocean Salinity (SMOS) data were used. The SMOS soil moisture dataset was obtained specifically for this project training a NN using SMOS brightness temperatures as input and using as reference for the training European Centre for Medium-Range Weather Forecasts (ECMWF) H-TESSEL SM fields. In this way, the SMOS NN SM dataset has a similar climatology to that of the model and it does not present a global bias with respect to the model. The DA experiments are computed using a surface-only Land Data Assimilation System (so-LDAS) based on the HTESSEL land surface model. This system is very computationally efficient and allows to perform long surface assimilation experiments (one whole year, 2012). SMOS NN SM DA experiments are compared to ASCAT SM DA experiments. In both cases, experiments with and without 2 m air temperature and relative humidity DA are discussed using different observation errors for the ASCAT and SMOS datasets. Seasonal, geographical and soil-depth-related differences between the results of those experiments are presented and discussed. The different SM analysed fields are evaluated against a large number of in situ measurements of SM. On average, the SM analysis gives in general similar results to the model open loop with no assimilation even if significant differences can be seen for specific sites with in situ measurements. The sensitivity to observation errors to the SM dataset slightly differs depending on the networks of in situ measurements, however it is relatively low for the tests

  4. Using high-resolution soil moisture modelling to assess the uncertainty of microwave remotely sensed soil moisture products at the correct spatial and temporal support

    NARCIS (Netherlands)

    Wanders, N.; Karssenberg, D.; Bierkens, M. F. P.; Van Dam, J. C.; De Jong, S. M.

    2012-01-01

    Soil moisture is a key variable in the hydrological cycle and important in hydrological modelling. When assimilating soil moisture into flood forecasting models, the improvement of forecasting skills depends on the ability to accurately estimate the spatial and temporal patterns of soil moisture con

  5. WRF fire simulation coupled with a fuel moisture model and smoke transport by WRF-Chem

    CERN Document Server

    Kochanski, Adam K; Mandel, Jan; Kim, Minjeong

    2012-01-01

    We describe two recent additions to WRF coupled with a fire spread model. Fire propagation is strongly dependent on fuel moisture, which in turn depends on the history of the atmosphere. We have implemented a equilibrium time-lag model of fuel moisture driven by WRF variables. The code allows the user to specify fuel parameters, with the defaults calibrated to the Canadian fire danger rating system for 10-hour fuel. The moisture model can run coupled with the atmosphere-fire model, or offline from WRF output to equilibrate the moisture over a period of time and to provide initial moisture conditions for a coupled atmosphere-fire-moisture simulation. The fire model also inserts smoke tracers into WRF-Chem to model the transport of fire emissions. The coupled model is available from OpenWFM.org. An earlier version of the fire model coupled with atmosphere is a part of WRF release.

  6. Time series modeling of soil moisture dynamics on a steep mountainous hillside

    Science.gov (United States)

    Kim, Sanghyun

    2016-05-01

    The response of soil moisture to rainfall events along hillslope transects is an important hydrologic process and a critical component of interactions between soil vegetation and the atmosphere. In this context, the research described in this article addresses the spatial distribution of soil moisture as a function of topography. In order to characterize the temporal variation in soil moisture on a steep mountainous hillside, a transfer function, including a model for noise, was introduced. Soil moisture time series with similar rainfall amounts, but different wetness gradients were measured in the spring and fall. Water flux near the soil moisture sensors was modeled and mathematical expressions were developed to provide a basis for input-output modeling of rainfall and soil moisture using hydrological processes such as infiltration, exfiltration and downslope lateral flow. The characteristics of soil moisture response can be expressed in terms of model structure. A seasonal comparison of models reveals differences in soil moisture response to rainfall, possibly associated with eco-hydrological process and evapotranspiration. Modeling results along the hillslope indicate that the spatial structure of the soil moisture response patterns mainly appears in deeper layers. Similarities between topographic attributes and stochastic model structures are spatially organized. The impact of temporal and spatial discretization scales on parameter expression is addressed in the context of modeling results that link rainfall events and soil moisture.

  7. Model for bidirectional movement of cytoplasmic dynein

    CERN Document Server

    Sumathy, S

    2014-01-01

    Cytoplasmic dynein exhibits a directional processive movement on microtubule filaments and is known to move in steps of varying length based on the number of ATP molecules bound to it and the load that it carries. It is experimentally observed that dynein takes occasional backward steps and the frequency of such backward steps increases as the load approaches the stall force. Using a stochastic process model, we investigate the bidirectional movement of single head of a dynein motor. The probability for backward step is implemented based on Crook's fluctuation theorem of non-equilibrium statistical mechanics. We find that the movement of dynein motor is characterized with negative velocity implying backward motion beyond stall force. We observe that the motor moves backward for super stall forces by hydrolyzing the ATP exactly the same way as it does while moving forward for sub stall forces.

  8. Influence of different substrate moistures on wood consumption and movement patterns of Microcerotermes crassus and Coptotermes gestroi (Blattodea: Termitidae, Rhinotermitidae).

    Science.gov (United States)

    Wong, Nellie; Lee, Chow-Yang

    2010-04-01

    Moisture is an important physical factor for the survival of termites. The effects of different moisture levels (0, 5, 10, 15, 20, and 25%) of a sand substrate on the behavior of laboratory groups of Microcerotermes crassus Snyder and Coptotermes gestroi (Wasmann) (Blattodea: Termitidae: Rhinotermitidae) were evaluated. Moisture content of sand affected wood consumption and influenced termite distribution across a moisture gradient for M. crassus. Changing the moisture parameters affected the location preference of C. gestroi, but the effect on wood consumption was not significant. Nonetheless, M. crassus and C. gestroi showed a similar distribution pattern of association with particular moisture levels.

  9. Physics Models of Pronuclear Movements in Eggs

    Directory of Open Access Journals (Sweden)

    Kang Cheng

    2005-01-01

    Full Text Available Based on published experimental data, Newton's laws, and Coulomb's law, we investigate natural and normal pronuclear movements in wild types of eggs and develop physics models to fit the experimental data quantitatively. The difference between our modeling calculated results and the experimental data is less than 20%. Our models explain why and how pronuclei move in even or in variant velocities. We hypothesize: During the migration, positively charged asters (or self assembled microtubules drive two negatively charged sperm and egg pronuclei to move towards each other. The driving force comes from a spontaneous and strong Electromagnetic Field (EMF. Hamilton's principle determines the path of these movements. A natural and normal EMF inside or around the pronuclei can be alternated environmentally. An abnormal EMF could induce aberrant embryos that cause life disease. We believe our models are helpful to further understand the mechanism of fertilization and have potential clinical value to prevent aberrant embryos that induce human life disease.

  10. Modeling and Mapping Soil Moisture of Plateau Pasture Using RADARSAT-2 Imagery

    OpenAIRE

    Xun Chai; Tingting Zhang; Yun Shao; Huaze Gong; Long Liu; Kaixin Xie

    2015-01-01

    Accurate soil moisture retrieval of a large area in high resolution is significant for plateau pasture. The object of this paper is to investigate the estimation of volumetric soil moisture in vegetated areas of plateau pasture using fully polarimetric C-band RADARSAT-2 SAR (Synthetic Aperture Radar) images. Based on the water cloud model, Chen model, and Dubois model, we proposed two developed algorithms for soil moisture retrieval and validated their performance using experimental data. We ...

  11. Agent Based Model of Livestock Movements

    Science.gov (United States)

    Miron, D. J.; Emelyanova, I. V.; Donald, G. E.; Garner, G. M.

    The modelling of livestock movements within Australia is of national importance for the purposes of the management and control of exotic disease spread, infrastructure development and the economic forecasting of livestock markets. In this paper an agent based model for the forecasting of livestock movements is presented. This models livestock movements from farm to farm through a saleyard. The decision of farmers to sell or buy cattle is often complex and involves many factors such as climate forecast, commodity prices, the type of farm enterprise, the number of animals available and associated off-shore effects. In this model the farm agent's intelligence is implemented using a fuzzy decision tree that utilises two of these factors. These two factors are the livestock price fetched at the last sale and the number of stock on the farm. On each iteration of the model farms choose either to buy, sell or abstain from the market thus creating an artificial supply and demand. The buyers and sellers then congregate at the saleyard where livestock are auctioned using a second price sealed bid. The price time series output by the model exhibits properties similar to those found in real livestock markets.

  12. Soil Moisture Data Assimilation in Soil Water Flow Modeling

    Science.gov (United States)

    Pachepsky, Y. A.; Guber, A.; Jacques, D.; Pan, F.; van Genuchten, M.; Cady, R. E.; Nicholson, T. J.

    2010-12-01

    Soil water flow modeling has multiple applications. This modeling is based on simplifications stemming from both conceptual uncertainty and lack of detailed knowledge about parameters. Modern soil moisture sensors can provide detailed information about changes in soil water content in time and with depth. This information can be used for data assimilation in soil water flow modeling. The ensemble Kalman filter appears to be an appropriate method for that. Earlier we demonstrated ensemble simulations of soil water flow by using sets of pedotransfer functions (empirical relationships between soil hydraulic properties and soil basic properties, such as particle size distribution, bulk density, organic carbon content, etc.). The objective of this work was to apply the data assimilation with the ensemble Kalman filter to soil water flow modeling, using soil water content monitoring with TDR probes and an ensemble of soil water flow models parameterized with different pedotransfer functions. Experiments were carried out at the Bekkevoort site, Belgium. Sixty time domain reflectometry (TDR) probes with two rods) were installed along the trench in loamy soil at 12 locations with 50-cm horizontal spacing at five depths (15, 35, 55, 75, and 95 cm). Water content and weather parameters were monitored for one year with 15 min frequency. Soil water flow was simulated using the HYDRUS6 software. Mean daily means of water contents at the observation depths were the measurements used in data assimilation. Eighteen pedotransfer functions for water retention and one for hydraulic conductivity were applied to generate ensembles to evaluate the uncertainty in simulation results, whereas the replicated measurements at each of measurement depths were used to characterize the uncertainty in data. Data assimilation appeared to be very efficient. Even assimilating measurements at a single depth provided substantial improvement in simulations at other observation depths. Results on

  13. Observational & modeling analysis of surface heat and moisture fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Smith, E. [Florida State Univ., Tallahassee, FL (United States)

    1995-09-01

    An observational and modeling study was conducted to help assess how well current GCMs are predicting surface fluxes under the highly variable cloudiness and flow conditions characteristic of the real atmosphere. The observational data base for the study was obtained from a network of surface flux stations operated during the First ISLSCP Field Experiment (FIFE). The study included examination of a surface-driven secondary circulation in the boundary layer resulting from a persistent cross-site gradient in soil moisture, to demonstrate the sensitivity of boundary layer dynamics to heterogeneous surface fluxes, The performance of a biosphere model in reproducing the measured surface fluxes was evaluated with and without the use of satellite retrieval of three key canopy variables with RMS uncertainties commensurate with those of the measurements themselves. Four sensible heat flux closure schemes currently being used in GCMs were then evaluated against the FIFE observations. Results indicate that the methods by which closure models are calibrated lead to exceedingly large errors when the schemes are applied to variable boundary layer conditions. 4 refs., 2 figs.

  14. Regional soil moisture simulation for Shaanxi Province using SWAT model validation and trend analysis

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The soil moisture in Shaanxi Province,a region with complex topography,is simulated using the distributed hydrological model Soil Water Assessment Tool(SWAT).Comparison and contrast of modeled and observed soil moisture show that the SWAT model can reasonably simulate the long-term trend in soil moisture and the spatiotemporal variability of soil moisture in the region.Comparisons to NCEP/NCAR and ERA40 reanalysis of soil moisture show that the trend of variability in soil moisture simulated by SWAT is more consistent with the observed.SWAT model results suggested that high soil moisture in surface soil layers appears in the southern Shaanxi with high vegetation cover,and the Qinling mountainous region with frequent orographic precipitation.In deeper soil layers,high soil moisture appears in the river basins and plains.The regional soil moisture showed a generally decreasing trend on all soil layers from 1951 to 2004,with a stronger and significant decreasing trend in deeper soil layers,especially in the northern parts of the province.

  15. Temporal Dynamics of Soil Moisture Variability at the Landscape Scale: Implications for Land Surface Models.

    Science.gov (United States)

    Montaldo, N.; Albertson, J. D.

    2001-12-01

    Meteorological and hydrological forecasting models share soil moisture as a critical boundary condition. Partitioning of received energy at the land surface depends directly on this variable, as does the partitioning of rainfall into its possible routes over and through the soil. In Land Surface Models (LSMs) the temporal dynamic of soil moisture spatial variability is a fundamental issue in large-scale flux predictions. From remote sensing observations soil moisture values are averaged in the horizontal over rather large regions (pixels). The averaging areas will be getting even larger as we move from aircraft mounted sensors to satellite mounting. These data are to be used ultimately to estimate spatial averages of other processes that depend on soil moisture, such as, runoff generation, drainage, evaporation, sensible heat fluxes, crop yield, microbial activity, etc. Consequently, the LSMs have to predict spatial averaged flux over large region from average values of the soil moisture. But soil moisture variances affect flux predictions, which depend nonlinearly on soil moisture, because many of the other processes possess distinct threshold aspects to their nonlinear dependence on soil moisture. Through application of well-developed Reynolds averaging rules from fluid mechanics to the equation of Richards and Darcy-Buckingham, we write a conservation equation for the horizontal variance of soil moisture. And, through closure arguments, we are able to describe the individual terms that produce and destroy spatial variance through time in terms of the mean soil moisture state and other observable system properties such as vegetation and soil properties variability. Finally, we calculate land surface fluxes from second order Taylor expansion, using our soil moisture variance closure model, and the other observable system properties. In this work, we demonstrate significant improvements in land surface large-scale flux predictions using the proposed soil moisture

  16. Temporal Dynamics of Soil Moisture Variability: Implications For Land Surface Models

    Science.gov (United States)

    Montaldo, N.; Albertson, J. D.

    Meteorological and hydrological forecasting models share soil moisture as a critical boundary condition. Partitioning of received energy at the land surface depends di- rectly on this variable, as does the partitioning of rainfall into its possible routes over and through the soil. In Land Surface Models (LSMs) the temporal dynamic of soil moisture spatial variability is a fundamental issue in large-scale flux predictions. From remote sensing observations soil moisture values are averaged in the horizontal over rather large regions (pixels). The averaging areas will be getting even larger as we move from aircraft mounted sensors to satellite mounting. These data are to be used ultimately to estimate spatial averages of other processes that depend on soil moisture, such as, runoff generation, drainage, evaporation, sensible heat fluxes, crop yield, mi- crobial activity, etc. Consequently, the LSMs have to predict spatial averaged flux over large region from average values of the soil moisture. But soil moisture variances af- fect flux predictions, which depend nonlinearly on soil moisture, because many of the other processes possess distinct threshold aspects to their nonlinear dependence on soil moisture. Through application of well-developed Reynolds averaging rules from fluid mechanics to the equation of Richards and Darcy-Buckingham, we write a con- servation equation for the horizontal variance of soil moisture. And, through closure arguments, we are able to describe the individual terms that produce and destroy spa- tial variance through time in terms of the mean soil moisture state and other observable system properties such as vegetation and soil properties variability. Finally, we calcu- late land surface fluxes from second order Taylor expansion, using our soil moisture variance closure model, and the other observable system properties. In this work, we demonstrate significant improvements in land surface large-scale flux predictions us- ing the proposed

  17. Local and Nonlocal Impacts of Soil Moisture Initialization on AGCM Seasonal Forecasts: A Model Sensitivity Study.

    Science.gov (United States)

    Zhang, H.; Frederiksen, C. S.

    2003-07-01

    Using a version of the Australian Bureau of Meteorology Research Centre (BMRC) atmospheric general circulation model, this study investigates the model's sensitivity to different soil moisture initial conditions in its dynamically extended seasonal forecasts of June-August 1998 climate anomalies, with focus on the south and northeast China regions where severe floods occurred. The authors' primary aim is to understand the model's responses to different soil moisture initial conditions in terms of the physical and dynamical processes involved. Due to a lack of observed global soil moisture data, the efficacy of using soil moisture anomalies derived from the NCEP-NCAR reanalysis is assessed. Results show that by imposing soil moisture percentile anomalies derived from the reanalysis data into the BMRC model initial condition, the regional features of the model's simulation of seasonal precipitation and temperature anomalies are modulated. Further analyses reveal that the impacts of soil moisture conditions on the model's surface temperature forecasts are mainly from localized interactions between land surface and the overlying atmosphere. In contrast, the model's sensitivity in its forecasts of rainfall anomalies is mainly due to the nonlocal impacts of the soil moisture conditions. Over the monsoon-dominated east Asian region, the contribution from local water recycling, through surface evaporation, to the model simulation of precipitation is limited. Rather, it is the horizontal moisture transport by the regional atmospheric circulation that is the dominant factor in controlling the model rainfall. The influence of different soil moisture conditions on the model forecasts of rainfall anomalies is the result of the response of regional circulation to the anomalous soil moisture condition imposed. Results from the BMRC model sensitivity study support similar findings from other model studies that have appeared in recent years and emphasize the importance of improving

  18. Modelling of heat and moisture transfer in buildings - I. Model program

    Energy Technology Data Exchange (ETDEWEB)

    Lu, X. [Laboratory of Structural Engineering and Building Physics, Department of Civil and Environmental Engineering, Helsinki University of Technology, Hut (Finland)

    2002-07-01

    The overall objective of this work is to develop an accurate model for predicting heat and moisture transfer in buildings including building envelopes and indoor air. The model is based on the fundamental thermodynamic relations. Darcy's law, Fick's law and Fourier's law are used in describing the transfer equations. The resultant nonlinear system of partial differential equations is discretized in space by the finite element method. The time marching scheme, Crank-Nicolson scheme, is used to advance the solution in time. The final numerical solution provides transient temperature and moisture distributions in building envelopes as well as temperature and moisture content for building's indoor air subject to outdoor weather conditions described as temperature, relative humidity, solar radiation and wind speed. A series measurements were conducted in order to investigate the model performance. The simulated values were compared against the actual measured values. A good agreement was obtained. (author)

  19. Potential and limitations of multidecadal satellite soil moisture observations for selected climate model evaluation studies

    Directory of Open Access Journals (Sweden)

    A. Loew

    2013-09-01

    Full Text Available Soil moisture is an essential climate variable (ECV of major importance for land–atmosphere interactions and global hydrology. An appropriate representation of soil moisture dynamics in global climate models is therefore important. Recently, a first multidecadal, observation-based soil moisture dataset has become available that provides information on soil moisture dynamics from satellite observations (ECVSM, essential climate variable soil moisture. The present study investigates the potential and limitations of this new dataset for several applications in climate model evaluation. We compare soil moisture data from satellite observations, reanalysis and simulations from a state-of-the-art land surface model and analyze relationships between soil moisture and precipitation anomalies in the different dataset. Other potential applications like model parameter optimization or model initialization are not investigated in the present study. In a detailed regional study, we show that ECVSM is capable to capture well the interannual and intraannual soil moisture and precipitation dynamics in the Sahelian region. Current deficits of the new dataset are critically discussed and summarized at the end of the paper to provide guidance for an appropriate usage of the ECVSM dataset for climate studies.

  20. Stochastic modelling of soil moisture dynamics in a grassland of Qilian Mountain at point scale

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Stochastic modeling of soil moisture dynamics is crucial to the quantitative understanding of plant responses to water stresses, hydrological control of nutrient cycling processes, water competition among plants, and some other ecological dynamics, and thus has become a hotspot in ecohydrology at present. In this paper, we based on the continuously monitored data of soil moisture during 2002-2005 and daily precipitation date of 1992-2006, and tried to make a probabilistic analysis of soil moisture dynamics at point scale in a grassland of Qilian Mountain by integrating the stochastic model improved by Laio and the Monte Carlo method. The results show that the inter-annual variations for the soil moisture patterns at different depths are very significant, and that the coefficient of variance (CV) of surface soil moisture (20 cm) is almost continually kept at about 0.23 whether in the rich or poor rainy years. Interestingly, it has been found that the maximal CV of soil moisture has not always appeared at the surface layer. Comparison of the analytically derived soil moisture probability density function (PDF) with the statistical distribution of the observed soil moisture data suggests that the stochastic model can reasonably describe and predict the soil moisture dynamics of the grassland in Qilian Mountain at point scale. By extracting the statistical information of the historical precipitation data in 1994-2006, and inputting them into the stochastic model, we analytically derived the long-term soil moisture PDF without considering the inter-annual climate fluctuations, and then numerically derived the one when considering the inter-annual fluctuation effects in combination with a Monte-Carlo procedure. It was found that, though the peak position of the probability density distribution significantly moved towards drought when considering the disturbance forces, and its width was narrowed, accordingly its peak value was increased, no significant bimodality was

  1. Spatial variability and its scale dependency of observed and modeled soil moisture under different climate conditions

    Directory of Open Access Journals (Sweden)

    B. Li

    2012-09-01

    Full Text Available Past studies on soil moisture spatial variability have been mainly conducted in catchment scales where soil moisture is often sampled over a short time period. Because of limited climate and weather conditions, the observed soil moisture often exhibited smaller dynamic ranges which prevented the complete revelation of soil moisture spatial variability as a function of mean soil moisture. In this study, spatial statistics (mean, spatial variability and skewness of in situ soil moisture measurements (from a continuously monitored network across the US, modeled and satellite retrieved soil moisture obtained in a warm season (198 days were examined at large extent scales (>100 km over three different climate regions. The investigation on in situ measurements revealed that their spatial moments strongly depend on climates, with distinct mean, spatial variability and skewness observed in each climate zone. In addition, an upward convex shape, which was revealed in several smaller scale studies, was observed for the relationship between spatial variability of in situ soil moisture and its spatial mean across dry, intermediate, and wet climates. These climate specific features were vaguely or partially observable in modeled and satellite retrieved soil moisture estimates, which is attributed to the fact that these two data sets do not have climate specific and seasonal sensitive mean soil moisture values, in addition to lack of dynamic ranges. From the point measurements to satellite retrievals, soil moisture spatial variability decreased in each climate region. The three data sources all followed the power law in the scale dependency of spatial variability, with coarser resolution data showing stronger scale dependency than finer ones. The main findings from this study are: (1 the statistical distribution of soil moisture depends on spatial mean soil moisture values and thus need to be derived locally within any given area; (2 the boundedness of soil

  2. Forward models and state estimation in compensatory eye movements

    NARCIS (Netherlands)

    M.A. Frens (Maarten); O. Donchin (Opher)

    2009-01-01

    textabstractThe compensatory eye movement (CEM) system maintains a stable retinal image, integrating information from different sensory modalities to compensate for head movements. Inspired by recent models of the physiology of limb movements, we suggest that CEM can be modeled as a control system w

  3. Forward models and state estimation in compensatory eye movements

    NARCIS (Netherlands)

    M.A. Frens (Maarten); O. Donchin (Opher)

    2009-01-01

    textabstractThe compensatory eye movement (CEM) system maintains a stable retinal image, integrating information from different sensory modalities to compensate for head movements. Inspired by recent models of the physiology of limb movements, we suggest that CEM can be modeled as a control system

  4. A Mulitivariate Statistical Model Describing the Compound Nature of Soil Moisture Drought

    Science.gov (United States)

    Manning, Colin; Widmann, Martin; Bevacqua, Emanuele; Maraun, Douglas; Van Loon, Anne; Vrac, Mathieu

    2017-04-01

    Soil moisture in Europe acts to partition incoming energy into sensible and latent heat fluxes, thereby exerting a large influence on temperature variability. Soil moisture is predominantly controlled by precipitation and evapotranspiration. When these meteorological variables are accumulated over different timescales, their joint multivariate distribution and dependence structure can be used to provide information of soil moisture. We therefore consider soil moisture drought as a compound event of meteorological drought (deficits of precipitation) and heat waves, or more specifically, periods of high Potential Evapotraspiration (PET). We present here a statistical model of soil moisture based on Pair Copula Constructions (PCC) that can describe the dependence amongst soil moisture and its contributing meteorological variables. The model is designed in such a way that it can account for concurrences of meteorological drought and heat waves and describe the dependence between these conditions at a local level. The model is composed of four variables; daily soil moisture (h); a short term and a long term accumulated precipitation variable (Y1 and Y_2) that account for the propagation of meteorological drought to soil moisture drought; and accumulated PET (Y_3), calculated using the Penman Monteith equation, which can represent the effect of a heat wave on soil conditions. Copula are multivariate distribution functions that allow one to model the dependence structure of given variables separately from their marginal behaviour. PCCs then allow in theory for the formulation of a multivariate distribution of any dimension where the multivariate distribution is decomposed into a product of marginal probability density functions and two-dimensional copula, of which some are conditional. We apply PCC here in such a way that allows us to provide estimates of h and their uncertainty through conditioning on the Y in the form h=h|y_1,y_2,y_3 (1) Applying the model to various

  5. Modeling moisture absorption kinetics of barley grain using viscoelastic model and neural networks

    Directory of Open Access Journals (Sweden)

    M Kamali

    2015-09-01

    Full Text Available Introduction: Barley is one of the most important grains with high digestible starch making it a main source of energy in human nutrition as well as in livestock rations formulation and feeding. Starch is the main part of barley grain and it has an inverse relation with its protein. It has a digestible foodstuff of 80 to 84 percent of its dry matter content. Barley as livestock foodstuff should be processed and it is done in several ways. A customary method for processing barley in dairy farms is its size reduction by milling (Hunt, 1996. An alternative method of barley processing is steam rolling. However, because of the high cost of steam generators a method of soaking with heating has been considered as an alternative method for steam rolling (Yang et al., 2000. The rate of moisture absorption by grains during the soaking process varies considerably and depends on the size of the grain, water temperature and the length of soaking. High temperature water soaking is an ordinary way to reduce the time duration for reaching a high rate of moisture absorption during the soaking process (Kashaninejad et al., 2009. Various studies have shown that these models have adequate accuracy in analyzing drying and moisture absorption processes for most agricultural products (Abu-Ghannam and McKenna, 1997. Some researchers have modeled beans moisture absorption behavior using 14 mathematical models and found that the Weibull model had the most conformity with variations in experimental data (Shafaei and Masoumi, 2014c. Observations made by researchers indicate that the moisture absorption process in various materials encompasses a primary phase with a fast rate and a second phase with a lower rate. The second phase in moisture absorption is called the relaxation phase. The main problem with all the mathematical and experimental models is the lack of the model’s ability to evaluate the rate of moisture absorption in the secondary phase. Artificial Neural

  6. Estimation of Soil Moisture Profile using a Simple Hydrology Model and Passive Microwave Remote Sensing

    Science.gov (United States)

    Soman, Vishwas V.; Crosson, William L.; Laymon, Charles; Tsegaye, Teferi

    1998-01-01

    Soil moisture is an important component of analysis in many Earth science disciplines. Soil moisture information can be obtained either by using microwave remote sensing or by using a hydrologic model. In this study, we combined these two approaches to increase the accuracy of profile soil moisture estimation. A hydrologic model was used to analyze the errors in the estimation of soil moisture using the data collected during Huntsville '96 microwave remote sensing experiment in Huntsville, Alabama. Root mean square errors (RMSE) in soil moisture estimation increase by 22% with increase in the model input interval from 6 hr to 12 hr for the grass-covered plot. RMSEs were reduced for given model time step by 20-50% when model soil moisture estimates were updated using remotely-sensed data. This methodology has a potential to be employed in soil moisture estimation using rainfall data collected by a space-borne sensor, such as the Tropical Rainfall Measuring Mission (TRMM) satellite, if remotely-sensed data are available to update the model estimates.

  7. Multi-site assimilation of a terrestrial biosphere model (BETHY) using satellite derived soil moisture data

    Science.gov (United States)

    Wu, Mousong; Sholze, Marko

    2017-04-01

    We investigated the importance of soil moisture data on assimilation of a terrestrial biosphere model (BETHY) for a long time period from 2010 to 2015. Totally, 101 parameters related to carbon turnover, soil respiration, as well as soil texture were selected for optimization within a carbon cycle data assimilation system (CCDAS). Soil moisture data from Soil Moisture and Ocean Salinity (SMOS) product was derived for 10 sites representing different plant function types (PFTs) as well as different climate zones. Uncertainty of SMOS soil moisture data was also estimated using triple collocation analysis (TCA) method by comparing with ASCAT dataset and BETHY forward simulation results. Assimilation of soil moisture to the system improved soil moisture as well as net primary productivity(NPP) and net ecosystem productivity (NEP) when compared with soil moisture derived from in-situ measurements and fluxnet datasets. Parameter uncertainties were largely reduced relatively to prior values. Using SMOS soil moisture data for assimilation of a terrestrial biosphere model proved to be an efficient approach in reducing uncertainty in ecosystem fluxes simulation. It could be further used in regional an global assimilation work to constrain carbon dioxide concentration simulation by combining with other sources of measurements.

  8. Inverse modeling of soil characteristics from surface soil moisture observations: potential and limitations

    Directory of Open Access Journals (Sweden)

    A. Loew

    2008-01-01

    Full Text Available Land surface models (LSM are widely used as scientific and operational tools to simulate mass and energy fluxes within the soil vegetation atmosphere continuum for numerous applications in meteorology, hydrology or for geobiochemistry studies. A reliable parameterization of these models is important to improve the simulation skills. Soil moisture is a key variable, linking the water and energy fluxes at the land surface. An appropriate parameterisation of soil hydraulic properties is crucial to obtain reliable simulation of soil water content from a LSM scheme. Parameter inversion techniques have been developed for that purpose to infer model parameters from soil moisture measurements at the local scale. On the other hand, remote sensing methods provide a unique opportunity to estimate surface soil moisture content at different spatial scales and with different temporal frequencies and accuracies. The present paper investigates the potential to use surface soil moisture information to infer soil hydraulic characteristics using uncertain observations. Different approaches to retrieve soil characteristics from surface soil moisture observations is evaluated and the impact on the accuracy of the model predictions is quantified. The results indicate that there is in general potential to improve land surface model parameterisations by assimilating surface soil moisture observations. However, a high accuracy in surface soil moisture estimates is required to obtain reliable estimates of soil characteristics.

  9. Bond-Slip Models for FPR-Concrete Interfaces Subjected to Moisture Conditions

    Directory of Open Access Journals (Sweden)

    Justin Shrestha

    2017-01-01

    Full Text Available Environmental related durability issues have been of great concerns in the structures strengthened with the fiber reinforced polymers (FRPs. In marine environment, moisture is one of the dominant factors that adversely affect the material properties and the bond interfaces. Several short-term and long-term laboratory experimental investigations have been conducted to study such behaviors but, still, there are insufficient constitutive bond models which could incorporate moisture exposure conditions. This paper proposed a very simple approach in determining the nonlinear bond-slip models for the FRP-concrete interface considering the effect of moisture conditions. The proposed models are based on the strain results of the experimental investigation conducted by the authors using 6 different commercial FRP systems exposed to the moisture conditions for the maximum period of 18 months. The exposure effect in the moisture conditions seems to have great dependency on the FRP system. Based on the contrasting differences in the results under moisture conditions, separate bond-slip models have been proposed for the wet-layup FRP and prefabricated FRP systems. As for the verification of the proposed model under moisture conditions, predicted pull-out load was compared with the experimental pull-out load. The results showed good agreement for all the FRP systems under investigation.

  10. Moisture buffering and its consequence in whole building hygrothermal modeling

    DEFF Research Database (Denmark)

    Rode, Carsten; Grau, Karl

    2008-01-01

    both. A new test method specifies a protocol for determination of what has recently been termed the Moisture Buffer Value (MBV) of building products. The paper presents the definition of MBV and introduces a test protocol which has been proposed for its experimental determination. The MBV is primarily...

  11. Modeling the Effects of Soil Moisture at a GPS-Interferometric Reflectometry Station

    Science.gov (United States)

    Chew, C.; Small, E. E.; Larson, K. M.; Nievinski, F. G.; Zavorotny, V.

    2011-12-01

    GPS-Interferometric Reflectometry (GPS-IR) uses ground-reflected GPS signals to estimate near-surface soil moisture. Data are recorded by high-precision, geodetic-quality GPS antennas/receivers, for example those that comprise NSF's EarthScope Plate Boundary Observatory. The ground reflections used in GPS-IR are representative of a ~1000 m2 area around an antenna. As the dielectric constant of the surface fluctuates, the phase, amplitude, and frequency of signal-to-noise ratio (SNR) data recorded by the GPS unit change. Based on field observations, it has been shown that these characteristics of the SNR data are sensitive to shallow soil moisture. A single-scattering, electrodynamic model was used to simulate SNR output over a range of soil moisture conditions. All simulations were for a 2.4 m tall antenna surrounded by a surface free of roughness or vegetation. The model was run using three different types of soil moisture profiles: constant with depth, monotonic variations with depth, and observed profiles interpolated from field data. For all profiles, amplitude, phase shift, and frequency changes were calculated from simulated SNR data. The three GPS metrics are well correlated with soil moisture content modeled at the soil surface because a majority of the incident microwave energy is reflected at the air-soil interface. When surface soil is dry relative to the underlying soil, GPS metrics are also strongly correlated with soil moisture averaged over the top 5 cm of the soil column. The relationship between GPS metrics and soil moisture averaged over 5 cm is not as strong when surface soil is relatively wet (>35% volumetric soil moisture). Interpolated profiles from field data resulted in a very strong correlation between SNR metrics and soil moisture averaged over the top 5 cm of soil, suggesting that soil moisture estimated from SNR data is useful for various hydrologic applications.

  12. Measuring and modeling the effect of surface moisture on the spectral reflectance of coastal beach sand.

    Science.gov (United States)

    Nolet, Corjan; Poortinga, Ate; Roosjen, Peter; Bartholomeus, Harm; Ruessink, Gerben

    2014-01-01

    Surface moisture is an important supply limiting factor for aeolian sand transport, which is the primary driver of coastal dune development. As such, it is critical to account for the control of surface moisture on available sand for dune building. Optical remote sensing has the potential to measure surface moisture at a high spatio-temporal resolution. It is based on the principle that wet sand appears darker than dry sand: it is less reflective. The goals of this study are (1) to measure and model reflectance under controlled laboratory conditions as function of wavelength (λ) and surface moisture (θ) over the optical domain of 350-2500 nm, and (2) to explore the implications of our laboratory findings for accurately mapping the distribution of surface moisture under natural conditions. A laboratory spectroscopy experiment was conducted to measure spectral reflectance (1 nm interval) under different surface moisture conditions using beach sand. A non-linear increase of reflectance upon drying was observed over the full range of wavelengths. Two models were developed and tested. The first model is grounded in optics and describes the proportional contribution of scattering and absorption of light by pore water in an unsaturated sand matrix. The second model is grounded in soil physics and links the hydraulic behaviour of pore water in an unsaturated sand matrix to its optical properties. The optical model performed well for volumetric moisture content θ 0.97), but underestimated reflectance for θ between 24-30% (R2 > 0.92), most notable around the 1940 nm water absorption peak. The soil-physical model performed very well (R2 > 0.99) but is limited to 4% > θ < 24%. Results from a field experiment show that a short-wave infrared terrestrial laser scanner (λ = 1550 nm) can accurately relate surface moisture to reflectance (standard error 2.6%), demonstrating its potential to derive spatially extensive surface moisture maps of a natural coastal beach.

  13. Measuring and modeling the effect of surface moisture on the spectral reflectance of coastal beach sand.

    Directory of Open Access Journals (Sweden)

    Corjan Nolet

    Full Text Available Surface moisture is an important supply limiting factor for aeolian sand transport, which is the primary driver of coastal dune development. As such, it is critical to account for the control of surface moisture on available sand for dune building. Optical remote sensing has the potential to measure surface moisture at a high spatio-temporal resolution. It is based on the principle that wet sand appears darker than dry sand: it is less reflective. The goals of this study are (1 to measure and model reflectance under controlled laboratory conditions as function of wavelength (λ and surface moisture (θ over the optical domain of 350-2500 nm, and (2 to explore the implications of our laboratory findings for accurately mapping the distribution of surface moisture under natural conditions. A laboratory spectroscopy experiment was conducted to measure spectral reflectance (1 nm interval under different surface moisture conditions using beach sand. A non-linear increase of reflectance upon drying was observed over the full range of wavelengths. Two models were developed and tested. The first model is grounded in optics and describes the proportional contribution of scattering and absorption of light by pore water in an unsaturated sand matrix. The second model is grounded in soil physics and links the hydraulic behaviour of pore water in an unsaturated sand matrix to its optical properties. The optical model performed well for volumetric moisture content θ 0.97, but underestimated reflectance for θ between 24-30% (R2 > 0.92, most notable around the 1940 nm water absorption peak. The soil-physical model performed very well (R2 > 0.99 but is limited to 4% > θ < 24%. Results from a field experiment show that a short-wave infrared terrestrial laser scanner (λ = 1550 nm can accurately relate surface moisture to reflectance (standard error 2.6%, demonstrating its potential to derive spatially extensive surface moisture maps of a natural coastal beach.

  14. Performance evaluation of WRF-Noah Land surface model estimated soil moisture for hydrological application: Synergistic evaluation using SMOS retrieved soil moisture

    Science.gov (United States)

    Srivastava, Prashant K.; Han, Dawei; Rico-Ramirez, Miguel A.; O'Neill, Peggy; Islam, Tanvir; Gupta, Manika; Dai, Qiang

    2015-10-01

    This study explores the performance of soil moisture data from the global European Centre for Medium Range Weather Forecasts (ECMWF) ERA interim reanalysis datasets using the Weather Research and Forecasting (WRF) mesoscale numerical weather model coupled with the Noah Land surface model for hydrological applications. For evaluating the performance of WRF for soil moisture estimation, three domains are taken into account. The domain with best performance is used for estimating the soil moisture deficit (SMD). Further, several approaches are presented in this study to evaluate the efficiency of WRF simulated soil moisture for SMD estimation and compared against Soil Moisture and Ocean Salinity (SMOS) downscaled and non-downscaled soil moisture. In this study, the first approach is based on the empirical relationship between WRF soil moisture and the SMD on a continuous time series basis, while the second approach is focused on the vegetation cover impact on SMD retrieval, depicted in terms of growing and non-growing seasons. The linear growing and non-growing seasonal model in combination performs well with the NSE = 0.79, RMSE = 0.011 m; Bias = 0.24 m, in comparison to linear model (NSE = 0.70, RMSE = 0.013 m; Bias = 0.01 m). The performance obtained using WRF soil moisture is comparable to SMOS level 2 product but lower than the downscaled SMOS datasets. The results indicate that methodologies could be useful for modelers working in the field of soil moisture information system and SMD estimation at a catchment scale. The study could be useful for ungauged basins that pose a challenge to hydrological modeling due to unavailability of datasets for proper model calibration and validation.

  15. Modelling soil moisture for a grassland and a woodland site in south-east England

    Directory of Open Access Journals (Sweden)

    E. Blyth

    2002-01-01

    Full Text Available This paper describes a comparison between two soil moisture prediction models. One is MORECS (Met Office Rainfall and Evaporation Calculation Scheme, the Met Office soil moisture model that is used by agriculture, flood modellers and weather forecasters to initialise their models. The other is MOSES (Met Office Surface Exchange Scheme, modified with a runoff generation module. The models are made compatible by increasing the vegetation information available to MOSES. Both models were run with standard parameters and were driven using meteorological observations at Wallingford (1995-1997. Detailed soil moisture measurements were available at a grassland site and a woodland site in this area. The comparison between the models and the observed soil moisture indicated that, for the grassland site, MORECS dried out too quickly in the spring and, for the woodland site, was too wet. Overall, the performance of MOSES was superior. The soil moisture predicted by the new, modified MOSES will be included as a product of Nimrod - the 5 km x 5km gridded network of observed meteorological data across the UK. Keywords: Soil moisture, model, observation, field capacity

  16. Conservative modelling of the moisture and heat transfer in building components under atmospheric excitation

    DEFF Research Database (Denmark)

    Janssen, Hans; Blocken, Bert; Carmeliet, Jan

    2007-01-01

    While the transfer equations for moisture and heat in building components are currently undergoing standardisation, atmospheric boundary conditions, conservative modelling and numerical efficiency are not addressed. In a first part, this paper adds a comprehensive description of those boundary co...

  17. A REVIEW OF THE ANALYSIS OF MOISTURE VARIABLES AND THE APPLICATION IN NUMERICAL MODELS

    Institute of Scientific and Technical Information of China (English)

    WANG Zai-zhi; YAN Jing-hua

    2007-01-01

    The application of the explicit microphysical process in the high-resolution mesoscale numerical models makes it necessary to analyze the moisture variables such as the cloud water, cloud ice and rain water to initialize the explicit predicted fields. While the inclusion of moisture variables in initial fields can influence the whole performance of the model significantly, it can also reduce the spin-up time and increase the short-term forecasting ability of the model since the dynamical fields become more accordant with the thermodynamic fields. Now the increase of the observing ability and the abundance of the data promote the development of ways to analyze the moisture variables. A review of some methods to analyze the moisture variables is presented, and the situation and problems of the application in the numerical models are also discussed in this paper.

  18. Hidden Markov models: the best models for forager movements?

    Directory of Open Access Journals (Sweden)

    Rocio Joo

    Full Text Available One major challenge in the emerging field of movement ecology is the inference of behavioural modes from movement patterns. This has been mainly addressed through Hidden Markov models (HMMs. We propose here to evaluate two sets of alternative and state-of-the-art modelling approaches. First, we consider hidden semi-Markov models (HSMMs. They may better represent the behavioural dynamics of foragers since they explicitly model the duration of the behavioural modes. Second, we consider discriminative models which state the inference of behavioural modes as a classification issue, and may take better advantage of multivariate and non linear combinations of movement pattern descriptors. For this work, we use a dataset of >200 trips from human foragers, Peruvian fishermen targeting anchovy. Their movements were recorded through a Vessel Monitoring System (∼1 record per hour, while their behavioural modes (fishing, searching and cruising were reported by on-board observers. We compare the efficiency of hidden Markov, hidden semi-Markov, and three discriminative models (random forests, artificial neural networks and support vector machines for inferring the fishermen behavioural modes, using a cross-validation procedure. HSMMs show the highest accuracy (80%, significantly outperforming HMMs and discriminative models. Simulations show that data with higher temporal resolution, HSMMs reach nearly 100% of accuracy. Our results demonstrate to what extent the sequential nature of movement is critical for accurately inferring behavioural modes from a trajectory and we strongly recommend the use of HSMMs for such purpose. In addition, this work opens perspectives on the use of hybrid HSMM-discriminative models, where a discriminative setting for the observation process of HSMMs could greatly improve inference performance.

  19. An extension of the talbot-ogden hydrology model to an affine multi-dimensional moisture content domain

    KAUST Repository

    Yu, Han

    2013-09-01

    The Talbot-Ogden hydrology model provides a fast mass conservative method to compute infiltration in unsaturated soils. As a replacement for a model based on Richards equation, it separates the groundwater movement into infiltration and redistribution for every time step. The typical feature making this method fast is the discretization of the moisture content domain rather than the spatial one. The Talbot-Ogden model rapidly determines how well ground water and aquifers are recharged only. Hence, it differs from models based on advanced reservoir modeling that are uniformly far more expensive computationally since they determine where the water moves in space instead, a completely different and more complex problem.According to the pore-size distribution curve for many soils, this paper extends the one dimensional moisture content domain into a two dimensional one by keeping the vertical spatial axis. The proposed extension can describe any pore-size or porosity distribution as an important soil feature. Based on this extension, infiltration and redistribution are restudied. The unconditional conservation of mass in the Talbot-Ogden model is inherited in this extended model. A numerical example is given for the extended model.

  20. Evaluation model of reinforcement structures of Small mass movement

    Directory of Open Access Journals (Sweden)

    Gustavo Antonio Piazza

    2015-04-01

    Full Text Available Mass movements can be the result of elevated precipitation events and inadequate policies of land use. This study aims at diagnosing the performance of a hillside stabilization structure that suffered a landslide in the meteorological event at the Itajaí Valley in 2008, and to propose a simple method for evaluating reinforcement structures of small mass movement. The study area is located at BR–470 – km 45, near to the city limit of Gaspar and Blumenau, in Santa Catarina, South Brazil. Tests were performed to determine the infiltration rate and soil moisture, as well as a survey of the floristic composition and slope. The mass movement still takes place and the stabilization structure is compromised. The use of gabion wall and other geotechnical techniques for environmental recovery were insufficient to provide the hillside stabilization. To a greater efficiency we suggest: slope reduction; soil compaction; suitable planting species (ecologic succession; and implementation of a comprehensive drainage system.

  1. Modeling Transient Root-zone Soil Moisture Dichotomies in Landscapes with Intermixed Land Covers

    Science.gov (United States)

    Patrignani, A.; Ochsner, T. E.

    2015-12-01

    Although large-scale in situ soil moisture monitoring networks are becoming increasingly valuable research tools, deficiencies of many existing networks include the small spatial support of each station, the low spatial density of stations, and the almost exclusive deployment of stations in grassland vegetation. These grassland soil moisture observations may not adequately represent the real soil moisture patterns in landscapes with intermixed land cover types. The objectives of this study were i) to compare root-zone soil moisture dynamics of two dominant vegetation types across Oklahoma, grassland (observed) and winter wheat cropland (simulated); ii) to relate the soil moisture dynamics of grassland and cropland vegetation using an artificial neural network (ANN) as a transfer function; and iii) to use the resulting ANN to estimate the soil moisture spatial patterns for a landscape of intermixed grassland and wheat cropland. Root-zone soil moisture was represented by plant available water (PAW) in the top 0.8 m of the soil profile. PAW under grassland was calculated from 18 years of soil moisture observations at 78 stations of the Oklahoma Mesonet, whereas PAW under winter wheat was simulated for the same 78 locations using a soil water balance model. Then, we trained an ANN to reproduce the simulated PAW under winter wheat using only seven inputs: day of the year, latitude and longitude, measured PAW under grassland, and percent sand, silt, and clay. The resulting ANN was used, along with grassland soil moisture observations, to estimate the detailed soil moisture pattern for a 9x9 km2 Soil Moisture Active Passive (SMAP) grid cell. The seasonal dynamics of root-zone PAW for grassland and winter wheat were strongly asynchronous, so grassland soil moisture observations rarely reflect cropland soil moisture conditions in the region. The simple ANN approach facilitated efficient and accurate prediction of the simulated PAW under winter wheat, RMSE = 24 mm, using

  2. Assimilation of ASCAT near-surface soil moisture into the SIM hydrological model over France

    Directory of Open Access Journals (Sweden)

    C. Draper

    2011-12-01

    Full Text Available This study examines whether the assimilation of remotely sensed near-surface soil moisture observations might benefit an operational hydrological model, specifically Météo-France's SAFRAN-ISBA-MODCOU (SIM model. Soil moisture data derived from ASCAT backscatter observations are assimilated into SIM using a Simplified Extended Kalman Filter (SEKF over 3.5 years. The benefit of the assimilation is tested by comparison to a delayed cut-off version of SIM, in which the land surface is forced with more accurate atmospheric analyses, due to the availability of additional atmospheric observations after the near-real time data cut-off. However, comparing the near-real time and delayed cut-off SIM models revealed that the main difference between them is a dry bias in the near-real time precipitation forcing, which resulted in a dry bias in the root-zone soil moisture and associated surface moisture flux forecasts. While assimilating the ASCAT data did reduce the root-zone soil moisture dry bias (by nearly 50%, this was more likely due to a bias within the SEKF, than due to the assimilation having accurately responded to the precipitation errors. Several improvements to the assimilation are identified to address this, and a bias-aware strategy is suggested for explicitly correcting the model bias. However, in this experiment the moisture added by the SEKF was quickly lost from the model surface due to the enhanced surface fluxes (particularly drainage induced by the wetter soil moisture states. Consequently, by the end of each winter, during which frozen conditions prevent the ASCAT data from being assimilated, the model land surface had returned to its original (dry-biased climate. This highlights that it would be more effective to address the precipitation bias directly, than to correct it by constraining the model soil moisture through data assimilation.

  3. A Brownian Bridge Movement Model to Track Mobile Targets

    Science.gov (United States)

    2016-09-01

    BRIDGE MOVEMENT MODEL TO TRACK MOBILE TARGETS by Chun Chieh Cheng September 2016 Thesis Advisor: Dashi I. Singham Second Reader: Michael P...DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE A BROWNIAN BRIDGE MOVEMENT MODEL TO TRACK MOBILE TARGETS 5. FUNDING NUMBERS 6. AUTHOR(S...Approved for public release. Distribution is unlimited. A BROWNIAN BRIDGE MOVEMENT MODEL TO TRACK MOBILE TARGETS Chun Chieh Cheng Major

  4. An Improved Walk Model for Train Movement on Railway Network

    Institute of Scientific and Technical Information of China (English)

    LI Ke-Ping; MAO Bo-Hua; GAO Zi-You

    2009-01-01

    In this paper, we propose an improved walk model for simulating the train movement on railway network. In the proposed method, walkers represent trains. The improved walk model is a kind of the network-based simulation analysis model. Using some management rules for walker movement, walker can dynamically determine its departure and arrival times at stations. In order to test the proposed method, we simulate the train movement on a part of railway network. The numerical simulation and analytical results demonstrate that the improved model is an effective tool for simulating the train movement on railway network. Moreover, it can well capture the characteristic behaviors of train scheduling in railway traffic.

  5. moisture transfer

    Directory of Open Access Journals (Sweden)

    Don Kulasiri

    2005-01-01

    model drying porous materials. Coupled partial differential equations governing the moisture and heat transfer can be solved using numerical techniques, and in this paper we solve them analytically in a setting suitable for industrial drying situations. We discuss the nature of the solutions using the physical properties of Pinus radiata. It is shown that the temperature gradients play a significant role in deciding the moisture profiles within the material when thickness is large and that models based only on moisture potential gradients may not be sufficient to explain the drying phenomena in moist porous materials.

  6. Modelling soil moisture at SMOS scale by use of a SVAT model over the Valencia Anchor Station

    Directory of Open Access Journals (Sweden)

    S. Juglea

    2010-01-01

    Full Text Available The main goal of the SMOS (Soil Moisture and Ocean Salinity mission is to deliver global fields of surface soil moisture and sea surface salinity using L-band (1.4 GHz radiometry. Within the context of the preparation for this mission over land, the Valencia Anchor Station experimental site, in Spain, was chosen to be one of the main test sites in Europe for the SMOS Calibration/Validation (Cal/Val activities. Ground and meteorological measurements over the area are used as the input of a Soil-Vegetation-Atmosphere-Transfer (SVAT model, SURFEX (Externalized Surface-module ISBA (Interactions between Soil-Biosphere-Atmosphere so as to simulate the surface soil moisture. The calibration as well as the validation of the ISBA model was made using in situ soil moisture measurements. It is shown that a good consistency was reached when point comparisons between simulated and in situ soil moisture measurements were made. In order to obtain an accurate soil moisture mapping over the Valencia Anchor Station (50×50 km2 area, a spatialization method has been applied. To validate the approach, a comparison with remote sensing data from the Advanced Microwave Scanning Radiometer on Earth observing System (AMSR-E and from the European Remote Sensing Satellites (ERS-Scat was performed. Despite the fact that AMSR-E surface soil moisture product is not reproducing accurately the absolute values, it provides trustworthy information on surface soil moisture temporal variability. However, during the vegetation growing season the signal is perturbed. By using the polarization ratio a better agreement is obtained. ERS-Scat soil moisture products were also used to be compared with the simulated spatialized soil moisture. The seasonal variations were well reproduced. However, the lack of soil moisture data over the area (45 observations for one year was a limit into completely understanding the soil moisture variability.

  7. Hierarchical animal movement models for population-level inference

    Science.gov (United States)

    Hooten, Mevin B.; Buderman, Frances E.; Brost, Brian M.; Hanks, Ephraim M.; Ivans, Jacob S.

    2016-01-01

    New methods for modeling animal movement based on telemetry data are developed regularly. With advances in telemetry capabilities, animal movement models are becoming increasingly sophisticated. Despite a need for population-level inference, animal movement models are still predominantly developed for individual-level inference. Most efforts to upscale the inference to the population level are either post hoc or complicated enough that only the developer can implement the model. Hierarchical Bayesian models provide an ideal platform for the development of population-level animal movement models but can be challenging to fit due to computational limitations or extensive tuning required. We propose a two-stage procedure for fitting hierarchical animal movement models to telemetry data. The two-stage approach is statistically rigorous and allows one to fit individual-level movement models separately, then resample them using a secondary MCMC algorithm. The primary advantages of the two-stage approach are that the first stage is easily parallelizable and the second stage is completely unsupervised, allowing for an automated fitting procedure in many cases. We demonstrate the two-stage procedure with two applications of animal movement models. The first application involves a spatial point process approach to modeling telemetry data, and the second involves a more complicated continuous-time discrete-space animal movement model. We fit these models to simulated data and real telemetry data arising from a population of monitored Canada lynx in Colorado, USA.

  8. Employing satellite retrieved soil moisture for parameter estimation of the hydrologic model mHM

    Science.gov (United States)

    Zink, Matthias; Mai, Juliane; Rakovec, Oldrich; Schrön, Martin; Kumar, Rohini; Schäfer, David; Samaniego, Luis

    2016-04-01

    Hydrological models are usually calibrated against observed streamflow at the catchment outlet and thus they are conditioned by an integral catchment signal. Rakovec et al. 2016 (JHM) recently demonstrated that constraining model parameters against river discharge is a necessary, but not a sufficient condition. Such a procedure ensures the fulfillment of the catchment's water balance but can lead to high predictive uncertainties of model internal states, like soil moisture, or a lack in spatial representativeness of the model. However, some hydrologic applications, as e.g. soil drought monitoring and prediction, rely on this information. Within this study we propose a framework in which the mesoscale Hydrologic Model (mHM) is calibrated with soil moisture retrievals from various sources. The aim is to condition the model on soil moisture (SM), while preserving good performance in streamflow estimation. We identify the most appropriate objective functions by conducting synthetic experiments. The best objective function is determined based on: 1) deviation between synthetic and simulated soil moisture, 2) nonparametric comparison of SM fields (e.g. copulas), and 3) by euclidian distance of model parameters, which is zero if the parameters of the synthetic data are recovered. Those objective functions performing best are used to calibrate mHM against different satellite soil moisture products, e.g. ESA-CCI, H-SAF, and in situ observations. This procedure is tested in three distinct European basins (upper Sava, Neckar, and upper Guadalquivir basin) ranging from snow domination to semi arid climatic conditions. Results obtained with the synthetic experiment indicate that objective functions focusing on the temporal dynamics of SM are preferable to objective functions aiming at spatial patterns or catchment averages. Since the deviation of soil moisture fields (1) and their copulas (2) don't lead to conclusive results, the decision of the best performing objective

  9. Integrating coarse-scale uncertain soil moisture data into a fine-scale hydrological modelling scenario

    Directory of Open Access Journals (Sweden)

    H. Vernieuwe

    2011-06-01

    Full Text Available In a hydrological modelling scenario, often the modeller is confronted with external data, such as remotely-sensed soil moisture observations, that become available to update the model output. However, the scale triplet (spacing, extent and support of these data is often inconsistent with that of the model. Furthermore, the external data can be cursed with epistemic uncertainty. Hence, a method is needed that not only integrates the external data into the model, but that also takes into account the difference in scale and the uncertainty of the observations. In this paper, a synthetic hydrological modelling scenario is set up in which a high-resolution distributed hydrological model is run over an agricultural field. At regular time steps, coarse-scale field-averaged soil moisture data, described by means of possibility distributions (epistemic uncertainty, are retrieved by synthetic aperture radar and assimilated into the model. A method is presented that allows to integrate the coarse-scale possibility distribution of soil moisture content data with the fine-scale model-based soil moisture data. To this end, a scaling relationship between field-averaged soil moisture content data and its corresponding standard deviation is employed.

  10. The impacts of assimilating satellite soil moisture into a rainfall-runoff model in a semi-arid catchment

    Science.gov (United States)

    Soil moisture plays a key role in runoff generation processes. As a result, the assimilation of soil moisture observations into rainfall-runoff models is increasingly being investigated. Given the scarcity of ground-based in situ measurements, satellite soil moisture observations offer a valuable da...

  11. Modelling active antennal movements of the American cockroach

    DEFF Research Database (Denmark)

    Pequeno-Zurro, Alejandro; Nitschke, Jahn; Szyszka, Paul

    2017-01-01

    and the spatial properties of encountered odorant concentrations. Video recordings reveal that the animal’s antennae exhibit systematic movements in the presence of behaviourally relevant odorants. We hypothesise a dynamic coupling between the left and right antenna modulated by odour stimulation. To test this we......, coupled Hopf oscillator to model antennal movements in response to odorant concentration, using this map for sensory drive signals for the model. We present simulation results of antennal movements in response to odorant concentrations....

  12. Modeling the Soil Moisture Parametrization in a Snow Dominated Mountainous Region

    Science.gov (United States)

    Kikine, Daniel; Sensoy, Aynur; Sorman, Arda

    2016-04-01

    The study quantifies the effects of both the soil moisture accounting and the temperature index in the event based as well as the continuous simulation of a model in a snow dominated basin. Physically based watershed model parameters are required to reproduce the historical flows and forecast the stream flows. This study demonstrates that parameterization of hydrological model is a favorable approach to perform forecasting because it employs the relationship of the calibrated model parameters and those of the watershed's physical properties. With this consideration, the temperature index (degree-day) snowmelt and the soil moisture accounting models within the Hydrologic Engineering Center's hydrologic modeling system (HEC-HMS) are applied to the Upper Euphrates watershed. The versatile 14-parameter soil moisture accounting (SMA) algorithm is utilized for a better simulation and parameterization of the watershed. The methodology was exemplified by performing various independent simulations using the meteorological data and the observed stream discharges. The soil moisture parameters were calibrated and modified according to their statistical relationships with the land use for the 2002 - 2008 period, the obtained parameter set are then validated for the 2009 - 2012 period. Model outputs are evaluated in comparison to satellite derived soil moisture and snow water equivalent data. Deterministic Numerical Weather Prediction data are used together with the conceptual model to forecast runoff for the melting period of the year 2015.

  13. Modeling and Mapping Soil Moisture of Plateau Pasture Using RADARSAT-2 Imagery

    Directory of Open Access Journals (Sweden)

    Xun Chai

    2015-01-01

    Full Text Available Accurate soil moisture retrieval of a large area in high resolution is significant for plateau pasture. The object of this paper is to investigate the estimation of volumetric soil moisture in vegetated areas of plateau pasture using fully polarimetric C-band RADARSAT-2 SAR (Synthetic Aperture Radar images. Based on the water cloud model, Chen model, and Dubois model, we proposed two developed algorithms for soil moisture retrieval and validated their performance using experimental data. We eliminated the effect of vegetation cover by using the water cloud model and minimized the effect of soil surface roughness by solving the Dubois equations. Two experimental campaigns were conducted in the Qinghai Lake watershed, northeastern Tibetan Plateau in September 2012 and May 2013, respectively, with simultaneous satellite overpass. Compared with the developed Chen model, the predicted soil moisture given by the developed Dubois model agreed better with field measurements in terms of accuracy and stability. The RMSE, R2, and RPD value of the developed Dubois model were (5.4, 0.8, 1.6 and (3.05, 0.78, 1.74 for the two experiments, respectively. Validation results indicated that the developed Dubois model, needing a minimum of prior information, satisfied the requirement for soil moisture inversion in the study region.

  14. Using Whole-House Field Tests to Empirically Derive Moisture Buffering Model Inputs

    Energy Technology Data Exchange (ETDEWEB)

    Woods, J.; Winkler, J.; Christensen, D.; Hancock, E.

    2014-08-01

    Building energy simulations can be used to predict a building's interior conditions, along with the energy use associated with keeping these conditions comfortable. These models simulate the loads on the building (e.g., internal gains, envelope heat transfer), determine the operation of the space conditioning equipment, and then calculate the building's temperature and humidity throughout the year. The indoor temperature and humidity are affected not only by the loads and the space conditioning equipment, but also by the capacitance of the building materials, which buffer changes in temperature and humidity. This research developed an empirical method to extract whole-house model inputs for use with a more accurate moisture capacitance model (the effective moisture penetration depth model). The experimental approach was to subject the materials in the house to a square-wave relative humidity profile, measure all of the moisture transfer terms (e.g., infiltration, air conditioner condensate) and calculate the only unmeasured term: the moisture absorption into the materials. After validating the method with laboratory measurements, we performed the tests in a field house. A least-squares fit of an analytical solution to the measured moisture absorption curves was used to determine the three independent model parameters representing the moisture buffering potential of this house and its furnishings. Follow on tests with realistic latent and sensible loads showed good agreement with the derived parameters, especially compared to the commonly-used effective capacitance approach. These results show that the EMPD model, once the inputs are known, is an accurate moisture buffering model.

  15. Using Whole-House Field Tests to Empirically Derive Moisture Buffering Model Inputs

    Energy Technology Data Exchange (ETDEWEB)

    Woods, J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Winkler, J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Christensen, D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hancock, E. [Mountain Energy Partnership, Longmont, CO (United States)

    2014-08-01

    Building energy simulations can be used to predict a building's interior conditions, along with the energy use associated with keeping these conditions comfortable. These models simulate the loads on the building (e.g., internal gains, envelope heat transfer), determine the operation of the space conditioning equipment, and then calculate the building's temperature and humidity throughout the year. The indoor temperature and humidity are affected not only by the loads and the space conditioning equipment, but also by the capacitance of the building materials, which buffer changes in temperature and humidity. This research developed an empirical method to extract whole-house model inputs for use with a more accurate moisture capacitance model (the effective moisture penetration depth model). The experimental approach was to subject the materials in the house to a square-wave relative humidity profile, measure all of the moisture transfer terms (e.g., infiltration, air conditioner condensate) and calculate the only unmeasured term: the moisture absorption into the materials. After validating the method with laboratory measurements, we performed the tests in a field house. A least-squares fit of an analytical solution to the measured moisture absorption curves was used to determine the three independent model parameters representing the moisture buffering potential of this house and its furnishings. Follow on tests with realistic latent and sensible loads showed good agreement with the derived parameters, especially compared to the commonly-used effective capacitance approach. These results show that the EMPD model, once the inputs are known, is an accurate moisture buffering model.

  16. A Hysteresis Model Suitable For Numerical Simulation Of Moisture Content in Wood

    DEFF Research Database (Denmark)

    Frandsen, Henrik Lund; Svensson, Staffan; Damkilde, Lars

    2007-01-01

    The equilibrium moisture content in wood depends not only on the current relative humidity in the ambient air but also on the history of the relative humidity variations. This hysteresis dependency of sorption in wood implies that in the worst case the moisture content for a given relative humidi...... temperatures. These features make the model relatively easy to implement into a numerical method, e.g. the Finite Element Method....... may deviate by 30-35%. While researchers seem to have reached a general agreement on the hypothesis for the sorption hysteresis phenomenon, only a few models describing the phenomenon are available. Current models as the independent domain model have numerical deficiencies and drawbacks. This paper...... presents a new hysteresis model, which mathematically resolves in closed form expressions, with the current relative humidity and moisture content as the only input parameters. Furthermore, the model has the advantage of being applicable to different sorption isotherms, i.e. different species and different...

  17. A Revised Multi-Fickian Moisture Transport Model To Describe Non-Fickian Effects In Wood

    DEFF Research Database (Denmark)

    Frandsen, Henrik Lund; Svensson, Staffan; Damkilde, Lars

    2007-01-01

    This paper presents a study and a refinement of the sorption rate model in a so-called multi-Fickian or multiphase model. This type of model describes the complex moisture transport system in wood, which consists of separate water vapor and bound-water diffusion interacting through sorption....... At high relative humidities, the effect of this complex moisture transport system becomes apparent, and since a single Fickian diffusion equation fails to model the behavior, it has been referred to as non-Fickian or anomalous behavior. At low relative humidities, slow bound-water transport and fast...... conditions for the model are discussed, since discrepancies from corresponding models of moisture transport in paper products have been found....

  18. A revised multi-Fickian moisture transport model to describe non-Fickian effects in wood

    DEFF Research Database (Denmark)

    Frandsen, Henrik Lund; Damkilde, Lars; Svensson, Staffan

    2007-01-01

    This paper presents a study and a refinement of the sorption rate model in a so-called multi-Fickian or multi-phase model. This type of model describes the complex moisture transport system in wood, which consists of separate water vapor and bound-water diffusion interacting through sorption....... At high relative humidities, the effect of this complex moisture transport system becomes apparent, and since a single Fickian diffusion equation fails to model the behavior, it has been referred to as non-Fickian or anomalous behavior. At low relative humidities, slow bound-water transport and fast...... conditions for the model are discussed, since discrepancies from corresponding models of moisture transport in paper products have been found. ©2007 by Walter de Gruyter....

  19. Multiscale analysis of surface soil moisture dynamics in a mesoscale catchment utilizing an integrated ecohydrological model

    Science.gov (United States)

    Korres, W.; Reichenau, T. G.; Schneider, K.

    2012-12-01

    Soil moisture is one of the fundamental variables in hydrology, meteorology and agriculture, influencing the partitioning of solar energy into latent and sensible heat flux as well as the partitioning of precipitation into runoff and percolation. Numerous studies have shown that in addition to natural factors (rainfall, soil, topography etc.) agricultural management is one of the key drivers for spatio-temporal patterns of soil moisture in agricultural landscapes. Interactions between plant growth, soil hydrology and soil nitrogen transformation processes are modeled by using a dynamically coupled modeling approach. The process-based ecohydrological model components of the integrated decision support system DANUBIA are used to identify the important processes and feedbacks determining soil moisture patterns in agroecosystems. Integrative validation of plant growth and surface soil moisture dynamics serves as a basis for a spatially distributed modeling analysis of surface soil moisture patterns in the northern part of the Rur catchment (1100 sq km), Western Germany. An extensive three year dataset (2007-2009) of surface soil moisture-, plant- (LAI, organ specific biomass and N) and soil- (texture, N, C) measurements was collected. Plant measurements were carried out biweekly for winter wheat, maize, and sugar beet during the growing season. Soil moisture was measured with three FDR soil moisture stations. Meteorological data was measured with an eddy flux station. The results of the model validation showed a very good agreement between the modeled plant parameters (biomass, green LAI) and the measured parameters with values between 0.84 and 0.98 (Willmotts index of agreement). The modeled surface soil moisture (0 - 20 cm) showed also a very favorable agreement with the measurements for winter wheat and sugar beet with an RMSE between 1.68 and 3.45 Vol.-%. For maize, the RMSE was less favorable particularly in the 1.5 months prior to harvest. The modeled soil

  20. Assessment of soil moisture fields from imperfect climate models with uncertain satellite observations

    Directory of Open Access Journals (Sweden)

    G. Schumann

    2009-03-01

    Full Text Available We demonstrate that global satellite products can be used to evaluate climate model soil moisture predictions but conclusions should be drawn with care. The quality of a limited area climate model (LAM was compared to a general circulation model (GCM using soil moisture data from two different Earth observing satellites within a model validation scheme that copes with the presence of uncertain data. Results showed that in the face of imperfect models and data, it is difficult to investigate the quality of current land surface schemes in simulating hydrology accurately. Nevertheless, a LAM provides, in general, a better representation of spatial patterns and dynamics of soil moisture. However, in months when data uncertainty is higher, particularly in colder months and in periods when vegetation cover and soil moisture are out of phase (e.g. August in the case of Western Europe, it is not possible to draw firm conclusions about model acceptability. Our work indicates that a higher resolution LAM has more benefits to soil moisture prediction than are due to the resolution alone and can be attributed to an overall intensification of the hydrological cycle relative to the GCM.

  1. Improvement of the integration of Soil Moisture Accounting into the NRCS-CN model

    Science.gov (United States)

    Durán-Barroso, Pablo; González, Javier; Valdés, Juan B.

    2016-11-01

    Rainfall-runoff quantification is one of the most important tasks in both engineering and watershed management as it allows the identification, forecast and explanation of the watershed response. This non-linear process depends on the watershed antecedent conditions, which are commonly related to the initial soil moisture content. Although several studies have highlighted the relevance of soil moisture measures to improve flood modelling, the discussion is still open in the literature about the approach to use in lumped model. The integration of these previous conditions in the widely used rainfall-runoff models NRCS-CN (e.g. National Resources Conservation Service - Curve Number model) could be handled in two ways: using the Antecedent Precipitation Index (API) concept to modify the model parameter; or alternatively, using a Soil Moisture Accounting (SMA) procedure into the NRCS-CN, being the soil moisture a state variable. For this second option, the state variable does not have a direct physical representation. This make difficult the estimation of the initial soil moisture store level. This paper presents a new formulation that overcomes such issue, the rainfall-runoff model called RSSa. Its suitability is evaluated by comparing the RSSa model with the original NRCS-CN model and alternatives SMA procedures in 12 watersheds located in six different countries, with different climatic conditions, from Mediterranean to Semi-arid regions. The analysis shows that the new model, RSSa, performs better when compared with previously proposed CN-based models. Finally, an assessment is made of the influence of the soil moisture parameter for each watershed and the relative weight of scale effects over model parameterization.

  2. Spatial Variation of Soil Type and Soil Moisture in the Regional Atmospheric Modeling System

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, R.

    2001-06-27

    Soil characteristics (texture and moisture) are typically assumed to be initially constant when performing simulations with the Regional Atmospheric Modeling System (RAMS). Soil texture is spatially homogeneous and time-independent, while soil moisture is often spatially homogeneous initially, but time-dependent. This report discusses the conversion of a global data set of Food and Agriculture Organization (FAO) soil types to RAMS soil texture and the subsequent modifications required in RAMS to ingest this information. Spatial variations in initial soil moisture obtained from the National Center for Environmental Predictions (NCEP) large-scale models are also introduced. Comparisons involving simulations over the southeastern United States for two different time periods, one during warmer, more humid summer conditions, and one during cooler, dryer winter conditions, reveals differences in surface conditions related to increases or decreases in near-surface atmospheric moisture con tent as a result of different soil properties. Three separate simulation types were considered. The base case assumed spatially homogeneous soil texture and initial soil moisture. The second case assumed variable soil texture and constant initial soil moisture, while the third case allowed for both variable soil texture and initial soil moisture. The simulation domain was further divided into four geographically distinct regions. It is concluded there is a more dramatic impact on thermodynamic variables (surface temperature and dewpoint) than on surface winds, and a more pronounced variability in results during the summer period. While no obvious trends in surface winds or dewpoint temperature were found relative to observations covering all regions and times, improvement in surface temperatures in most regions and time periods was generally seen with the incorporation of variable soil texture and initial soil moisture.

  3. Two-dimensional vertical moisture-pressure dynamics above groundwater waves: Sand flume experiments and modelling

    Science.gov (United States)

    Shoushtari, Seyed Mohammad Hossein Jazayeri; Cartwright, Nick; Perrochet, Pierre; Nielsen, Peter

    2017-01-01

    of moisture content relative to the suction head was observed indicating that the response time of the moisture content to watertable motion is greater than that of the pore water pressure. The observed moisture-pressure dynamics are qualitatively reproduced using a hysteretic Richards' equation model. However, quantitative differences exist which are likely to be due to previous findings that demonstrated that the Richards' equation model is unable to accurately reproduce the observed watertable wave dispersion, particularly at shorter period oscillations.

  4. Multilayer soil model for improvement of soil moisture estimation using the small perturbation method

    Science.gov (United States)

    Song, Kaijun; Zhou, Xiaobing; Fan, Yong

    2009-12-01

    A multilayer soil model is presented for improved estimation of soil moisture content using the first-order small perturbation method (SPM) applied to measurements of radar backscattering coefficient. The total reflection coefficient of the natural bare soil including volume scattering contribution is obtained using the multilayer model. The surface reflection terms in SPM model are replaced by the total reflection coefficient from the multilayer soil surface in estimating soil moisture. The difference between the modified SPM model and the original SPM surface model is that the modified SPM model includes both the surface scattering and the volumetric scattering of the natural bare soil. Both the modified SPM model and the original SPM model are tested in soil moisture retrievals using experimental microwave backscattering coefficient data in the literature. Results show that the mean square errors between the measured data and the values estimated by the modified SPM model from all samples are 5.2%, while errors from the original SPM model are 8.4%. This indicates that the capability of estimating soil moisture by the SPM model is improved when the surface reflection terms are replaced by the total reflection coefficients of multilayer soil model over bare or very sparsely vegetation covered fields.

  5. A new Model Applicable for Finite Element Simulations of Moisture Transport in Wood

    DEFF Research Database (Denmark)

    Frandsen, Henrik Lund; Svensson, Staffan; Damkilde, Lars

    2006-01-01

    mathematical models for hysteresis e.g. the independent domain model are complicated and have numerical deficiencies. The paper presents a new hysteresis model with closed-form expressions and current relative humidity and moisture content as the only input parameters. In addition the method is general...

  6. Modelling of runoff generation and soil moisture dynamics for hillslopes and micro-catchments

    Science.gov (United States)

    Bronstert, Axel; Plate, Erich J.

    1997-11-01

    The modelling of hillslope hydrology is of great importance not only for the reason that all non-plain, i.e. hilly or mountainous, landscapes can be considered as being composed of a mosaic of hillslopes. A hillslope model may also be used for both research purposes and for application-oriented, detailed, hillslope-scale hydrological studies in conjunction with related scientific disciplines such as geotechnics, geo-chemistry and environmental technology. Despite the current limited application of multi-process and multi-dimensional hydrological models (particularly at the hillslope scale), hardly any comprehensive model has been available for operational use. In this paper we introduce a model which considers most of the relevant hillslope hydrological processes. Some recent applications are described which demonstrate its ability to narrow the stated gap in hillslope hydrological modelling. The modelling system accounts for the hydrological processes of interception, evapotranspiration, infiltration, soil-moisture movement (where the flow processes can be modelled in three dimensions), surface runoff, subsurface stormflow and streamflow discharge. The relevant process interactions are also included. Special regard has been given to consideration of state-of-the-art knowledge concerning rapid soilwater flow processes during storm conditions (e.g. macropore infiltration, lateral subsurface stormflow, return flow) and to its transfer to and inclusion within an operational modelling scheme. The model is "physically based" in the sense that its parameters have a physical meaning and can be obtained or derived from field measurements. This somewhat weaker than usual definition of a physical basis implies that some of the sub-models (still) contain empirical components, that the effects of the high spatial and temporal variability found in nature cannot always be expressed within the various physical laws, i.e. that the laws are scale dependent, and that due to

  7. Using high-resolution soil moisture modelling to assess the uncertainty of microwave remotely sensed soil moisture products at the correct spatial and temporal support

    Science.gov (United States)

    Wanders, N.; Karssenberg, D.; Bierkens, M. F. P.; Van Dam, J. C.; De Jong, S. M.

    2012-04-01

    Soil moisture is a key variable in the hydrological cycle and important in hydrological modelling. When assimilating soil moisture into flood forecasting models, the improvement of forecasting skills depends on the ability to accurately estimate the spatial and temporal patterns of soil moisture content throughout the river basin. Space-borne remote sensing may provide this information with a high temporal and spatial resolution and with a global coverage. Currently three microwave soil moisture products are available: AMSR-E, ASCAT and SMOS. The quality of these satellite-based products is often assessed by comparing them with in-situ observations of soil moisture. This comparison is however hampered by the difference in spatial and temporal support (i.e., resolution, scale), because the spatial resolution of microwave satellites is rather low compared to in-situ field measurements. Thus, the aim of this study is to derive a method to assess the uncertainty of microwave satellite soil moisture products at the correct spatial support. To overcome the difference in support size between in-situ soil moisture observations and remote sensed soil moisture, we used a stochastic, distributed unsaturated zone model (SWAP, van Dam (2000)) that is upscaled to the support of different satellite products. A detailed assessment of the SWAP model uncertainty is included to ensure that the uncertainty in satellite soil moisture is not overestimated due to an underestimation of the model uncertainty. We simulated unsaturated water flow up to a depth of 1.5m with a vertical resolution of 1 to 10 cm and on a horizontal grid of 1 km2 for the period Jan 2010 - Jun 2011. The SWAP model was first calibrated and validated on in-situ data of the REMEDHUS soil moisture network (Spain). Next, to evaluate the satellite products, the model was run for areas in the proximity of 79 meteorological stations in Spain, where model results were aggregated to the correct support of the satellite

  8. Demand and routing models for urban goods movement simulation

    OpenAIRE

    Polimeni, Antonio; Russo, Francesco; Vitetta, Antonino

    2010-01-01

    This paper presents a macro-architecture for simulating goods movements in an urban area. Urban goods supply is analysed when the retailer is the decision-maker and chooses to supply his/her shop. Two components are considered: demand in terms of goods supply and vehicle routing with constraints to simulate goods movements. To analyse demand we consider a multi-step model, while to analyse goods movements a Vehicle Routing Problem with Time Windows (VRPTW) is formalized. We exa...

  9. Evaluation of random cascade hierarchical and statistical arrangement model in disaggregation of SMOS soil moisture

    Science.gov (United States)

    Hosseini, M.; Magagi, R.; Goita, K.

    2013-12-01

    Soil moisture is an important parameter in hydrology that can be derived from remote sensing. In different studies, it was shown that optical-thermal, active and passive microwave remote sensing data can be used for soil moisture estimation. However, the most promising approach to estimate soil moisture in large areas is passive microwave radiometry. Global estimation of soil moisture is now operational by using remote sensing techniques. The Advanced Microwave Scanning Radiometer-Earth Observing System Sensor (AMSR-E) and Soil Moisture and Ocean Salinity (SMOS) passive microwave radiometers that were lunched on 2002 and 2009 respectively along with the upcoming Soil Moisture Active-Passive (SMAP) satellite that was planned to be lunched in the time frame of 2014-2015 make remote sensing to be more useful in soil moisture estimation. However, the spatial resolutions of AMSR-E, SMOS and SMAP are 60 km, 40 km and 10 km respectively. These very low spatial resolutions can not show the temporal and spatial variability of soil moisture in field or small scales. So, using disaggregation methods is required to efficiently using the passive microwave derived soil moisture information in different scales. The low spatial resolutions of passive microwave satellites can be improved by using disaggregation methods. Random Cascade (RC) model (Over and Gupta, 1996) is used in this research to downscale the 40 km resolution of SMOS satellite. By using this statistical method, the SMOS soil moisture resolutions are improved to 20 km, 10 km, 5 km and 2.5 km, respectively. The data that were measured during Soil Moisture Active Passive Validation Experiment 2012 (SMAPVEX12) field campaign are used to do the experiments. Totally the ground data and SMOS images that were obtained during 13 different days from 7-June-2012 to 13-July-2012 are used. By comparison with ground soil moisture, it is observed that the SMOS soil moisture is underestimated for all the images and so bias amounts

  10. Mesoscopic Modeling of Concrete under Different Moisture Conditions and Loading Rates

    DEFF Research Database (Denmark)

    Pedersen, Ronnie

    2013-01-01

    We present a mesoscopic finite element model for simulating the rate- and moisture-dependent material behavior of concrete. The idealized mesostructure consists of aggregates surrounded by an interfacial transition zone embedded in the bulk material. We examine the influence of the most significa....... The results indicate that the loading rate has a stronger influence than the saturation level on fracture processes and global strength....... constitutive model parameters on global and local response. Different distributions and shapes of the aggregates are tested. Three model parameter sets, corresponding to different moisture conditions, are employed in the analysis of two specimens in which the applied loading rate is significantly different...

  11. Calibration of a Hydrologic Model via Densely Distributed Soil Moisture Observations

    Science.gov (United States)

    Thorstensen, A. R.; Nguyen, P.; Hsu, K. L.; Sorooshian, S.

    2014-12-01

    The complexity of a catchment's physical heterogeneities is often addressed through calibration via observed streamflow. As hydrologic models move from lumped to distributed, and Earth observations increase in number and variety, the question is raised as to whether or not such distributed observations can be used to satisfy the possibly heterogenic calibration needs of a catchment. The goal of this study is to examine if calibration of a distributed hydrologic model using soil moisture observations can improve simulated streamflow. The NWS's Hydrology Laboratory Research Distributed Hydrologic Model (HL-RDHM) is used in this study. HL-RDHM uses the Sacramento Heat Transfer with enhanced Evapotranspiration for rainfall-runoff production and can convert conceptual storages to soil layers. This allows for calibration of conceptual parameters based on observed soil moisture profiles. HL-RDHM is calibrated using scalar multipliers of a-priori grids derived from soil surveys, with the premise that heterogeneity of these grids is correct. This assumption is relaxed to study the benefit of distributed calibration. Soil moisture measurements in the Turkey River Basin, which was equipped with 20 in-situ soil moisture sites for the Iowa Flood Studies campaign, were used for calibration of parameters related to soil moisture (i.e. storage and release parameters). The Shuffled Complex Evolution method was used to calibrate pixels collocated with in-situ probes based on soil moisture RMSE at point scale. Methods to allocate calibrated parameter values to remaining pixels include an averaging method, spatial interpolation, and a similarity method. Calibration was done for spring 2013, and validation for 2009 and 2011. Results show that calibration using stream gauges remains the superior method, especially for correlation. This is because calibration based on streamflow can correct peak timing by adjusting routing parameters. Such adjustments using soil moisture cannot be done

  12. Modelling soil moisture at SMOS scale by use of a SVAT model over the Valencia Anchor Station

    Directory of Open Access Journals (Sweden)

    S. Juglea

    2010-05-01

    Full Text Available The main goal of the SMOS (Soil Moisture and Ocean Salinity mission is to deliver global fields of surface soil moisture and sea surface salinity using L-band (1.4 GHz radiometry. Within the context of the Science preparation for SMOS, the Valencia Anchor Station (VAS experimental site, in Spain, was chosen to be one of the main test sites in Europe for Calibration/Validation (Cal/Val activities. In this framework, the paper presents an approach consisting in accurately simulating a whole SMOS pixel by representing the spatial and temporal heterogeneity of the soil moisture fields over the wide VAS surface (50×50 km2. Ground and meteorological measurements over the area are used as the input of a Soil-Vegetation-Atmosphere-Transfer (SVAT model, SURFEX (Externalized Surface - module ISBA (Interactions between Soil-Biosphere-Atmosphere to simulate the spatial and temporal distribution of surface soil moisture. The calibration as well as the validation of the ISBA model are performed using in situ soil moisture measurements. It is shown that a good consistency is reached when point comparisons between simulated and in situ soil moisture measurements are made.

    Actually, an important challenge in remote sensing approaches concerns product validation. In order to obtain an representative soil moisture mapping over the Valencia Anchor Station (50×50 km2 area, a spatialization method is applied. For verification, a comparison between the simulated spatialized soil moisture and remote sensing data from the Advanced Microwave Scanning Radiometer on Earth observing System (AMSR-E and from the European Remote Sensing Satellites (ERS-SCAT is performed. Despite the fact that AMSR-E surface soil moisture product is not reproducing accurately the absolute values, it provides trustworthy information on surface soil moisture temporal variability. However, during the vegetation growing season the signal is perturbed. By using the

  13. Assimilation of SMOS brightness temperatures or soil moisture retrievals into a land surface model

    Science.gov (United States)

    De Lannoy, Gabriëlle J. M.; Reichle, Rolf H.

    2016-12-01

    Three different data products from the Soil Moisture Ocean Salinity (SMOS) mission are assimilated separately into the Goddard Earth Observing System Model, version 5 (GEOS-5) to improve estimates of surface and root-zone soil moisture. The first product consists of multi-angle, dual-polarization brightness temperature (Tb) observations at the bottom of the atmosphere extracted from Level 1 data. The second product is a derived SMOS Tb product that mimics the data at a 40° incidence angle from the Soil Moisture Active Passive (SMAP) mission. The third product is the operational SMOS Level 2 surface soil moisture (SM) retrieval product. The assimilation system uses a spatially distributed ensemble Kalman filter (EnKF) with seasonally varying climatological bias mitigation for Tb assimilation, whereas a time-invariant cumulative density function matching is used for SM retrieval assimilation. All assimilation experiments improve the soil moisture estimates compared to model-only simulations in terms of unbiased root-mean-square differences and anomaly correlations during the period from 1 July 2010 to 1 May 2015 and for 187 sites across the US. Especially in areas where the satellite data are most sensitive to surface soil moisture, large skill improvements (e.g., an increase in the anomaly correlation by 0.1) are found in the surface soil moisture. The domain-average surface and root-zone skill metrics are similar among the various assimilation experiments, but large differences in skill are found locally. The observation-minus-forecast residuals and analysis increments reveal large differences in how the observations add value in the Tb and SM retrieval assimilation systems. The distinct patterns of these diagnostics in the two systems reflect observation and model errors patterns that are not well captured in the assigned EnKF error parameters. Consequently, a localized optimization of the EnKF error parameters is needed to further improve Tb or SM retrieval

  14. Observations and stochastic modeling of soil moisture control on evapotranspiration in a Californian oak savanna

    Science.gov (United States)

    Chen, Xingyuan; Rubin, Yoram; Ma, Siyan; Baldocchi, Dennis

    2008-08-01

    The study of water exchange between soil, plants, and the atmosphere in response to seasonal or periodic droughts is critical to modeling the hydrologic cycle and biogeochemical processes in water-controlled ecosystems. An essential step in such studies is to characterize changes in evaporation and transpiration under water stress. The objectives of this study are to investigate how soil moisture controls the evapotranspiration in a Californian oak savanna that experiences seasonal droughts, using multiyear field observations at the daily and stand scale, and to model these controls stochastically. The influence of soil moisture on evapotranspiration at the stand scale is studied using correlations between tower-based evapotranspiration measurements and representative soil moisture obtained by aggregating point measurements. The observed pattern of this effect is found in agreement with an existing model that features a linear reduction of the evapotranspiration when soil moisture falls below a critical value. The model parameters are inferred using a Bayesian framework, and they are found to vary from year to year because of climate variability. The comparison between various aggregations of soil moisture at the stand scale from point measurements demonstrates that the spatial variability of the soil moisture and the water uptake capacity limited by the root biomass need be taken into account to produce a model that is most resistant to interannual variability. Finally, the parameterized model is used to predict the actual evapotranspiration with uncertainty estimates determined using the joint distribution of the parameters derived from the Bayesian framework. The satisfactory agreement between the predicted and measured evapotranspiration suggests that the calibrated model can be incorporated into water balance studies in the future.

  15. Energy-optimal control model for train movements

    Institute of Scientific and Technical Information of China (English)

    Li Ke-Ping; Gao Zi-You; Mao Bao-Hua

    2007-01-01

    In this paper, we propose a new cellular automaton (CA) model for train movement simulations under mixed traffic conditions. A kind of control strategy is employed for trains to reduce energy consumption. In the proposed CA model, the driver controls the train movements by using some updated rules. In order to obtain a good insight into the evolution behaviours of the rail traffic flow, we investigate the space-time diagram of the rail traffic flow and the trajectories of the train movements. The numerical simulation results demonstrate that the proposed CA model can well describe the dynamic behaviours of the train movements. Some complex phenomena of train movements can be reproduced, such as the train delay propagations, etc.

  16. MODELLING SYNERGISTIC EYE MOVEMENTS IN THE VISUAL FIELD

    Directory of Open Access Journals (Sweden)

    BARITZ Mihaela

    2015-06-01

    Full Text Available Some theoretical and practical considerations about eye movements in visual field are presented in the first part of this paper. These movements are developed into human body to be synergistic and are allowed to obtain the visual perception in 3D space. The theoretical background of the eye movements’ analysis is founded on the establishment of movement equations of the eyeball, as they consider it a solid body with a fixed point. The exterior actions, the order and execution of the movements are ensured by the neural and muscular external system and thus the position, stability and movements of the eye can be quantified through the method of reverse kinematic. The purpose of these researches is the development of a simulation model of human binocular visual system, an acquisition methodology and an experimental setup for data processing and recording regarding the eye movements, presented in the second part of the paper. The modeling system of ocular movements aims to establish the binocular synergy and limits of visual field changes in condition of ocular motor dysfunctions. By biomechanical movements of eyeball is established a modeling strategy for different sort of processes parameters like convergence, fixation and eye lens accommodation to obtain responses from binocular balance. The results of modelling processes and the positions of eye ball and axis in visual field are presented in the final part of the paper.

  17. A Soil Moisture-Heat Based Early Establishment Model of Riparian White Alder (Alnus rhombifolia)

    Science.gov (United States)

    Jablkowski, P.; Johnson, E. A.; Martin, Y. E.

    2013-12-01

    Establishment of fluvially dispersed seeds on accreted gravel-sand bars is limited by water availability in streams. Past establishment models have used the stream/water table recession rate, and maximum root growth rate to determine the elevation limit of seedling establishment. This approach neglects the role of the saturated-unsaturated vadose zone in providing water to recently germinated seedlings, the physical processes that determine the soil moisture content, and the effect moisture deficit has on seedling root growth. This study combines a soil moisture-heat budget and a seedling root growth model that responds to soil moisture availability to find the elevation limit of establishment of white alder (Alnus rhombifolia) on vertically accreted bars along the south fork Eel River in the Angelo Coast Range Reserve, California. To establish successfully, seedling roots must maintain a connection with sufficient moisture to avoid water stress. This will depend on the elevation of the bar, the stream recession rate, the root growth rate, and the diurnal cycle of soil moisture. A one-dimensional moisture-heat budget of the top 15 centimeters of sediment was validated at two locations characterized by sand and clay-gravel textures respectively, using soil moisture and temperature measurements at 5, 10 and 15 cm, net radiation, air temperature, humidity, wind velocity and precipitation measured during spring-summer stream recession. Two patterns in soil water content were apparent: an average daily moisture decrease at each depth driven by stream/water table recession, and a diurnal pattern of isothermal liquid and vapour flux increasing soil water content in the upper 15 cm between 12:00 pm and 5:00 pm PDT. To determine seedling root growth rates, white alder seedlings were grown in growth chambers under a range of reduced matric potentials using polyethylene glycol. Root length measurements were made at 4 hour intervals and a quadratic equation was fit to the root

  18. Soil Moisture Estimate Under Forest Using a Semi-Empirical Model at P-Band

    Science.gov (United States)

    Truong-Loi, My-Linh; Saatchi, Sassan; Jaruwatanadilok, Sermsak

    2013-01-01

    Here we present the result of a semi-empirical inversion model for soil moisture retrieval using the three backscattering coefficients: sigma(sub HH), sigma(sub VV) and sigma(sub HV). In this paper we focus on the soil moisture estimate and use the biomass as an ancillary parameter estimated automatically from the algorithm and used as a validation parameter, We will first remind the model analytical formulation. Then we will sow some results obtained with real SAR data and compare them to ground estimates.

  19. Modeling the Effect of Vegetation on Passive Microwave Remote Sensing of Soil Moisture

    Science.gov (United States)

    Liu, Y. P.; Inguva, R.; Crosson, W. L.; Coleman, T. L.; Laymon, C.; Fahsi, A.

    1998-01-01

    The effect of vegetation on passive microwave remote sensing of soil moisture is studied. The radiative transfer modeling work of Njoku and Kong is applied to a stratified medium of which the upper layer is treated as a layer of vegetation. An effective dielectric constant for this vegetation layer is computed using estimates of the dielectric constant of individual components of the vegetation layer. The horizontally-polarized brightness temperature is then computed as a function of the incidence angle. Model predictions are used to compare with the data obtained in the Huntsville '96, remote sensing of soil moisture experiment, and with predictions obtained using a correction procedure of Jackson and Schmugge.

  20. A Polarimetric First-Order Model of Soil Moisture Effects on the DInSAR Coherence

    Directory of Open Access Journals (Sweden)

    Simon Zwieback

    2015-06-01

    Full Text Available Changes in soil moisture between two radar acquisitions can impact the observed coherence in differential interferometry: both coherence magnitude |Υ| and phase Φ are affected. The influence on the latter potentially biases the estimation of deformations. These effects have been found to be variable in magnitude and sign, as well as dependent on polarization, as opposed to predictions by existing models. Such diversity can be explained when the soil is modelled as a half-space with spatially varying dielectric properties and a rough interface. The first-order perturbative solution achieves–upon calibration with airborne L band data–median correlations ρ at HH polarization of 0.77 for the phase Φ, of 0.50 for |Υ|, and for the phase triplets ≡ of 0.56. The predictions are sensitive to the choice of dielectric mixing model, in particular the absorptive properties; the differences between the mixing models are found to be partially compensatable by varying the relative importance of surface and volume scattering. However, for half of the agricultural fields the Hallikainen mixing model cannot reproduce the observed sensitivities of the phase to soil moisture. In addition, the first-order expansion does not predict any impact on the HV coherence, which is however empirically found to display similar sensitivities to soil moisture as the co-pol channels HH and VV. These results indicate that the first-order solution, while not able to reproduce all observed phenomena, can capture some of the more salient patterns of the effect of soil moisture changes on the HH and VV DInSAR signals. Hence it may prove useful in separating the deformations from the moisture signals, thus yielding improved displacement estimates or new ways for inferring soil moisture.

  1. A non-equilibrium model for soil heating and moisture transport during extreme surface heating

    Directory of Open Access Journals (Sweden)

    W. J. Massman

    2015-03-01

    Full Text Available With increasing use of prescribed fire by land managers and increasing likelihood of wildfires due to climate change comes the need to improve modeling capability of extreme heating of soils during fires. This issue is addressed here by developing a one-dimensional non-equilibrium model of soil evaporation and transport of heat, soil moisture, and water vapor, for use with surface forcing ranging from daily solar cycles to extreme conditions encountered during fires. The model employs a linearized Crank–Nicolson scheme for the conservation equations of energy and mass and its performance is evaluated against dynamic soil temperature and moisture observations obtained during laboratory experiments on soil samples exposed to surface heat fluxes ranging between 10 000 and 50 000 W m−2. The Hertz–Knudsen equation is the basis for constructing the model's non-equilibrium evaporative source term. The model includes a dynamic residual soil moisture as a function of temperature and soil water potential, which allows the model to capture some of the dynamic aspects of the strongly bound soil moisture that seems to require temperatures well beyond 150 °C to fully evaporate. Furthermore, the model emulates the observed increase in soil moisture ahead of the drying front and the hiatus in the soil temperature rise during the strongly evaporative stage of drying. It also captures the observed rapid evaporation of soil moisture that occurs at relatively low temperatures (50–90 °C. Sensitivity analyses indicate that the model's success results primarily from the use of a temperature and moisture potential dependent condensation coefficient in the evaporative source term. The model's solution for water vapor density (and vapor pressure, which can exceed one standard atmosphere, cannot be experimentally verified, but they are supported by results from (earlier and very different models developed for somewhat different purposes and for different porous

  2. Modeling heat and moisture transport in firefighter protective clothing during flash fire exposure

    Energy Technology Data Exchange (ETDEWEB)

    Chitrphiromsri, Patirop; Kuznetsov, Andrey V. [North Carolina State University, Department of Mechanical and Aerospace Engineering, Raleigh, NC 27695-7910 (United States)

    2005-01-01

    In this paper, a model of heat and moisture transport in firefighter protective clothing during a flash fire exposure is presented. The aim of this study is to investigate the effect of coupled heat and moisture transport on the protective performance of the garment. Computational results show the distribution of temperature and moisture content in the fabric during the exposure to the flash fire as well as during the cool-down period. Moreover, the duration of the exposure during which the garment protects the firefighter from getting second and third degree burns from the flash fire exposure is numerically predicted. A complete model for the fire-fabric-air gap-skin system is presented. (orig.)

  3. Observing and modeling links between soil moisture, microbes and CH4 fluxes from forest soils

    Science.gov (United States)

    Christiansen, Jesper; Levy-Booth, David; Barker, Jason; Prescott, Cindy; Grayston, Sue

    2017-04-01

    Soil moisture is a key driver of methane (CH4) fluxes in forest soils, both of the net uptake of atmospheric CH4 and emission from the soil. Climate and land use change will alter spatial patterns of soil moisture as well as temporal variability impacting the net CH4 exchange. The impact on the resultant net CH4 exchange however is linked to the underlying spatial and temporal distribution of the soil microbial communities involved in CH4 cycling as well as the response of the soil microbial community to environmental changes. Significant progress has been made to target specific CH4 consuming and producing soil organisms, which is invaluable in order to understand the microbial regulation of the CH4 cycle in forest soils. However, it is not clear as to which extent soil moisture shapes the structure, function and abundance of CH4 specific microorganisms and how this is linked to observed net CH4 exchange under contrasting soil moisture regimes. Here we report on the results from a research project aiming to understand how the CH4 net exchange is shaped by the interactive effects soil moisture and the spatial distribution CH4 consuming (methanotrophs) and producing (methanogens). We studied the growing season variations of in situ CH4 fluxes, microbial gene abundances of methanotrophs and methanogens, soil hydrology, and nutrient availability in three typical forest types across a soil moisture gradient in a temperate rainforest on the Canadian Pacific coast. Furthermore, we conducted laboratory experiments to determine whether the net CH4 exchange from hydrologically contrasting forest soils responded differently to changes in soil moisture. Lastly, we modelled the microbial mediation of net CH4 exchange along the soil moisture gradient using structural equation modeling. Our study shows that it is possible to link spatial patterns of in situ net exchange of CH4 to microbial abundance of CH4 consuming and producing organisms. We also show that the microbial

  4. A large scale hydrological model combining Budyko hypothesis and stochastic soil moisture model

    Science.gov (United States)

    Cong, Z.; Zhang, X.

    2012-04-01

    Based on the Budyko hypothesis, the actual evapotranspiration, E,is controlled by the water conditions and the energy conditions, which are represented by the amount of annual precipitation, P and potential evaporation, E0, respectively. Some theoretical or empirical equations have been proposed to represent the Budyko curve. We here select Choudhury's equation to describe the Budyko curve (Mezentsev, 1954; Choudhury, 1999; Yang et al., 2008; Roderick and Farquhar, 2011). ɛ = (1+ φ -α)-1/α ,ɛ = E-,φ = E0 P P Rodriguez-Iturbe et al. (1999) proposed a stochastic soil moisture model based on a Poisson distributed rainfall assumption. Porporato et al. (2004) described the average water balance based on stochastic soil moisture model as following, γ- 1 ɛ = 1 -φ(·γ)φ--(·e-γ),γ = Zr- Γ γ- - Γ γ-,γ h φ φ where, h means the average rainfall depth, Zr means basin water storage ability. Combining these two equation, we can get the relation between α and γ. Then we develop a large scale hydrological model to estimate annual runoff from P, E0, h and Zr. ( -α)- 1/α 0.5946 Zr- R = (1- ɛ)P,ɛ = 1+ φ ,a = 0.7078γ ,γ = h This method has good performance when it is applied to estimate annual runoff in the Yellow River Basin and the Yangtze River Basin. The impacts of climate changes (P, E0 and h) and human activities (Zr) are also discussed with this method.

  5. Quantification of top soil moisture patterns : Evaluation of field methods, process-based modelling, remote sensing and an integrated approach

    NARCIS (Netherlands)

    van der Kwast, J.

    2009-01-01

    There is an urgent need for operational models that can accurately predict soil moisture patterns in space and time. High spatial and temporal variability of soil moisture and its low degree of autocorrelation complicate the modelling with process-based models. The aim of this research was to evalua

  6. Impacts and implementation of fuel moisture release and radiation properties in modelling of pulverized fuel combustion processes

    DEFF Research Database (Denmark)

    Yin, Chungen

    2015-01-01

    Pulverized fuels (PF) prepared and fired in utility boilers usually contain a certain amount of moisture, either free moisture or chemically bound moisture. In PF furnaces, radiation which is the principal mode of heat transfer consists of contribution from both gas and particle phase. This paper...... presents different methods for fuel moisture release and new models for gas and particle radiative properties, and demonstrates their implementation, importance and impacts in PF combustion modelling via a comprehensive CFD study of a pulverized coal-fired utility boiler. To conclude, it is recommended...... to add the free moisture into the primary air stream while lump the moisture retained in the feed after the mills with volatiles in PF combustion modelling. For gas and particle radiation in PF boilers, it is found that particle radiation largely overwhelms gas radiation due to high particle loading...

  7. Social network models predict movement and connectivity in ecological landscapes

    Science.gov (United States)

    Fletcher, Robert J.; Acevedo, M.A.; Reichert, Brian E.; Pias, Kyle E.; Kitchens, Wiley M.

    2011-01-01

    Network analysis is on the rise across scientific disciplines because of its ability to reveal complex, and often emergent, patterns and dynamics. Nonetheless, a growing concern in network analysis is the use of limited data for constructing networks. This concern is strikingly relevant to ecology and conservation biology, where network analysis is used to infer connectivity across landscapes. In this context, movement among patches is the crucial parameter for interpreting connectivity but because of the difficulty of collecting reliable movement data, most network analysis proceeds with only indirect information on movement across landscapes rather than using observed movement to construct networks. Statistical models developed for social networks provide promising alternatives for landscape network construction because they can leverage limited movement information to predict linkages. Using two mark-recapture datasets on individual movement and connectivity across landscapes, we test whether commonly used network constructions for interpreting connectivity can predict actual linkages and network structure, and we contrast these approaches to social network models. We find that currently applied network constructions for assessing connectivity consistently, and substantially, overpredict actual connectivity, resulting in considerable overestimation of metapopulation lifetime. Furthermore, social network models provide accurate predictions of network structure, and can do so with remarkably limited data on movement. Social network models offer a flexible and powerful way for not only understanding the factors influencing connectivity but also for providing more reliable estimates of connectivity and metapopulation persistence in the face of limited data.

  8. Single Plant Root System Modeling under Soil Moisture Variation

    Science.gov (United States)

    Yabusaki, S.; Fang, Y.; Chen, X.; Scheibe, T. D.

    2016-12-01

    A prognostic Virtual Plant-Atmosphere-Soil System (vPASS) model is being developed that integrates comprehensively detailed mechanistic single plant modeling with microbial, atmospheric, and soil system processes in its immediate environment. Three broad areas of process module development are targeted: Incorporating models for root growth and function, rhizosphere interactions with bacteria and other organisms, litter decomposition and soil respiration into established porous media flow and reactive transport models Incorporating root/shoot transport, growth, photosynthesis and carbon allocation process models into an integrated plant physiology model Incorporating transpiration, Volatile Organic Compounds (VOC) emission, particulate deposition and local atmospheric processes into a coupled plant/atmosphere model. The integrated plant ecosystem simulation capability is being developed as open source process modules and associated interfaces under a modeling framework. The initial focus addresses the coupling of root growth, vascular transport system, and soil under drought scenarios. Two types of root water uptake modeling approaches are tested: continuous root distribution and constitutive root system architecture. The continuous root distribution models are based on spatially averaged root development process parameters, which are relatively straightforward to accommodate in the continuum soil flow and reactive transport module. Conversely, the constitutive root system architecture models use root growth rates, root growth direction, and root branching to evolve explicit root geometries. The branching topologies require more complex data structures and additional input parameters. Preliminary results are presented for root model development and the vascular response to temporal and spatial variations in soil conditions.

  9. Patterns and scaling properties of surface soil moisture in an agricultural landscape: An ecohydrological modeling study

    Science.gov (United States)

    Korres, W.; Reichenau, T. G.; Schneider, K.

    2013-08-01

    Soil moisture is a key variable in hydrology, meteorology and agriculture. Soil moisture, and surface soil moisture in particular, is highly variable in space and time. Its spatial and temporal patterns in agricultural landscapes are affected by multiple natural (precipitation, soil, topography, etc.) and agro-economic (soil management, fertilization, etc.) factors, making it difficult to identify unequivocal cause and effect relationships between soil moisture and its driving variables. The goal of this study is to characterize and analyze the spatial and temporal patterns of surface soil moisture (top 20 cm) in an intensively used agricultural landscape (1100 km2 northern part of the Rur catchment, Western Germany) and to determine the dominant factors and underlying processes controlling these patterns. A second goal is to analyze the scaling behavior of surface soil moisture patterns in order to investigate how spatial scale affects spatial patterns. To achieve these goals, a dynamically coupled, process-based and spatially distributed ecohydrological model was used to analyze the key processes as well as their interactions and feedbacks. The model was validated for two growing seasons for the three main crops in the investigation area: Winter wheat, sugar beet, and maize. This yielded RMSE values for surface soil moisture between 1.8 and 7.8 vol.% and average RMSE values for all three crops of 0.27 kg m-2 for total aboveground biomass and 0.93 for green LAI. Large deviations of measured and modeled soil moisture can be explained by a change of the infiltration properties towards the end of the growing season, especially in maize fields. The validated model was used to generate daily surface soil moisture maps, serving as a basis for an autocorrelation analysis of spatial patterns and scale. Outside of the growing season, surface soil moisture patterns at all spatial scales depend mainly upon soil properties. Within the main growing season, larger scale

  10. Heat and Moisture Transport in Unsaturated Porous Media -- A Coupled Model in Terms of Chemical Potential

    CERN Document Server

    Sullivan, Eric

    2013-01-01

    Transport phenomena in porous media are commonplace in our daily lives. Examples and applications include heat and moisture transport in soils, baking and drying of food stuffs, curing of cement, and evaporation of fuels in wild fires. Of particular interest to this study are heat and moisture transport in unsaturated soils. Historically, mathematical models for these processes are derived by coupling classical Darcy's, Fourier's, and Fick's laws with volume averaged conservation of mass and energy and empirically based source and sink terms. Recent experimental and mathematical research has proposed modifications and suggested limitations in these classical equations. The primary goal of this thesis is to derive a thermodynamically consistent system of equations for heat and moisture transport in terms of the chemical potential that addresses some of these limitations. The physical processes of interest are primarily diffusive in nature and, for that reason, we focus on using the macroscale chemical potentia...

  11. Design of a global soil moisture initialization procedure for the simple biosphere model

    Science.gov (United States)

    Liston, G. E.; Sud, Y. C.; Walker, G. K.

    1993-01-01

    Global soil moisture and land-surface evapotranspiration fields are computed using an analysis scheme based on the Simple Biosphere (SiB) soil-vegetation-atmosphere interaction model. The scheme is driven with observed precipitation, and potential evapotranspiration, where the potential evapotranspiration is computed following the surface air temperature-potential evapotranspiration regression of Thomthwaite (1948). The observed surface air temperature is corrected to reflect potential (zero soil moisture stress) conditions by letting the ratio of actual transpiration to potential transpiration be a function of normalized difference vegetation index (NDVI). Soil moisture, evapotranspiration, and runoff data are generated on a daily basis for a 10-year period, January 1979 through December 1988, using observed precipitation gridded at a 4 deg by 5 deg resolution.

  12. Understanding eye movements in face recognition using hidden Markov models.

    Science.gov (United States)

    Chuk, Tim; Chan, Antoni B; Hsiao, Janet H

    2014-09-16

    We use a hidden Markov model (HMM) based approach to analyze eye movement data in face recognition. HMMs are statistical models that are specialized in handling time-series data. We conducted a face recognition task with Asian participants, and model each participant's eye movement pattern with an HMM, which summarized the participant's scan paths in face recognition with both regions of interest and the transition probabilities among them. By clustering these HMMs, we showed that participants' eye movements could be categorized into holistic or analytic patterns, demonstrating significant individual differences even within the same culture. Participants with the analytic pattern had longer response times, but did not differ significantly in recognition accuracy from those with the holistic pattern. We also found that correct and wrong recognitions were associated with distinctive eye movement patterns; the difference between the two patterns lies in the transitions rather than locations of the fixations alone.

  13. The impact of model and rainfall forcing errors on characterizing soil moisture uncertainty in land surface modeling

    Directory of Open Access Journals (Sweden)

    V. Maggioni

    2012-10-01

    Full Text Available The contribution of rainfall forcing errors relative to model (structural and parameter uncertainty in the prediction of soil moisture is investigated by integrating the NASA Catchment Land Surface Model (CLSM, forced with hydro-meteorological data, in the Oklahoma region. Rainfall-forcing uncertainty is introduced using a stochastic error model that generates ensemble rainfall fields from satellite rainfall products. The ensemble satellite rain fields are propagated through CLSM to produce soil moisture ensembles. Errors in CLSM are modeled with two different approaches: either by perturbing model parameters (representing model parameter uncertainty or by adding randomly generated noise (representing model structure and parameter uncertainty to the model prognostic variables. Our findings highlight that the method currently used in the NASA GEOS-5 Land Data Assimilation System to perturb CLSM variables poorly describes the uncertainty in the predicted soil moisture, even when combined with rainfall model perturbations. On the other hand, by adding model parameter perturbations to rainfall forcing perturbations, a better characterization of uncertainty in soil moisture simulations is observed. Specifically, an analysis of the rank histograms shows that the most consistent ensemble of soil moisture is obtained by combining rainfall and model parameter perturbations. When rainfall forcing and model prognostic perturbations are added, the rank histogram shows a U-shape at the domain average scale, which corresponds to a lack of variability in the forecast ensemble. The more accurate estimation of the soil moisture prediction uncertainty obtained by combining rainfall and parameter perturbations is encouraging for the application of this approach in ensemble data assimilation systems.

  14. On the treatment of evapotranspiration, soil moisture accounting, and aquifer recharge in monthly water balance models.

    Science.gov (United States)

    Alley, W.M.

    1984-01-01

    Several two- to six-parameter regional water balance models are examined by using 50-year records of monthly streamflow at 10 sites in New Jersey. These models include variants of the Thornthwaite-Mather model, the Palmer model, and the more recent Thomas abcd model. Prediction errors are relatively similar among the models. However, simulated values of state variables such as soil moisture storage differ substantially among the models, and fitted parameter values for different models sometimes indicated an entirely different type of basin response to precipitation.-from Author

  15. Assimilation of ASCAT near-surface soil moisture into the French SIM hydrological model

    Directory of Open Access Journals (Sweden)

    C. Draper

    2011-06-01

    Full Text Available The impact of assimilating near-surface soil moisture into the SAFRAN-ISBA-MODCOU (SIM hydrological model over France is examined. Specifically, the root-zone soil moisture in the ISBA land surface model is constrained over three and a half years, by assimilating the ASCAT-derived surface degree of saturation product, using a Simplified Extended Kalman Filter. In this experiment ISBA is forced with the near-real time SAFRAN analysis, which analyses the variables required to force ISBA from relevant observations available before the real time data cut-off. The assimilation results are tested against ISBA forecasts generated with a higher quality delayed cut-off SAFRAN analysis. Ideally, assimilating the ASCAT data will constrain the ISBA surface state to correct for errors in the near-real time SAFRAN forcing, the most significant of which was a substantial dry bias caused by a dry precipitation bias. The assimilation successfully reduced the mean root-zone soil moisture bias, relative to the delayed cut-off forecasts, by close to 50 % of the open-loop value. The improved soil moisture in the model then led to significant improvements in the forecast hydrological cycle, reducing the drainage, runoff, and evapotranspiration biases (by 17 %, 11 %, and 70 %, respectively. When coupled to the MODCOU hydrogeological model, the ASCAT assimilation also led to improved streamflow forecasts, increasing the mean discharge ratio, relative to the delayed cut off forecasts, from 0.68 to 0.76. These results demonstrate that assimilating near-surface soil moisture observations can effectively constrain the SIM model hydrology, while also confirming the accuracy of the ASCAT surface degree of saturation product. This latter point highlights how assimilation experiments can contribute towards the difficult issue of validating remotely sensed land surface observations over large spatial scales.

  16. Continuous-time discrete-space models for animal movement

    Science.gov (United States)

    Hanks, Ephraim M.; Hooten, Mevin B.; Alldredge, Mat W.

    2015-01-01

    The processes influencing animal movement and resource selection are complex and varied. Past efforts to model behavioral changes over time used Bayesian statistical models with variable parameter space, such as reversible-jump Markov chain Monte Carlo approaches, which are computationally demanding and inaccessible to many practitioners. We present a continuous-time discrete-space (CTDS) model of animal movement that can be fit using standard generalized linear modeling (GLM) methods. This CTDS approach allows for the joint modeling of location-based as well as directional drivers of movement. Changing behavior over time is modeled using a varying-coefficient framework which maintains the computational simplicity of a GLM approach, and variable selection is accomplished using a group lasso penalty. We apply our approach to a study of two mountain lions (Puma concolor) in Colorado, USA.

  17. Determination of suitable drying curve model for bread moisture loss during baking

    Science.gov (United States)

    Soleimani Pour-Damanab, A. R.; Jafary, A.; Rafiee, S.

    2013-03-01

    This study presents mathematical modelling of bread moisture loss or drying during baking in a conventional bread baking process. In order to estimate and select the appropriate moisture loss curve equation, 11 different models, semi-theoretical and empirical, were applied to the experimental data and compared according to their correlation coefficients, chi-squared test and root mean square error which were predicted by nonlinear regression analysis. Consequently, of all the drying models, a Page model was selected as the best one, according to the correlation coefficients, chi-squared test, and root mean square error values and its simplicity. Mean absolute estimation error of the proposed model by linear regression analysis for natural and forced convection modes was 2.43, 4.74%, respectively.

  18. Forward models and state estimation in compensatory eye movements

    Directory of Open Access Journals (Sweden)

    Maarten A Frens

    2009-11-01

    Full Text Available The compensatory eye movement system maintains a stable retinal image, integrating information from different sensory modalities to compensate for head movements. Inspired by recent models of physiology of limb movements, we suggest that compensatory eye movements (CEM can be modeled as a control system with three essential building blocks: a forward model that predicts the effects of motor commands; a state estimator that integrates sensory feedback into this prediction; and, a feedback controller that translates a state estimate into motor commands. We propose a specific mapping of nuclei within the CEM system onto these control functions. Specifically, we suggest that the Flocculus is responsible for generating the forward model prediction and that the Vestibular Nuclei integrate sensory feedback to generate an estimate of current state. Finally, the brainstem motor nuclei – in the case of horizontal compensation this means the Abducens Nucleus and the Nucleus Prepositus Hypoglossi – implement a feedback controller, translating state into motor commands. While these efforts to understand the physiological control system as a feedback control system are in their infancy, there is the intriguing possibility that compensatory eye movements and targeted voluntary movements use the same cerebellar circuitry in fundamentally different ways.

  19. Soil moisture data for the validation of permafrost models using direct and indirect measurement approaches at three alpine sites

    Directory of Open Access Journals (Sweden)

    Cécile ePellet

    2016-01-01

    Full Text Available 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 the spatial distribution and temporal evolution of soil moisture at three high elevation sites with different ground properties and thermal regimes. The observed temporal evolution of measured soil moisture is characteristic for sites with seasonal freeze/thaw cycles and consistent with the respective site-specific properties, demonstrating the general applicability of continuous monitoring of soil moisture at high elevation areas. The obtained soil moisture data were then used for the calibration and validation of two different model approaches in permafrost research in order to characterize the lateral and vertical distribution of ice content in the ground. Calibration of the geophysically based four-phase model (4PM with spatially distributed soil moisture data yielded satisfactory two dimensional distributions of water-, ice- and air content. Similarly, soil moisture time series significantly improved the calibration of the one-dimensional heat and mass transfer model COUP, yielding physically consistent soil moisture and temperature data matching observations at different depths.

  20. Simultaneous assimilation of in situ soil moisture and streamflow in the SWAT model using the Extended Kalman Filter

    Science.gov (United States)

    Sun, Leqiang; Seidou, Ousmane; Nistor, Ioan; Goïta, Kalifa; Magagi, Ramata

    2016-12-01

    The Extended Kalman Filter (EKF) is used to assimilate in situ surface soil moisture and streamflow observation at the outlet of an experimental watershed outlet into a semi-distributed SWAT (Soil and Water Assessment Tool) model. Watershed scale, instead of HRU scale soil moisture was used in state vector to reduce computational burden. Numerical experiments were designed to select the best state vector which consists of streamflow and soil moisture in all vertical soil layers. Compared to open-loop model and direct-insert method, the estimate of both soil moisture and streamflow has been improved by EKF assimilation. The combined assimilation of surface soil moisture and streamflow outperforms the assimilation with only surface soil moisture or streamflow especially in the estimate of full profile soil moisture. The NSC has been improved to 0.63 from -4.45 and the RMSE has been reduced to 12.34 mm from 47.44 mm in open-loop. Such improvement is also reflected in the short term forecast of soil moisture. The improvement of streamflow prediction is relatively moderate in both simulation and forecast mode compared to quality of the soil moisture prediction. The quantification of the model error, especially the error covariance between different state variables, was found to be critical to the estimate of the state variable corresponding to the error covariance.

  1. Modeling of human movement monitoring using Bluetooth Low Energy technology.

    Science.gov (United States)

    Mokhtari, G; Zhang, Q; Karunanithi, M

    2015-01-01

    Bluetooth Low Energy (BLE) is a wireless communication technology which can be used to monitor human movements. In this monitoring system, a BLE signal scanner scans signal strength of BLE tags carried by people, to thus infer human movement patterns within its monitoring zone. However to the extent of our knowledge one main aspect of this monitoring system which has not yet been thoroughly investigated in literature is how to build a sound theoretical model, based on tunable BLE communication parameters such as scanning time interval and advertising time interval, to enable the study and design of effective and efficient movement monitoring systems. In this paper, we proposed and developed a statistical model based on Monte-Carlo simulation, which can be utilized to assess impacts of BLE technology parameters in terms of latency and efficiency, on a movement monitoring system, and can thus benefit a more efficient system design.

  2. Soil physical data and modeling soil moisture flow

    NARCIS (Netherlands)

    Wesseling, J.G.

    2009-01-01

    De fysische eigenschappen van grof-gestruktureerd bodemmateriaal zijn bepaald aan kunstmatig gemaakte monsters, evenals het effekt van het toevoegen van 10 vol.% organische stof. Deze eigenschappen zijn toegepast in modelberekeningen met het nieuw ontwikkelde model SoWaM. De beregeningsbehoefte van

  3. Theoretical Model for Predicting Moisture Ratio during Drying of Spherical Particles in a Rotary Dryer

    Directory of Open Access Journals (Sweden)

    F. T. Ademiluyi

    2013-01-01

    Full Text Available A mathematical model was developed for predicting the drying kinetics of spherical particles in a rotary dryer. Drying experiments were carried out by drying fermented ground cassava particles in a bench scale rotary dryer at inlet air temperatures of 115–230°C, air velocities of 0.83 m/s–1.55 m/s, feed mass of 50–500 g, drum drive speed of 8 rpm, and feed drive speed of 100 rpm to validate the model. The data obtained from the experiments were used to calculate the experimental moisture ratio which compared well with the theoretical moisture ratio calculated from the newly developed Abowei-Ademiluyi model. The comparisons and correlations of the results indicate that validation and performance of the established model are rather reasonable.

  4. Digital Modeling Phenomenon Of Surface Ground Movement

    Directory of Open Access Journals (Sweden)

    Ioan Voina

    2016-11-01

    Full Text Available With the development of specialized software applications it was possible to approach and resolve complex problems concerning automating and process optimization for which are being used field data. Computerized representation of the shape and dimensions of the Earth requires a detailed mathematical modeling, known as "digital terrain model". The paper aims to present the digital terrain model of Vulcan mining, Hunedoara County, Romania. Modeling consists of a set of mathematical equations that define in detail the surface of Earth and has an approximate surface rigorously and mathematical, that calculated the land area. Therefore, the digital terrain model means a digital representation of the earth's surface through a mathematical model that approximates the land surface modeling, which can be used in various civil and industrial applications in. To achieve the digital terrain model of data recorded using linear and nonlinear interpolation method based on point survey which highlights the natural surface studied. Given the complexity of this work it is absolutely necessary to know in detail of all topographic elements of work area, without the actions to be undertaken to project and manipulate would not be possible. To achieve digital terrain model, within a specialized software were set appropriate parameters required to achieve this case study. After performing all steps we obtained digital terrain model of Vulcan Mine. Digital terrain model is the complex product, which has characteristics that are equivalent to the specialists that use satellite images and information stored in a digital model, this is easier to use.

  5. Combining modelled and remote sensing soil moisture anomalies for an operational global drought monitoring

    Science.gov (United States)

    Cammalleri, Carmelo; Vogt, Jürgen

    2017-04-01

    Soil moisture anomalies (i.e., deviations from the climatology) are often seen as a reliable tool to monitor and quantify the occurrence of drought events and their potential impacts, especially in agricultural and naturally vegetated lands. Soil moisture datasets (or their proxy) can be derived from a variety of sources, including land-surface models and thermal and microwave satellite remote sensing images. However, each data source has different advantages and drawbacks that prevent to unequivocally prefer one dataset over the others, especially in global applications that encompass a wide range of soil moisture regimes. The analysis of the spatial reliability of the different datasets at global scale is further complicated by the lack of reliable long-term soil moisture records for a ground validation over most regions. To overcome this limitation, in recent years the Triple Collocation (TC) technique has been deployed in order to quantify the likely errors associated to three mutually-independent datasets without assuming that one of them represents the "truth". In this study, three global datasets of soil moisture anomalies are investigated: the first one derived from the runs of the Lisflood hydrological model, the second one obtained from the combined active/passive microwave dataset produced in the framework of the European Space Agency (ESA) Climate Change Initiative (CCI), and the last one derived from the Moderate-Resolution Imaging Spectroradiometer (MODIS) Land Surface Temperature (LST) observations. A preliminary analysis of the three datasets aimed at detecting the areas where the TC technique can be successfully applied, hence the spatial distribution of the random error variance for each model is evaluated. This study allows providing useful advises for a robust combination of the three datasets into a single product for a more reliable global drought monitoring.

  6. Modelling of Specific Moisture Extraction Rate and Leakage Ratio in a Condensing Tumble Dryer

    OpenAIRE

    Stawreberg, Lena; Nilsson, Lars

    2010-01-01

    Abstract The use of tumble dryers in households is becoming more common. Tumble dryers, however, consume large amounts of electric energy. A statistical model over the tumble dryer is created from a design of experiments. The model will be used to find the best settings for the power supply to the heater, the internal airflow and the external airflow in order to reach a high specific moisture extraction rate (SMER) and a low leakage ratio of water vapour. The aim also involves expl...

  7. Research on the Estimation Model of Soil Moisture Content Based on the Characteristics of Thermal Infrared Data

    Institute of Scientific and Technical Information of China (English)

    Jun; XU; Jianjun; JIANG

    2013-01-01

    With the portable Fourier Transform Infrared Spectroscopy (FTIR), the reflectance spectra of soil samples with different moisture content are measured in laboratory for expounding the characteristic of radiation in the thermal infrared part of the spectrum with different soil moisture content. A model of estimating the moisture content in soil is attempted to make based on Moisture Diagnostic Index (MDI). In general,the spectral characteristic of soil emissivity in laboratory includes the following aspects.Firstly,in the region of 8.0-9.5 μm,along with the increase of soil moisture content,the emissivity of soil increases to varying degrees. The spectral curves are parallel relatively and have a tendency to become horizontal and the absorbed characteristic of reststrahlen is also weakened relatively with the increase of soil moisture in this region.Secondly,in the region of 11.0-14.0 μm,the emissivity of soil has a tendency of increasing.There is an absorption value near about 12.7 μm. As the soil moisture content increases,the depth of absorption also increases. This phenomenon may be caused by soil moisture absorption. Methods as derivative, difference and standardized ratio transformation may weaken the background noise effectively to the spectrum data. Especially using the ratio of the emissivity to the average of 8-14 μm may obviously enhance the correlation between soil moisture and soil emissivity. According to the result of correlation analysis, the 8.237 μm is regarded as the best detecting band for soil moisture content. Moreover,based on the Moisture Diagnostic Index ( MDI) in the 8.194-8.279 μm, the logarithmic model of estimating soil moisture is made.

  8. Round Robin evaluation of soil moisture retrieval models for the MetOp-A ASCAT Instrument

    Science.gov (United States)

    Gruber, Alexander; Paloscia, Simonetta; Santi, Emanuele; Notarnicola, Claudia; Pasolli, Luca; Smolander, Tuomo; Pulliainen, Jouni; Mittelbach, Heidi; Dorigo, Wouter; Wagner, Wolfgang

    2014-05-01

    Global soil moisture observations are crucial to understand hydrologic processes, earth-atmosphere interactions and climate variability. ESA's Climate Change Initiative (CCI) project aims to create a global consistent long-term soil moisture data set based on the merging of the best available active and passive satellite-based microwave sensors and retrieval algorithms. Within the CCI, a Round Robin evaluation of existing retrieval algorithms for both active and passive instruments was carried out. In this study we present the comparison of five different retrieval algorithms covering three different modelling principles applied to active MetOp-A ASCAT L1 backscatter data. These models include statistical models (Bayesian Regression and Support Vector Regression, provided by the Institute for Applied Remote Sensing, Eurac Research Viale Druso, Italy, and an Artificial Neural Network, provided by the Institute of Applied Physics, CNR-IFAC, Italy), a semi-empirical model (provided by the Finnish Meteorological Institute), and a change detection model (provided by the Vienna University of Technology). The algorithms were applied on L1 backscatter data within the period of 2007-2011, resampled to a 12.5 km grid. The evaluation was performed over 75 globally distributed, quality controlled in situ stations drawn from the International Soil Moisture Network (ISMN) using surface soil moisture data from the Global Land Data Assimilation System (GLDAS-) Noah land surface model as second independent reference. The temporal correlation between the data sets was analyzed and random errors of the the different algorithms were estimated using the triple collocation method. Absolute soil moisture values as well as soil moisture anomalies were considered including both long-term anomalies from the mean seasonal cycle and short-term anomalies from a five weeks moving average window. Results show a very high agreement between all five algorithms for most stations. A slight

  9. Modeling the Hellenic karst catchments with the Sacramento Soil Moisture Accounting model

    Science.gov (United States)

    Katsanou, K.; Lambrakis, N.

    2017-01-01

    Karst aquifers are very complex due to the presence of dual porosity. Rain-runoff hydrological models are frequently used to characterize these aquifers and assist in their management. The calibration of such models requires knowledge of many parameters, whose quality can be directly related to the quality of the simulation results. The Sacramento Soil Moisture Accounting (SAC-SMA) model includes a number of physically based parameters that permit accurate simulations and predictions of the rain-runoff relationships. Due to common physical characteristics of mature karst structures, expressed by sharp recession limbs of the runoff hydrographs, the calibration of the model becomes relatively simple, and the values of the parameters range within narrow bands. The most sensitive parameters are those related to groundwater storage regulated by the zone of the epikarst. The SAC-SMA model was calibrated for data from the mountainous part of the Louros basin, north-western Greece, which is considered to be representative of such geological formations. Visual assessment of the hydrographs as statistical outcomes revealed that the SAC-SMA model simulated the timing and magnitude of the peak flow and the shape of recession curves well.

  10. Modeling the Hellenic karst catchments with the Sacramento Soil Moisture Accounting model

    Science.gov (United States)

    Katsanou, K.; Lambrakis, N.

    2017-05-01

    Karst aquifers are very complex due to the presence of dual porosity. Rain-runoff hydrological models are frequently used to characterize these aquifers and assist in their management. The calibration of such models requires knowledge of many parameters, whose quality can be directly related to the quality of the simulation results. The Sacramento Soil Moisture Accounting (SAC-SMA) model includes a number of physically based parameters that permit accurate simulations and predictions of the rain-runoff relationships. Due to common physical characteristics of mature karst structures, expressed by sharp recession limbs of the runoff hydrographs, the calibration of the model becomes relatively simple, and the values of the parameters range within narrow bands. The most sensitive parameters are those related to groundwater storage regulated by the zone of the epikarst. The SAC-SMA model was calibrated for data from the mountainous part of the Louros basin, north-western Greece, which is considered to be representative of such geological formations. Visual assessment of the hydrographs as statistical outcomes revealed that the SAC-SMA model simulated the timing and magnitude of the peak flow and the shape of recession curves well.

  11. Precipitation extreme changes exceeding moisture content increases in MIROC and IPCC climate models.

    Science.gov (United States)

    Sugiyama, Masahiro; Shiogama, Hideo; Emori, Seita

    2010-01-12

    Precipitation extreme changes are often assumed to scale with, or are constrained by, the change in atmospheric moisture content. Studies have generally confirmed the scaling based on moisture content for the midlatitudes but identified deviations for the tropics. In fact half of the twelve selected Intergovernmental Panel on Climate Change (IPCC) models exhibit increases faster than the climatological-mean precipitable water change for high percentiles of tropical daily precipitation, albeit with significant intermodel scatter. Decomposition of the precipitation extreme changes reveals that the variations among models can be attributed primarily to the differences in the upward velocity. Both the amplitude and vertical profile of vertical motion are found to affect precipitation extremes. A recently proposed scaling that incorporates these dynamical effects can capture the basic features of precipitation changes in both the tropics and midlatitudes. In particular, the increases in tropical precipitation extremes significantly exceed the precipitable water change in Model for Interdisciplinary Research on Climate (MIROC), a coupled general circulation model with the highest resolution among IPCC climate models whose precipitation characteristics have been shown to reasonably match those of observations. The expected intensification of tropical disturbances points to the possibility of precipitation extreme increases beyond the moisture content increase as is found in MIROC and some of IPCC models.

  12. An Early Childhood Movement Laboratory Model: Kindergym

    Science.gov (United States)

    Marston, Rip

    2004-01-01

    Early childhood motor activity programs at institutions of higher learning can operate within the tripartite mission of the university while serving a vital function in providing leadership and guidance to educators. This article describes the University of Northern Iowa's Kindergym model. Within this model, curricular areas of games/sports,…

  13. A note on the Hybrid Soil Moisture Deficit Model v2.0

    Directory of Open Access Journals (Sweden)

    Schulte Rogier P.O.

    2015-12-01

    Full Text Available The Hybrid Soil Moisture Deficit (HSMD model has been used for a wide range of applications, including modelling of grassland productivity and utilisation, assessment of agricultural management opportunities such as slurry spreading, predicting nutrient emissions to the environment and risks of pathogen transfer to water. In the decade since its publication, various ad hoc modifications have been developed and the recent publication of the Irish Soil Information System has facilitated improved assessment of the spatial soil moisture dynamics. In this short note, we formally present a new version of the model (HSMD2.0, which includes two new soil drainage classes, as well as an optional module to account for the topographic wetness index at any location. In addition, we present a new Indicative Soil Drainage Map for Ireland, based on the Irish Soil Classification system, developed as part of the Irish Soil Information System.

  14. Mathematical Modeling of Moisture Sorption Isotherms and Determination of Isosteric Heats of Sorption of Ziziphus Leaves

    Directory of Open Access Journals (Sweden)

    Amel Saad

    2014-01-01

    Full Text Available Desorption and adsorption equilibrium moisture isotherms of Ziziphus spina-christi leaves were determined using the gravimetric-static method at 30, 40, and 50°C for water activity (aw ranging from 0.057 to 0.898. At a given aw, the results show that the moisture content decreases with increasing temperature. A hysteresis effect was observed. The experimental data of sorption were fitted by eight models (GAB, BET, Henderson-Thompson, modified-Chung Pfost, Halsey, Oswin, Peleg, and Adam and Shove. After evaluating the models according to several criteria, the Peleg and Oswin models were found to be the most suitable for describing the sorption curves. The net isosteric heats of desorption and adsorption of Ziziphus spina-christi leaves were calculated by applying the Clausius-Clapeyron equation to the sorption isotherms and an expression for predicting these thermodynamic properties was given.

  15. Modelling moisture content and dry matter loss during storage of logging residues for energy

    Energy Technology Data Exchange (ETDEWEB)

    Filbakk, Tore; Hoeiboe, Olav Albert (Dept. of Ecology and Natural Resource Management, Norwegian Univ. of Life Sciences, Aas (Norway)); Dibdiakova, Janka (Norwegian Forest and Landscape Inst., Aas (Norway)); Nurmi, Juha (Finnish Forest Research Inst., Kannus (Finland))

    2011-04-15

    To achieve optimal utilisation of logging residues for energy, it is important to know how different handling and storage methods affect fuel properties. The aim of this study was to model how the moisture content and dry matter losses of logging residues develop during storage. Logging residues were collected from five different stands of spruce and pine during different seasons of the year and stored in the same location. The logging residues were stored in covered piles of bundled residues and loose residues. Only minor differences were found in the moisture content profiles between piles of bundles and loose residues. Logging residues located in the centre of both types of piles had considerably lower moisture content than the outer parts. The moisture content significantly affected dry matter loss, with the highest dry matter losses being found in the samples with the least favourable drying conditions. The dry matter losses varied between 1 and 3% per month. Significantly higher dry matter losses were found in the spruce bundles than in the pine bundles. Seasoned logging residues had the lowest dry matter loss, while the logging residues harvested and piled in the autumn had the highest loss

  16. Modelling of coupled heat and moisture flows around a buried electrical cable

    Directory of Open Access Journals (Sweden)

    Eslami Hossein

    2016-01-01

    Full Text Available The admissible current within a buried electrical power cable is limited by the maximum allowed temperature of the cable (Joule effect. The thermal properties of the surrounding soil controls heat dissipation around the cable. The main focus of the study was to evaluate the coupled heat and moisture flow around such buried electrical cables. The heat dissipation of a buried power cable was simulated in the surrounding soil at unsteady conditions. The hydro-thermal coupling was modelled by taking into account the moisture flow of liquid water and vapour, and the heat flow in the soil by convection and advection. As the thermal vapour diffusion enhancement factor (η appears to be a key parameter, the sensitivity study of the coupled heat and moisture flow in the ground regarding this parameter was performed. The variations of the degree of saturation and the temperature of the surrounding soil were studied over 180 days of heating. The results showed that the moisture flow was mainly caused by the vapour transport under temperature gradients. These results emphasized the significant effect of the hydrothermal characteristics of surrounding soil. The radius of influence of the power cable was also evaluated.

  17. Assimilation of Satellite Soil Moisture observation with the Particle Filter-Markov Chain Monte Carlo and Geostatistical Modeling

    Science.gov (United States)

    Moradkhani, Hamid; Yan, Hongxiang

    2016-04-01

    Soil moisture simulation and prediction are increasingly used to characterize agricultural droughts but the process suffers from data scarcity and quality. The satellite soil moisture observations could be used to improve model predictions with data assimilation. Remote sensing products, however, are typically discontinuous in spatial-temporal coverages; while simulated soil moisture products are potentially biased due to the errors in forcing data, parameters, and deficiencies of model physics. This study attempts to provide a detailed analysis of the joint and separate assimilation of streamflow and Advanced Scatterometer (ASCAT) surface soil moisture into a fully distributed hydrologic model, with the use of recently developed particle filter-Markov chain Monte Carlo (PF-MCMC) method. A geostatistical model is introduced to overcome the satellite soil moisture discontinuity issue where satellite data does not cover the whole study region or is significantly biased, and the dominant land cover is dense vegetation. The results indicate that joint assimilation of soil moisture and streamflow has minimal effect in improving the streamflow prediction, however, the surface soil moisture field is significantly improved. The combination of DA and geostatistical approach can further improve the surface soil moisture prediction.

  18. Evaluating the Potential Use of Remotely-Sensed and Model-Simulated Soil Moisture for Agricultural Drought Risk Monitoring

    Science.gov (United States)

    Yan, Hongxiang; Moradkhani, Hamid

    2016-04-01

    Current two datasets provide spatial and temporal resolution of soil moisture at large-scale: the remotely-sensed soil moisture retrievals and the model-simulated soil moisture products. Drought monitoring using remotely-sensed soil moisture is emerging, and the soil moisture simulated using land surface models (LSMs) have been used operationally to monitor agriculture drought in United States. Although these two datasets yield important drought information, their drought monitoring skill still needs further quantification. This study provides a comprehensive assessment of the potential of remotely-sensed and model-simulated soil moisture data in monitoring agricultural drought over the Columbia River Basin (CRB), Pacific Northwest. Two satellite soil moisture datasets were evaluated, the LPRM-AMSR-E (unscaled, 2002-2011) and ESA-CCI (scaled, 1979-2013). The USGS Precipitation Runoff Modeling System (PRMS) is used to simulate the soil moisture from 1979-2011. The drought monitoring skill is quantified with two indices: drought area coverage (the ability of drought detection) and drought severity (according to USDM categories). The effects of satellite sensors (active, passive), multi-satellite combined, length of climatology, climate change effect, and statistical methods are also examined in this study.

  19. Modeling soil moisture processes and recharge under a melting snowpack

    Science.gov (United States)

    Flint, A.L.; Flint, L.E.; Dettinger, M.D.

    2008-01-01

    Recharge into granitic bedrock under a melting snowpack is being investigated as part of a study designed to understand hydrologic processes involving snow at Yosemite National Park in the Sierra Nevada Mountains of California. Snowpack measurements, accompanied by water content and matric potential measurements of the soil under the snowpack, allowed for estimates of infiltration into the soil during snowmelt and percolation into the bedrock. During portions of the snowmelt period, infiltration rates into the soil exceeded the permeability of the bedrock and caused ponding to be sustained at the soil-bedrock interface. During a 5-d period with little measured snowmelt, drainage of the ponded water into the underlying fractured granitic bedrock was estimated to be 1.6 cm d?1, which is used as an estimate of bedrock permeability. The numerical simulator TOUGH2 was used to reproduce the field data and evaluate the potential for vertical flow into the fractured bedrock or lateral flow at the bedrock-soil interface. During most of the snowmelt season, the snowmelt rates were near or below the bedrock permeability. The field data and model results support the notion that snowmelt on the shallow soil overlying low permeability bedrock becomes direct infiltration unless the snowmelt rate greatly exceeds the bedrock permeability. Late in the season, melt rates are double that of the bedrock permeability (although only for a few days) and may tend to move laterally at the soil-bedrock interface downgradient and contribute directly to streamflow. ?? Soil Science Society of America.

  20. Investigation of the Moisture Recycling Ratio over South America: A Modelling Approach using HadCM3

    Science.gov (United States)

    Charan Pattnayak, Kanhu; Gloor, Emanuel; Tindall, Julia; Briener, Roel

    2017-04-01

    It is a well-known fact that precipitation relies on terrestrial evaporation (moisture recycling). This study makes use of new definitions of moisture recycling from van der Ent, et al. 2010 to study the complete process of continental moisture feedback. Earlier studies have shown that there exist many regions over the globe that relies heavily on recycled moisture as well as that supplies moisture. In South America, the Río de la Plata basin depends on evaporation from the Amazon forest for 70% of its water resources. Stable water isotope (δ18O) can be used, as a good proxy for precipitation and it is a better tool to study convective processes and hydrological cycle. Analysing the δ18O would help to identify the moisture source for precipitation. In this study, we try to explain to the relation between δ18O and the moisture recycling ratio using atmospheric component of Hadley Centre Coupled Climate Model (HadCM3). And also we analyse the impact of land cover change on δ18O and the moisture recycling ratio. Further, we will analyse the changes of moisture recycling pattern from pre-industrial to the present scenario.

  1. [Transferability of Hyperspectral Model for Estimating Soil Organic Matter Concerned with Soil Moisture].

    Science.gov (United States)

    Chen, Yi-yun; Qi, Kun; Liu, Yao-lin; He, Jian-hua; Jiang, Qing-hu

    2015-06-01

    Hyperspectral remote sensing, known as the state-of-the-art technology in the field of remote sensing, can be used to retrieve physical and chemical properties of surface objects based on the interactions between electromagnetic waves and the objects. Soil organic matter (SOM) is one of the most important parameters used in the assessment of soil fertility. Quick estimation of SOM with hyperspectral remote sensing technique can provide essential soil data to support the development of precision agriculture. The presence of external parameters, however, may affect the modeling precision, and further handicap the transfer ability of existing model. With the aim to study the effects of soil moisture on the Vis/NIR estimation of soil organic matter, and the capacity of direct standardization(DS)algorithm in the calibration transfer, 95 soil samples collected in the Jianghan plain were rewetted and air-dried. Reflectance of these samples at 13 moisture levels was measured. Results show that the model calibrated using air-dried samples has the highest prediction accuracy. This model, however, was not suitable for SOM prediction of the rewetted samples. Prediction bias and RPD improved from -8.34-3.32 g x kg(-1) and 0.64-2.04 to 0 and 7.01, when DS algorithm was applied to the spectra of the rewetted samples. DS algorithm has been proven to be effective in removing the effects of soil moisture on the Vis/NIR estimation of SOM, ensuring a transferrable model for SOM prediction with soil samples at different moisture levels.

  2. Modeling of movements in sports training

    Directory of Open Access Journals (Sweden)

    Kashuba V.A.

    2010-08-01

    Full Text Available Aggregate data are expounded about methodical approaches at the modeling of technique of motor actions in sport. Practical material is presented on questions of design and perfection of technique of motor actions on the example of different types of sport. The model of technique of running step is offered on a line in short-track. A cross-correlation analysis between resulting speed of general centre-of-mass body of sportsmen and biomechanics descriptions exposed six important indexes. These indexes are plugged in a statistical model at run on a line. It is set that on the initial stages of preparation of sportsmen it is necessary to take into account the biokinematics and biodynamic structure of technique of motive actions.

  3. Representation of Boundary Layer Moisture Transport in Cloud-Resolving Models

    Science.gov (United States)

    Moeng, C. L.; Arakawa, A.

    2012-12-01

    One of the important roles of the PBL is to transport moisture from the surface to the cloud layer. However, how this transport process can be accounted for in cloud-resolving models (CRMs) is not sufficiently clear and has rarely been examined. A typical CRM can resolve the bulk feature of large convection systems but not the small-scale convection and turbulence motions that carry a large portion of the moisture fluxes. We use a large-eddy simulation of a tropical deep convection system as a benchmark to examine the subgrid-scale (SGS) moisture transport into a cloud system. First we show that most of the PBL moisture transport to the cloud layer occurs in small areas under low-level updrafts, with rain, or under thick clouds. To represent this spatial distribution of the moisture transport in CRMs, we propose and (a priori) test an updraft-downdraft scheme, which expresses the SGS flux in terms of the differences between the mean SGS updraft-downdraft properties. We show that this SGS scheme works extremely well for CRMs with a 1 to 10 km horizontal grid spacing. The closure issue is to estimate the mean SGS updraft-downdraft properties in terms of the CRM resolved flow field.he figure shows the contours of SGS latent heat fluxes at z~300m with a cutoff width of 4 km. The top panel is retrieved from a LES of a tropical deep convection system and bottom panel calculated from the updraft-downdraft scheme with A1=0.4 and the mean SGS updraft-downdraft properties diagnosed from the LES.

  4. A toy model of tropical convection with a moisture storage closure

    National Research Council Canada - National Science Library

    Masunaga, Hirohiko; Sumi, Yukari

    2017-01-01

    .... A closure representing the consumption efficiency of water vapor into precipitation is introduced using the moisture storage ratio, or the degree to which the vertical moisture advection associated...

  5. Effects of polyols on the stability of whey proteins in intermediate-moisture food model systems.

    Science.gov (United States)

    Liu, Xiaoming; Zhou, Peng; Tran, Amy; Labuza, Ted P

    2009-03-25

    The objective of this study was to investigate the influence of polyols on the stability of whey proteins in an intermediate-moisture food model system and to elucidate the effect of polyols on the hardening of whey protein-based bars during storage. Four major polyols, glycerol, propylene glycol, maltitol, and sorbitol, were evaluated in model systems, which contained whey protein isolate, polyols, and water. The results showed that glycerol was the most effective polyol in lowering water activity and provided the soft texture of intermediate-moisture foods, followed by sorbitol and maltitol. These three polyols stabilized the native structure of whey proteins, provided a desired texture, and slowed the hardening of the model systems. Propylene glycol should not be used in whey protein-based high-protein intermediate-moisture foods because it caused changes in protein conformation and stability as observed by differential scanning calorimeter and Fourier transform infrared spectroscopy and resulted in aggregation of whey proteins and hardening of the bar texture during storage, causing loss in product quality.

  6. Modeling Physical Stability of Amorphous Solids Based on Temperature and Moisture Stresses.

    Science.gov (United States)

    Zhu, Donghua Alan; Zografi, George; Gao, Ping; Gong, Yuchuan; Zhang, Geoff G Z

    2016-09-01

    Isothermal microcalorimetry was utilized to monitor the crystallization process of amorphous ritonavir (RTV) and its hydroxypropylmethylcellulose acetate succinate-based amorphous solid dispersion under various stressed conditions. An empirical model was developed: ln(τ)=ln(A)+EaRT-b⋅wc, where τ is the crystallization induction period, A is a pre-exponential factor, Ea is the apparent activation energy, b is the moisture sensitivity parameter, and wc is water content. To minimize the propagation of errors associated with the estimates, a nonlinear approach was used to calculate mean estimates and confidence intervals. The physical stability of neat amorphous RTV and RTV in hydroxypropylmethylcellulose acetate succinate solid dispersions was found to be mainly governed by the nucleation kinetic process. The impact of polymers and moisture on the crystallization process can be quantitatively described by Ea and b in this Arrhenius-type model. The good agreement between the measured values under some less stressful test conditions and those predicted, reflected by the slope and R(2) of the correlation plot of these 2 sets of data on a natural logarithm scale, indicates its predictability of long-term physical stability of amorphous RTV in solid dispersions. To further improve the model, more understanding of the impact of temperature and moisture on the amorphous physical stability and fundamentals regarding nucleation and crystallization is needed.

  7. Optimization of electronic enclosure design for thermal and moisture management using calibrated models of progressive complexity

    DEFF Research Database (Denmark)

    Mohanty, Sankhya; Staliulionis, Zygimantas; Shojaee Nasirabadi, Parizad

    2016-01-01

    The thermal and moisture management of electronic enclosures are fields of high interest in recent years. It is now generally accepted that the protection of electronic devices is dependent on avoiding critical levels of relative humidity (typically 60–90%) during operations. Leveraging the devel......The thermal and moisture management of electronic enclosures are fields of high interest in recent years. It is now generally accepted that the protection of electronic devices is dependent on avoiding critical levels of relative humidity (typically 60–90%) during operations. Leveraging...... the development of rigorous calibrated CFD models as well as simple predictive numerical tools, the current paper tackles the optimization of critical features of a typical two-chamber electronic enclosure. The progressive optimization strategy begins the design parameter selection by initially using simpler...... equivalent RC-circuit models for concentration of water vapor and temperature in the electronic enclosure. After reducing the potential parameter-value space for the critical features using the RC-approach, the optimization strategy uses simpler 2D CFD models of temperature and moisture transport to further...

  8. Modeling of Water Movement Near Saturation

    Science.gov (United States)

    Ippisch, O.; Graf, H.; Bastian, P.; Roth, K.

    Water transport in unsaturated porous media is often described using Richards' equa- tion. However Richards' equation is based on the assumption that the gas phase is mobile enough to be always (nearly) at atmospheric pressure. This assumption is not valid if the porous medium is nearly saturated with water. The difference between model calculations using Richards' equation and a multiphase formulation is analyzed and compared to results from multistep outflow experiments with columns of sintered glass. The chosen parameterization for the hydraulic param- eters (van Genuchten/Brooks-Corey) proves to expecially important.

  9. Land surface model performance using cosmic-ray and point-scale soil moisture measurements for calibration

    Science.gov (United States)

    Iwema, Joost; Rosolem, Rafael; Rahman, Mostaquimur; Blyth, Eleanor; Wagener, Thorsten

    2017-06-01

    At very high resolution scale (i.e. grid cells of 1 km2), land surface model parameters can be calibrated with eddy-covariance flux data and point-scale soil moisture data. However, measurement scales of eddy-covariance and point-scale data differ substantially. In our study, we investigated the impact of reducing the scale mismatch between surface energy flux and soil moisture observations by replacing point-scale soil moisture data with observations derived from Cosmic-Ray Neutron Sensors (CRNSs) made at larger spatial scales. Five soil and evapotranspiration parameters of the Joint UK Land Environment Simulator (JULES) were calibrated against point-scale and Cosmic-Ray Neutron Sensor soil moisture data separately. We calibrated the model for 12 sites in the USA representing a range of climatic, soil, and vegetation conditions. The improvement in latent heat flux estimation for the two calibration solutions was assessed by comparison to eddy-covariance flux data and to JULES simulations with default parameter values. Calibrations against the two soil moisture products alone did show an advantage for the cosmic-ray technique. However, further analyses of two-objective calibrations with soil moisture and latent heat flux showed no substantial differences between both calibration strategies. This was mainly caused by the limited effect of calibrating soil parameters on soil moisture dynamics and surface energy fluxes. Other factors that played a role were limited spatial variability in surface fluxes implied by soil moisture spatio-temporal stability, and data quality issues.

  10. Soil Thermal and Moisture Regimes in the Canadian Regional Climate Model

    Science.gov (United States)

    Sushama, L.; Laprise, R.; Caya, D.

    2004-05-01

    Soil moisture, with its high spatial and temporal variability, is important in understanding and predicting a large number of processes including land-atmospheric interactions. In many northern-latitude regions, spring melt-water derived from the winter snow pack represents the greatest source for the yearly ground moisture budget. The ability of the Canadian Regional Climate model (CRCM4.0) with its three-layer, physically based, land-surface scheme (CLASS) to simulate the hydrological cycle, especially the soil moisture and thermal regimes, over a domain covering Eastern Canada and part of Eastern United States, is investigated. The CRCM was driven by NCEP reanalyses and was run at 45-km horizontal grid-point spacing for a five-year period from 1993-1997. The model simulates reasonably well the annual cycle of soil moisture variation. Air-soil temperature phase-space diagrams are examined for regions with (1) no snow-cover, (2) seasonal snow-cover and (3) permanent snow-cover. The annual air/soil thermal orbits help assess the nature of the heat transfer process in the subsurface qualitatively and hence in identifying areas of conductive and non-conductive regimes of the subsurface. In high-latitude cold regions with permanent snow-cover, the heat transfer is predominantly conductive, whereas in regions with seasonal snow-cover, the heat transfer is mostly non-conductive during periods of phase change. The top layers in regions of no snow-cover, in the domain considered, also exhibit seasonal nonconductive type of heat transfer. The hydrological fields such as snow-cover, precipitation and runoff are also verified against observations over two northern basins. The simulated basin average values of the various hydrological fields agree very well with observations. The closely coupled average energy partitioning and water partitioning are also simulated reasonably well in the model.

  11. Evaluation of a simple, point-scale hydrologic model in simulating soil moisture using the Delaware environmental observing system

    Science.gov (United States)

    Legates, David R.; Junghenn, Katherine T.

    2017-02-01

    Many local weather station networks that measure a number of meteorological variables (i.e., mesonetworks) have recently been established, with soil moisture occasionally being part of the suite of measured variables. These mesonetworks provide data from which detailed estimates of various hydrological parameters, such as precipitation and reference evapotranspiration, can be made which, when coupled with simple surface characteristics available from soil surveys, can be used to obtain estimates of soil moisture. The question is Can meteorological data be used with a simple hydrologic model to estimate accurately daily soil moisture at a mesonetwork site? Using a state-of-the-art mesonetwork that also includes soil moisture measurements across the US State of Delaware, the efficacy of a simple, modified Thornthwaite/Mather-based daily water balance model based on these mesonetwork observations to estimate site-specific soil moisture is determined. Results suggest that the model works reasonably well for most well-drained sites and provides good qualitative estimates of measured soil moisture, often near the accuracy of the soil moisture instrumentation. The model exhibits particular trouble in that it cannot properly simulate the slow drainage that occurs in poorly drained soils after heavy rains and interception loss, resulting from grass not being short cropped as expected also adversely affects the simulation. However, the model could be tuned to accommodate some non-standard siting characteristics.

  12. Modeling Uncertainty of Directed Movement via Markov Chains

    Directory of Open Access Journals (Sweden)

    YIN Zhangcai

    2015-10-01

    Full Text Available Probabilistic time geography (PTG is suggested as an extension of (classical time geography, in order to present the uncertainty of an agent located at the accessible position by probability. This may provide a quantitative basis for most likely finding an agent at a location. In recent years, PTG based on normal distribution or Brown bridge has been proposed, its variance, however, is irrelevant with the agent's speed or divergent with the increase of the speed; so they are difficult to take into account application pertinence and stability. In this paper, a new method is proposed to model PTG based on Markov chain. Firstly, a bidirectional conditions Markov chain is modeled, the limit of which, when the moving speed is large enough, can be regarded as the Brown bridge, thus has the characteristics of digital stability. Then, the directed movement is mapped to Markov chains. The essential part is to build step length, the state space and transfer matrix of Markov chain according to the space and time position of directional movement, movement speed information, to make sure the Markov chain related to the movement speed. Finally, calculating continuously the probability distribution of the directed movement at any time by the Markov chains, it can be get the possibility of an agent located at the accessible position. Experimental results show that, the variance based on Markov chains not only is related to speed, but also is tending towards stability with increasing the agent's maximum speed.

  13. Modeling movement and fidelity of American black ducks

    Science.gov (United States)

    Zimpfer, N.L.; Conroy, M.J.

    2006-01-01

    Spatial relationships among stocks of breeding waterfowl can be an important component of harvest management. Prediction and optimal harvest management under adaptive harvest management (AHM) requires information on the spatial relationships among breeding populations (fidelity and inter-year exchange), as well as rates of movements from breeding to harvest regions. We used band-recovery data to develop a model to estimate probabilities of movement for American black ducks (Anas rubripes) among 3 Canadian breeding strata and 6 harvest regions (3 in Canada, and 3 in the United States) over the period 1965-1998. Model selection criteria suggested that models containing area-, year-, and age-specific recovery rates with area- and sex-specific movement rates were the best for modeling movement. Movement by males to southern harvest areas was variable depending on the originating area. Males from the western breeding area predominantly moved to the Mississippi Flyway or southern Atlantic Flyway (??ij = 0.353, SE = 0.0187 and ??ij = 0.473, SE = 0.037, respectively), whereas males that originated in the eastern and central breeding strata moved to the northern Atlantic flyway (??ij = 0.842, SE = 0.010 and ??ij = 0.578, SE = 0.0222, respectively). We used combined recoveries and recaptures in Program MARK to estimate fidelity to the 3 Canadian breeding strata. Information criteria identified a model containing sex- and age-specific fidelity for black ducks. Estimates of fidelity were 0.9695 (SE = 0.0249) and 0.9554 (SE = 0.0434) for adult males and females, respectively. Estimates of fidelity for juveniles were slightly lower at 0.9210 (SE = 0.0931) and 0.8870 (SE = 0.0475) for males and females, respectively. These models have application to the development of spatially stratified black duck harvest management models for use in AHM.

  14. A Parameterized Inversion Model for Soil Moisture and Biomass from Polarimetric Backscattering Coefficients

    Science.gov (United States)

    Truong-Loi, My-Linh; Saatchi, Sassan; Jaruwatanadilok, Sermsak

    2012-01-01

    A semi-empirical algorithm for the retrieval of soil moisture, root mean square (RMS) height and biomass from polarimetric SAR data is explained and analyzed in this paper. The algorithm is a simplification of the distorted Born model. It takes into account the physical scattering phenomenon and has three major components: volume, double-bounce and surface. This simplified model uses the three backscattering coefficients ( sigma HH, sigma HV and sigma vv) at low-frequency (P-band). The inversion process uses the Levenberg-Marquardt non-linear least-squares method to estimate the structural parameters. The estimation process is entirely explained in this paper, from initialization of the unknowns to retrievals. A sensitivity analysis is also done where the initial values in the inversion process are varying randomly. The results show that the inversion process is not really sensitive to initial values and a major part of the retrievals has a root-mean-square error lower than 5% for soil moisture, 24 Mg/ha for biomass and 0.49 cm for roughness, considering a soil moisture of 40%, roughness equal to 3cm and biomass varying from 0 to 500 Mg/ha with a mean of 161 Mg/ha

  15. Validating modeled soil moisture with in-situ data for agricultural drought monitoring in West Africa

    Science.gov (United States)

    McNally, A.; Yatheendradas, S.; Jayanthi, H.; Funk, C. C.; Peters-Lidard, C. D.

    2011-12-01

    The declaration of famine in Somalia on July 21, 2011 highlights the need for regional hydroclimate analysis at a scale that is relevant for agropastoral drought monitoring. A particularly critical and robust component of such a drought monitoring system is a land surface model (LSM). We are currently enhancing the Famine Early Warning Systems Network (FEWS NET) monitoring activities by configuring a custom instance of NASA's Land Information System (LIS) called the FEWS NET Land Data Assimilation System (FLDAS). Using the LIS Noah LSM, in-situ measurements, and remotely sensed data, we focus on the following question: How can Noah be best parameterized to accurately simulate hydroclimate variables associated with crop performance? Parameter value testing and validation is done by comparing modeled soil moisture against fortuitously available in-situ soil moisture observations in the West Africa. Direct testing and application of the FLDAS over African agropastoral locations is subject to some issues: [1] In many regions that are vulnerable to food insecurity ground based measurements of precipitation, evapotranspiration and soil moisture are sparse or non-existent, [2] standard landcover classes (e.g., the University of Maryland 5 km dataset), do not include representations of specific agricultural crops with relevant parameter values, and phenologies representing their growth stages from the planting date and [3] physically based land surface models and remote sensing rain data might still need to be calibrated or bias-corrected for the regions of interest. This research aims to address these issues by focusing on sites in the West African countries of Mali, Niger, and Benin where in-situ rainfall and soil moisture measurements are available from the African Monsoon Multidisciplinary Analysis (AMMA). Preliminary results from model experiments over Southern Malawi, validated with Normalized Difference Vegetation Index (NDVI) and maize yield data, show that the

  16. Remotely sensed latent heat fluxes for improving model predictions of soil moisture: a case study

    Directory of Open Access Journals (Sweden)

    J. M. Schuurmans

    2010-08-01

    Full Text Available This paper investigates whether the use of remotely sensed latent heat fluxes improves the accuracy of spatially-distributed soil moisture predictions by a hydrological model. By using real data we aim to show the potential and limitations in practice. We use (i satellite data of both ASTER and MODIS for the same two days in the summer of 2006 that, in association with the Surface Energy Balance Algorithm for Land (SEBAL, provides us the spatial distribution of daily ETact and (ii an operational physically based distributed (25 m×25 m hydrological model of a small catchment (70 km2 in The Netherlands that simulates the water flow in both the unsaturated and saturated zone. Firstly, model outcomes of ETact are compared to the processed satellite data. Secondly, we perform data assimilation that updates the modelled soil moisture. We show that remotely sensed ETact is useful in hydrological modelling for two reasons. Firstly, in the procedure of model calibration: comparison of modeled and remotely sensed ETact together with the outcomes of our data assimilation procedure points out potential model errors (both conceptual and flux-related. Secondly, assimilation of remotely sensed ETact results in a realistic spatial adjustment of soil moisture, except for the area with forest and deep groundwater levels. As both ASTER and MODIS images were available for the same days, this study provides also an excellent opportunity to compare the worth of these two satellite sources. It is shown that, although ASTER provides much better insight in the spatial distribution of ETact due to its higher spatial resolution than MODIS, they appeared in this study just as useful.

  17. Mapping Seasonal Evapotranspiration and Root Zone Soil Moisture using a Hybrid Modeling Approach over Vineyards

    Science.gov (United States)

    Geli, H. M. E.

    2015-12-01

    Estimates of actual crop evapotranspiration (ETa) at field scale over the growing season are required for improving agricultural water management, particularly in water limited and drought prone regions. Remote sensing data from multiple platforms such as airborne and Landsat-based sensors can be used to provide these estimates. Combining these data with surface energy balance models can provide ETa estimates at sub- field scale as well as information on vegetation stress and soil moisture conditions. However, the temporal resolution of airborne and Landsat data does not allow for a continuous ETa monitoring over the course of the growing season. This study presents the application of a hybrid ETa modeling approach developed for monitoring daily ETa and root zone available water at high spatial resolutions. The hybrid ETa modeling approach couples a thermal-based energy balance model with a water balance-based scheme using data assimilation. The two source energy balance (TSEB) model is used to estimate instantaneous ETa which can be extrapolated to daily ETa using a water balance model modified to use the reflectance-based basal crop coefficient for interpolating ETa in between airborne and/or Landsat overpass dates. Moreover, since it is a water balance model, the soil moisture profile is also estimated. The hybrid ETa approach is applied over vineyard fields in central California. High resolution airborne and Landsat imagery were used to drive the hybrid model. These images were collected during periods that represented different vine phonological stages in 2013 growing season. Estimates of daily ETa and surface energy balance fluxes will be compared with ground-based eddy covariance tower measurements. Estimates of soil moisture at multiple depths will be compared with measurements.

  18. Combining Spatial and Telemetric Features for Learning Animal Movement Models

    CERN Document Server

    Kapicioglu, Berk; Wikelski, Martin; Broderick, Tamara

    2012-01-01

    We introduce a new graphical model for tracking radio-tagged animals and learning their movement patterns. The model provides a principled way to combine radio telemetry data with an arbitrary set of userdefined, spatial features. We describe an efficient stochastic gradient algorithm for fitting model parameters to data and demonstrate its effectiveness via asymptotic analysis and synthetic experiments. We also apply our model to real datasets, and show that it outperforms the most popular radio telemetry software package used in ecology. We conclude that integration of different data sources under a single statistical framework, coupled with appropriate parameter and state estimation procedures, produces both accurate location estimates and an interpretable statistical model of animal movement.

  19. Modelling of sediment movement in the surf and swash zones

    Institute of Scientific and Technical Information of China (English)

    TOKPOHOZIN N B; KOUNOUHEWA B; AVOSSEVOU G Y H; HOUEKPOHEHAM A; AWANOU C N

    2015-01-01

    Under the action of marine currents, non-cohesive sediments evolve by bed-load, by saltation or suspension depending on their granulometry. Several authors have considered that the movement of sediment is bidimensional and modelized the effects of swell by a constant velocitynear the seabed. Here we have studied the velocity profile of fluctuating currents near the seabed and studied the movement of sediment in 3D. The results show that in the areas of study (surf and swash) the movement of sediment occurs in a volume, and the evolution of sediment varies from an areato another. The obtained theoretical profiles of the position and velocity vectors confirm the observations of several authors.

  20. Learning Predictive Movement Models From Fabric-Mounted Wearable Sensors.

    Science.gov (United States)

    Michael, Brendan; Howard, Matthew

    2016-12-01

    The measurement and analysis of human movement for applications in clinical diagnostics or rehabilitation is often performed in a laboratory setting using static motion capture devices. A growing interest in analyzing movement in everyday environments (such as the home) has prompted the development of "wearable sensors", with the most current wearable sensors being those embedded into clothing. A major issue however with the use of these fabric-embedded sensors is the undesired effect of fabric motion artefacts corrupting movement signals. In this paper, a nonparametric method is presented for learning body movements, viewing the undesired motion as stochastic perturbations to the sensed motion, and using orthogonal regression techniques to form predictive models of the wearer's motion that eliminate these errors in the learning process. Experiments in this paper show that standard nonparametric learning techniques underperform in this fabric motion context and that improved prediction accuracy can be made by using orthogonal regression techniques. Modelling this motion artefact problem as a stochastic learning problem shows an average 77% decrease in prediction error in a body pose task using fabric-embedded sensors, compared to a kinematic model.

  1. From Sub-basin to Grid Scale Soil Moisture Disaggregation in SMART, A Semi-distributed Hydrologic Modeling Framework

    Science.gov (United States)

    Ajami, H.; Sharma, A.

    2016-12-01

    A computationally efficient, semi-distributed hydrologic modeling framework is developed to simulate water balance at a catchment scale. The Soil Moisture and Runoff simulation Toolkit (SMART) is based upon the delineation of contiguous and topologically connected Hydrologic Response Units (HRUs). In SMART, HRUs are delineated using thresholds obtained from topographic and geomorphic analysis of a catchment, and simulation elements are distributed cross sections or equivalent cross sections (ECS) delineated in first order sub-basins. ECSs are formulated by aggregating topographic and physiographic properties of the part or entire first order sub-basins to further reduce computational time in SMART. Previous investigations using SMART have shown that temporal dynamics of soil moisture are well captured at a HRU level using the ECS delineation approach. However, spatial variability of soil moisture within a given HRU is ignored. Here, we examined a number of disaggregation schemes for soil moisture distribution in each HRU. The disaggregation schemes are either based on topographic based indices or a covariance matrix obtained from distributed soil moisture simulations. To assess the performance of the disaggregation schemes, soil moisture simulations from an integrated land surface-groundwater model, ParFlow.CLM in Baldry sub-catchment, Australia are used. ParFlow is a variably saturated sub-surface flow model that is coupled to the Common Land Model (CLM). Our results illustrate that the statistical disaggregation scheme performs better than the methods based on topographic data in approximating soil moisture distribution at a 60m scale. Moreover, the statistical disaggregation scheme maintains temporal correlation of simulated daily soil moisture while preserves the mean sub-basin soil moisture. Future work is focused on assessing the performance of this scheme in catchments with various topographic and climate settings.

  2. On the comparison between the LISFLOOD modelled and the ERS/SCAT derived soil moisture estimates

    Directory of Open Access Journals (Sweden)

    G. Laguardia

    2008-12-01

    Full Text Available In order to evaluate the reliability of the soil moisture product obtained by means of the LISFLOOD hydrological model (De Roo et al., 2000, we compare it to soil moisture estimates derived from ERS scatterometer data (Wagner et al., 1999b.

    Once evaluated the effect of scale mismatch, we calculate the root mean square error and the correlation between the two soil moisture time series on a pixel basis and we assess the fraction of variance that can be explained by a set of input parameter fields that vary from elevation and soil depth to rainfall statistics and missing or snow covered ERS images.

    The two datasets show good agreement over large regions, with 90% of the area having a positive correlation coefficient and 66% having a root mean square error minor than 0.5 pF units. Major inconsistencies are located in mountainous regions such as the Alps or Scandinavia where both the methodologies suffer from insufficiently resolved land surface processes at the given spatial resolution, as well as from limited availability of satellite data on the one hand and the uncertainties in meteorological data retrieval on the other hand.

  3. HYGROSCOPIC MOISTURE SORPTION KINETICS MODELING OF CORN STOVER AND ITS FRACTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Igathinathane, C. [Mississippi State University (MSU); Pordesimo, L. O. [Mississippi State University (MSU); Womac, A.R. [University of Tennessee; Sokhansanj, Shahabaddine [ORNL

    2009-01-01

    Corn stover, a major crop-based lignocellulosic biomass feedstock, is required to be at an optimum moisture content for efficient bioconversion processes. Environmental conditions surrounding corn stover, as in storage facilities, affect its moisture due to hygroscopic sorption or desorption. The measurement and modeling of sorption characteristics of corn stover and its leaf, husk, and stalk fractions are useful from utilization and storage standpoints, hence investigated in this article. A benchtop low-temperature humidity chamber provided the test environments of 20 C, 30 C, and 40 C at a constant 95% relative humidity. Measured sorption characteristics with three replications for each fraction were obtained from instantaneous sample masses and initial moisture contents. Observed sorption characteristics were fitted using exponential, Page, and Peleg models. Corn stover fractions displayed a rapid initial moisture uptake followed by a slower sorption rates and eventually becoming almost asymptotic after 25 h. Sorption characteristics of all corn stover fractions were significantly different (P < 0.0001) but not the effect of temperature (P > 0.05) on these fractions. The initial 30 min of sorption was found to be critical due to peak rates of sorption from storage, handling, and processing standpoints. The Page and Peleg models had comparable performance fitting the sorption curves (R2 = 0.995), however the exponential model (R2 = 0.91) was not found suitable because of patterned residuals. The Arrhenius type relationship (P < 0.05; R2 = 0.80) explained the temperature variation of the fitted sorption model parameters. The Peleg model fitted constants, among the sorption models studied, had the best fit (R2 = 0.93) with the Arrhenius relationship. A developed method of mass proportion, involving individual corn stover fraction dry matter ratios, predicted the whole corn stover sorption characteristics from that of its individual fractions. Sorption

  4. Research on the method for retrieving soil moisture using thermal inertia model

    Institute of Scientific and Technical Information of China (English)

    LIU; Zhenhua; ZHAO; Yingshi

    2006-01-01

    In order to improve accuracy of soil moisture inversion using remote sensing, a new thermal inertia model is proposed in this paper. The improved model needs only surface maximum temperature as the temperature parameter input instead of input of the surface temperature difference, as well as the surface sensible and latent fluxes are introduced into boundary conditions of thermal conductivity equation. Furthermore, surface soil conductive heat transfer equation of two-layer model is used to solve the soil thermal inertia so that the remote sensing thermal inertia method can be applied to regions with better-covered vegetation, but usually only for the bare areas or worse vegetation covered areas. The model has been tested at several locations in the area of west Inner Mongolia. Comparing the simulation of the new model with the measurements obtained by apparent thermal inertia and by field test, the result shows that the inertia thermal model can be used to estimate soil moisture in more reasonable accuracy.

  5. Merging Alternate Remotely-Sensed Soil Moisture Retrievals Using a Non-Static Model Combination Approach

    Directory of Open Access Journals (Sweden)

    Seokhyeon Kim

    2016-06-01

    Full Text Available Soil moisture is an important variable in the coupled hydrologic and climate system. In recent years, microwave-based soil moisture products have been shown to be a viable alternative to in situ measurements. A popular way to measure the performance of soil moisture products is to calculate the temporal correlation coefficient (R against in situ measurements or other appropriate reference datasets. In this study, an existing linear combination method improving R was modified to allow for a non-static or nonstationary model combination as the basis for improving remotely-sensed surface soil moisture. Previous research had noted that two soil moisture products retrieved using the Japan Aerospace Exploration Agency (JAXA and Land Parameter Retrieval Model (LPRM algorithms from the same Advanced Microwave Scanning Radiometer 2 (AMSR2 sensor are spatially complementary in terms of R against a suitable reference over a fixed period. Accordingly, a linear combination was proposed to maximize R using a set of spatially-varying, but temporally-fixed weights. Even though this approach showed promising results, there was room for further improvements, in particular using non-static or dynamic weights that take account of the time-varying nature of the combination algorithm being approximated. The dynamic weighting was achieved by using a moving window. A number of different window sizes was investigated. The optimal weighting factors were determined for the data lying within the moving window and then used to dynamically combine the two parent products. We show improved performance for the dynamically-combined product over the static linear combination. Generally, shorter time windows outperform the static approach, and a 60-day time window is suggested to be the optimum. Results were validated against in situ measurements collected from 124 stations over different continents. The mean R of the dynamically-combined products was found to be 0.57 and 0

  6. Modelling of moisture adsorption for sugar palm (Arenga pinnata) starch film

    Science.gov (United States)

    Jatmiko, Tri Hadi; Poeloengasih, Crescentiana D.; Prasetyo, Dwi Joko; Hernawan

    2017-03-01

    Sorption characteristic of food products is important for design, optimization, storage and modelling. Sugar palm starch film with two different plasticizers (sorbitol and glycerol) with varied concentration studied for its adsorption isotherm characteristic. The data of adsorption isotherm fitted with GAB, Oswin, Smith and Peleg models. All models describe the experiment data well, but Peleg model is better than the other models on both sugar palm starch film plasticized with sorbitol and glycerol. Moisture sorption of sugar palm starch increased linearly with plasticizer concentration. A new model by taking account of plasticizer concentration describes the experiment data well with an average of coefficients of determination (R2) 0.9913 and 0.9939 for film plasticized with glycerol and sorbitol respectively.

  7. Calibration of soil moisture flow simulation models aided by the active heated fiber optic distributed temperature sensing AHFO

    Science.gov (United States)

    Rodriguez-Sinobas, Leonor; Zubelzu, Sergio; Sobrino, Fernando Fernando; Sánchez, Raúl

    2017-04-01

    Most of the studies dealing with the development of water flow simulation models in soils, are calibrated using experimental data measured by soil probe sensors or tensiometers which locate at specific points in the study area. However since the beginning of the XXI century, the use of Distributed Fiber Optic Temperature Measurement for estimating temperature variation along a cable of fiber optic has been assessed in multiple environmental applications. Recently, its application combined with an active heating pulses technique (AHFO) has been reported as a sensor to estimate soil moisture. This method applies a known amount of heat to the soil and monitors the temperature evolution, which mainly depends on the soil moisture content. Thus, it allows estimations of soil water content every 12.5 cm along the fiber optic cable, as long as 1500 m , with 2 % accuracy , every second. This study presents the calibration of a soil water flow model (developed in Hydrus 2D) with the AHFO technique. The model predicts the distribution of soil water content of a green area irrigated by sprinkler irrigation. Several irrigation events have been evaluated in a green area located at the ETSI Agronómica, Agroalimentaria y Biosistemas in Madrid where an installation of 147 m of fiber optic cable at 15 cm depth is deployed. The Distribute Temperature Sensing unit was a SILIXA ULTIMA SR (Silixa Ltd, UK) and has spatial and temporal resolution of 0.29 m. Data logged in the DTS unit before, during and after the irrigation event were used to calibrate the estimations in the Hydrus 2D model during the infiltration and redistribution of soil water content within the irrigation interval. References: Karandish, F., & Šimůnek, J. (2016). A field-modeling study for assessing temporal variations of soil-water-crop interactions under water-saving irrigation strategies. Agricultural Water Management, 178, 291-303. Li, Y., Šimůnek, J., Jing, L., Zhang, Z., & Ni, L. (2014). Evaluation of

  8. MODELING MOISTURE DIFFUSIVITY AND ENERGY CONSUMPTION OF CANTALOUPE SEEDS IN FIXED AND FLUIDIZED BED CONDITIONS

    Directory of Open Access Journals (Sweden)

    Reza Amiri Chayjan

    2012-12-01

    Full Text Available   Background.The main goal in cantaloupe seed drying is the reduction of its moisture content to a safe level, allowing storage in a long period of time. Fluidized bed dryer is a drying process with better heat and mass transfer and shorter drying time. This method is a gentle and uniform drying procedure. Fluidized bed is suitable for sensitive and high moisture materials. Drying parameters of moisture diffusivity and energy are vitally important in modelling and optimizing of the seed dryer system. Material and methods. This study investigated thin layer characteristics of cantaloupe seeds under fixed, semi fluidized and fluidized bed drying with initial moisture content about 61.99% (d.b.. A laboratory fluid- ized bed dryer was utilized in this research. Air temperature levels of 45, 55, 65 and 75°C were applied in drying experiments. Effective moisture diffusivity (Deff of cantaloupe seeds was computed by Fick’s second law in diffusion. Activation energy and specific energy consumption of cantaloupe seeds under different drying conditions were calculated. Results.Calculated values of Deff for drying experiments were in the range of 2.23·10-10and 8.61·10-10m2/s. Values of Deff increased as the input air temperature increased. Activation energy values were computed be- tween 39.21 and 37.55 kJ/mol for 45°C to 75°C, respectively. Specific energy consumption for cantaloupe seeds was calculated at the boundary of 1.58·105and 6.18·105kJ/kg. Conclusion.Results indicated that applying the fluidized bed condition is more effective for convective drying of cantaloupe seeds. Increasing air velocity tends to decrease in activation energy. Decreasing in drying air temperature in different bed conditions caused increase in the energy value. The aforesaid drying parameters are necessary to optimize the operational condition of fluidized bed dryer and to perfect design of the system.  

  9. A simple moisture advection model of specific humidity change over land in response to SST warming

    Science.gov (United States)

    Chadwick, Robin; Good, Peter; Willett, Kate

    2017-04-01

    A new, simple conceptual model of surface specific humidity change (∆q) over land has been developed, based on the effect of increased moisture advection from the oceans in response to sea surface temperature (SST) warming. In this model, future q over land is determined by scaling the present-day pattern of land q by the fractional increase in the oceanic moisture source. Simple model estimates agree well with climate model projections of future ∆q (mean spatial correlation coefficient 0.87), so ∆q over both land and ocean can be viewed primarily as a thermodynamic process controlled by SST warming. Precipitation change (∆P) is also affected by ∆q, and the new simple model can be included in a decomposition of tropical precipitation change, where it provides increased physical understanding of the processes that drive ∆P over land. Confidence in the thermodynamic part of extreme precipitation change over land is increased by this improved understanding, and this should scale approximately with Clausius-Clapeyron oceanic q increases under SST warming. Residuals between actual climate model ∆q and simple model estimates are often associated with regions of large circulation change, and can be thought of as the 'dynamical' part of specific humidity change. The simple model is used to explore inter-model uncertainty in ∆q, and there are substantial contributions to uncertainty from both the thermodynamic (simple model) and 'dynamical' (residual) terms. The largest cause of inter-model uncertainty within the thermodynamic term is uncertainty in the magnitude of global mean SST warming.

  10. Phenylalanine ab initio models for the simulation of skin natural moisturizing factor

    Science.gov (United States)

    Carvalho, B. G.; Raniero, L. J.; Martin, A. A.; Favero, P. P.

    2013-04-01

    In this study, we evaluated models that can be used to simulate amino acids in biological environments via density functional theory (DFT). The goal was to obtain realistic representations that combine computational economy and result quality when compared to experimental data. We increased the complexity of the models by using a model of an amino acid in a vacuum, followed by a water-solvated amino acid model. To consider pH variation, we simulated zwitterionic and nonionic amino acid configurations. The amino acid chosen for testing was phenylalanine, an aromatic amino acid present in high concentrations in the natural moisturizing factor of skin that plays a fundamental role in ultraviolet protection and vitiligo disease. To validate the models, vibrational modes and electronic properties were calculated and compared to experimental results.

  11. Monitoring Soil Moisture Deficit Effects on Vegetation Parameters Using Radiative Transfer Models Inversion and Hyperspectral Measurements Under Controlled Conditions

    Science.gov (United States)

    Bayat, Bagher; Van der Tol, Christiaan; Verhoef, Wouter

    2016-08-01

    Plant-available soil moisture is a key element which affects plant properties in their ecosystems. This study shows Poa pratensis -a species of grass- responses to soil moisture deficit during an artificial drought episode in a greenhouse experiment. We used radiative transfer model inversion to monitor the gradual manifestation of soil moisture deficit effects on vegetation in a laboratory setting. Plots of 21 cm x 14.5 cm surface area with Poa pratensis plants that formed a closed canopy were subjected to water stress for 40 days. In a regular weekly schedule, canopy reflectance was measured. The 1-D bidirectional canopy reflectance model SAIL, coupled with the leaf optical properties model PROSPECT, was inverted using hyperspectral measurements by means of an iterative optimization method to retrieve vegetation biophysical and biochemical parameters (mainly; LAI, Cab, Cw, Cdm and Cs). The relationships between these retrieved parameters with soil moisture content were established in two separated groups; stress and non-stressed. All parameters retrieved by model inversion using canopy spectral data showed good correlation with soil moisture content in the drought episode. These parameters co- varied with soil moisture content under the stress condition (Chl: R2= 0.91, Cw: R2= 0.97, Cs: R2= 0.88 and LAI: R2=0.48) at the canopy level.

  12. Moisture-related mechanical properties of softwood: 3D micromechanical modeling

    DEFF Research Database (Denmark)

    Qing, Hai; Mishnaevsky, Leon

    2009-01-01

    Computational micromechanical analysis of the influence of moisture, density and microstructure of latewood on its hydroelastic and shrinkage properties is carried out. The elastic properties of cell sublayers have been determined using the unit cell models as for fiber reinforced composites (two...... increase with increasing MFAs in layer S2, while the reverse is true in the transverse plane. The shrinkage coefficients of wood depend strongly on the shape of the hexagon-shaped cells. Wood density has a strong effect on both the Young’s modulus and the transverse Young’s modulus....

  13. Human Posture and Movement Prediction based on Musculoskeletal Modeling

    DEFF Research Database (Denmark)

    Farahani, Saeed Davoudabadi

    2014-01-01

    Abstract This thesis explores an optimization-based formulation, so-called inverse-inverse dynamics, for the prediction of human posture and motion dynamics performing various tasks. It is explained how this technique enables us to predict natural kinematic and kinetic patterns for human posture...... and motion using AnyBody Modeling System (AMS). AMS uses inverse dynamics to analyze musculoskeletal systems and is, therefore, limited by its dependency on input kinematics. We propose to alleviate this dependency by assuming that voluntary postures and movement strategies in humans are guided by a desire...... investigated, a scaling to the mean height and body mass may be sufficient, while other questions require subject-specific models. The movement is parameterized by means of time functions controlling selected degrees-of-freedom (DOF). Subsequently, the parameters of these functions, usually referred...

  14. Robust Initial Wetness Condition Framework of an Event-Based Rainfall–Runoff Model Using Remotely Sensed Soil Moisture

    Directory of Open Access Journals (Sweden)

    Wooyeon Sunwoo

    2017-01-01

    Full Text Available Runoff prediction in limited-data areas is vital for hydrological applications, such as the design of infrastructure and flood defenses, runoff forecasting, and water management. Rainfall–runoff models may be useful for simulation of runoff generation, particularly event-based models, which offer a practical modeling scheme because of their simplicity. However, there is a need to reduce the uncertainties related to the estimation of the initial wetness condition (IWC prior to a rainfall event. Soil moisture is one of the most important variables in rainfall–runoff modeling, and remotely sensed soil moisture is recognized as an effective way to improve the accuracy of runoff prediction. In this study, the IWC was evaluated based on remotely sensed soil moisture by using the Soil Conservation Service-Curve Number (SCS-CN method, which is one of the representative event-based models used for reducing the uncertainty of runoff prediction. Four proxy variables for the IWC were determined from the measurements of total rainfall depth (API5, ground-based soil moisture (SSMinsitu, remotely sensed surface soil moisture (SSM, and soil water index (SWI provided by the advanced scatterometer (ASCAT. To obtain a robust IWC framework, this study consists of two main parts: the validation of remotely sensed soil moisture, and the evaluation of runoff prediction using four proxy variables with a set of rainfall–runoff events in the East Asian monsoon region. The results showed an acceptable agreement between remotely sensed soil moisture (SSM and SWI and ground based soil moisture data (SSMinsitu. In the proxy variable analysis, the SWI indicated the optimal value among the proposed proxy variables. In the runoff prediction analysis considering various infiltration conditions, the SSM and SWI proxy variables significantly reduced the runoff prediction error as compared with API5 by 60% and 66%, respectively. Moreover, the proposed IWC framework with

  15. Calibration Of Hydrological Models Based On Remotely Sensed Soil Moisture And Evapotranspiration

    Science.gov (United States)

    Lopez, P.; Strohmeier, S.; Sutanudjaja, E.; Haddad, M.; Karrou, M.; Sterk, G.; Schellekens, J.; Bierkens, M. F.

    2016-12-01

    The increasing water demand over recent decades together with the climate change impacts on water resources, especially in dry areas, may lead to growing problems with water availability. Investigating and developing novel strategies to assess and manage water resources have turned into a key issue, leading to increasing efforts to enhance and improve hydrological models and datasets. Despite campaigns to increase the quality and the temporal and spatial availability of ground-based hydro-meteorological data, many river basins around the world, including the Oum Er Rbia in Morocco, still have a limited number of in-situ observations. This in turn limits the application of hydrological models. Recently developed global earth observation products may unlock a greater capability of basin scale hydrological modeling for advanced water management. This study aims to evaluate the applicability of earth observation products for hydrological model simulation in comparison with in-situ data for water resources management and water allocation of the Moroccan Oum Er Rbia river basin. Two different hydrological models (SWAT and PCR-GLOBWB) were applied to inter-compare various combinations of in-situ and global earth observation data. Global earth observation products were obtained from various sources including meteorological data from the WATCH Forcing Data methodology applied to ERA-Interim reanalysis data and the Multi-Source Weighted-Ensemble Precipitation (MSWEP); the remotely sensed ESA CCI surface soil moisture Soil Water Index combined product and the GLEAM evapotranspiration data from satellite-based observations. The daily data were provided for the time period from 1979 to 2012. Due to insufficient in-situ discharge observations available in the basin, local calibration of both hydrological models was based on global evapotranspiration and soil moisture data, covering additional aspects of the hydrological cycle to further reduce modeling uncertainty. Preliminary

  16. Calibration of a geophysically based model using soil moisture measurements in mountainous terrains

    Science.gov (United States)

    Pellet, Cécile; Hilbich, Christin; Marmy, Antoine; Hauck, Christian

    2016-04-01

    The use of geophysical methods in the field of permafrost research is well established and crucial since it is the only way to infer the composition of the subsurface material. Since geophysical measurements are indirect, ambiguities in the interpretation of the results can arise, hence the simultaneous use of several methods (e.g. electrical resistivity tomography and refraction seismics) is often necessary. The so-called four-phase model, 4PM (Hauck et al., 2011) constitutes a further step towards clarification of interpretation from geophysical measurements. It uses two well-known petrophysical relationships, namely Archie's law and an extension of Timur's time-averaged equation for seismic P-wave velocities, to quantitatively estimate the different phase contents (air, water and ice) in the ground from tomographic electric and seismic measurements. In this study, soil moisture measurements were used to calibrate the 4PM in order to assess the spatial distribution of water, ice and air content in the ground at three high elevation sites with different ground properties and thermal regimes. The datasets used here were collected as part of the SNF-project SOMOMOUNT. Within the framework of this project a network of six entirely automated soil moisture stations was installed in Switzerland along an altitudinal gradient ranging from 1'200 m. a.s.l. to 3'400 m. a.s.l. The standard instrumentation of each station comprises the installation of Frequency Domain Reflectometry (FDR) and Time Domain Reflectometry (TDR) sensors for long term monitoring coupled with repeated Electrical Resistivity Tomography (ERT) and Refraction Seismic Tomography (RST) as well as spatial FDR (S-FDR) measurements. The use of spatially distributed soil moisture data significantly improved the 4PM calibration process and a semi-automatic calibration scheme was developed. This procedure was then tested at three different locations, yielding satisfactory two dimensional distributions of water

  17. The importance of spatial resolution and convective parameterisation in modelling soil moisture - precipitation feedbacks

    Science.gov (United States)

    Garcia-Carreras, Luis; Taylor, Christopher M.; Roberts, Malcolm; Marsham, John H.

    2017-04-01

    Soil moisture influences low-level temperature and humidity, which can strongly affect convective development. The location of convection in turn alters the soil moisture anomalies present on the following day, providing a feedback mechanism. Satellite observations show that in the tropics afternoon rainfall falls preferentially where the ground is drier than its surroundings. A large number of global weather and climate models, on the other hand, show a positive soil moisture - rainfall feedback, inconsistent with observations. This systematic bias will tend to exaggerate drought impacts in global atmospheric models, and points to missing fundamental processes in the models related to the coupling between the surface and convection. While the source of this error is still unclear, it has been hypothesized that the triggering of parameterisations of convection is excessively sensitive to low-level moisture, leading to convection initiating preferentially over wet soils. Here we quantify the soil-moisture - precipitation feedback sign using the same method as in Taylor et al. (Nature, 2012), which is now part of the ESMValTool model evaluation toolbox. We analyse multi-year global simulations using the Met Office Unified Model (MetUM) with different resolutions and representations of convection. Three simulations are run at 15 km grid-spacing with different representations of convection: 1. the standard operational MetUM parameterisation scheme, 2. 'convection permitting', where the parameterisations of shallow and deep convection are turned off, and 3. only the parameterisation of shallow convection is turned on. The use of the same resolution and setup, except for the representation of convection, allows us to exclude any effects from changing resolution. Additional simulations at 30, 50 and 150 km grid-spacings using the standard MetUM parameterisation of convection scheme are then used to explore the impact of resolution. All simulations show daytime

  18. Downscaling Soil Moisture in the Southern Great Plains Through a Calibrated Multifractal Model for Land Surface Modeling Applications

    Science.gov (United States)

    Mascaro, Giuseppe; Vivoni, Enrique R.; Deidda, Roberto

    2010-01-01

    Accounting for small-scale spatial heterogeneity of soil moisture (theta) is required to enhance the predictive skill of land surface models. In this paper, we present the results of the development, calibration, and performance evaluation of a downscaling model based on multifractal theory using aircraft!based (800 m) theta estimates collected during the southern Great Plains experiment in 1997 (SGP97).We first demonstrate the presence of scale invariance and multifractality in theta fields of nine square domains of size 25.6 x 25.6 sq km, approximately a satellite footprint. Then, we estimate the downscaling model parameters and evaluate the model performance using a set of different calibration approaches. Results reveal that small-scale theta distributions are adequately reproduced across the entire region when coarse predictors include a dynamic component (i.e., the spatial mean soil moisture ) and a stationary contribution accounting for static features (i.e., topography, soil texture, vegetation). For wet conditions, we found similar multifractal properties of soil moisture across all domains, which we ascribe to the signature of rainfall spatial variability. For drier states, the theta fields in the northern domains are more intermittent than in southern domains, likely because of differences in the distribution of vegetation coverage. Through our analyses, we propose a regional downscaling relation for coarse, satellite-based soil moisture estimates, based on ancillary information (static and dynamic landscape features), which can be used in the study area to characterize statistical properties of small-scale theta distribution required by land surface models and data assimilation systems.

  19. Moisture Transport in Wood

    DEFF Research Database (Denmark)

    Astrup, T.; Hansen, K. K.; Hoffmeyer, P.

    2005-01-01

    Modelling of moisture transport in wood is of great importance as most mechanical and physical properties of wood depend on moisture content. Moisture transport in porous materials is often described by Ficks second law, but several observations indicate that this does not apply very well to wood....... Recently at the Technical University of Denmark, Department of Civil Engineering, a new model for moisture transport in wood has been developed. The model divides the transport into two phases, namely water vapour in the cell lumens and bound water in the cell walls....

  20. Moisture Transport in Wood

    DEFF Research Database (Denmark)

    Astrup, T.; Hansen, K. K.; Hoffmeyer, P.;

    2005-01-01

    Modelling of moisture transport in wood is of great importance as most mechanical and physical properties of wood depend on moisture content. Moisture transport in porous materials is often described by Ficks second law, but several observations indicate that this does not apply very well to wood....... Recently at the Technical University of Denmark, Department of Civil Engineering, a new model for moisture transport in wood has been developed. The model divides the transport into two phases, namely water vapour in the cell lumens and bound water in the cell walls....

  1. What do moisture recycling estimates tell? Lessons from an extreme global land-cover change model experiment

    Directory of Open Access Journals (Sweden)

    H. F. Goessling

    2011-04-01

    Full Text Available Moisture evaporated from the continents (recycled moisture contributes up to 80% to the total atmospheric moisture content and, hence, precipitation in some regions. Recycling estimates are traditionally used to indicate a region's rainfall-dependence on land-surface evaporation. Accordingly, recycling estimates are employed to deduce the hydrological consequences of land-cover change. However, moisture is not a passive but an active constituent of the atmosphere. Recent studies indicate that at small scales (up to 1000 km local to regional evaporation-precipitation coupling by far dominates the atmospheric precipitation response, while the water-balance effect from moisture recycling in the traditional sense seems to be of minor importance. The value of moisture recycling estimates as indicator for consequences of land-cover change is therefore questionable. However, since atmospheric moisture is still subject to mass conservation, the relevance of moisture recycling may come into play at the continental scale.

    To explore the relevance of recycling estimates regarding land-cover change at the continental scale, we conduct two global experiments with an atmospheric general circulation model: (I with present-day conditions and (II with extreme land-cover change conditions, namely with totally suppressed continental evaporation. Using the simulated fields of moisture, wind, and evaporation from the present-day experiment, we quantify continental moisture recycling with a vertically integrating tracing scheme. We then compare the computed recycling patterns with the hydrological changes that follow the suppression of continental evaporation.

    While under present-day conditions the fraction of recycled moisture increases from continental upstream to downstream regions with respect to the prevailing winds, the suppression of continental evaporation leads to severe precipitation loss in almost all continental regions, no matter if

  2. Moisture Flux Convergence in Regional and Global Climate Models: Implications for Droughts in the Southwestern United States Under Climate Change

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Yanhong; Leung, Lai-Yung R.; Salathe, E.; Dominguez, Francina; Nijssen, Bart; Lettenmaier, D. P.

    2012-05-10

    The water cycle of the southwestern United States (SW) is dominated by winter storms that maintain a positive annual net precipitation. Analysis of the control and future climate from four pairs of regional and global climate models (RCMs and GCMs) shows that the RCMs simulate a higher fraction of transient eddy moisture fluxes because the hydrodynamic instabilities associated with flow over complex terrain are better resolved. Under global warming, this enables the RCMs to capture the response of transient eddies to increased atmospheric stability that allows more moisture to converge on the windward side of the mountains by blocking. As a result, RCMs simulate enhanced transient eddy moisture convergence in the SW compared to GCMs, although both robustly simulate drying due to enhanced moisture divergence by the divergent mean flow in a warmer climate. This enhanced convergence leads to reduced susceptibility to hydrological change in the RCMs compared to GCMs.

  3. Modeling Surface Roughness to Estimate Surface Moisture Using Radarsat-2 Quad Polarimetric SAR Data

    Science.gov (United States)

    Nurtyawan, R.; Saepuloh, A.; Budiharto, A.; Wikantika, K.

    2016-08-01

    Microwave backscattering from the earth's surface depends on several parameters such as surface roughness and dielectric constant of surface materials. The two parameters related to water content and porosity are crucial for estimating soil moisture. The soil moisture is an important parameter for ecological study and also a factor to maintain energy balance of land surface and atmosphere. Direct roughness measurements to a large area require extra time and cost. Heterogeneity roughness scale for some applications such as hydrology, climate, and ecology is a problem which could lead to inaccuracies of modeling. In this study, we modeled surface roughness using Radasat-2 quad Polarimetric Synthetic Aperture Radar (PolSAR) data. The statistical approaches to field roughness measurements were used to generate an appropriate roughness model. This modeling uses a physical SAR approach to predicts radar backscattering coefficient in the parameter of radar configuration (wavelength, polarization, and incidence angle) and soil parameters (surface roughness and dielectric constant). Surface roughness value is calculated using a modified Campbell and Shepard model in 1996. The modification was applied by incorporating the backscattering coefficient (σ°) of quad polarization HH, HV and VV. To obtain empirical surface roughness model from SAR backscattering intensity, we used forty-five sample points from field roughness measurements. We selected paddy field in Indramayu district, West Java, Indonesia as the study area. This area was selected due to intensive decreasing of rice productivity in the Northern Coast region of West Java. Third degree polynomial is the most suitable data fitting with coefficient of determination R2 and RMSE are about 0.82 and 1.18 cm, respectively. Therefore, this model is used as basis to generate the map of surface roughness.

  4. DO3SE modelling of soil moisture to determine ozone flux to European forest trees

    Directory of Open Access Journals (Sweden)

    M. Schaub

    2011-12-01

    Full Text Available The DO3SE (Deposition of O3 for Stomatal Exchange model is an established tool for estimating ozone (O3 deposition, stomatal flux and impacts to a variety of vegetation types across Europe. It has been embedded within the EMEP (European Monitoring and Evaluation Programme photochemical model to provide a policy tool capable of relating the risk of vegetation damage to O3 precursor emission scenarios for use in policy formulation. A key limitation of regional flux-based risk assessments so far has been the approximation that soil water deficits are not limiting O3 flux due to the unavailability of evaluated methods for modelling soil water deficits and their influence on stomatal conductance (gsto, and ultimately O3 flux. This paper describes the development and evaluation of a method to estimate soil moisture status and its influence on gsto for a variety of forest tree species. The soil moisture module uses the Penman-Monteith energy balance method to drive water cycling through the soil-plant-atmosphere system and empirical data describing gsto relationships with pre-dawn leaf water status to estimate the biological control of transpiration. We trial four different methods to estimate this biological control of the transpiration stream, which vary from simple methods that relate soil water content or potential directly to gsto to more complex methods that incorporate hydraulic resistance and plant capacitance that control water flow through the plant system. These methods are evaluated against field data describing a variety of soil water variables, gsto and transpiration data for Norway spruce (Picea abies, Scots pine (Pinus sylvestris, birch (Betula pendula, aspen (Populus tremuloides, beech (Fagus sylvatica and holm oak (Quercus ilex collected from ten sites across Europe and North America. Modelled estimates of these variables show consistency with observed data when applying the simple empirical methods, with the timing and magnitude of

  5. Train Control System Formalization Modeling oriented Movement Authority

    Directory of Open Access Journals (Sweden)

    Xiaoming Wang

    2012-09-01

    Full Text Available Chinese Train Control System-3(CTCS-3 was integrated via various control system devices, assurance of CTCS-3 system transmission probability relied on empirical judgment, it is necessary to form its formalization to support integration for system stability of the whole CTCS-3. Movement Authority(MA acts on the whole information process of CTCS-3 to control train, its process properties can be as the reflection of CTCS probability. Aiming at that,  paper selected MA as the objective, proposed MA-oriented CTCS-3 formalization modeling. Paper designed generation and transmission algorithms of MA, formed MA computation models for application functions. Based on computation models, paper constructed MA hierarchical Colored Petri Nets(CPN models, and completed MA timed CPN model, the report and experimental result demonstrate that the model proposed is effective and can reflect CTCS-3 system properties accurately. 

  6. Field measurements, simulation modeling and development of analysis for moisture stressed corn and soybeans, 1982 studies

    Science.gov (United States)

    Blad, B. L.; Norman, J. M.; Gardner, B. R.

    1983-01-01

    The experimental design, data acquisition and analysis procedures for agronomic and reflectance data acquired over corn and soybeans at the Sandhills Agricultural Laboratory of the University of Nebraska are described. The following conclusions were reached: (1) predictive leaf area estimation models can be defined which appear valid over a wide range of soils; (2) relative grain yield estimates over moisture stressed corn were improved by combining reflectance and thermal data; (3) corn phenology estimates using the model of Badhwar and Henderson (1981) exhibited systematic bias but were reasonably accurate; (4) canopy reflectance can be modelled to within approximately 10% of measured values; and (5) soybean pubescence significantly affects canopy reflectance, energy balance and water use relationships.

  7. Hidden Markov modelling of movement data from fish

    DEFF Research Database (Denmark)

    Pedersen, Martin Wæver

    Movement data from marine animals tagged with electronic tags are becoming increasingly diverse and plentiful. This trend entails a need for statistical methods that are able to filter the observations to extract the ecologically relevant content. This dissertation focuses on the development...... state HMM is employed to deal with this task. Specifically, the continuous horizontal plane is discretised into grid cells, which enables a state-space model for the geographical location to be estimated on this grid. The estimation model for location is extended with an additional state representing...

  8. Lipid and moisture content modeling of amphidromous Dolly Varden using bioelectrical impedance analysis

    Science.gov (United States)

    Stolarski, J.T.; Margraf, F.J.; Carlson, J.G.; Sutton, T.M.

    2014-01-01

    The physiological well-being or condition of fish is most commonly estimated from aspects of individual morphology. However, these metrics may be only weakly correlated with nutritional reserves stored as lipid, the primary form of accumulated energy in fish. We constructed and evaluated bioelectrical impedance analysis (BIA) models as an alternative method of assessing condition in amphidromous Dolly Varden Salvelinus malma collected from nearshore estuarine and lotic habitats of the Alaskan Arctic. Data on electrical resistance and reactance were collected from the lateral and ventral surfaces of 192 fish, and whole-body percent lipid and moisture content were determined using standard laboratory methods. Significant inverse relationships between temperature and resistance and reactance prompted the standardization of these data to a constant temperature using corrective equations developed herein. No significant differences in resistance or reactance were detected among spawning and nonspawning females after accounting for covariates, suggesting that electrical pathways do not intersect the gonads. Best-fit BIA models incorporating electrical variables calculated from the lateral and ventral surfaces produced the strongest associations between observed and model-predicted estimates of proximate content. These models explained between 6% and 20% more of the variability in laboratory-derived estimates of proximate content than models developed from single-surface BIA data and 32% more than models containing only length and weight data. While additional research is required to address the potential effects of methodological variation, bioelectrical impedance analysis shows promise as a way to provide high-quality, minimally invasive estimates of Dolly Varden lipid or moisture content in the field with only small increases in handling time.

  9. Calibrating a large-extent high-resolution coupled groundwater-land surface model using soil moisture and discharge data

    NARCIS (Netherlands)

    Sutanudjaja, E.H.; Beek, L.P.H. van; Jong, S.M. de; Geer, F.C. van; Bierkens, M.F.P.

    2014-01-01

    We explore the possibility of using remotely sensed soil moisture data and in situ discharge observations to calibrate a large-extent hydrological model. The model used is PCR-GLOBWB-MOD, which is a physically based and fully coupled groundwater-land surface model operating at a daily basis and havi

  10. Modeling rapid mass movements using the shallow water equations

    Directory of Open Access Journals (Sweden)

    S. Hergarten

    2014-11-01

    Full Text Available We propose a new method to model rapid mass movements on complex topography using the shallow water equations in Cartesian coordinates. These equations are the widely used standard approximation for the flow of water in rivers and shallow lakes, but the main prerequisite for their application – an almost horizontal fluid table – is in general not satisfied for avalanches and debris flows in steep terrain. Therefore, we have developed appropriate correction terms for large topographic gradients. In this study we present the mathematical formulation of these correction terms and their implementation in the open source flow solver GERRIS. This novel approach is evaluated by simulating avalanches on synthetic and finally natural topographies and the widely used Voellmy flow resistance law. The results are tested against analytical solutions and the commercial avalanche model RAMMS. The overall results are in excellent agreement with the reference system RAMMS, and the deviations between the different models are far below the uncertainties in the determination of the relevant fluid parameters and involved avalanche volumes in reality. As this code is freely available and open source, it can be easily extended by additional fluid models or source areas, making this model suitable for simulating several types of rapid mass movements. It therefore provides a valuable tool assisting regional scale natural hazard studies.

  11. MODIS Inundation Estimate Assimilation into Soil Moisture Accounting Hydrologic Model: A Case Study in Southeast Asia

    Directory of Open Access Journals (Sweden)

    Ari Posner

    2014-11-01

    Full Text Available Flash Flood Guidance consists of indices that estimate the amount of rain of a certain duration that is needed over a given small basin in order to cause minor flooding. Backwater catchment inundation from swollen rivers or regional groundwater inputs are not significant over the spatial and temporal scales for the majority of upland flash flood prone basins, as such, these effects are not considered. However, some lowland areas and flat terrain near large rivers experience standing water long after local precipitation has ceased. NASA is producing an experimental product from the MODIS that detects standing water. These observations were assimilated into the hydrologic model in order to more accurately represent soil moisture conditions within basins, from sources of water from outside of the basin. Based on the upper soil water content, relations are used to derive an error estimate for the modeled soil saturation fraction; whereby, the soil saturation fraction model state can be updated given the availability of satellite observed inundation. Model error estimates were used in a Monte Carlo ensemble forecast of soil water and flash flood potential. Numerical experiments with six months of data (July 2011–December 2011 showed that MODIS inundation data, when assimilated to correct soil moisture estimates, increased the likelihood that bankfull flow would occur, over non-assimilated modeling, at catchment outlets for approximately 44% of basin-days during the study time period. While this is a much more realistic representation of conditions, no actual events occurred allowing for validation during the time period.

  12. Mold appearance and modeling on selected corn stover components during moisture sorption.

    Science.gov (United States)

    Igathinathane, C; Womac, A R; Pordesimo, L O; Sokhansanj, S

    2008-09-01

    Occurrence of mold was visually monitored for 26days on samples of major anatomical components of corn stover maintained at several storage temperatures (T) and water activities (a(w)). Glass desiccators with saturated salt solutions placed in temperature controlled chambers provided simulated storage conditions with temperatures ranging from 10 degrees C to 40 degrees C and water activities ranging from 0.11 to 0.98. Mold affected leaf, stalk skin, and stalk pith equally at water activity greater than 0.9. As expected, a combination of increased water activity greater than 0.9 and temperatures greater than 30 degrees C was conducive to mold growth. Based on material moisture content during the initial mold growth, it was postulated that among the corn stover components the stalk pith was the least resistant to mold growth followed by stalk skin and leaf for the studied range of temperature and water activity. Mold growth models fitted well with the observation. A linear mold-free days predictions using a three-parameter regression model (T, a(w), and T x a(w)) was superior (R(2)=0.99) to other models considered. The exponential spoilage model using two parameter T and a(w) also gave comparable performance (R(2)=0.95). Among the independent factors, T x a(w) product was the most significant (p=0.0069) followed by T (p=0.0114), and a(w) (p=0.3140) in explaining the experimental data. The developed models can be applied to predict the safe storage period of corn stover components exposed to various temperature and moisture environmental conditions.

  13. Simplified floor-area-based energy-moisture-economic model for residential buildings

    Science.gov (United States)

    Martinez, Luis A.

    In the United States, 21% of all energy is used in residential buildings (40% of which is for heating and cooling homes). Promising improvements in residential building energy efficiency are underway such as the Building America Program and the Passive House Concept. The ability of improving energy efficiency in buildings is enhanced by building energy modeling tools, which are well advanced and established but lack generality (each building has to be modeled individually) and require high cost, which limits many residential buildings from taking advantage of such powerful tools. This dissertation attempts to develop guidelines based on a per-building-floor-area basis for designing residential buildings that achieve maximum energy efficiency and minimum life cycle cost. Energy and moisture-mass conservation principles were formulated for residential buildings on a per-building-floor-area basis. This includes thermal energy balance, moisture-mass conservation and life cycle cost. The analysis also includes the effects of day-lighting, initial cost estimation and escalation rates. The model was implemented on Excel so it is available for broader audiences and was validated using the standard BESTEST validation procedure for energy models yielding satisfactory results for different scenarios, within a 90% confidence interval. Using the model, parametric optimization studies were conducted in order to study how each variable affects energy and life cycle cost. An efficient whole-building optimization procedure was developed to determine the optimal design based on key design parameters. Whole-building optimization studies were conducted for 12 climate zones using four different criteria: minimum energy consumption, minimum life cycle cost (35 years) using constant energy costs and minimum life cycle cost (35 years) varying escalation rates (-5%, 10%). Conclusions and recommendations were inferred on how to design an optimal house, using each criterion and for all

  14. Linking soil moisture balance and source-responsive preferential flow models for estimating groundwater recharge

    Science.gov (United States)

    Cuthbert, M. O.; Mackay, R.; Nimmo, J. R.

    2012-04-01

    Results are presented of a detailed study into the vadose zone and shallow water table hydrodynamics of a fieldsite in Shropshire, UK. Tensiometry reveals that the loamy sand topsoil wets up via macropore flow and subsequent redistribution of moisture into the soil matrix. However, recharge does not occur until near-positive pressures are achieved at the top of the glaciofluvial outwash material that underlies the topsoil, about 1 m above the water table. Once this occurs, very rapid water table rises follow. This threshold behaviour is attributed to the vertical discontinuity in the macropore system due to seasonal ploughing of the topsoil, and a lower permeability plough/iron pan restricting matrix flow between the topsoil and the lower outwash deposits. Thus, although the wetting process in the topsoil is highly complex, a soil moisture balance model (SMBM) is shown to be skilful in predicting the initiation of preferential flow from the base of the topsoil into the lower outwash horizon. The rapidity of the response at the water table suggests that Stokes type film flow rather than Richards type capillarity dominated flow is occurring and this conjecture is tested using a range of numerical models. A variation of the source-responsive model proposed by Nimmo (2010) is shown to reproduce the observed water table dynamics well, when linked to a SMBM as the source of recharge from the topsoil. The results reveal new insights into preferential flow processes in cultivated soils. If the conceptual and numerical models can be shown to be transferable to other ploughed soils, it promises to be a very useful and practical approach to accounting for preferential flow in studies of groundwater recharge estimation. Nimmo, J. R. (2010). Theory for Source-Responsive and Free-Surface Film Modeling of Unsaturated Flow. Vadose Zone Journal, 9, 295-306.

  15. Integration of soil moisture remote sensing and hydrologic modeling using data assimilation

    Science.gov (United States)

    Houser, Paul R.; Shuttleworth, W. James; Famiglietti, James S.; Gupta, Hoshin V.; Syed, Kamran H.; Goodrich, David C.

    1998-12-01

    The feasibility of synthesizing distributed fields of soil moisture by the novel application of four-dimensional data assimilation (4DDA) applied in a hydrological model is explored. Six 160-km2 push broom microwave radiometer (PBMR) images gathered over the Walnut Gulch experimental watershed in southeast Arizona were assimilated into the Topmodel-based Land-Atmosphere Transfer Scheme (TOPLATS) using several alternative assimilation procedures. Modification of traditional assimilation methods was required to use these high-density PBMR observations. The images were found to contain horizontal correlations that imply length scales of several tens of kilometers, thus allowing information to be advected beyond the area of the image. Information on surface soil moisture also was assimilated into the subsurface using knowledge of the surface- subsurface correlation. Newtonian nudging assimilation procedures are preferable to other techniques because they nearly preserve the observed patterns within the sampled region but also yield plausible patterns in unmeasured regions and allow information to be advected in time.

  16. The benefits of using remotely sensed soil moisture in parameter identification of large-scale hydrological models

    Science.gov (United States)

    Karssenberg, D.; Wanders, N.; de Roo, A.; de Jong, S.; Bierkens, M. F.

    2013-12-01

    Large-scale hydrological models are nowadays mostly calibrated using observed discharge. As a result, a large part of the hydrological system that is not directly linked to discharge, in particular the unsaturated zone, remains uncalibrated, or might be modified unrealistically. Soil moisture observations from satellites have the potential to fill this gap, as these provide the closest thing to a direct measurement of the state of the unsaturated zone, and thus are potentially useful in calibrating unsaturated zone model parameters. This is expected to result in a better identification of the complete hydrological system, potentially leading to improved forecasts of the hydrograph as well. Here we evaluate this added value of remotely sensed soil moisture in calibration of large-scale hydrological models by addressing two research questions: 1) Which parameters of hydrological models can be identified by calibration with remotely sensed soil moisture? 2) Does calibration with remotely sensed soil moisture lead to an improved calibration of hydrological models compared to approaches that calibrate only with discharge, such that this leads to improved forecasts of soil moisture content and discharge as well? To answer these questions we use a dual state and parameter ensemble Kalman filter to calibrate the hydrological model LISFLOOD for the Upper Danube area. Calibration is done with discharge and remotely sensed soil moisture acquired by AMSR-E, SMOS and ASCAT. Four scenarios are studied: no calibration (expert knowledge), calibration on discharge, calibration on remote sensing data (three satellites) and calibration on both discharge and remote sensing data. Using a split-sample approach, the model is calibrated for a period of 2 years and validated for the calibrated model parameters on a validation period of 10 years. Results show that calibration with discharge data improves the estimation of groundwater parameters (e.g., groundwater reservoir constant) and

  17. On the Comparison of the Global Surface Soil Moisture product and Land Surface Modeling

    Science.gov (United States)

    Delorme, B., Jr.; Ottlé, C.; Peylin, P.; Polcher, J.

    2016-12-01

    Thanks to its large spatio-temporal coverage, the new ESA CCI multi-instruments dataset offers a good opportunity to assess and improve land surface models parametrization. In this study, the ESA CCI surface soil moisture (SSM) combined product (v2.2) has been compared to the simulated top first layers of the ORCHIDEE LSM (the continental part of the IPSL earth system model), in order to evaluate its potential of improvements with data assimilation techniques. The ambition of the work was to develop a comprehensive comparison methodology by analyzing simultaneously the temporal and spatial structures of both datasets. We analyzed the SSM synoptic, seasonal, and inter-annual variations by decomposing the signals into fast and slow components. ORCHIDEE was shown to adequately reproduce the observed SSM dynamics in terms of temporal correlation. However, these correlation scores are supposed to be strongly influenced by SSM seasonal variability and the quality of the model input forcing. Autocorrelation and spectral analyses brought out disagreements in the temporal inertia of the upper soil moisture reservoirs. By linking our results to land cover maps, we found that ORCHIDEE is more dependent on rainfall events compared to the observations in regions with sparse vegetation cover. These diflerences might be due to a wrong partition of rainfall between soil evaporation, transpiration, runofl and drainage in ORCHIDEE. To refine this analysis, a single value decomposition (SVD) of the co-variability between rainfall provided by WFDEI and soil moisture was pursued over Central Europe and South Africa. It showed that spatio-temporal co-varying patterns between ORCHIDEE and rainfall and the ESA-CCI product and rainfall are in relatively good agreement. However, the leading SVD pattern, which exhibits a strong annual cycle and explains the same portion of covariance for both datasets, explains a much larger fraction of variance for ORCHIDEE than for the ESA-CCI product

  18. Monte Carlo Simulation of Kinesin Movement with a Lattice Model

    Institute of Scientific and Technical Information of China (English)

    WANG Hong; DOU Shuo-Xing; WANG Peng-Ye

    2005-01-01

    @@ Kinesin is a processive double-headed molecular motor that moves along a microtubule by taking about 8nm steps. It generally hydrolyzes one ATP molecule for taking each forward step. The processive movement of the kinesin molecular motors is numerically simulated with a lattice model. The motors are considered as Brownian particles and the ATPase processes of both heads are taken into account. The Monte Carlo simulation results agree well with recent experimental observations, especially on the relation of velocity versus ATP and ADP concentrations.

  19. Modeling of movement-related potentials using a fractal approach.

    Science.gov (United States)

    Uşakli, Ali Bülent

    2010-06-01

    In bio-signal applications, classification performance depends greatly on feature extraction, which is also the case for electroencephalogram (EEG) based applications. Feature extraction, and consequently classification of EEG signals is not an easy task due to their inherent low signal-to-noise ratios and artifacts. EEG signals can be treated as the output of a non-linear dynamical (chaotic) system in the human brain and therefore they can be modeled by their dimension values. In this study, the variance fractal dimension technique is suggested for the modeling of movement-related potentials (MRPs). Experimental data sets consist of EEG signals recorded during the movements of right foot up, lip pursing and a simultaneous execution of these two tasks. The experimental results and performance tests show that the proposed modeling method can efficiently be applied to MRPs especially in the binary approached brain computer interface applications aiming to assist severely disabled people such as amyotrophic lateral sclerosis patients in communication and/or controlling devices.

  20. Eemian tropical and subtropical African moisture transport: an isotope modelling study

    Energy Technology Data Exchange (ETDEWEB)

    Herold, Marcus; Lohmann, Gerrit [Alfred Wegener Institute for Polar and Marine Research, Bremerhaven (Germany); MARUM, Center for Marine Environmental Sciences, Bremen (Germany)

    2009-12-15

    During the last interglacial insolation maximum (Eemian, MIS 5e) the tropical and subtropical African hydrological cycle was enhanced during boreal summer months. The climate anomalies are examined with a General Circulation Model (ECHAM4) that is equipped with a module for the direct simulation of {sup 18}O and deuterium (H{sub 2} {sup 18} O and HDO, respectively) in all components of the hydrological cycle. A mechanism is proposed to explain the physical processes that lead to the modelled anomalies. Differential surface heating due to anomalies in orbital insolation forcing induce a zonal flow which results in enhanced moisture advection and precipitation. Increased cloud cover reduces incoming short wave radiation and induces a cooling between 10 N and 20 N. The isotopic composition of rainfall at these latitudes is therefore significantly altered. Increased amount of precipitation and stronger advection of moisture from the Atlantic result in isotopically more depleted rainfall in the Eemian East African subtropics compared to pre-industrial climate. The East-West gradient of the isotopic rainfall composition reverses in the Eemian simulation towards depleted values in the east, compared to more depleted western African rainfall in the pre-industrial simulation. The modelled re-distribution of {delta}{sup 18}O and {delta}D is the result of a change in the forcing of the zonal flow anomaly. We conclude that the orbitally induced forcing for African monsoon maxima extends further eastward over the continent and leaves a distinct isotopic signal that can be tested against proxy archives, such as lake sediment cores from the Ethiopian region. (orig.)

  1. Modelling water flow and seasonal soil moisture dynamics in analluvial groundwater-fed wetland

    Directory of Open Access Journals (Sweden)

    I. Joris

    2003-01-01

    Full Text Available Complex interactions occur in riparian wetlands between groundwater, surface water and climatic conditions. Knowledge of the hydrology of these systems is necessary to understand their functioning and their value and models are a useful and probably essential tool to capture their hydrological complexity. In this study, a 2D-model describing saturated-unsaturated water flow is applied to a transect through a groundwater-fed riparian wetland located along the middle reach of the river Dijle. The transect has high levees close to the river and a depression further into the floodplain. Scaling factors are introduced to describe the variability of soil hydraulic properties along the transect. Preliminary model calculations for one year show a good agreement between model calculations and measurements and demonstrate the capability of the model to capture the internal groundwater dynamics. Seasonal variations in soil moisture are reproduced well by the model thus translating external hydrological boundary conditions to root zone conditions. The model proves to be a promising tool for assessing effects of changes in hydrological boundary conditions on vegetation type distribution and to gain more insight in the highly variable internal flow processes of riparian wetlands. Keywords: riparian wetland,eco-hydrology, upward seepage, floodplain hydrology

  2. A synergistic approach for soil moisture estimation using modified Dubois model with dual-polarized SAR and optical satellite data

    Science.gov (United States)

    Thanabalan, P.; Vidhya, R.

    2016-05-01

    This paper discusses about an estimation of soil moisture in agricultural region using SAR data with the use of HH and HV polarization. In this study the semi empirical approach derived by Dubois et al (1) was modified to work using (σdegHH) and σ°VV) so that soil moisture can be obtained for the larger area extent. The optical remote sensing is helps to monitor changes in vegetation biomass and canopy cover surface reflectance by using NDVI and LAI from which the site suitability from different land use/land cover are identified. The second use involves retrieve the backscattering coefficient valuesσ°) derived from SAR for soil moisture studies. In SAR techniques, the relative surface roughness can be directly estimate using surface roughness derivation empirical algorithms. The mid incidence angle is used to overcome the incidence angle effect and it worked successfully to this study. The modified Dubois Model (MDM) in combination with The Topp's et al (2) model is used to retrieve soil moisture. These two models have equations (HH, VV) and two independent variables i.e. root mean square height (s) and dielectric constant (epsilon). The linear regression analysis is performed and the surface roughness derived from SAR is well correlated with ground surface roughness having the value of (r2 = 0.69). By using the dielectric constant (epsilon) the modified Dubois model in combination with Topp's model are performed and the soil moisture is derived from SAR having value of (r2 = 0.60). Thus, the derived model is having good scope for soil moisture monitoring with present availability of SAR datasets.

  3. The firmness of stored tomatoes (cv. Tradiro). 1. Kinetic and near infrared models to describe firmness and moisture loss

    NARCIS (Netherlands)

    Dijk, van C.; Boeriu, C.G.; Peter, F.; Stolle-Smits, T.; Tijskens, L.M.M.

    2006-01-01

    The aim of this research was to develop practical applicable models capable to describe and to predict the temperature dependent firmness and moisture loss of tomatoes during storage. To gather the required information to develop these models batches of 20 tomatoes (cv. Tradiro), each harvested at

  4. The firmness of stored tomatoes (cv. Tradiro). 1. Kinetic and near infrared models to describe firmness and moisture loss

    NARCIS (Netherlands)

    Dijk, van C.; Boeriu, C.G.; Peter, F.; Stolle-Smits, T.; Tijskens, L.M.M.

    2006-01-01

    The aim of this research was to develop practical applicable models capable to describe and to predict the temperature dependent firmness and moisture loss of tomatoes during storage. To gather the required information to develop these models batches of 20 tomatoes (cv. Tradiro), each harvested at t

  5. Estimating irrigated areas from satellite and model soil moisture data over the contiguous US

    Science.gov (United States)

    Zaussinger, Felix; Dorigo, Wouter; Gruber, Alexander

    2017-04-01

    Information about irrigation is crucial for a number of applications such as drought- and yield management and contributes to a better understanding of the water-cycle, land-atmosphere interactions as well as climate projections. Currently, irrigation is mainly quantified by national agricultural statistics, which do not include spatial information. The digital Global Map of Irrigated Areas (GMIA) has been the first effort to quantify irrigation at the global scale by merging these statistics with remote sensing data. Also, the MODIS-Irrigated Agriculture Dataset (MirAD-US) was created by merging annual peak MODIS-NDVI with US county level irrigation statistics. In this study we aim to map irrigated areas by confronting time series of various satellite soil moisture products with soil moisture from the ERA-Interim/Land reanalysis product. We follow the assumption that irrigation signals are not modelled in the reanalysis product, nor contributing to its forcing data, but affecting the spatially continuous remote sensing observations. Based on this assumption, spatial patterns of irrigation are derived from differences between the temporal slopes of the modelled and remotely sensed time series during the irrigation season. Results show that a combination of ASCAT and ERA-Interim/Land show spatial patterns which are in good agreement with the MIrAD-US, particularly within the Mississippi Delta, Texas and eastern Nebraska. In contrast, AMSRE shows weak agreements, plausibly due to a higher vegetation dependency of the soil moisture signal. There is no significant agreement to the MIrAD-US in California, which is possibly related to higher crop-diversity and lower field sizes. Also, a strong signal in the region of the Great Corn Belt is observed, which is generally not outlined as an irrigated area. It is not yet clear to what extent the signal obtained in the Mississippi Delta is related to re-reflection effects caused by standing water due to flood or furrow

  6. Assessment of model behavior and acceptable forcing data uncertainty in the context of land surface soil moisture estimation

    Science.gov (United States)

    Dumedah, Gift; Walker, Jeffrey P.

    2017-03-01

    The sources of uncertainty in land surface models are numerous and varied, from inaccuracies in forcing data to uncertainties in model structure and parameterizations. Majority of these uncertainties are strongly tied to the overall makeup of the model, but the input forcing data set is independent with its accuracy usually defined by the monitoring or the observation system. The impact of input forcing data on model estimation accuracy has been collectively acknowledged to be significant, yet its quantification and the level of uncertainty that is acceptable in the context of the land surface model to obtain a competitive estimation remain mostly unknown. A better understanding is needed about how models respond to input forcing data and what changes in these forcing variables can be accommodated without deteriorating optimal estimation of the model. As a result, this study determines the level of forcing data uncertainty that is acceptable in the Joint UK Land Environment Simulator (JULES) to competitively estimate soil moisture in the Yanco area in south eastern Australia. The study employs hydro genomic mapping to examine the temporal evolution of model decision variables from an archive of values obtained from soil moisture data assimilation. The data assimilation (DA) was undertaken using the advanced Evolutionary Data Assimilation. Our findings show that the input forcing data have significant impact on model output, 35% in root mean square error (RMSE) for 5cm depth of soil moisture and 15% in RMSE for 15cm depth of soil moisture. This specific quantification is crucial to illustrate the significance of input forcing data spread. The acceptable uncertainty determined based on dominant pathway has been validated and shown to be reliable for all forcing variables, so as to provide optimal soil moisture. These findings are crucial for DA in order to account for uncertainties that are meaningful from the model standpoint. Moreover, our results point to a proper

  7. Soil Moisture Data Assimilation in the NASA Land Information System for Local Modeling Applications and Improved Situational Awareness

    Science.gov (United States)

    Case, Jonathan L.; Blakenship, Clay B.; Zavodsky, Bradley T.

    2014-01-01

    As part of the NASA Soil Moisture Active Passive (SMAP) Early Adopter (EA) program, the NASA Shortterm Prediction Research and Transition (SPoRT) Center has implemented a data assimilation (DA) routine into the NASA Land Information System (LIS) for soil moisture retrievals from the European Space Agency's Soil Moisture Ocean Salinity (SMOS) satellite. The SMAP EA program promotes application-driven research to provide a fundamental understanding of how SMAP data products will be used to improve decision-making at operational agencies. SPoRT has partnered with select NOAA/NWS Weather Forecast Offices (WFOs) that use output from a real-time regional configuration of LIS, without soil moisture DA, to initialize local numerical weather prediction (NWP) models and enhance situational awareness. Improvements to local NWP with the current LIS have been demonstrated; however, a better representation of the land surface through assimilation of SMOS (and eventually SMAP) retrievals is expected to lead to further model improvement, particularly during warm-season months. SPoRT will collaborate with select WFOs to assess the impact of soil moisture DA on operational forecast situations. Assimilation of the legacy SMOS instrument data provides an opportunity to develop expertise in preparation for using SMAP data products shortly after the scheduled launch on 5 November 2014. SMOS contains a passive L-band radiometer that is used to retrieve surface soil moisture at 35-km resolution with an accuracy of 0.04 cu cm cm (exp -3). SMAP will feature a comparable passive L-band instrument in conjunction with a 3-km resolution active radar component of slightly degraded accuracy. A combined radar-radiometer product will offer unprecedented global coverage of soil moisture at high spatial resolution (9 km) for hydrometeorological applications, balancing the resolution and accuracy of the active and passive instruments, respectively. The LIS software framework manages land surface model

  8. Uncertainty of Deardorff’s soil moisture model based on continuous TDR measurements for sandy loam soil

    Directory of Open Access Journals (Sweden)

    Brandyk Andrzej

    2016-03-01

    Full Text Available Knowledge on soil moisture is indispensable for a range of hydrological models, since it exerts a considerable influence on runoff conditions. Proper tools are nowadays applied in order to gain in-sight into soil moisture status, especially of uppermost soil layers, which are prone to weather changes and land use practices. In order to establish relationships between meteorological conditions and topsoil moisture, a simple model would be required, characterized by low computational effort, simple structure and low number of identified and calibrated parameters. We demonstrated, that existing model for shallow soils, considering mass exchange between two layers (the upper and the lower, as well as with the atmosphere and subsoil, worked well for sandy loam with deep ground water table in Warsaw conurbation. GLUE (Generalized Likelihood Uncertainty Estimation linked with GSA (Global Sensitivity Analysis provided for final determination of parameter values and model confidence ranges. Including the uncertainty in a model structure, caused that the median soil moisture solution of the GLUE was shifted from the one optimal in deterministic sense. From the point of view of practical model application, the main shortcoming were the underestimated water exchange rates between the lower soil layer (ranging from the depth of 0.1 to 0.2 m below ground level and subsoil. General model quality was found to be satisfactory and promising for its utilization for establishing measures to regain retention in urbanized conditions.

  9. Assimilation of ASAR Data with a Hydrologic and Semi-empirical Backscattering Coupled Model to Estimate Soil Moisture

    Institute of Scientific and Technical Information of China (English)

    LIU Qian; WANG Mingyu; ZHAO Yingshi

    2010-01-01

    The most promising approach for studying soil moisture is the assimilation of observation data and computational modeling.However,there is much uncertainty in the assimilation process,which affects the assimilation results.This research developed a one-dimensional soil moisture assimilation scheme based on the Ensemble Kalman Filter(EnKF)and Genetic Algorithm(GA).A two-dimensional hydrologic model-Distributed Hydrology-Soil-Vegetation Model(DHSVM)was coupled with a semi-empirical backscattering model(Oh).The Advanced Synthetic Apertture Radar(ASAR)data were assimilated with this coupled model and the field observation data were used to validate this scheme in the soil moisture assimilation experiment.In order to improve the assimilation results,a cost function was set up based on the distance between the simulated backscattering coefficient from the coupled model and the observed backscattering coefficient from ASAR.The EnKF and GA were used to re-initialize and re-parameterize the simulation process,respectively.The assimilation results were compared with the free-run simulations from hydrologic model and the field observation data.The results obtained indicate that this assimilation scheme is practical and it can improve the accuracy of soil moisture estimation significantly.

  10. Smart Irrigation From Soil Moisture Forecast Using Satellite And Hydro -Meteorological Modelling

    Science.gov (United States)

    Corbari, Chiara; Mancini, Marco; Ravazzani, Giovanni; Ceppi, Alessandro; Salerno, Raffaele; Sobrino, Josè

    2017-04-01

    Increased water demand and climate change impacts have recently enhanced the need to improve water resources management, even in those areas which traditionally have an abundant supply of water. The highest consumption of water is devoted to irrigation for agricultural production, and so it is in this area that efforts have to be focused to study possible interventions. The SIM project funded by EU in the framework of the WaterWorks2014 - Water Joint Programming Initiative aims at developing an operational tool for real-time forecast of crops irrigation water requirements to support parsimonious water management and to optimize irrigation scheduling providing real-time and forecasted soil moisture behavior at high spatial and temporal resolutions with forecast horizons from few up to thirty days. This study discusses advances in coupling satellite driven soil water balance model and meteorological forecast as support for precision irrigation use comparing different case studies in Italy, in the Netherlands, in China and Spain, characterized by different climatic conditions, water availability, crop types and irrigation techniques and water distribution rules. Herein, the applications in two operative farms in vegetables production in the South of Italy where semi-arid climatic conditions holds, two maize fields in Northern Italy in a more water reach environment with flood irrigation will be presented. This system combines state of the art mathematical models and new technologies for environmental monitoring, merging ground observed data with Earth observations. Discussion on the methodology approach is presented, comparing for a reanalysis periods the forecast system outputs with observed soil moisture and crop water needs proving the reliability of the forecasting system and its benefits. The real-time visualization of the implemented system is also presented through web-dashboards.

  11. Modelling and monitoring of passive control structures in human movement

    Science.gov (United States)

    Hemami, Hooshang; Hemami, Mahmoud

    2014-09-01

    Passive tissues, ligaments and cartilage are vital to human movement. Their contribution to stability, joint function and joint integrity is essential. The articulation of their functions and quantitative assessment of what they do in a healthy or injured state are important in athletics, orthopaedics, medicine and health. In this paper, the role of cartilage and ligaments in stability of natural contacts, connections and joints is articulated by including them in two very simple skeletal systems: one- and three-link rigid body systems. Based on the Newton-Euler equations, a state space presentation of the dynamics is discussed that allows inclusion of ligament and cartilage structures in the model, and allows for Lyapunov stability studies for the original and reduced systems. The connection constraints may be holonomic and non-holonomic depending on the structure of the passive elements. The development is pertinent to the eventual design of a computational framework for the study of human movement that involves computer models of all the relevant skeletal, neural and physiological elements of the central nervous system (CNS). Such a structure also permits testing of different hypotheses about the functional neuroanatomy of the CNS, and the study of the effects and dynamics of disease, deterioration, aging and injuries. The formulation here is applied to one- and three-link systems. Digital computer simulations of a two rigid body system are presented to demonstrate the feasibility and effectiveness of the approach and the methods.

  12. Model selection for the extraction of movement primitives.

    Science.gov (United States)

    Endres, Dominik M; Chiovetto, Enrico; Giese, Martin A

    2013-01-01

    A wide range of blind source separation methods have been used in motor control research for the extraction of movement primitives from EMG and kinematic data. Popular examples are principal component analysis (PCA), independent component analysis (ICA), anechoic demixing, and the time-varying synergy model (d'Avella and Tresch, 2002). However, choosing the parameters of these models, or indeed choosing the type of model, is often done in a heuristic fashion, driven by result expectations as much as by the data. We propose an objective criterion which allows to select the model type, number of primitives and the temporal smoothness prior. Our approach is based on a Laplace approximation to the posterior distribution of the parameters of a given blind source separation model, re-formulated as a Bayesian generative model. We first validate our criterion on ground truth data, showing that it performs at least as good as traditional model selection criteria [Bayesian information criterion, BIC (Schwarz, 1978) and the Akaike Information Criterion (AIC) (Akaike, 1974)]. Then, we analyze human gait data, finding that an anechoic mixture model with a temporal smoothness constraint on the sources can best account for the data.

  13. Model selection for the extraction of movement primitives

    Directory of Open Access Journals (Sweden)

    Dominik M Endres

    2013-12-01

    Full Text Available A wide range of blind source separation methods have been used in motor control research for the extraction of movement primitives from EMG and kinematic data. Popular examples are principal component analysis (PCA,independent component analysis (ICA, anechoic demixing, and the time-varying synergy model. However, choosing the parameters of these models, or indeed choosing the type of model, is often done in a heuristic fashion, driven by result expectations as much as by the data. We propose an objective criterion which allows to select the model type, number of primitives and the temporal smoothness prior. Our approach is based on a Laplace approximation to the posterior distribution of the parameters of a given blind source separation model, re-formulated as a Bayesian generative model.We first validate our criterion on ground truth data, showing that it performs at least as good as traditional model selection criteria (Bayesian information criterion, BIC and the Akaike Information Criterion (AIC. Then, we analyze human gait data, finding that an anechoic mixture model with a temporal smoothness constraint on the sources can best account for the data.

  14. Modelling Fine Scale Movement Corridors for the Tricarinate Hill Turtle

    Science.gov (United States)

    Mondal, I.; Kumar, R. S.; Habib, B.; Talukdar, G.

    2016-06-01

    Habitat loss and the destruction of habitat connectivity can lead to species extinction by isolation of population. Identifying important habitat corridors to enhance habitat connectivity is imperative for species conservation by preserving dispersal pattern to maintain genetic diversity. Circuit theory is a novel tool to model habitat connectivity as it considers habitat as an electronic circuit board and species movement as a certain amount of current moving around through different resistors in the circuit. Most studies involving circuit theory have been carried out at small scales on large ranging animals like wolves or pumas, and more recently on tigers. This calls for a study that tests circuit theory at a large scale to model micro-scale habitat connectivity. The present study on a small South-Asian geoemydid, the Tricarinate Hill-turtle (Melanochelys tricarinata), focuses on habitat connectivity at a very fine scale. The Tricarinate has a small body size (carapace length: 127-175 mm) and home range (8000-15000 m2), with very specific habitat requirements and movement patterns. We used very high resolution Worldview satellite data and extensive field observations to derive a model of landscape permeability at 1 : 2,000 scale to suit the target species. Circuit theory was applied to model potential corridors between core habitat patches for the Tricarinate Hill-turtle. The modelled corridors were validated by extensive ground tracking data collected using thread spool technique and found to be functional. Therefore, circuit theory is a promising tool for accurately identifying corridors, to aid in habitat studies of small species.

  15. Calibration of a large-scale hydrological model using satellite-based soil moisture and evapotranspiration products

    Directory of Open Access Journals (Sweden)

    P. López López

    2017-06-01

    Full Text Available A considerable number of river basins around the world lack sufficient ground observations of hydro-meteorological data for effective water resources assessment and management. Several approaches can be developed to increase the quality and availability of data in these poorly gauged or ungauged river basins; among them, the use of Earth observations products has recently become promising. Earth observations of various environmental variables can be used potentially to increase knowledge about the hydrological processes in the basin and to improve streamflow model estimates, via assimilation or calibration. The present study aims to calibrate the large-scale hydrological model PCRaster GLOBal Water Balance (PCR-GLOBWB using satellite-based products of evapotranspiration and soil moisture for the Moroccan Oum er Rbia River basin. Daily simulations at a spatial resolution of 5  ×  5 arcmin are performed with varying parameters values for the 32-year period 1979–2010. Five different calibration scenarios are inter-compared: (i reference scenario using the hydrological model with the standard parameterization, (ii calibration using in situ-observed discharge time series, (iii calibration using the Global Land Evaporation Amsterdam Model (GLEAM actual evapotranspiration time series, (iv calibration using ESA Climate Change Initiative (CCI surface soil moisture time series and (v step-wise calibration using GLEAM actual evapotranspiration and ESA CCI surface soil moisture time series. The impact on discharge estimates of precipitation in comparison with model parameters calibration is investigated using three global precipitation products, including ERA-Interim (EI, WATCH Forcing methodology applied to ERA-Interim reanalysis data (WFDEI and Multi-Source Weighted-Ensemble Precipitation data by merging gauge, satellite and reanalysis data (MSWEP. Results show that GLEAM evapotranspiration and ESA CCI soil moisture may be used for model

  16. Calibration of a large-scale hydrological model using satellite-based soil moisture and evapotranspiration products

    Science.gov (United States)

    López López, Patricia; Sutanudjaja, Edwin H.; Schellekens, Jaap; Sterk, Geert; Bierkens, Marc F. P.

    2017-06-01

    A considerable number of river basins around the world lack sufficient ground observations of hydro-meteorological data for effective water resources assessment and management. Several approaches can be developed to increase the quality and availability of data in these poorly gauged or ungauged river basins; among them, the use of Earth observations products has recently become promising. Earth observations of various environmental variables can be used potentially to increase knowledge about the hydrological processes in the basin and to improve streamflow model estimates, via assimilation or calibration. The present study aims to calibrate the large-scale hydrological model PCRaster GLOBal Water Balance (PCR-GLOBWB) using satellite-based products of evapotranspiration and soil moisture for the Moroccan Oum er Rbia River basin. Daily simulations at a spatial resolution of 5 × 5 arcmin are performed with varying parameters values for the 32-year period 1979-2010. Five different calibration scenarios are inter-compared: (i) reference scenario using the hydrological model with the standard parameterization, (ii) calibration using in situ-observed discharge time series, (iii) calibration using the Global Land Evaporation Amsterdam Model (GLEAM) actual evapotranspiration time series, (iv) calibration using ESA Climate Change Initiative (CCI) surface soil moisture time series and (v) step-wise calibration using GLEAM actual evapotranspiration and ESA CCI surface soil moisture time series. The impact on discharge estimates of precipitation in comparison with model parameters calibration is investigated using three global precipitation products, including ERA-Interim (EI), WATCH Forcing methodology applied to ERA-Interim reanalysis data (WFDEI) and Multi-Source Weighted-Ensemble Precipitation data by merging gauge, satellite and reanalysis data (MSWEP). Results show that GLEAM evapotranspiration and ESA CCI soil moisture may be used for model calibration resulting in

  17. Evaluating Land-Atmosphere Moisture Feedbacks in Earth System Models With Spaceborne Observations

    Science.gov (United States)

    Levine, P. A.; Randerson, J. T.; Lawrence, D. M.; Swenson, S. C.

    2016-12-01

    We have developed a set of metrics for measuring the feedback loop between the land surface moisture state and the atmosphere globally on an interannual time scale. These metrics consider both the forcing of terrestrial water storage (TWS) on subsequent atmospheric conditions as well as the response of TWS to antecedent atmospheric conditions. We designed our metrics to take advantage of more than one decade's worth of satellite observations of TWS from the Gravity Recovery and Climate Experiment (GRACE) along with atmospheric variables from the Atmospheric Infrared Sounder (AIRS), the Global Precipitation Climatology Project (GPCP), and Clouds and the Earths Radiant Energy System (CERES). Metrics derived from spaceborne observations were used to evaluate the strength of the feedback loop in the Community Earth System Model (CESM) Large Ensemble (LENS) and in several models that contributed simulations to Phase 5 of the Coupled Model Intercomparison Project (CMIP5). We found that both forcing and response limbs of the feedback loop were generally stronger in tropical and temperate regions in CMIP5 models and even more so in LENS compared to satellite observations. Our analysis suggests that models may overestimate the strength of the feedbacks between the land surface and the atmosphere, which is consistent with previous studies conducted across different spatial and temporal scales.

  18. Is that really my movement? - Students' experiences of a video-supported interactive learning model for movement awareness.

    Science.gov (United States)

    Backåberg, Sofia; Gummesson, Christina; Brunt, David; Rask, Mikael

    2015-01-01

    Healthcare staff and students have a great risk of developing musculoskeletal symptoms. One cause of this is heavy load related work activities such as manual handling, in which the quality of individual work technique may play a major role. Preventive interventions and well-defined educational strategies to support movement awareness and long-lasting movement changes need to be developed. The aim of the present study was to explore nursing students' experiences of a newly developed interactive learning model for movement awareness. The learning model, which is based on a life-world perspective with focus on interpersonal interaction, has been used with 11 undergraduate students from the second and final year. Each student participated in three individual video sessions with a facilitator. Two individual interviews were carried out with each student during the learning process and one interview 12-18 months after the last session. The interviews were audio-recorded and transcribed verbatim, and a phenomenological hermeneutic method inspired by Paul Ricoeur and described by Lindseth and Norberg was used to interpret the interviews and diary notes. The interpretation resulted in three key themes and nine subthemes. The key themes were; "Obtaining better preconditions for bodily awareness," "Experiencing changes in one's own movement," and "Experiencing challenges in the learning process." The interactive learning model entails a powerful and challenging experience that develops movement awareness. The experience of meaningfulness and usefulness emerges increasingly and alternates with a feeling of discomfort. The learning model may contribute to the body of knowledge of well-defined educational strategies in movement awareness and learning in, for example, preventive interventions and ergonomic education. It may also be valuable in other practical learning situations where movement awareness is required.

  19. Is that really my movement?—Students' experiences of a video-supported interactive learning model for movement awareness

    Directory of Open Access Journals (Sweden)

    Sofia Backåberg

    2015-08-01

    Full Text Available Healthcare staff and students have a great risk of developing musculoskeletal symptoms. One cause of this is heavy load related work activities such as manual handling, in which the quality of individual work technique may play a major role. Preventive interventions and well-defined educational strategies to support movement awareness and long-lasting movement changes need to be developed. The aim of the present study was to explore nursing students’ experiences of a newly developed interactive learning model for movement awareness. The learning model, which is based on a life-world perspective with focus on interpersonal interaction, has been used with 11 undergraduate students from the second and final year. Each student participated in three individual video sessions with a facilitator. Two individual interviews were carried out with each student during the learning process and one interview 12–18 months after the last session. The interviews were audio-recorded and transcribed verbatim, and a phenomenological hermeneutic method inspired by Paul Ricoeur and described by Lindseth and Norberg was used to interpret the interviews and diary notes. The interpretation resulted in three key themes and nine subthemes. The key themes were; “Obtaining better preconditions for bodily awareness,” “Experiencing changes in one's own movement,” and “Experiencing challenges in the learning process.” The interactive learning model entails a powerful and challenging experience that develops movement awareness. The experience of meaningfulness and usefulness emerges increasingly and alternates with a feeling of discomfort. The learning model may contribute to the body of knowledge of well-defined educational strategies in movement awareness and learning in, for example, preventive interventions and ergonomic education. It may also be valuable in other practical learning situations where movement awareness is required.

  20. Is that really my movement?—Students' experiences of a video-supported interactive learning model for movement awareness

    Science.gov (United States)

    Backåberg, Sofia; Gummesson, Christina; Brunt, David; Rask, Mikael

    2015-01-01

    Healthcare staff and students have a great risk of developing musculoskeletal symptoms. One cause of this is heavy load related work activities such as manual handling, in which the quality of individual work technique may play a major role. Preventive interventions and well-defined educational strategies to support movement awareness and long-lasting movement changes need to be developed. The aim of the present study was to explore nursing students’ experiences of a newly developed interactive learning model for movement awareness. The learning model, which is based on a life-world perspective with focus on interpersonal interaction, has been used with 11 undergraduate students from the second and final year. Each student participated in three individual video sessions with a facilitator. Two individual interviews were carried out with each student during the learning process and one interview 12–18 months after the last session. The interviews were audio-recorded and transcribed verbatim, and a phenomenological hermeneutic method inspired by Paul Ricoeur and described by Lindseth and Norberg was used to interpret the interviews and diary notes. The interpretation resulted in three key themes and nine subthemes. The key themes were; “Obtaining better preconditions for bodily awareness,” “Experiencing changes in one's own movement,” and “Experiencing challenges in the learning process.” The interactive learning model entails a powerful and challenging experience that develops movement awareness. The experience of meaningfulness and usefulness emerges increasingly and alternates with a feeling of discomfort. The learning model may contribute to the body of knowledge of well-defined educational strategies in movement awareness and learning in, for example, preventive interventions and ergonomic education. It may also be valuable in other practical learning situations where movement awareness is required. PMID:26274385

  1. Evaluation of moisture sources of the Central European summer flood of May/June 2013 based on an ensemble of regional climate model simulations

    Science.gov (United States)

    Kelemen, Fanni D.; Ludwig, Patrick; Reyers, Mark; Ulbrich, Sven; Pinto, Joaquim G.

    2015-04-01

    In May/June 2013, heavy precipitation hit Central Europe, triggering damaging floods both on the Danube and on Elbe basins. In this study, we perform a detailed analysis of the synoptic development of the event based on an ensemble of regional climate model simulations performed with the COSMO-CLM. Simulations are performed with reanalysis data boundary conditions in multiple set-ups and horizontal resolutions of 0.375° and 0.125°. In particular, the aim is to identify potential moisture sources, and how they contributed to the event quantitatively. A control simulation with undisturbed (reanalysis) boundary conditions and sensitivity experiments with modified evaporation characteristics are performed to distinguish the role of moisture evaporated from marine and land areas. To keep the structure of the simulations close to reality as possible, spectral nudging is applied on the upper level atmospheric wind fields. For all simulations, the synoptic situations and cyclone tracks are evaluated against an independent reanalysis dataset, and simulated precipitation amounts are validated against E-OBS precipitation data. In general, the upper level atmospheric characteristics, which trigger the cyclones, are similar in the simulations compared to the reanalysis. Moreover, the time evolution of the precipitation event is well simulated. Nevertheless there are some differences in the spatial and temporal distribution of the precipitation. In both, the reanalysis and the control simulation, the cyclones relevant for this event were moving westward (retrograde movement), counterclockwise from the Mediterranean region over Eastern Europe towards the northern slopes of the Alps. The pre-existing moist soil over East and Central Europe and the circulation associated with the cyclones contributed to intense evapotranspiration, and thus the westward propagating cyclones brought a lot of moisture along their tracks towards Central Europe. The sensitivity studies performed with

  2. Fuel moisture content estimation: a land-surface modelling approach applied to African savannas

    Science.gov (United States)

    Ghent, D.; Spessa, A.; Kaduk, J.; Balzter, H.

    2009-04-01

    Despite the importance of fire to the global climate system, in terms of emissions from biomass burning, ecosystem structure and function, and changes to surface albedo, current land-surface models do not adequately estimate key variables affecting fire ignition and propagation. Fuel moisture content (FMC) is considered one of the most important of these variables (Chuvieco et al., 2004). Biophysical models, with appropriate plant functional type parameterisations, are the most viable option to adequately predict FMC over continental scales at high temporal resolution. However, the complexity of plant-water interactions, and the variability associated with short-term climate changes, means it is one of the most difficult fire variables to quantify and predict. Our work attempts to resolve this issue using a combination of satellite data and biophysical modelling applied to Africa. The approach we take is to represent live FMC as a surface dryness index; expressed as the ratio between the Normalised Difference Vegetation Index (NDVI) and land-surface temperature (LST). It has been argued in previous studies (Sandholt et al., 2002; Snyder et al., 2006), that this ratio displays a statistically stronger correlation to FMC than either of the variables, considered separately. In this study, simulated FMC is constrained through the assimilation of remotely sensed LST and NDVI data into the land-surface model JULES (Joint-UK Land Environment Simulator). Previous modelling studies of fire activity in Africa savannas, such as Lehsten et al. (2008), have reported significant levels of uncertainty associated with the simulations. This uncertainty is important because African savannas are among some of the most frequently burnt ecosystems and are a major source of greenhouse trace gases and aerosol emissions (Scholes et al., 1996). Furthermore, regional climate model studies indicate that many parts of the African savannas will experience drier and warmer conditions in future

  3. Nematode survival in relation to soil moisture

    NARCIS (Netherlands)

    Simons, W.R.

    1973-01-01

    Established nematode populations are very persistent in the soil. It is known that they need sufficient soil moisture for movement, feeding and reproduction (fig. 5), and that there are adverse soil moisture conditions which they cannot survive. The influence of soil moisture on survival of nematode

  4. Nematode survival in relation to soil moisture

    NARCIS (Netherlands)

    Simons, W.R.

    1973-01-01

    Established nematode populations are very persistent in the soil. It is known that they need sufficient soil moisture for movement, feeding and reproduction (fig. 5), and that there are adverse soil moisture conditions which they cannot survive. The influence of soil moisture on survival

  5. Modeling pedestrian evacuation movement in a swaying ship

    CERN Document Server

    Chen, Juan; Lo, SM

    2015-01-01

    With the advance in living standard, cruise travel has been rapidly expanding around the world in recent years. The transportation of passengers in water has also made a rapid development. It is expected that ships will be more and more widely used. Unfortunately, ship disasters occurred in these years caused serious losses. It raised the concern on effectiveness of passenger evacuation on ships. The present study thus focuses on pedestrian evacuation features on ships. On ships, passenger movements are affected by the periodical water motion and thus are quite different from the characteristic when walking on static horizontal floor. Taking into consideration of this special feature, an agent-based pedestrian model is formulized and the effect of ship swaying on pedestrian evacuation efficiency is investigated. Results indicated that the proposed model can be used to quantify the special evacuation process on ships.

  6. Measuring and modeling the effect of surface moisture on the spectral reflectance of coastal beach sand

    NARCIS (Netherlands)

    Nolet, Corjan; Poortinga, Ate; Roosjen, Peter; Bartholomeus, Harm; Ruessink, Gerben

    2014-01-01

    Surface moisture is an important supply limiting factor for aeolian sand transport, which is the primary driver of coastal dune development. As such, it is critical to account for the control of surface moisture on available sand for dune building. Optical remote sensing has the potential to measure

  7. Modelling soil moisture under different land covers in a sub-humid environment of Western Ghats, India

    Indian Academy of Sciences (India)

    B Venkatesh; Lakshman Nandagiri; B K Purandara; V B Reddy

    2011-06-01

    The objective of this study is to apply and test a simple parametric water balance model for prediction of soil moisture regime in the presence of vegetation. The intention was to evaluate the differences in model parameterization and performance when applied to small watersheds under three different types of land covers (Acacia, degraded forest and natural forest). The watersheds selected for this purpose are located in the sub-humid climate within the Western Ghats, Karnataka, India. Model calibration and validation were performed using a dataset comprising depth-averaged soil moisture content measurements made at weekly time steps from October 2004 to December 2008. In addition to this, a sensitivity analysis was carried out with respect to the water-holding capacity of the soils with the aim of explaining the suitability and adaptation of exotic vegetation types under the prevailing climatic conditions. Results indicated reasonably good performance of the model in simulating the pattern and magnitude of weekly average soil moisture content in 150 cm deep soil layer under all three land covers. This study demonstrates that a simple, robust and parametrically parsimonious model is capable of simulating the temporal dynamics of soil moisture content under distinctly different land covers. Also, results of sensitivity analysis revealed that exotic plant species such as Acacia have adapted themselves effectively to the local climate.

  8. Hardware scale modelling of summertime patterns of urban dew and surface moisture in Vancouver, BC, Canada

    Science.gov (United States)

    Richards, K.

    There is growing interest in dew as a potential source of fresh water, and also in the study of urban dew. In this research, a 1:8 scale, out-of-doors hardware model was constructed in Vancouver, BC, Canada, to study dew in an urban residential landscape. It consisted of three wooden houses (1.08 m tall), a paved street, small trees and a grassed urban park. The internal thermal mass (ITM) approach was used to scale the buildings. The model was validated to a first approximation using data from full-scale sites in Vancouver. It performed well. Results indicate that, while the primary control on dew deposition is weather, weather effects are modified by substrate type and site geometry. On nights with abundant dew (0.1-0.3 mm day -1), association was seen in the model between the distributions of surface temperature, sky view, and surface moisture (dew+guttation) accumulation on grass. The model roof was often a site of significant accumulation with a mean dewfall of 0.09 mm day -1. The amount of water that could potentially be collected from a roof is far less than that which may be collected from dense fog using fog nets. Nevertheless, dew is not a negligible term in the urban water balance and its potential for collection should not be lightly dismissed.

  9. Cytokines and VEGF Induction in Orthodontic Movement in Animal Models

    Directory of Open Access Journals (Sweden)

    M. Di Domenico

    2012-01-01

    Full Text Available Orthodontics is a branch of dentistry that aims at the resolution of dental malocclusions. The specialist carries out the treatment using intraoral or extraoral orthodontic appliances that require forces of a given load level to obtain a tooth movement in a certain direction in dental arches. Orthodontic tooth movement is dependent on efficient remodeling of periodontal ligament and alveolar bone, correlated with several biological and mechanical responses of the tissues surrounding the teeth. A periodontal ligament placed under pressure will result in bone resorption whereas a periodontal ligament under tension results in bone formation. In the primary stage of the application of orthodontic forces, an acute inflammation occurs in periodontium. Several proinflammatory cytokines are produced by immune-competent cells migrating by means of dilated capillaries. In this paper we summarize, also through the utilization of animal models, the role of some of these molecules, namely, interleukin-1β and vascular endothelial growth factor, that are some proliferation markers of osteoclasts and osteoblasts, and the macrophage colony stimulating factor.

  10. Coupled stochastic soil moisture simulation-optimization model of deficit irrigation

    Science.gov (United States)

    Alizadeh, Hosein; Mousavi, S. Jamshid

    2013-07-01

    This study presents an explicit stochastic optimization-simulation model of short-term deficit irrigation management for large-scale irrigation districts. The model which is a nonlinear nonconvex program with an economic objective function is built on an agrohydrological simulation component. The simulation component integrates (1) an explicit stochastic model of soil moisture dynamics of the crop-root zone considering interaction of stochastic rainfall and irrigation with shallow water table effects, (2) a conceptual root zone salt balance model, and 3) the FAO crop yield model. Particle Swarm Optimization algorithm, linked to the simulation component, solves the resulting nonconvex program with a significantly better computational performance compared to a Monte Carlo-based implicit stochastic optimization model. The model has been tested first by applying it in single-crop irrigation problems through which the effects of the severity of water deficit on the objective function (net benefit), root-zone water balance, and irrigation water needs have been assessed. Then, the model has been applied in Dasht-e-Abbas and Ein-khosh Fakkeh Irrigation Districts (DAID and EFID) of the Karkheh Basin in southwest of Iran. While the maximum net benefit has been obtained for a stress-avoidance (SA) irrigation policy, the highest water profitability has been resulted when only about 60% of the water used in the SA policy is applied. The DAID with respectively 33% of total cultivated area and 37% of total applied water has produced only 14% of the total net benefit due to low-valued crops and adverse soil and shallow water table conditions.

  11. Subgrid Parameterization of the Soil Moisture Storage Capacity for a Distributed Rainfall-Runoff Model

    Directory of Open Access Journals (Sweden)

    Weijian Guo

    2015-05-01

    Full Text Available Spatial variability plays an important role in nonlinear hydrologic processes. Due to the limitation of computational efficiency and data resolution, subgrid variability is usually assumed to be uniform for most grid-based rainfall-runoff models, which leads to the scale-dependence of model performances. In this paper, the scale effect on the Grid-Xinanjiang model was examined. The bias of the estimation of precipitation, runoff, evapotranspiration and soil moisture at the different grid scales, along with the scale-dependence of the effective parameters, highlights the importance of well representing the subgrid variability. This paper presents a subgrid parameterization method to incorporate the subgrid variability of the soil storage capacity, which is a key variable that controls runoff generation and partitioning in the Grid-Xinanjiang model. In light of the similar spatial pattern and physical basis, the soil storage capacity is correlated with the topographic index, whose spatial distribution can more readily be measured. A beta distribution is introduced to represent the spatial distribution of the soil storage capacity within the grid. The results derived from the Yanduhe Basin show that the proposed subgrid parameterization method can effectively correct the watershed soil storage capacity curve. Compared to the original Grid-Xinanjiang model, the model performances are quite consistent at the different grid scales when the subgrid variability is incorporated. This subgrid parameterization method reduces the recalibration necessity when the Digital Elevation Model (DEM resolution is changed. Moreover, it improves the potential for the application of the distributed model in the ungauged basin.

  12. Estimating soil hydraulic properties from soil moisture time series by inversion of a dual-permeability model

    Science.gov (United States)

    Dalla Valle, Nicolas; Wutzler, Thomas; Meyer, Stefanie; Potthast, Karin; Michalzik, Beate

    2017-04-01

    Dual-permeability type models are widely used to simulate water fluxes and solute transport in structured soils. These models contain two spatially overlapping flow domains with different parameterizations or even entirely different conceptual descriptions of flow processes. They are usually able to capture preferential flow phenomena, but a large set of parameters is needed, which are very laborious to obtain or cannot be measured at all. Therefore, model inversions are often used to derive the necessary parameters. Although these require sufficient input data themselves, they can use measurements of state variables instead, which are often easier to obtain and can be monitored by automated measurement systems. In this work we show a method to estimate soil hydraulic parameters from high frequency soil moisture time series data gathered at two different measurement depths by inversion of a simple one dimensional dual-permeability model. The model uses an advection equation based on the kinematic wave theory to describe the flow in the fracture domain and a Richards equation for the flow in the matrix domain. The soil moisture time series data were measured in mesocosms during sprinkling experiments. The inversion consists of three consecutive steps: First, the parameters of the water retention function were assessed using vertical soil moisture profiles in hydraulic equilibrium. This was done using two different exponential retention functions and the Campbell function. Second, the soil sorptivity and diffusivity functions were estimated from Boltzmann-transformed soil moisture data, which allowed the calculation of the hydraulic conductivity function. Third, the parameters governing flow in the fracture domain were determined using the whole soil moisture time series. The resulting retention functions were within the range of values predicted by pedotransfer functions apart from very dry conditions, where all retention functions predicted lower matrix potentials

  13. Application of HEC-HMS in a Cold Region Watershed and Use of RADARSAT-2 Soil Moisture in Initializing the Model

    Directory of Open Access Journals (Sweden)

    Hassan A. K. M. Bhuiyan

    2017-02-01

    Full Text Available This paper presents an assessment of the applicability of using RADARSAT-2-derived soil moisture data in the Hydrologic Modelling System developed by the Hydrologic Engineering Center (HEC-HMS for flood forecasting with a case study in the Sturgeon Creek watershed in Manitoba, Canada. Spring flooding in Manitoba is generally influenced by both winter precipitation and soil moisture conditions in the fall of the previous year. As a result, the soil moisture accounting (SMA and the temperature index algorithms are employed in the simulation. Results from event and continuous simulations of HEC-HMS show that the model is suitable for flood forecasting in Manitoba. Soil moisture data from the Manitoba Agriculture field survey and RADARSAT-2 satellite were used to set the initial soil moisture for the event simulations. The results confirm the benefit of using satellite data in capturing peak flows in a snowmelt event. A sensitivity analysis of SMA parameters, such as soil storage, maximum infiltration, soil percolation, maximum canopy storage and tension storage, was performed and ranked to determine which parameters have a significant impact on the performance of the model. The results show that the soil moisture storage was the most sensitive parameter. The sensitivity analysis of initial soil moisture in a snowmelt event shows that cumulative flow and peak flow are highly influenced by the initial soil moisture setting of the model. Therefore, there is a potential to utilize RADARSAT-2-derived soil moisture for hydrological modelling in other snow-dominated Manitoba watersheds.

  14. DYNAMICS MODEL OF MOISTURE IN PAPER INSULATION-TRANSFORMER OIL SYSTEM IN NON-STATIONARY THERMAL MODES OF THE POWER TRANSFORMER

    Directory of Open Access Journals (Sweden)

    V.V. Vasilevskij

    2016-06-01

    Full Text Available Introduction. An important problem in power transformers resource prognosis is the formation of moisture dynamics trends of transformer insulation. Purpose. Increasing the accuracy of power transformer insulation resource assessment based on accounting of moisture dynamics in interrelation with temperature dynamics. Working out of moisture dynamics model in paper insulation-transformer oil system in conjunction with thermodynamic model, load model and technical maintenance model. Methodology. The mathematical models used for describe the moisture dynamics are grounded on nonlinear differential equations. Interrelation moisture dynamics model with thermodynamic, load and technical maintenance models described by UML model. For confirming the adequacy of model used computer simulation. Results. We have implemented the model of moisture dynamics in power transformers insulation in interrelation with other models, which describe the state of power transformer in operation. The proposed model allows us to form detailed trends of moisture dynamics in power transformers insulation basing on monitoring data or power transformers operational factors simulation results. We have performed computer simulation of moisture exchange processes and calculation of transformer insulation resource for different moisture trends. Originality. The offered model takes into account moisture dynamics in power transformers insulation under the influence of changes of the power transformers thermal mode and operational factors. Practical value. The offered model can be used in power transformers monitoring systems for automation of resource assessment of oil-immersed power transformers paper insulation at different phase of lifecycle. Model also can be used for assessment of projected economic efficiency of power transformers exploitation in projected operating conditions.

  15. Parametric Hidden Markov Models for Recognition and Synthesis of Movements

    DEFF Research Database (Denmark)

    Herzog, Dennis; Krüger, Volker; Grest, Daniel

    2008-01-01

    the applicability for online recognition based on very noisy 3D tracking data. The use of a parametric representation of movements is shown in a robot demo, where a robot removes objects from a table as demonstrated by an advisor. The synthesis for motor control is performed for arbitrary table-top positions.......In humanoid robotics, the recognition and synthesis of parametric movements plays an extraordinary role for robot human interaction. Such a parametric movement is a movement of a particular type (semantic), for example, similar pointing movements performed at different table-top positions....... For understanding the whole meaning of a movement of a human, the recognition of its type, likewise its parameterization are important. Only both together convey the whole meaning. Vice versa, for mimicry, the synthesis of movements for the motor control of a robot needs to be parameterized, e.g., by the relative...

  16. From EMPD to CFD – overview of different approaches for Heat Air and Moisture modeling in IEA Annex 41

    DEFF Research Database (Denmark)

    Janssens, Arnold; Woloszyn, Monica; Rode, Carsten;

    2008-01-01

    This paper provides an overview of the recent developments of Heat, Air and Moisture modeling of Whole Buildings, which were carried out within a collaborative project of the International Energy Agency. The project has strived to advance the possibilities to calculate the integrated phenomena of...

  17. From EMPD to CFD – overview of different approaches for Heat Air and Moisture modeling in IEA Annex 41

    DEFF Research Database (Denmark)

    Woloszyn, Monika; Rode, Carsten; Kalagasidis, Angela S.;

    2009-01-01

    This paper provides an overview of the recent developments of Heat, Air and Moisture modeling of Whole Buildings, which were carried out within a collaborative project of the International Energy Agency. The project has strived to advance the possibilities to calculate the integrated phenomena of...

  18. Experimental validation of coupled heat, air and moisture transfer modeling in multilayer building components

    Science.gov (United States)

    Ferroukhi, M. Y.; Abahri, K.; Belarbi, R.; Limam, K.; Nouviaire, A.

    2016-10-01

    The present paper lies to study the coupled heat, air and moisture transfer in multi-layer building materials. Concerning the modeling part, the interest is to predict the hygrothermal behavior, by developing a macroscopic model that incorporates simultaneously the diffusive, convective and conductive effects on the building elements. Heat transfer is considered in the strongly coupled situation where the mass and heat flux are temperature, vapor pressure and total pressure dependents. The model input parameters are evaluated experimentally through the development of various experimental prototypes in the laboratory. Thereafter, an experimental setup has been established in order to evaluate the hygrothermal process of several multilayer walls configurations. The experimental procedure consists to follow the temperature and relative humidity evolutions within the samples thickness, submitted to controlled and fixed boundary conditions. This procedure points out diverging conclusion between different testing materials combinations (e.g. red-brick and polystyrene). In fact, the hygrothermal behavior of the tested configurations is completely dependent on both materials selection and their thermophysical properties. Finally, comparison between numerical and experimental results showed good agreement with acceptable errors margins with an average of 3 %.

  19. Comparison Experiments of Different Model Error Schemes in Ensemble Kalman Filter Soil Moisture Assimilation

    Science.gov (United States)

    Nie, Suping; Zhu, Jiang; Luo, Yong

    2010-05-01

    The purpose of this study is to explore the performances of different model error scheme in soil moisture data assimilation. Based on the ensemble Kalman filter (EnKF) and the atmosphere-vegetation interaction model (AVIM), point-scale analysis results for three schemes, 1) covariance inflation (CI), 2) direct random disturbance (DRD), and 3) error source random disturbance (ESRD), are combined under conditions of different observational error estimations, different observation layers, and different observation intervals using a series of idealized experiments. The results shows that all these schemes obtain good assimilation results when the assumed observational error is an accurate statistical representation of the actual error used to perturb the original truth value, and the ESRD scheme has the least root mean square error (RMSE). Overestimation or underestimation of the observational errors can affect the assimilation results of CI and DRD schemes sensitively. The performances of these two schemes deteriorate obviously while the ESRD scheme keeps its capability well. When the observation layers or observation interval increase, the performances of both CI and DRD schemes decline evidently. But for the ESRD scheme, as it can assimilate multi-layer observations coordinately, the increased observations improve the assimilation results further. Moreover, as the ESRD scheme contains a certain amount of model error estimation functions in its assimilation process, it also has a good performance in assimilating sparse-time observations.

  20. Impact of rainfall spatial distribution on rainfall-runoff modelling efficiency and initial soil moisture conditions estimation

    Directory of Open Access Journals (Sweden)

    Y. Tramblay

    2011-01-01

    Full Text Available A good knowledge of rainfall is essential for hydrological operational purposes such as flood forecasting. The objective of this paper was to analyze, on a relatively large sample of flood events, how rainfall-runoff modeling using an event-based model can be sensitive to the use of spatial rainfall compared to mean areal rainfall over the watershed. This comparison was based not only on the model's efficiency in reproducing the flood events but also through the estimation of the initial conditions by the model, using different rainfall inputs. The initial conditions of soil moisture are indeed a key factor for flood modeling in the Mediterranean region. In order to provide a soil moisture index that could be related to the initial condition of the model, the soil moisture output of the Safran-Isba-Modcou (SIM model developed by Météo-France was used. This study was done in the Gardon catchment (545 km2 in South France, using uniform or spatial rainfall data derived from rain gauge and radar for 16 flood events. The event-based model considered combines the SCS runoff production model and the Lag and Route routing model. Results show that spatial rainfall increases the efficiency of the model. The advantage of using spatial rainfall is marked for some of the largest flood events. In addition, the relationship between the model's initial condition and the external predictor of soil moisture provided by the SIM model is better when using spatial rainfall, in particular when using spatial radar data with R2 values increasing from 0.61 to 0.72.

  1. A coupled force-restore model of surface temperature and soil moisture using the maximum entropy production model of heat fluxes

    Science.gov (United States)

    Huang, S.-Y.; Wang, J.

    2016-07-01

    A coupled force-restore model of surface soil temperature and moisture (FRMEP) is formulated by incorporating the maximum entropy production model of surface heat fluxes and including the gravitational drainage term. The FRMEP model driven by surface net radiation and precipitation are independent of near-surface atmospheric variables with reduced sensitivity to the uncertainties of model input and parameters compared to the classical force-restore models (FRM). The FRMEP model was evaluated using observations from two field experiments with contrasting soil moisture conditions. The modeling errors of the FRMEP predicted surface temperature and soil moisture are lower than those of the classical FRMs forced by observed or bulk formula based surface heat fluxes (bias 1 ~ 2°C versus ~4°C, 0.02 m3 m-3 versus 0.05 m3 m-3). The diurnal variations of surface temperature, soil moisture, and surface heat fluxes are well captured by the FRMEP model measured by the high correlations between the model predictions and observations (r ≥ 0.84). Our analysis suggests that the drainage term cannot be neglected under wet soil condition. A 1 year simulation indicates that the FRMEP model captures the seasonal variation of surface temperature and soil moisture with bias less than 2°C and 0.01 m3 m-3 and correlation coefficients of 0.93 and 0.9 with observations, respectively.

  2. Tidal Movement of Nioghalvfjerdsfjorden Glacier, Northeast Greenland: Observations and Modelling

    DEFF Research Database (Denmark)

    Reeh, Niels; Mayer, C.; Olesen, O. B.

    2000-01-01

    , 1997 and 1998. As part of this work, tidal-movement observations were carried out by simultaneous differential global positioning system (GPS) measurements at several locations distributed on the glacier surface. The GPS observations were performed continuously over several tidal cycles. At the same....... The observations show that the main part of the glacier tongue responds as a freely floating plate to the phase and amplitude of the local tide in the sea. However, kilometre-wide flexure zones exist along the marginal and upstream grounding lines. Attempts to model the observed tidal deflection and tilt patterns...... in the flexure zone by elastic-beam theory are unsuccessful, in contrast to previous findings by other investigators. The strongest disagreement between our measurements and results derived from elastic-beam theory is a significant variation of the phase of the tidal records with distance from the grounding line...

  3. Results from Assimilating AMSR-E Soil Moisture Estimates into a Land Surface Model Using an Ensemble Kalman Filter in the Land Information System

    Science.gov (United States)

    Blankenship, Clay B.; Crosson, William L.; Case, Jonathan L.; Hale, Robert

    2010-01-01

    Improve simulations of soil moisture/temperature, and consequently boundary layer states and processes, by assimilating AMSR-E soil moisture estimates into a coupled land surface-mesoscale model Provide a new land surface model as an option in the Land Information System (LIS)

  4. Modeling movements of a long hand-held tool with effects of moments of inertia.

    Science.gov (United States)

    Lin, Chiuhsiang Joe; Chen, Hung-Jen

    2014-04-01

    The current experiment aimed to investigate the effects of weight position on movement time in target acquisition tasks. Subsequently, a simple mathematical model was developed to describe the movement time with the moments of inertia. Ten right-handed participants conducted continuous Fitts pointing tasks using a laparoscopic instrument as a long hand-held tool. The results showed significant effects of weight position on movement time. Furthermore, an extended Fitts' law model is proposed for the moments of inertia produced by the hand, instrument, and a constant mass in different positions. This predictive model accounted for 63% of the variance in movement time. The predictive model proposed in the present study can be applied not only to estimate movement time given a particular target width, instrument movement amplitude, and weight position of a long hand-held tool but also to standardize movement time and establish training standards.

  5. Application of HEC-HMS in a Cold Region Watershed and Use of RADARSAT-2 Soil Moisture in Initializing the Model

    OpenAIRE

    Hassan A. K. M. Bhuiyan; Heather McNairn; Jarrett Powers; Amine Merzouki

    2017-01-01

    This paper presents an assessment of the applicability of using RADARSAT-2-derived soil moisture data in the Hydrologic Modelling System developed by the Hydrologic Engineering Center (HEC-HMS) for flood forecasting with a case study in the Sturgeon Creek watershed in Manitoba, Canada. Spring flooding in Manitoba is generally influenced by both winter precipitation and soil moisture conditions in the fall of the previous year. As a result, the soil moisture accounting (SMA) and the temperatur...

  6. Improved large-scale hydrological modelling through the assimilation of streamflow and downscaled satellite soil moisture observations

    Science.gov (United States)

    López López, Patricia; Wanders, Niko; Schellekens, Jaap; Renzullo, Luigi J.; Sutanudjaja, Edwin H.; Bierkens, Marc F. P.

    2016-07-01

    The coarse spatial resolution of global hydrological models (typically >  0.25°) limits their ability to resolve key water balance processes for many river basins and thus compromises their suitability for water resources management, especially when compared to locally tuned river models. A possible solution to the problem may be to drive the coarse-resolution models with locally available high-spatial-resolution meteorological data as well as to assimilate ground-based and remotely sensed observations of key water cycle variables. While this would improve the resolution of the global model, the impact of prediction accuracy remains largely an open question. In this study, we investigate the impact of assimilating streamflow and satellite soil moisture observations on the accuracy of global hydrological model estimations, when driven by either coarse- or high-resolution meteorological observations in the Murrumbidgee River basin in Australia. To this end, a 0.08° resolution version of the PCR-GLOBWB global hydrological model is forced with downscaled global meteorological data (downscaled from 0.5° to 0.08° resolution) obtained from the WATCH Forcing Data methodology applied to ERA-Interim (WFDEI) and a local high-resolution, gauging-station-based gridded data set (0.05°). Downscaled satellite-derived soil moisture (downscaled from ˜  0.5° to 0.08° resolution) from the remote observation system AMSR-E and streamflow observations collected from 23 gauging stations are assimilated using an ensemble Kalman filter. Several scenarios are analysed to explore the added value of data assimilation considering both local and global meteorological data. Results show that the assimilation of soil moisture observations results in the largest improvement of the model estimates of streamflow. The joint assimilation of both streamflow and downscaled soil moisture observations leads to further improvement in streamflow simulations (20 % reduction in RMSE). Furthermore

  7. Soil moisture modelling of a SMOS pixel: interest of using the PERSIANN database over the Valencia Anchor Station

    Directory of Open Access Journals (Sweden)

    S. Juglea

    2010-08-01

    Full Text Available In the framework of Soil Moisture and Ocean Salinity (SMOS Calibration/Validation (Cal/Val activities, this study addresses the use of the PERSIANN-CCS1database in hydrological applications to accurately simulate a whole SMOS pixel by representing the spatial and temporal heterogeneity of the soil moisture fields over a wide area (50×50 km2. The study focuses on the Valencia Anchor Station (VAS experimental site, in Spain, which is one of the main SMOS Cal/Val sites in Europe.

    A faithful representation of the soil moisture distribution at SMOS pixel scale (50×50 km2 requires an accurate estimation of the amount and temporal/spatial distribution of precipitation. To quantify the gain of using the comprehensive PERSIANN database instead of sparsely distributed rain gauge measurements, comparisons between in situ observations and satellite rainfall data are done both at point and areal scale. An overestimation of the satellite rainfall amounts is observed in most of the cases (about 66% but the precipitation occurrences are in general retrieved (about 67%.

    To simulate the high variability in space and time of surface soil moisture, a Soil Vegetation Atmosphere Transfer (SVAT model – ISBA (Interactions between Soil Biosphere Atmosphere is used. The interest of using satellite rainfall estimates as well as the influence that the precipitation events can induce on the modelling of the water content in the soil is depicted by a comparison between different soil moisture data. Point-like and spatialized simulated data using rain gauge observations or PERSIANN – CCS database as well as ground measurements are used. It is shown that a good adequacy is reached in most part of the year, the precipitation differences having less impact upon the simulated soil moisture. The behaviour of simulated surface soil moisture at SMOS scale is verified by the use of remote sensing data from the Advanced

  8. An empirical movement model for sixgill sharks in Puget Sound: Combining observed and unobserved behavior

    OpenAIRE

    Phillip S. LEVIN, Peter HORNE, Kelly S. ANDREWS, Greg WILLIAMS

    2012-01-01

    Understanding the movement of animals is fundamental to population and community ecology. Historically, it has been difficult to quantify movement patterns of most fishes, but technological advances in acoustic telemetry have increased our abilities to monitor their movement. In this study, we combined small-scale active acoustic tracking with large-scale passive acoustic monitoring to develop an empirical movement model for sixgill sharks in Puget Sound, WA, USA. We began by testing whether ...

  9. Modeling Movement Primitives with Hidden Markov Models for Robotic and Biomedical Applications.

    Science.gov (United States)

    Karg, Michelle; Kulić, Dana

    2017-01-01

    Movement primitives are elementary motion units and can be combined sequentially or simultaneously to compose more complex movement sequences. A movement primitive timeseries consist of a sequence of motion phases. This progression through a set of motion phases can be modeled by Hidden Markov Models (HMMs). HMMs are stochastic processes that model time series data as the evolution of a hidden state variable through a discrete set of possible values, where each state value is associated with an observation (emission) probability. Each motion phase is represented by one of the hidden states and the sequential order by their transition probabilities. The observations of the MP-HMM are the sensor measurements of the human movement, for example, motion capture or inertial measurements. The emission probabilities are modeled as Gaussians. In this chapter, the MP-HMM modeling framework is described and applications to motion recognition and motion performance assessment are discussed. The selected applications include parametric MP-HMMs for explicitly modeling variability in movement performance and the comparison of MP-HMMs based on the loglikelihood, the Kullback-Leibler divergence, the extended HMM-based F-statistic, and gait-specific reference-based measures.

  10. Moisture-induced quality changes of hen egg white proteins in a protein/water model system.

    Science.gov (United States)

    Rao, Qinchun; Rocca-Smith, Jeancarlo R; Labuza, Theodore P

    2012-10-24

    In recent years, the intermediate-moisture foods (IMF), such as nutrition and energy bars, are a rapidly growing segment of the global food market. However, due to moisture-induced protein aggregation, commercial high protein nutrition bars generally become harder over time, thus losing product acceptability. In this study, the objectives were to investigate the moisture-induced protein aggregation in a hen egg white proteins/water dough model system (water activity (a(w)): 0.95) and to evaluate its molecular mechanisms and controlling factors. During storage at three different temperatures (23, 35, and 45 °C) for 70 days, four selected physicochemical changes of the dough system were analyzed: the a(w), the color (L* value), the fluorescent Maillard compounds (fluorescence intensity (FI) value), and the remaining free amino groups. Overall, the physicochemical changes of egg white proteins in the dough system are closely related to the glass transition temperature (T(g)). The effect of moisture content on both the L* and FI values occurred as a function of storage time at 45 °C due to the Maillard reaction. The change of the remaining free amino groups at different temperatures was derived from the coaction of both the Maillard reaction and enzymatic hydrolysis from molds. Additionally, through analyzing the buffer-soluble egg white proteins using gel electrophoresis, our results showed that moisture-induced aggregates were produced by two chemical reactions during storage: the disulfide interaction and the Maillard reaction. Furthermore, the effect of two processes during manufacturing, desugarization and dry-heat pasteurization, on the physicochemical changes of the egg white proteins was elucidated. In order to prevent or reduce moisture-induced protein aggregation during product storage and distribution, two potential solutions were also discussed.

  11. Temperature Knowledge and Model Correlation for the Soil Moisture Active and Passive (SMAP) Reflector Mesh

    Science.gov (United States)

    Mikhaylov, Rebecca; Dawson, Douglas; Kwack, Eug

    2014-01-01

    NASA's Earth observing Soil Moisture Active & Passive (SMAP) Mission is scheduled to launch in November 2014 into a 685 km near-polar, sun synchronous orbit. SMAP will provide comprehensive global mapping measurements of soil moisture and freeze/thaw state in order to enhance understanding of the processes that link the water, energy, and carbon cycles. The primary objectives of SMAP are to improve worldwide weather and flood forecasting, enhance climate prediction, and refine drought and agriculture monitoring during its 3 year mission. The SMAP instrument architecture incorporates an L-band radar and an L-band radiometer which share a common feed horn and parabolic mesh reflector. The instrument rotates about the nadir axis at approximately 15 rpm, thereby providing a conically scanning wide swath antenna beam that is capable of achieving global coverage within 3 days. In order to make the necessary precise surface emission measurements from space, a temperature knowledge of 60 deg C for the mesh reflector is required. In order to show compliance, a thermal vacuum test was conducted using a portable solar simulator to illuminate a non flight, but flight-like test article through the quartz window of the vacuum chamber. The molybdenum wire of the antenna mesh is too fine to accommodate thermal sensors for direct temperature measurements. Instead, the mesh temperature was inferred from resistance measurements made during the test. The test article was rotated to five separate angles between 10 deg and 90 deg via chamber breaks to simulate the maximum expected on-orbit solar loading during the mission. The resistance measurements were converted to temperature via a resistance versus temperature calibration plot that was constructed from data collected in a separate calibration test. A simple thermal model of two different representations of the mesh (plate and torus) was created to correlate the mesh temperature predictions to within 60 deg C. The on-orbit mesh

  12. Modeling the influence of temperature, water activity and water mobility on the persistence of Salmonella in low-moisture foods.

    Science.gov (United States)

    Farakos, S M Santillana; Frank, J F; Schaffner, D W

    2013-09-02

    Salmonella can survive in low-moisture foods for long periods of time. Reduced microbial inactivation during heating is believed to be due to the interaction of cells and water, and is thought to be related to water activity (a(w)). Little is known about the role of water mobility in influencing the survival of Salmonella in low-moisture foods. The aim of this study was to determine how the physical state of water in low-moisture foods influences the survival of Salmonella and to use this information to develop mathematical models that predict the behavior of Salmonella in these foods. Whey protein powder of differing water mobilities was produced by pH adjustment and heat denaturation, and then equilibrated to aw levels between 0.19±0.03 and 0.54±0.02. Water mobility was determined by wide-line proton-NMR. Powders were inoculated with a four-strain cocktail of Salmonella, vacuum-sealed and stored at 21, 36, 50, 60, 70 and 80°C. Survival data was fitted to the log-linear, the Geeraerd-tail, the Weibull, the biphasic-linear and the Baranyi models. The model with the best ability to describe the data over all temperatures, water activities and water mobilities (f(test)water mobility on the survival of Salmonella was evaluated using multiple linear regression. Secondary models were developed and then validated in dry non-fat dairy and grain, and low-fat peanut and cocoa products within the range of the modeled data. Water activity significantly influenced the survival of Salmonella at all temperatures, survival increasing with decreasing a(w). Water mobility did not significantly influence survival independent of a(w). Secondary models were useful in predicting the survival of Salmonella in various low-moisture foods providing a correlation of R=0.94 and an acceptable prediction performance of 81%. The % bias and % discrepancy results showed that the models were more accurate in predicting survival in non-fat food systems as compared to foods containing low

  13. Updated global soil map for the Weather Research and Forecasting model and soil moisture initialization for the Noah land surface model

    Science.gov (United States)

    DY, C. Y.; Fung, J. C. H.

    2016-08-01

    A meteorological model requires accurate initial conditions and boundary conditions to obtain realistic numerical weather predictions. The land surface controls the surface heat and moisture exchanges, which can be determined by the physical properties of the soil and soil state variables, subsequently exerting an effect on the boundary layer meteorology. The initial and boundary conditions of soil moisture are currently obtained via National Centers for Environmental Prediction FNL (Final) Operational Global Analysis data, which are collected operationally in 1° by 1° resolutions every 6 h. Another input to the model is the soil map generated by the Food and Agriculture Organization of the United Nations - United Nations Educational, Scientific and Cultural Organization (FAO-UNESCO) soil database, which combines several soil surveys from around the world. Both soil moisture from the FNL analysis data and the default soil map lack accuracy and feature coarse resolutions, particularly for certain areas of China. In this study, we update the global soil map with data from Beijing Normal University in 1 km by 1 km grids and propose an alternative method of soil moisture initialization. Simulations of the Weather Research and Forecasting model show that spinning-up the soil moisture improves near-surface temperature and relative humidity prediction using different types of soil moisture initialization. Explanations of that improvement and improvement of the planetary boundary layer height in performing process analysis are provided.

  14. Simulating train movement in railway traffic using a car-following model

    Institute of Scientific and Technical Information of China (English)

    Li Ke-Ping; Guan Li-Jia

    2009-01-01

    Based on a car-following model, in this paper, we propose a new traffic model for simulating train movement in railway traffic. In the proposed model, some realistic characteristics of train movement are considered, such as the distance headway and the safety stopping distance. Using the proposed traffic model, we analyse the space-time diagram of traffic flow, the trajectory of train movement, etc. Simulation results demonstrate that the proposed model can be successfully used for simulating the train movement. Some complex phenomena can be reproduced, such as the complex acceleration and deceleration of trains and the propagation of train delay.

  15. Impact of moisture divergence on systematic errors in precipitation around the Tibetan Plateau in a general circulation model

    Science.gov (United States)

    Zhang, Yi; Li, Jian

    2016-11-01

    Current state-of-the-art atmospheric general circulation models tend to strongly overestimate the amount of precipitation around steep mountains, which constitutes a stubborn systematic error that causes the climate drift and hinders the model performance. In this study, two contrasting model tests are performed to investigate the sensitivity of precipitation around steep slopes. The first model solves a true moisture advection equation, whereas the second solves an artificial advection equation with an additional moisture divergence term. It is shown that the orographic precipitation can be largely impacted by this term. Excessive (insufficient) precipitation amounts at the high (low) parts of the steep slopes decrease (increase) when the moisture divergence term is added. The precipitation changes between the two models are primarily attributed to large-scale precipitation, which is directly associated with water vapor saturation and condensation. Numerical weather prediction experiments using these two models suggest that precipitation differences between the models emerge shortly after the model startup. The implications of the results are also discussed.

  16. Dynamical movement primitives: learning attractor models for motor behaviors.

    Science.gov (United States)

    Ijspeert, Auke Jan; Nakanishi, Jun; Hoffmann, Heiko; Pastor, Peter; Schaal, Stefan

    2013-02-01

    Nonlinear dynamical systems have been used in many disciplines to model complex behaviors, including biological motor control, robotics, perception, economics, traffic prediction, and neuroscience. While often the unexpected emergent behavior of nonlinear systems is the focus of investigations, it is of equal importance to create goal-directed behavior (e.g., stable locomotion from a system of coupled oscillators under perceptual guidance). Modeling goal-directed behavior with nonlinear systems is, however, rather difficult due to the parameter sensitivity of these systems, their complex phase transitions in response to subtle parameter changes, and the difficulty of analyzing and predicting their long-term behavior; intuition and time-consuming parameter tuning play a major role. This letter presents and reviews dynamical movement primitives, a line of research for modeling attractor behaviors of autonomous nonlinear dynamical systems with the help of statistical learning techniques. The essence of our approach is to start with a simple dynamical system, such as a set of linear differential equations, and transform those into a weakly nonlinear system with prescribed attractor dynamics by means of a learnable autonomous forcing term. Both point attractors and limit cycle attractors of almost arbitrary complexity can be generated. We explain the design principle of our approach and evaluate its properties in several example applications in motor control and robotics.

  17. Recording Lifetime Behavior and Movement in an Invertebrate Model

    Science.gov (United States)

    Zou, Sige; Liedo, Pablo; Altamirano-Robles, Leopoldo; Cruz-Enriquez, Janeth; Morice, Amy; Ingram, Donald K.; Kaub, Kevin; Papadopoulos, Nikos; Carey, James R.

    2011-01-01

    Characterization of lifetime behavioral changes is essential for understanding aging and aging-related diseases. However, such studies are scarce partly due to the lack of efficient tools. Here we describe and provide proof of concept for a stereo vision system that classifies and sequentially records at an extremely fine scale six different behaviors (resting, micro-movement, walking, flying, feeding and drinking) and the within-cage (3D) location of individual tephritid fruit flies by time-of-day throughout their lives. Using flies fed on two different diets, full sugar-yeast and sugar-only diets, we report for the first time their behavioral changes throughout their lives at a high resolution. We have found that the daily activity peaks at the age of 15–20 days and then gradually declines with age for flies on both diets. However, the overall daily activity is higher for flies on sugar-only diet than those on the full diet. Flies on sugar-only diet show a stronger diurnal localization pattern with higher preference to staying on the top of the cage during the period of light-off when compared to flies on the full diet. Clustering analyses of age-specific behavior patterns reveal three distinct young, middle-aged and old clusters for flies on each of the two diets. The middle-aged groups for flies on sugar-only diet consist of much younger age groups when compared to flies on full diet. This technology provides research opportunities for using a behavioral informatics approach for understanding different ways in which behavior, movement, and aging in model organisms are mutually affecting. PMID:21559058

  18. Evaluating Heating and Moisture Variability Associated with MJO Events in a Low-Dimension Dynamic Model with Observations and Reanalyses

    Science.gov (United States)

    Stachnik, J. P.; Waliser, D. E.; Majda, A.; Stechmann, S.

    2013-12-01

    The Madden-Julian Oscillation (MJO) is the leading mode of intraseasonal variability in the tropics. Despite its importance toward determining large-scale variability at both low-latitudes and the extratropics, MJO prediction often suffers from low skill regarding event initiation and its overall simulation remains a challenge in many global climate models (GCMs). The MJO 'skeleton' model, originally developed by Majda and Stechmann (2009), is a new low-order dynamic model that is capable of reproducing several salient features of the MJO despite its many simplifications relative to higher-order GCMs. Among their successes, the newest version of the skeleton model is able to reproduce the intermittent generation of MJO events, including organization into MJO wave trains that experience both growth and decay. This study presents an analysis of initiation events in the skeleton model. Higher-order features, such as the organization into wave trains, are examined herein and we document the simulated heating and moisture variability in the model compared to satellite-derived observations and reanalyses. We likewise present a composite analysis of the thermodynamic fields related to the initiation of primary and successive MJO events, as well as those precursor conditions leading to quiescent periods of the MJO. Time permitting, we also evaluate the multi-scale structures and other aspects of heating and moisture variability in the model (e.g., asymmetry between active and inactive periods) compared to distributions of integrated heating and moisture in Tropical Rainfall Measuring Mission (TRMM) observations and other datasets.

  19. A general discrete-time modeling framework for animal movement using multistate random walks

    OpenAIRE

    McClintock, B.T.; King, R; Thomas, L.; Matthiopoulos, J.; McConnell, B.J.; Morales, J.M.

    2012-01-01

    Recent developments in animal tracking technology have permitted the collection of detailed data on the movement paths of individuals from many species. However, analysis methods for these data have not developed at a similar pace, largely due to a lack of suitable candidate models, coupled with the technical difficulties of fitting such models to data. To facilitate a general modeling framework, we propose that complex movement paths can be conceived as a series of movement strategies among ...

  20. Modeling of water transport in roof tiles by removal of moisture at isothermal conditions

    Science.gov (United States)

    da Silva, Wilton Pereira; de Oliveira Farias, Vera Solange; de Araújo Neves, Gelmires; de Lima, Antonio Gilson Barbosa

    2012-05-01

    The main objective of this article is to describe the drying process of ceramic roof tiles, shaped from red clay, using diffusion models. Samples of the product with initial moisture content of 0.24 (db) were placed inside an oven in the temperatures of 55.6, 69.7, 82.7 and 98.6°C; and the data of the drying kinetics were obtained. The analytical solutions of the diffusion equation for the parallelepiped with boundary conditions of the first and third kinds were used to describe the drying processes. The process parameters were determined using an optimization algorithm based on inverse method coupled to the analytical solutions. The analysis of the results makes it possible to affirm that the boundary condition of the third kind satisfactorily describes the drying processes. The values obtained for the convective mass transfer coefficient were between 8.25 × 10-7 and 1.64 × 10-6 m s-1, and for the effective water diffusivity were between 9.21 × 10-9 and 1.80 × 10-8 m2 s-1.

  1. Model-based surface soil moisture (SSM) retrieval algorithm using multi-temporal RISAT-1 C-band SAR data

    Science.gov (United States)

    Pandey, Dharmendra K.; Maity, Saroj; Bhattacharya, Bimal; Misra, Arundhati

    2016-05-01

    Accurate measurement of surface soil moisture of bare and vegetation covered soil over agricultural field and monitoring the changes in surface soil moisture is vital for estimation for managing and mitigating risk to agricultural crop, which requires information and knowledge to assess risk potential and implement risk reduction strategies and deliver essential responses. The empirical and semi-empirical model-based soil moisture inversion approach developed in the past are either sensor or region specific, vegetation type specific or have limited validity range, and have limited scope to explain physical scattering processes. Hence, there is need for more robust, physical polarimetric radar backscatter model-based retrieval methods, which are sensor and location independent and have wide range of validity over soil properties. In the present study, Integral Equation Model (IEM) and Vector Radiative Transfer (VRT) model were used to simulate averaged backscatter coefficients in various soil moisture (dry, moist and wet soil), soil roughness (smooth to very rough) and crop conditions (low to high vegetation water contents) over selected regions of Gujarat state of India and the results were compared with multi-temporal Radar Imaging Satellite-1 (RISAT-1) C-band Synthetic Aperture Radar (SAR) data in σ°HH and σ°HV polarizations, in sync with on field measured soil and crop conditions. High correlations were observed between RISAT-1 HH and HV with model simulated σ°HH & σ°HV based on field measured soil with the coefficient of determination R2 varying from 0.84 to 0.77 and RMSE varying from 0.94 dB to 2.1 dB for bare soil. Whereas in case of winter wheat crop, coefficient of determination R2 varying from 0.84 to 0.79 and RMSE varying from 0.87 dB to 1.34 dB, corresponding to with vegetation water content values up to 3.4 kg/m2. Artificial Neural Network (ANN) methods were adopted for model-based soil moisture inversion. The training datasets for the NNs were

  2. A land surface soil moisture data assimilation framework in consideration of the model subgrid-scale heterogeneity and soil water thawing and freezing

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The Ensemble Kalman Filter (EnKF) is well known and widely used in land data assimilation for its high precision and simple operation. The land surface models used as the forecast operator in a land data assimilation system are usually designed to consider the model subgrid-heterogeneity and soil water thawing and freezing. To neglect their effects could lead to some errors in soil moisture assimilation. The dual EnKF method is employed in soil moisture data assimilation to build a soil moisture data as- similation framework based on the NCAR Community Land Model version 2.0 (CLM 2.0) in considera- tion of the effects of the model subgrid-heterogeneity and soil water thawing and freezing: Liquid volumetric soil moisture content in a given fraction is assimilated through the state filter process, while solid volumetric soil moisture content in the same fraction and solid/liquid volumetric soil moisture in the other fractions are optimized by the parameter filter. Preliminary experiments show that this dual EnKF-based assimilation framework can assimilate soil moisture more effectively and precisely than the usual EnKF-based assimilation framework without considering the model subgrid-scale heteroge- neity and soil water thawing and freezing. With the improvement of soil moisture simulation, the soil temperature-simulated precision can be also improved to some extent.

  3. A land surface soil moisture data assimilation framework in consideration of the model subgrid-scale heterogeneity and soil water thawing and freezing

    Institute of Scientific and Technical Information of China (English)

    TIAN XiangJun; XIE ZhengHui

    2008-01-01

    The Ensemble Kalman Filter (EnKF) is well known and widely used in land data assimilation for its high precision and simple operation. The land surface models used as the forecast operator in a land data assimilation system are usually designed to consider the model subgrid-heterogeneity and soil water thawing and freezing. To neglect their effects could lead to some errors in soil moisture assimilation.The dual EnKF method is employed in soil moisture data assimilation to build a soil moisture data assimilation framework based on the NCAR Community Land Model version 2.0 (CLM 2.0) in consideration of the effects of the model subgrid-heterogeneity and soil water thawing and freezing: Liquid volumetric soil moisture content in a given fraction is assimilated through the state filter process,while solid volumetric soil moisture content in the same fraction and solid/liquid volumetric soil moisture in the other fractions are optimized by the parameter filter. Preliminary experiments show that this dual EnKF-based assimilation framework can assimilate soil moisture more effectively and precisely than the usual EnKF-based assimilation framework without considering the model subgrid-scale heterogeneity and soil water thawing and freezing. With the improvement of soil moisture simulation,the soil temperature-simulated precision can be also improved to some extent.

  4. Model for processive movement of myosin Ⅴ and myosin Ⅵ

    Institute of Scientific and Technical Information of China (English)

    Xie Ping; Dou Shuo-Xing; Wang Peng-Ye

    2005-01-01

    Myosin Ⅴ and myosin Ⅵ are two classes of two-headed molecular motors of the myosin superfamily that move processively along helical actin filaments in opposite directions. Here we present a hand-over-hand model for their processive movements. In the model, the moving direction of a dimeric molecular motor is automatically determined by the relative orientation between its two heads at free state and its head's binding orientation on track filament.This determines that myosin Ⅴ moves toward the barbed end and myosin Ⅵ moves toward the pointed end of actin.During the moving period in one step, one head remains bound to actin for myosin Ⅴ whereas two heads are detached for myosin Ⅵ: the moving manner is determined by the length of neck domain. This naturally explains the similar dynamic behaviours but opposite moving directions of myosin Ⅵ and mutant myosin Ⅴ (the neck of which is truncated to only one-sixth of the native length). Because of different moving manners, myosin Ⅵ and mutant myosin Ⅴ exhibit significantly broader step-size distribution than native myosin Ⅴ. However, all the three motors give the same mean step size of ~36nm (the pseudo-repeat of actin helix). All these theoretical results are in agreement with previous experimental ones.

  5. Modeling crawling cell movement on soft engineered substrates.

    Science.gov (United States)

    Löber, Jakob; Ziebert, Falko; Aranson, Igor S

    2014-03-07

    Self-propelled motion, emerging spontaneously or in response to external cues, is a hallmark of living organisms. Systems of self-propelled synthetic particles are also relevant for multiple applications, from targeted drug delivery to the design of self-healing materials. Self-propulsion relies on the force transfer to the surrounding. While self-propelled swimming in the bulk of liquids is fairly well characterized, many open questions remain in our understanding of self-propelled motion along substrates, such as in the case of crawling cells or related biomimetic objects. How is the force transfer organized and how does it interplay with the deformability of the moving object and the substrate? How do the spatially dependent traction distribution and adhesion dynamics give rise to complex cell behavior? How can we engineer a specific cell response on synthetic compliant substrates? Here we generalize our recently developed model for a crawling cell by incorporating locally resolved traction forces and substrate deformations. The model captures the generic structure of the traction force distribution and faithfully reproduces experimental observations, like the response of a cell on a gradient in substrate elasticity (durotaxis). It also exhibits complex modes of cell movement such as "bipedal" motion. Our work may guide experiments on cell traction force microscopy and substrate-based cell sorting and can be helpful for the design of biomimetic "crawlers" and active and reconfigurable self-healing materials.

  6. Showing a model's eye movements in examples does not improve learning of problem-solving tasks

    NARCIS (Netherlands)

    van Marlen, Tim; van Wermeskerken, Margot; Jarodzka, Halszka; van Gog, Tamara

    2016-01-01

    Eye movement modeling examples (EMME) are demonstrations of a computer-based task by a human model (e.g., a teacher), with the model's eye movements superimposed on the task to guide learners' attention. EMME have been shown to enhance learning of perceptual classification tasks; however, it is an

  7. Showing a model's eye movements in examples does not improve learning of problem-solving tasks

    NARCIS (Netherlands)

    van Marlen, Tim; van Wermeskerken, Margot; Jarodzka, Halszka; van Gog, Tamara

    2016-01-01

    Eye movement modeling examples (EMME) are demonstrations of a computer-based task by a human model (e.g., a teacher), with the model's eye movements superimposed on the task to guide learners' attention. EMME have been shown to enhance learning of perceptual classification tasks; however, it is an o

  8. Correlation Between Soil Moisture and Dust Emissions: An Investigation for Global Climate Modeling

    Science.gov (United States)

    Fredrickson, Carley; Tan, Qian

    2017-01-01

    This work is using the newly available NASA SMAP soil moisture measurement data to evaluate its impact on the atmospheric dust emissions. Dust is an important component of atmospheric aerosols, which affects both climate and air quality. In this work, we focused on semi-desert regions, where dust emissions show seasonal variations due to soil moisture changes, i.e. in Sahel of Africa. We first identified three Aerosol Robotic Network (AERONET) sites in the Sahel (IER_Cinzana, Banizoumbou, and Zinder_Airport). We then utilized measurements of aerosol optical depth (AOD), fine mode fraction, size distribution, and single-scattering albedo and its wave-length dependence to select dust plumes from the available measurements We matched the latitude and longitude of the AERONET station to the corresponding SMAP data cell in the years 2015 and 2016, and calculated their correlation coefficient. Additionally, we looked at the correlation coefficient with a three-day and a five-day shift to check the impact of soil moisture on dust plumes with some time delay. Due to the arid nature of Banizoumbou and Zinder_Airport, no correlation was found to exist between local soil moisture and dust aerosol load. While IER_Cinzana had soil moisture levels above the satellite threshold of 0.02cm3/cm3, R-value approaching zero indicated no presence of a correlation. On the other hand, Ilorin demonstrated a significant negative correlation between aerosol optical depth and soil moisture. When isolating the analysis to Ilorin's dry season, a negative correlation of -0.593 was the largest dust-isolated R-value recorded, suggesting that soil moisture is driven the dust emission in this semi-desert region during transitional season.

  9. A theoretical model describing diffusion of a mixture of different types of ions in pore solution of concrete coupled to moisture transport

    OpenAIRE

    Johannesson, Björn

    2000-01-01

    A theoretical model is established for diffusion of different types of ions in pore solution of concrete and the coupling to moisture flow and moisture content. Mass exchanges between ions in pore solution and solid hydration products in the concrete are also considered. The basic concepts behind the so-called mixture theory are used.

  10. An empirical movement model for sixgill sharks in Puget Sound: Combining observed and unobserved behavior

    Institute of Scientific and Technical Information of China (English)

    Phillip S. LEVIN; Peter HORNE; Kelly S. ANDREWS; Greg WILLIAMS

    2012-01-01

    Understanding the movement of animals is fundamental to population and community ecology.Historically,it has been difficult to quantify movement patterns of most fishes,but technological advances in acoustic telemetry have increased our abilities to monitor their movement.In this study,we combined small-scale active acoustic tracking with large-scale passive acoustic monitoring to develop an empirical movement model for sixgill sharks in Puget Sound,WA,USA.We began by testing whether a correlated random walk model described the daily movement of sixgills; however,the model failed to capture home-ranging behavior.We added this behavior and used the resultant model (a biased random walk model) to determine whether daily movement patterns are able to explain large-scale seasonal movement.The daily model did not explain the larger-scale patterns of movement observed in the passive monitoring data.In order to create the large-scale patterns,sixgills must have performed behaviors (large,fast directed movements) that were unobserved during small-scale active tracking.In addition,seasonal shifts in location were not captured by the daily model.We added these ‘unobserved' behaviors to the model and were able to capture large-scale seasonal movement of sixgill sharks over 150 days.The development of empirical models of movement allows researchers to develop hypotheses and test mechanisms responsible for a species movement behavior and spatial distribution.This knowledge will increase our ability to successfully manage species of concern [Current Zoology 58 (1):103-115,2012].

  11. Mathematical Modelling of Translation and Rotation Movement in Quad Tiltrotor

    Directory of Open Access Journals (Sweden)

    Andi Dharmawan

    2017-06-01

    Full Text Available Quadrotor as one type of UAV (Unmanned Aerial Vehicle is an underactuated mechanical system. It means that the system has some control inputs is lower than its DOF (Degrees of Freedom. This condition causes quadrotor to have limited mobility because of its inherent under actuation, namely, the availability of four independent control signals (four-speed rotating propellers versus 6 degrees of freedom parameterizing quadrotor position or orientation in space. If a quadrotor is made to have 6 DOF, a full motion control system to optimize the flight will be different from before. So it becomes necessary to develop over actuated quad tiltrotor. Quad tiltrotor has control signals more than its DOF. Therefore, we can refer it to the overactuated system. We need a good control system to fly the quad tiltrotor. Good control systems can be designed using the model of the quad tiltrotor system. We can create quad tiltrotor model using its dynamics based on Newton-Euler approach. After we have a set of model, we can simulate the control system using some control method. There are several control methods that we can use in the quad tiltrotor flight system. However, we can improve the control by implementing a modern control system that uses the concept of state space. The simulations show that the quad tiltrotor has done successful translational motion without significant interference. Also, undesirable rotation movement in the quad tiltrotor flight when performing the translational motions resulting from the transition process associated with the tilt rotor change was successfully reduced below 1 degree.

  12. Use of the Sacramento Soil Moisture Accounting Model in Areas with Insufficient Forcing Data

    Science.gov (United States)

    Kuzmin, V.

    2009-04-01

    The Sacramento Soil Moisture Accounting model (SAC-SMA) is known as a very reliable and effective hydrological model. It is widely used by the U.S. National Weather Service (NWS) and many organizations in other countries for operational forecasting of flash floods. As a purely conceptual model, the SAC-SMA requires a periodic re-calibration. However, this procedure is not trivial in watersheds with little or no historical data, in areas with changing watershed properties, in a changing climate environment, in regions with low quality and low spatial resolution forcing data etc. In such cases, so-called physically based models with measurable parameters also may not be an alternative, because they usually require high quality forcing data and, hence, are quite expensive. Therefore, this type of models can not be implemented in countries with scarce surface observation data. To resolve this problem, we offer using a very fast and efficient automatic calibration algorithm, a Stepwise Line Search (SLS), which has been implementing in NWS since 2005, and also its modifications that were developed especially for automated operational forecasting of flash floods in regions where high resolution and high quality forcing data are not available. The SLS-family includes several simple yet efficient calibration algorithms: 1) SLS-F, which supposes simultaneous natural smoothing of the response surface by quasi-local estimation of F-indices, what allows finding the most stable and reliable parameters that can be different from "global" optima in usual sense. (Thus, this method slightly transforms the original objective function); 2) SLS-2L (Two-Loop SLS), which is suitable for basins where hydraulic properties of soil are unknown; 3) SLS-2LF, which represents a conjunction of the SLS-F and SLS-2L algorithms and allows obtaining the SAC-SMA parameters that can be transferred to ungauged catchments; 4) SLS-E, which also supposes stochastic filtering of the model input through

  13. Modeling spatial and seasonal soil moisture in a semi arid hillslope: The impact of integrating soil surface seal parameters

    Science.gov (United States)

    Sela, Shai; Svoray, Tal; Assouline, Shmuel

    2010-05-01

    Modeling hillslope hydrology and the complex and coupled reaction of runoff processes to rainfall, lies in the focus of a growing number of research studies. The ability to characterize and understand the mechanisms underlying the complex hillslope soil moisture patterns, which trigger spatially variable non linear runoff initiation, still remains a current hydrological challenge especially in ungauged catchments. In humid climates, connectivity of transient moisture patches was suggested as a unifying concept for studying thresholds for subsurface flow and redistribution of soil moisture at the hillslope scale. In semiarid areas, however, transient moisture patches control also the differentiation between evaporation and surface runoff and the ability to identify a unifying concept controlling the large variability of soil moisture at the hillslope scale remains an open research gap. At the LTER Lehavim site in the center of Israel (31020' N, 34045' E) a typical hillslope (0.115 km2) was chosen offering different aspects and a classic geomorphologic banding. The annual rainfall is 290 mm, the soils are brown lithosols and arid brown loess and the dominant rock formations are Eocenean limestone and chalk with patches of calcrete. The vegetation is characterised by scattered dwarf shrubs (dominant species Sarcopoterium spinosum) and patches of herbaceous vegetation, mostly annuals, are spread between rocks and dwarf shrubs. An extensive spatial database of soil hydraulic and environmental parameters (e.g. slope, radiation, bulk density) was measured in the field and interpolated to continuous maps using geostatistical techniques and physically based modelling. To explore the effect of soil surface sealing, Mualem and Assouline (1989) equations describing the change in hydraulic parameters resulting from soil seal formation were applied. Two simple indices were developed to describe local evaporation values and contribution of water from rock outcrops to the soil

  14. Body Movement Music Score – Introduction of a newly developed model for the analysis and description of body qualities, movement and music in music therapy

    Directory of Open Access Journals (Sweden)

    Hanna Agnieszka Skrzypek

    2017-01-01

    Full Text Available Background In music therapy, there is a range of music therapy concepts that, in addition to music, describe and analyse the body and movement. A model that equally examines the body, movement and music has not been developed. The Body Movement Music Score (BMMS is a newly developed and evaluated music therapy model for analysing body qualities, movement, playing style of musical instruments and music and to describe body behaviour and body expression, movement behaviour and movement expression, playing behaviour and musical expression in music therapy treatment. The basis for the development of the Body Movement Music Score was the evaluation of the analytical movement model Emotorics-Emotive Body Movement Mind Paradigm (Emotorics-EBMMP by Yona Shahar Levy for the analysis and description of the emotive-motor behaviour and movement expression of schizophrenic patients in music therapy treatment. Participants and procedure The application of the Body Movement Music Score is presented in a videotaped example from the music therapy treatment of one schizophrenic patient. Results The results of applying the Body Movement Music Score are presented in the form of Body Qualities I Analysis, Body Qualities II Analysis, Movement Analysis, Playing Style Analysis and Music Analysis Profiles. Conclusions The Body Movement Music Score has been developed and evaluated for the music therapy treatment of schizophrenic patients. For the development of the model, a proof of reliability is necessary to verify the reliability and limitations of the model in practice and show that the Body Movement Music Score could be used for both practical and clinical work, for documentation purposes and to impact research in music therapy.

  15. Measurement and modelling of moisture-electrical resistivity relationship of fine-grained unsaturated soils and electrical anisotropy

    Science.gov (United States)

    Merritt, A. J.; Chambers, J. E.; Wilkinson, P. B.; West, L. J.; Murphy, W.; Gunn, D.; Uhlemann, S.

    2016-01-01

    A methodology for developing resistivity-moisture content relationships of materials associated with a clayey landslide is presented. Key elements of the methodology include sample selection and preparation, laboratory measurement of resistivity with changing moisture content, and the derivation of models describing the relationship between resistivity and moisture content. Laboratory resistivity measurements show that the techniques utilised (samples and square array) have considerable potential as a means of electropetrophysical calibration of engineering soils and weak rock. Experimental electrical resistivity results show a hierarchy of values dependent on sample lithology, with silty clay exhibiting the lowest resistivities, followed by siltstones and sands, which return the highest resistivities. In addition, finer grained samples show a greater degree of anisotropy between measurement orientations than coarser grained samples. However, suitability of results in light of issues such as sample cracking and electrical conduction must be identified and accounted for if the results are to be accurately up-scaled to inverted model resistivity results. The existence of directional anisotropy makes model calibration curve selection more difficult due to variability in the range of measured laboratory resistances. The use of larger measurement array size means that experimental data will be more representative of bulk lithological properties. In addition, use of electrodes with a relatively high surface area (wide diameter) help maintain low contact resistances and repeat measurement error, relative to narrow electrodes. Variation exists between the fit of experimental data and petrophysical models. Model fit is best for clay-dominated samples but fits less well for sand-dominated samples. Waxman-Smits equation is appropriately applied in this investigation as all samples have considerable clay mineral content, as is shown in non-negligible CEC results. The

  16. Using Distributed-Hydrology-Soil-Vegetation Model to Study Road Effects on Stream flow and Soil Moisture

    Science.gov (United States)

    Cuo, L.; Giambelluca, T. W.; Ziegler, A. D.; Nullet, M. A.

    2003-12-01

    The distributed-hydrology-soil-vegetation model (DHSVM) was applied in Pang Khum Experimental Watershed (PKEW), located near 19.05\\deg N, 98.65\\deg E in the mountainous region of northern Thailand, headwaters of the Chao Phraya River system. PKEW has a highly seasonal rainfall regime, with 90% of the annual 1200-1400 mm rainfall occurring during the southwest summer monsoon. The elevation of PKEW ranges from approximately 1100 to 1500 m. Total road area including road banks is about 1.2% of the basin area. About 57% of the road area occurs on slopes steeper than 10%. All roads are unpaved. Land cover in PKEW is affected by swidden agriculture. Six land cover and nine soil classes are identified in the basin. We have been working in the area since 1997 as part of the Thailand Roads Project (TRP). Within the basin, we are monitoring microclimate at two sites, soil moisture at four sites, and rainfall at five sites. Streamflow is measured at the outlet. Based on digital elevation data, DHSVM explicitly accounts for the spatial distribution of the stream and road networks, soil depth, soil and vegetation types. The model run period, including warm up, calibration and validation, is from August 1997 to January 2001. Field measurements provide forcing data, calibration data, and guidance in parameter selection. Model calibration and validation were done by aggregating simulated hourly soil moisture and stream flow into daily values and comparing them with aggregated daily measurements. For the calibration period, RMSEs of soil moisture and streamflow were lower than the observed variability as represented by the standard deviation, median absolute deviation, and (for stream flow) interquartile range. Model performance drops in validation period, but RMSEs remain near or lower than observed variability. We ran DHSVM with and without roads to examine their effects. Significant effects of roads were found despite the very low proportion of the watershed covered by roads

  17. Varying applicability of four different satellite-derived soil moisture products to global gridded crop model evaluation

    Science.gov (United States)

    Sakai, Toru; Iizumi, Toshichika; Okada, Masashi; Nishimori, Motoki; Grünwald, Thomas; Prueger, John; Cescatti, Alessandro; Korres, Wolfgang; Schmidt, Marius; Carrara, Arnaud; Loubet, Benjamin; Ceschia, Eric

    2016-06-01

    Satellite-derived daily surface soil moisture products have been increasingly available, but their applicability to global gridded crop model (GGCM) evaluation is unclear. This study compares four different soil moisture products with the flux tower site observation at 18 cropland sites across the world where either of maize, soybean, rice and wheat is grown. These products include the first and second versions of Climate Change Initiative Soil Moisture (CCISM-1 and CCISM-2) datasets distributed by the European Space Agency and two different AMSR-E (Advanced Microwave Scanning Radiometer-Earth Observing System)-derived soil moisture datasets, separately provided by the Japan Aerospace Exploration Agency (AMSRE-J) and U.S. National Aeronautics and Space Administration (AMSRE-N). The comparison demonstrates varying reliability of these products in representing major characteristics of temporal pattern of cropland soil moisture by product and crop. Possible reasons for the varying reliability include the differences in sensors, algorithms, bands and criteria used when estimating soil moisture. Both the CCISM-1 and CCISM-2 products appear the most reliable for soybean- and wheat-growing area. However, the percentage of valid data of these products is always lower than other products due to relatively strict criteria when merging data derived from multiple sources, although the CCISM-2 product has much more data with valid retrievals than the CCISM-1 product. The reliability of the AMSRE-J product is the highest for maize- and rice-growing areas and comparable to or slightly lower than the CCISM products for soybean- and wheat-growing areas. The AMSRE-N is the least reliable in most location-crop combinations. The reliability of the products for rice-growing area is far lower than that of other upland crops likely due to the extensive use of irrigation and patch distribution of rice paddy in the area examined here. We conclude that the CCISM-1, CCISM-2 and AMSRE

  18. Multi-model assessment of the impact of soil moisture initialization on mid-latitude summer predictability

    Science.gov (United States)

    Ardilouze, Constantin; Batté, L.; Bunzel, F.; Decremer, D.; Déqué, M.; Doblas-Reyes, F. J.; Douville, H.; Fereday, D.; Guemas, V.; MacLachlan, C.; Müller, W.; Prodhomme, C.

    2017-02-01

    Land surface initial conditions have been recognized as a potential source of predictability in sub-seasonal to seasonal forecast systems, at least for near-surface air temperature prediction over the mid-latitude continents. Yet, few studies have systematically explored such an influence over a sufficient hindcast period and in a multi-model framework to produce a robust quantitative assessment. Here, a dedicated set of twin experiments has been carried out with boreal summer retrospective forecasts over the 1992-2010 period performed by five different global coupled ocean-atmosphere models. The impact of a realistic versus climatological soil moisture initialization is assessed in two regions with high potential previously identified as hotspots of land-atmosphere coupling, namely the North American Great Plains and South-Eastern Europe. Over the latter region, temperature predictions show a significant improvement, especially over the Balkans. Forecast systems better simulate the warmest summers if they follow pronounced dry initial anomalies. It is hypothesized that models manage to capture a positive feedback between high temperature and low soil moisture content prone to dominate over other processes during the warmest summers in this region. Over the Great Plains, however, improving the soil moisture initialization does not lead to any robust gain of forecast quality for near-surface temperature. It is suggested that models biases prevent the forecast systems from making the most of the improved initial conditions.

  19. Experimental Analysis and Simultaneous Heat and Moisture Transfer with Coupled CFD Model for Convective Drying of Moist Object

    Science.gov (United States)

    Chandramohan, V. P.

    2016-01-01

    Convective drying of rectangular-shaped moist object has been analyzed both experimentally and numerically. Transient mass of the potato sample is measured experimentally. Moisture content, diffusivity, and density of the object are calculated at different drying air temperatures from 40°C to 70°C with an air velocity of 2 m/s. A three-dimensional (3D) finite volume method (FVM) based numerical model is developed to predict the temperature and moisture distribution. A computational fluid dynamics (CFD) code is used for predicting heat and mass transfer coefficients required in the boundary conditions of the heat and mass transfer model. The experimental and numerical data are compared and good agreement is observed.

  20. Moisture and drug solid-state monitoring during a continuous drying process using empirical and mass balance models

    DEFF Research Database (Denmark)

    Fonteyne, Margot; Gildemyn, Delphine; Peeters, Elisabeth

    2014-01-01

    was chosen as model formulation. For the development of the NIR-based moisture determination model, 15 calibration experiments in the fluid bed dryer were performed. Six test experiments were conducted afterwards, and the product was monitored in-line with NIR and Raman spectroscopy during drying......Classically, the end point detection during fluid bed drying has been performed using indirect parameters, such as the product temperature or the humidity of the outlet drying air. This paper aims at comparing those classic methods to both in-line moisture and solid-state determination by means...... of Process Analytical Technology (PAT) tools (Raman and NIR spectroscopy) and a mass balance approach. The six-segmented fluid bed drying system being part of a fully continuous from-powder-to-tablet production line (ConsiGma™-25) was used for this study. A theophylline:lactose:PVP (30:67.5:2.5) blend...

  1. Determination of the moisture content of Nordic spruce wood through cone heater experiments and an integral model

    DEFF Research Database (Denmark)

    Mindykowski, Pierrick Anthony; Jørgensen, M.; Svensson, Staffan

    2015-01-01

    The combination of cone heater experiments and an integral model was used to determine the moisture content of Nordic spruce with varying degree of drying. Nine specimens of Nordic spruce were pre-heated to 105°C in a convective oven for durations ranging from 0 days (no drying) and up to 63 days...... in increments of 7 days. The fuel moisture content was measured by weighting the specimens before and after the pre-heating. A mass loss cone was used to determine the time for piloted ignition of each specimen. A high-flux asymptotic solution from an integral model permitted to determine that the ignition...... is developed that can be used to determine the time to ignition of a piece of wet spruce, and it is suggested that this method can be used for establishing similar equations for other types of moist wood....

  2. Microcosm Experiments and Modeling of Microbial Movement Under Unsaturated Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Brockman, F.J.; Kapadia, N.; Williams, G.; Rockhold, M.

    2006-04-05

    Colonization of bacteria in porous media has been studied primarily in saturated systems. In this study we examine how microbial colonization in unsaturated porous media is controlled by water content and particle size. This is important for understanding the feasibility and success of bioremediation via nutrient delivery when contaminant degraders are at low densities and when total microbial populations are sparse and spatially discontinuous. The study design used 4 different sand sizes, each at 4 different water contents; experiments were run with and without acetate as the sole carbon source. All experiments were run in duplicate columns and used the motile organism Pseudomonas stutzeri strain KC, a carbon tetrachloride degrader. At a given sand size, bacteria traveled further with increasing volumetric water content. At a given volumetric water content, bacteria generally traveled further with increasing sand size. Water redistribution, solute transport, gas diffusion, and bacterial colonization dynamics were simulated using a numerical finite-difference model. Solute and bacterial transport were modeled using advection-dispersion equations, with reaction rate source/sink terms to account for bacterial growth and substrate utilization, represented using dual Monod-type kinetics. Oxygen transport and diffusion was modeled accounting for equilibrium partitioning between the aqueous and gas phases. The movement of bacteria in the aqueous phase was modeled using a linear impedance model in which the term D{sub m} is a coefficient, as used by Barton and Ford (1995), representing random motility. The unsaturated random motility coefficients we obtained (1.4 x 10{sup -6} to 2.8 x 10{sup -5} cm{sup 2}/sec) are in the same range as those found by others for saturated systems (3.5 x 10{sup -6} to 3.5 x 10{sup -5} cm{sup 2}/sec). The results show that some bacteria can rapidly migrate in well sorted unsaturated sands (and perhaps in relatively high porosity, poorly

  3. Modeling crawling cell movement on soft engineered substrates

    Science.gov (United States)

    Aronson, Igor

    2014-03-01

    Self-propelled motion, emerging spontaneously or in response to external cues, is a hallmark of living organisms. Systems of self-propelled synthetic particles are also relevant for multiple applications, from targeted drug delivery to the design of self-healing materials. Self-propulsion relies on the force transfer to the surrounding. While self-propelled swimming in the bulk of liquids is fairly well characterized, many open questions remain in our understanding of self-propelled motion along substrates, such as in the case of crawling cells or related biomimetic objects. How is the force transfer organized and how does it interplay with the deformability of the moving object and the substrate? How do the spatially dependent traction distribution and adhesion dynamics give rise to complex cell behavior? How can we engineer a specific cell response on synthetic compliant substrates? Here we present a phase-field model for a crawling cell by incorporating locally resolved traction forces and substrate deformations. The model captures the generic structure of the traction force distribution and faithfully reproduces experimental observations, like the response of a cell on a gradient in substrate elasticity (durotaxis). It also exhibits complex modes of cell movement such as ``bipedal'' motion. Our work may guide experiments on cell traction force microscopy and substrate-based cell sorting and can be helpful for the design of biomimetic ``crawlers'' and active and reconfigurable self-healing materials. This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering, under Contract DE-AC02-06CH11357.

  4. Contaminant plume configuration and movement: an experimental model

    Science.gov (United States)

    Alencoao, A.; Reis, A.; Pereira, M. G.; Liberato, M. L. R.; Caramelo, L.; Amraoui, M.; Amorim, V.

    2009-04-01

    The relevance of Science and Technology in our daily routines makes it compulsory to educate citizens who have both scientific literacy and scientific knowledge. These will allow them to be intervening citizens in a constantly changing society. Thus, physical and natural sciences are included in school curricula, both in primary and secondary education, with the fundamental aim of developing in the students the skills, attitudes and knowledge needed for the understanding of the planet Earth and its real problems. On the other hand, teaching in Geosciences is more and more based on practical methodologies which use didactic material, sustaining teachers' pedagogical practices and facilitating students' learning tasks suggested on the syllabus defined for each school level. Themes related to exploring the different components of the Hydrological Cycle and themes related to natural environment protection and preservation, namely water resources and soil contamination by industrial and urban sewage are examples of subject matters included on the Portuguese syllabus. These topics motivated the conception and construction of experimental models for the study of the propagation of pollutants on a porous medium. The experimental models allow inducing a horizontal flux of water though different kinds of permeable substances (e.g. sand, silt), with contamination spots on its surface. These experimental activities facilitate the student to understand the flow path of contaminating substances on the saturated zone and to observe the contaminant plume configuration and movement. The activities are explored in a teaching and learning process perspective where the student builds its own knowledge through real question- problem based learning which relate Science, Technology and Society. These activities have been developed in the framework of project ‘Water in the Environment' (CV/PVI/0854) of the POCTI Program (Programa Operacional "Ciência, Tecnologia, Inovação") financed

  5. Effects of moisture release and radiation properties in pulverized fuel combustion: A CFD modelling study

    DEFF Research Database (Denmark)

    Yin, Chungen

    2016-01-01

    Pulverized fuels (PF) prepared and fired in utility boilers always contain some moisture. For some fuels with high moisture contents (e.g., brown coals), the share of the evaporation enthalpy is quite significant compared to the heat released during combustion, which often needs to be reclaimed.......g., oxy-fuel or air–fuel), account for the variations in CO2 and H2O concentrations in a flame, and include the impacts of other participating gases (e.g., CO and hydrocarbons) needs to be derived for combustion CFD community....

  6. Incorporating moisture content in modeling the surface energy balance of debris-covered Changri Nup Glacier, Nepal

    Science.gov (United States)

    Giese, Alexandra; Boone, Aaron; Morin, Samuel; Lejeune, Yves; Wagnon, Patrick; Dumont, Marie; Hawley, Robert

    2016-04-01

    Glaciers whose ablation zones are covered in supraglacial debris comprise a significant portion of glaciers in High Mountain Asia and two-thirds in the South Central Himalaya. Such glaciers evade traditional proxies for mass balance because they are difficult to delineate remotely and because they lose volume via thinning rather than via retreat. Additionally, their surface energy balance is significantly more complicated than their clean counterparts' due to a conductive heat flux from the debris-air interface to the ice-debris boundary, where melt occurs. This flux is a function of the debris' thickness; thermal, radiative, and physical properties; and moisture content. To date, few surface energy balance models have accounted for debris moisture content and phase changes despite the fact that they are well-known to affect fluxes of mass, latent heat, and conduction. In this study, we introduce a new model, ISBA-DEB, which is capable of solving not only the heat equation but also moisture transport and retention in the debris. The model is based upon Meteo-France's Interactions between Soil, Biosphere, and Atmosphere (ISBA) soil and vegetation model, significantly adapted for debris and coupled with the snowpack model Crocus within the SURFEX platform. We drive the model with continuous ERA-Interim reanalysis data, adapted to the local topography (i.e. considering local elevation and shadowing) and downscaled and de-biased using 5 years of in-situ meteorological data at Changri Nup glacier [(27.859N, 86.847E)] in the Khumbu Himal. The 1-D model output is then evaluated through comparison with measured temperature in and ablation under a 10-cm thick debris layer on Changri Nup. We have found that introducing a non-equilibrium model for water flow, rather than using the mixed-form Richard's equation alone, promotes greater consistency with moisture observations. This explicit incorporation of moisture processes improves simulation of the snow-debris-ice column

  7. Using SMOS brightness temperature and derived surface-soil moisture to characterize surface conditions and validate land surface models.

    Science.gov (United States)

    Polcher, Jan; Barella-Ortiz, Anaïs; Piles, Maria; Gelati, Emiliano; de Rosnay, Patricia

    2017-04-01

    The SMOS satellite, operated by ESA, observes the surface in the L-band. On continental surface these observations are sensitive to moisture and in particular surface-soil moisture (SSM). In this presentation we will explore how the observations of this satellite can be exploited over the Iberian Peninsula by comparing its results with two land surface models : ORCHIDEE and HTESSEL. Measured and modelled brightness temperatures show a good agreement in their temporal evolution, but their spatial structures are not consistent. An empirical orthogonal function analysis of the brightness temperature's error identifies a dominant structure over the south-west of the Iberian Peninsula which evolves during the year and is maximum in autumn and winter. Hypotheses concerning forcing-induced biases and assumptions made in the radiative transfer model are analysed to explain this inconsistency, but no candidate is found to be responsible for the weak spatial correlations. The analysis of spatial inconsistencies between modelled and measured TBs is important, as these can affect the estimation of geophysical variables and TB assimilation in operational models, as well as result in misleading validation studies. When comparing the surface-soil moisture of the models with the product derived operationally by ESA from SMOS observations similar results are found. The spatial correlation over the IP between SMOS and ORCHIDEE SSM estimates is poor (ρ 0.3). A single value decomposition (SVD) analysis of rainfall and SSM shows that the co-varying patterns of these variables are in reasonable agreement between both products. Moreover the first three SVD soil moisture patterns explain over 80% of the SSM variance simulated by the model while the explained fraction is only 52% of the remotely sensed values. These results suggest that the rainfall-driven soil moisture variability may not account for the poor spatial correlation between SMOS and ORCHIDEE products. Other reasons have to

  8. Integrating real-time and manual monitored data to predict hillslope soil moisture dynamics with high spatio-temporal resolution using linear and non-linear models

    Science.gov (United States)

    Zhu, Qing; Zhou, Zhiwen; Duncan, Emily W.; Lv, Ligang; Liao, Kaihua; Feng, Huihui

    2017-02-01

    Spatio-temporal variability of soil moisture (θ) is a challenge that remains to be better understood. A trade-off exists between spatial coverage and temporal resolution when using the manual and real-time θ monitoring methods. This restricted the comprehensive and intensive examination of θ dynamics. In this study, we integrated the manual and real-time monitored data to depict the hillslope θ dynamics with good spatial coverage and temporal resolution. Linear (stepwise multiple linear regression-SMLR) and non-linear (support vector machines-SVM) models were used to predict θ at 39 manual sites (collected 1-2 times per month) with θ collected at three real-time monitoring sites (collected every 5 mins). By comparing the accuracies of SMLR and SVM for each depth and manual site, an optimal prediction model was then determined at this depth of this site. Results showed that θ at the 39 manual sites can be reliably predicted (root mean square errors model. The subsurface flow dynamics was an important factor that determined whether the relationship was linear or non-linear. Depth to bedrock, elevation, topographic wetness index, profile curvature, and θ temporal stability influenced the selection of prediction model since they were related to the subsurface soil water distribution and movement. Using this approach, hillslope θ spatial distributions at un-sampled times and dates can be predicted. Missing information of hillslope θ dynamics can be acquired successfully.

  9. Modelling moisture diffusivity of pomegranate seed cultivars under fixed, semi fluidized and fluidized bed using mathematical and neural network methods.

    Science.gov (United States)

    Chayjan, Reza Amiri; Salari, Kamran; Barikloo, Hossein

    2012-04-02

    Modelling moisture diffusivity of pomegranate cultivars is considered to be a major aspect of the drying process optimization. Its goal is mainly to apply the optimum drying method and conditions in which the final product meets the required standards. Temperature is the major parameter which affects the moisture diffusivity. This parameter is not equal for different cultivars of pomegranate. So modelling of moisture diffusivity is important in designing, optimizing and adjusting the dryer system. This research studied thin layer drying of three cultivars of pomegranate seeds (Alak, Siah and Malas) under fixed, semi fluidized and fluidized bed conditions. Drying process of samples was implemented at 50, 60, 70 and 80°C air temperature levels. Second law of Fick in diffusion was utilized to compute the effective moisture diffusivity (D(eff)) of the seeds. Linear and artificial neural networks (ANNs) also were used to model D(eff) of seeds. Maximum and minimum values of the D(eff) were related to Malas and Alak cultivars, respectively. Three linear models were found to fit the experimental data with average R2 = 0.9350, 0.9320 and 0.9400 for Alak, Siah and Malas cultivars, respectively. The best results for neural network were related to feed forward neural network with training algorithm of Levenberg-Marquardt was appertained to the topology of 3-4-3-1 and threshold function of LOGSIG. By the use of this structure, R2 = 0.9972 was determined. A direct relationship was found between D(eff) and thickness of fleshy section of the seeds. The Siah cultivar has the highest value of D(eff). This is due to higher volume of fleshy section of the Siah cultivar. Cultivar type and air velocity have the highest and the least effect on D(eff), respectively.

  10. Correcting satellite-based precipitation products from SMOS soil moisture data assimilation using two models of different complexity

    Science.gov (United States)

    Román-Cascón, Carlos; Pellarin, Thierry; Gibon, François

    2017-04-01

    Real-time precipitation information at the global scale is quite useful information for many applications. However, satellite-based precipitation products in real time are known to be biased from real values observed in situ. On the other hand, the information about precipitation contained in soil moisture data can be very useful to improve precipitation estimation, since the evolution of this variable is highly influenced by the amount of rainfall at a certain area after a rain event. In this context, the soil moisture data from the Soil Moisture Ocean Salinity (SMOS) satellite is used to correct the precipitation provided by real-time satellite-based products such as CMORPH, TRMM-3B42RT or PERSIANN. In this work, we test an assimilation algorithm based on the data assimilation of SMOS measurements in two models of different complexity: a simple hydrological model (Antecedent Precipitation Index (API)) and a state-of-the-art complex land-surface model (Surface Externalisée (SURFEX)). We show how the assimilation technique, based on a particle filter method, leads to the improvement of correlation and root mean squared error (RMSE) of precipitation estimates, with slightly better results for the simpler (and less expensive computationally) API model. This methodology has been evaluated for six years in ten sites around the world with different features, showing the limitations of the methodology in regions affected by mountainous terrain or by high radio-frequency interferences (RFI), which notably affect the quality of the soil moisture retrievals from brightness temperatures by SMOS. The presented results are promising for a potential near-real time application at the global scale.

  11. 'Initial' Soil Moisture Effects on the Climate in China——A Regional Climate Model Study

    Institute of Scientific and Technical Information of China (English)

    SHI Xueli

    2009-01-01

    In this study, the effects of 'initial' soil moisture (SM) in arid and semi-arid Northwestern China on subsequent climate were investigated with a regional climate model. Besides the control simulations (denoted as CTL), a series of sensitivity experi-ments were conducted, including the DRY and WET experiments, in which the simulated 'initial' SM over the region 30-50°N, 75 -105°E was only 5% and 50%, and up to 150% and 200% of the simulated value in the CTL, respectively. The results show that SM change can modify the subsequent climate in not only the SM-change region proper but also the far downstream regions in Eastern and even Northeastern China. The SM-change effects are generally more prominent in the WET than in the DRY experiments. After the SM is initially increased, the SM in the SM-change region is always higher than that in the CTL, the latent (sensible) heat flux there increases (decreases), and the surface air temperature decreases. Spatially, the most prominent changes in the WET experiments are surface air temperature decrease, geopotential height decrease and corresponding abnormal changes of cyclonic wind vectors at the mid-upper troposphere levels. Generally opposite effects exist in the DRY experiments but with much weaker intensity. In addi-tion, the differences between the results obtained from the two sets of sensitivity experiments and those of the CTL are not always consistent with the variation of the initial SM. Being different from the variation of temperature, the rainfall modifications caused by initial SM change are not so distinct and in fact they show some common features in the WET and DRY experiments. This might imply that SM is only one of the factors that impact the subsequent climate, and its effect is involved in complex processes within the atmosphere, which needs further investigation.

  12. Effective roughness modelling as a tool for soil moisture retrieval from C- and L-band SAR

    Directory of Open Access Journals (Sweden)

    H. Lievens

    2011-01-01

    Full Text Available Soil moisture retrieval from Synthetic Aperture Radar (SAR using state-of-the-art back-scatter models is not fully operational at present, mainly due to difficulties involved in the parameterisation of soil surface roughness. Recently, increasing interest has been drawn to the use of calibrated or effective roughness parameters, as they circumvent issues known to the parameterisation of field-measured roughness. This paper analyses effective roughness parameters derived from C- and L-band SAR observations over a large number of agricultural seedbed sites in Europe. It shows that param-eters may largely differ between SAR acquisitions, as they are related to the observed backscatter coefficients and variations in the local incidence angle. Therefore, a statistical model is developed that allows for estimating effective roughness parameters from microwave backscatter observations. Subsequently, these parameters can be propagated through the Integral Equation Model (IEM for soil moisture retrieval. It is shown that fairly accurate soil moisture results are obtained both at C- and L-band, with an RMSE ranging between 4 vol% and 6.5 vol%.

  13. A state-space model for estimating detailed movements and home range from acoustic receiver data

    DEFF Research Database (Denmark)

    Pedersen, Martin Wæver; Weng, Kevin

    2013-01-01

    We present a state-space model for acoustic receiver data to estimate detailed movement and home range of individual fish while accounting for spatial bias. An integral part of the approach is the detection function, which models the probability of logging tag transmissions as a function...... is used to estimate home range and movement of a reef fish in the Pacific Ocean....

  14. Modeling moisture diffusivity, activation energy and specific energy consumption of squash seeds in a semi fluidized and fluidized bed drying.

    Science.gov (United States)

    Chayjan, Reza Amiri; Salari, Kamran; Abedi, Qasem; Sabziparvar, Ali Akbar

    2013-08-01

    This study investigated thin layer drying of squash seeds under semi fluidized and fluidized bed conditions with initial moisture content about 83.99% (d.b.). An experimental fluidized bed dryer was also used in this study. Air temperature levels of 50, 60, 70 and 80 °C were applied in drying samples. To estimate the drying kinetic of squash seed, seven mathematical models were used to fit the experimental data of thin layer drying. Among the applied models, Two-term model has the best performance to estimate the thin layer drying behavior of the squash seeds. Fick's second law in diffusion was used to determine the effective moisture diffusivity of squash seeds. The range of calculated values of effective moisture diffusivity for drying experiments were between 0.160 × 10(-9) and 0.551 × 10(-10) m(2)/s. Moisture diffusivity values decreased as the input air temperature decreased. Activation energy values were found to be between 31.94 and 34.49 kJ/mol for 50 °C to 80 °C, respectively. The specific energy consumption for squash seeds was calculated at the boundary of 0.783 × 10(6) and 2.303 × 10(6) kJ/kg. Increasing in drying air temperature in different bed conditions led to decrease in specific energy value. Results showed that applying the semi fluidized bed condition is more effective for convective drying of squash seeds. The aforesaid drying characteristics are useful to select the best operational point of fluidized bed dryer and to precise design of system.

  15. Characterization of fracture patterns and hygric properties for moisture flow modelling in cracked concrete

    DEFF Research Database (Denmark)

    Rouchier, Simon; Janssen, Hans; Rode, Carsten

    2012-01-01

    Several years after their installation, building materials such as concrete present signs of ageing in the form of fractures covering a wide range of sizes, from microscopic to macroscopic cracks. All sizes of fractures can have a strong influence on heat and moisture flow in the building envelop...

  16. Modeling of combined physical-mechanical moisture induced damage in asphaltic mixes

    NARCIS (Netherlands)

    Kringos, N.

    2007-01-01

    Moisture induced damage in asphaltic mixes is recognized as a major issue, resulting to the need for frequent maintenance operations. This does not only imply high maintenance costs, but also temporary closure of traffic and hence increased road congestion. Given the high costs for the road authorit

  17. Assessment of some soil thermal conductivity models via variations in temperature and bulk density at low moisture range

    Science.gov (United States)

    Mahdavi, Seyed Mohamad; Neyshabouri, Mohammad Reza; Fujimaki, Haruyuki

    2016-08-01

    Simulation of heat transfer in soil under steady and unsteady situations requires reliable estimate of soil thermal conductivity (λ) at varying environmental conditions. In the current work several soil thermal conductivity predicting models including I) de Vries, II) Campbell, III) combined de Vries and Campbell and IV) de Vries-Nobre were evaluated for the four soils of coarse sand, sandy loam, loam and clay loam textured at varying in temperature and bulk density at low moisture range. Thermal conductivities measured by the cylindrical probe method served as the reference for models assessment. Results showed that approximately same thermal conductivities obtained by the five methods at low moisture range (θ ≤ 0.05 m3/m3). Also the de Vries and de Vries-Campbell models produced accurate than Campbell and de vries-Nobre models. The accuracy of the two models increased with soil compaction but decreased with temperature rise. Campbell model showed more reliability at higher (311.16 and 321.16 K) temperatures; but its accuracy declined with soil compaction in current work. It seems that assuming needle shape for the soil particles is far away from the reality whereas assuming spherical shapes may be more realistic and produced more satisfactory prediction of thermal conductivity. The compaction would alter particle arrangement and may increase the contact area of particles; and then make them behave more or less spherical shape.it seems thermal conductivity in solid particles increase via increasing in temperature. Since a modified mineral shape factor, g m , was developed as a combination between sphere and needle according to geometric mean particle diameter as well as bulk density and temperature as modifying factors. This factor increased the accuracy of de Vries-Nobre model up to 10.37%. Regarding nonlinear regression model, moisture content, bulk density, temperature and quartz content demonstrated significant effect on soil thermal conductivity in our

  18. Modeling of Batter Pile Behavior under Lateral Soil Movement

    Science.gov (United States)

    Chen, C. Y.; Hsu, H. Q.

    2017-06-01

    Pile foundation is frequently used when structures are located on weak sublayers or are at risk from lateral loadings such as earthquakes. The design of pile foundations has recently become crucial to stop slope movement. To understand the behavior of pile foundations subjected to lateral soil movement, the three-dimensional Fast Lagrangian Analysis of Continua (FLAC3D) program was used to perform numerical simulations, which can reduce the cost of field testing. Vertical piles and batter piles were combined into 3 × 3 pile groups, and the response of batter piles to soil movement was analyzed. The outer batter piles led to an increased bending moment in the middle, vertical pile row. Increasing the pile spacing and the presence of battered piles reduced the pile group’s displacement. The batter pile group’s maximum bending moment was smaller than the vertical pile group’s in sand soil, but 5-8 times higher in clay soil.

  19. Assimilation of leaf area index and surface soil moisture satellite observations into the SIM hydrological model over France

    Science.gov (United States)

    Fairbairn, David; Calvet, Jean-Christophe; Mahfouf, Jean-Francois; Barbu, Alina

    2016-04-01

    Hydrological models have a variety of uses, including flood and drought prediction and water management. The SAFRAN-ISBA-MODCOU (SIM) hydrological model consists of three stages: An atmospheric analysis (SAFRAN) over France, which forces a land surface model (ISBA-A-gs), which then provides drainage and runoff inputs to a hydrological model (MODCOU). The river discharge from MODCOU is validated using observed river discharge over France. Data assimilation (DA) combines a short model forecast from the past with observations to improve the estimate of the model state. The ISBA-A-gs representation of soil moisture and its influence by vegetation can be improved by assimilating surface soil moisture (SSM) and leaf area index (LAI) observations respectively. The Advanced Scatterometer (ASCAT) on board the MetOP satellite measures a low-frequency microwave signal, which is used to retrieve daily SSM over France. The SPOT-VGT sensor observes LAI over France at a temporal frequency of about 10 days. The Simplified Extended Kalman (SEKF) filter combines the model and observed variables by weighting them according to their respective accuracies. Although the SEKF makes incorrect linear assumptions, past experiments have shown that it improves on the model estimates of SSM and LAI. However, due to nonlinearities in the land surface model, improvements in SSM and LAI do not imply improved soil moisture fluxes (drainage, runoff and evapotranspiration). This study indirectly examines the impact of the SEKF on the soil moisture fluxes using the MODCOU hydrological model. The ISBA-A-gs model appears to underestimate the LAI for grasslands in winter and spring, which results in an underestimation (overestimation) of evapotranspiration (drainage and runoff). The excess water flowing into the rivers and aquifers contributes to an overestimation of the MODCOU discharge. Assimilating LAI observations slightly increases the LAI analysis in winter and spring and therefore reduces the

  20. Soil Moisture and Vegetation Controls on Surface Energy Balance Using the Maximum Entropy Production Model of Evapotranspiration

    Science.gov (United States)

    Wang, J.; Parolari, A.; Huang, S. Y.

    2014-12-01

    The objective of this study is to formulate and test plant water stress parameterizations for the recently proposed maximum entropy production (MEP) model of evapotranspiration (ET) over vegetated surfaces. . The MEP model of ET is a parsimonious alternative to existing land surface parameterizations of surface energy fluxes from net radiation, temperature, humidity, and a small number of parameters. The MEP model was previously tested for vegetated surfaces under well-watered and dry, dormant conditions, when the surface energy balance is relatively insensitive to plant physiological activity. Under water stressed conditions, however, the plant water stress response strongly affects the surface energy balance. This effect occurs through plant physiological adjustments that reduce ET to maintain leaf turgor pressure as soil moisture is depleted during drought. To improve MEP model of ET predictions under water stress conditions, the model was modified to incorporate this plant-mediated feedback between soil moisture and ET. We compare MEP model predictions to observations under a range of field conditions, including bare soil, grassland, and forest. The results indicate a water stress function that combines the soil water potential in the surface soil layer with the atmospheric humidity successfully reproduces observed ET decreases during drought. In addition to its utility as a modeling tool, the calibrated water stress functions also provide a means to infer ecosystem influence on the land surface state. Challenges associated with sampling model input data (i.e., net radiation, surface temperature, and surface humidity) are also discussed.

  1. An efficient regional energy-moisture balance model for simulation of the Greenland Ice Sheet response to climate change

    Directory of Open Access Journals (Sweden)

    A. Robinson

    2010-04-01

    Full Text Available In order to explore the response of the Greenland ice sheet (GIS to climate change on long (centennial to multi-millennial time scales, a regional energy-moisture balance model has been developed. This model simulates seasonal variations of temperature and precipitation over Greenland and explicitly accounts for elevation and albedo feedbacks. From these fields, the annual mean surface temperature and surface mass balance can be determined and used to force an ice sheet model. The melt component of the surface mass balance is computed here using both a positive degree day approach and a more physically-based alternative that includes insolation and albedo explicitly. As a validation of the climate model, we first simulated temperature and precipitation over Greenland for the prescribed, present-day topography. Our simulated climatology compares well to observations and does not differ significantly from that of a simple parameterization used in many previous simulations. Furthermore, the calculated surface mass balance using both melt schemes falls within the range of recent regional climate model results. For a prescribed, ice-free state, the differences in simulated climatology between the regional energy-moisture balance model and the simple parameterization become significant, with our model showing much stronger summer warming. When coupled to a three-dimensional ice sheet model and initialized with present-day conditions, the two melt schemes both allow realistic simulations of the present-day GIS.

  2. Toward the quantification of a conceptual framework for movement ecology using circular statistical modeling.

    Directory of Open Access Journals (Sweden)

    Ichiro Ken Shimatani

    Full Text Available To analyze an animal's movement trajectory, a basic model is required that satisfies the following conditions: the model must have an ecological basis and the parameters used in the model must have ecological interpretations, a broad range of movement patterns can be explained by that model, and equations and probability distributions in the model should be mathematically tractable. Random walk models used in previous studies do not necessarily satisfy these requirements, partly because movement trajectories are often more oriented or tortuous than expected from the models. By improving the modeling for turning angles, this study aims to propose a basic movement model. On the basis of the recently developed circular auto-regressive model, we introduced a new movement model and extended its applicability to capture the asymmetric effects of external factors such as wind. The model was applied to GPS trajectories of a seabird (Calonectris leucomelas to demonstrate its applicability to various movement patterns and to explain how the model parameters are ecologically interpreted under a general conceptual framework for movement ecology. Although it is based on a simple extension of a generalized linear model to circular variables, the proposed model enables us to evaluate the effects of external factors on movement separately from the animal's internal state. For example, maximum likelihood estimates and model selection suggested that in one homing flight section, the seabird intended to fly toward the island, but misjudged its navigation and was driven off-course by strong winds, while in the subsequent flight section, the seabird reset the focal direction, navigated the flight under strong wind conditions, and succeeded in approaching the island.

  3. From near-surface to root-zone soil moisture using an exponential filter: an assessment of the method based on in-situ observations and model simulations

    Directory of Open Access Journals (Sweden)

    C. Albergel

    2008-12-01

    Full Text Available A long term data acquisition effort of profile soil moisture is under way in southwestern France at 13 automated weather stations. This ground network was developed in order to validate remote sensing and model soil moisture estimates. In this paper, both those in situ observations and a synthetic data set covering continental France are used to test a simple method to retrieve root zone soil moisture from a time series of surface soil moisture information. A recursive exponential filter equation using a time constant, T, is used to compute a soil water index. The Nash and Sutcliff coefficient is used as a criterion to optimise the T parameter for each ground station and for each model pixel of the synthetic data set. In general, the soil water indices derived from the surface soil moisture observations and simulations agree well with the reference root-zone soil moisture. Overall, the results show the potential of the exponential filter equation and of its recursive formulation to derive a soil water index from surface soil moisture estimates. This paper further investigates the correlation of the time scale parameter T with soil properties and climate conditions. While no significant relationship could be determined between T and the main soil properties (clay and sand fractions, bulk density and organic matter content, the modelled spatial variability and the observed inter-annual variability of T suggest that a weak climate effect may exist.

  4. Velocity-based movement modeling for individual and population level inference.

    Directory of Open Access Journals (Sweden)

    Ephraim M Hanks

    Full Text Available Understanding animal movement and resource selection provides important information about the ecology of the animal, but an animal's movement and behavior are not typically constant in time. We present a velocity-based approach for modeling animal movement in space and time that allows for temporal heterogeneity in an animal's response to the environment, allows for temporal irregularity in telemetry data, and accounts for the uncertainty in the location information. Population-level inference on movement patterns and resource selection can then be made through cluster analysis of the parameters related to movement and behavior. We illustrate this approach through a study of northern fur seal (Callorhinus ursinus movement in the Bering Sea, Alaska, USA. Results show sex differentiation, with female northern fur seals exhibiting stronger response to environmental variables.

  5. Velocity-based movement modeling for individual and population level inference.

    Science.gov (United States)

    Hanks, Ephraim M; Hooten, Mevin B; Johnson, Devin S; Sterling, Jeremy T

    2011-01-01

    Understanding animal movement and resource selection provides important information about the ecology of the animal, but an animal's movement and behavior are not typically constant in time. We present a velocity-based approach for modeling animal movement in space and time that allows for temporal heterogeneity in an animal's response to the environment, allows for temporal irregularity in telemetry data, and accounts for the uncertainty in the location information. Population-level inference on movement patterns and resource selection can then be made through cluster analysis of the parameters related to movement and behavior. We illustrate this approach through a study of northern fur seal (Callorhinus ursinus) movement in the Bering Sea, Alaska, USA. Results show sex differentiation, with female northern fur seals exhibiting stronger response to environmental variables.

  6. Convective moisture adjustment time scale as a key factor in regulating model amplitude of the Madden-Julian Oscillation

    Science.gov (United States)

    Jiang, Xianan; Zhao, Ming; Maloney, Eric D.; Waliser, Duane E.

    2016-10-01

    Despite its pronounced impacts on weather extremes worldwide, the Madden-Julian Oscillation (MJO) remains poorly represented in climate models. Here we present findings that point to some necessary ingredients to produce a strong MJO amplitude in a large set of model simulations from a recent model intercomparison project. While surface flux and radiative heating anomalies are considered important for amplifying the MJO, their strength per unit MJO precipitation anomaly is found to be negatively correlated to MJO amplitude across these multimodel simulations. However, model MJO amplitude is found to be closely tied to a model's convective moisture adjustment time scale, a measure of how rapidly precipitation must increase to remove excess column water vapor, or alternately the efficiency of surface precipitation generation per unit column water vapor anomaly. These findings provide critical insights into key model processes for the MJO and pinpoint a direction for improved model representation of the MJO.

  7. Modeling movement disorders¿CRPS-related dystonia explained by abnormal proprioceptive reflexes

    NARCIS (Netherlands)

    Mugge, W.; Munts, A.G.; Schouten, Alfred Christiaan; van der Helm, F.C.T.

    2012-01-01

    Humans control their movements using adaptive proprioceptive feedback from muscle afferents. The interaction between proprioceptive reflexes and biomechanical properties of the limb is essential in understanding the etiology of movement disorders. A non-linear neuromuscular model of the wrist incorp

  8. Regional moisture change over India during the past Millennium: A comparison of multi-proxy reconstructions and climate model simulations

    Science.gov (United States)

    Polanski, Stefan; Fallah, Bijan; Befort, Daniel J.; Prasad, Sushma; Cubasch, Ulrich

    2014-11-01

    The Indian Monsoon Variability during the past Millennium has been simulated with the ECHAM5 model in two different time slices: Medieval Climate Anomaly and the Little Ice Age. The simulations are compared with new centennial-resolving paleo-reconstructions inferred from various well-dated multi-proxies from two core regions, the Himalaya and Central India. A qualitative moisture index is derived from the proxies and compared with simulated moisture anomalies. The reconstructed paleo-hydrological changes between the Little Ice Age and the Medieval Climate Anomaly depict a dipole pattern between Himalaya and Central India, which is also captured by the model. In the Medieval Climate Anomaly the model exhibits stronger (weaker) dipole signals during summer (winter) compared to Little Ice Age. In summer (winter) months of "Medieval Climate Anomaly minus Little Ice Age" the model simulates wetter conditions over eastern (western and central) Himalaya. Over Central India, a simulated weakening of Indian Summer Monsoon during warmer climate is coincident with reconstructed drying signal in the Lonar Lake record. Based on the model simulations, we can differentiate three physical mechanisms which can lead to the moisture anomalies: (i) the western and central Himalaya are influenced by extra-tropical Westerlies during winter, (ii) the eastern Himalaya is affected by summer variations of temperature gradient between Bay of Bengal and Indian subcontinent and by a zonal band of intensified Indian-East Asian monsoon link north of 25°N, and (iii) Central India is dominated by summer sea surface temperature anomalies in the northern Arabian Sea which have an effect on the large-scale advection of moist air masses. The temperatures in the Arabian Sea are linked to the Indo Pacific Warm Pool, which modulates the Indian monsoon strength.

  9. Modeling Unidirectional Pedestrian Movement: An Investigation of Diffusion Behavior in the Built Environment

    Directory of Open Access Journals (Sweden)

    Ying Liu

    2015-01-01

    Full Text Available Unidirectional pedestrian movement is a special phenomenon in the evacuation process of large public buildings and urban environments at pedestrian scale. Several macroscopic models for collective behaviors have been built to predict pedestrian flow. However, current models do not explain the diffusion behavior in pedestrian crowd movement, which can be important in representing spatial-temporal crowd density differentiation in the movement process. This study builds a macroscopic model for describing crowd diffusion behavior and evaluating unidirectional pedestrian flow. The proposed model employs discretization of time and walking speed in geometric distribution to calculate downstream pedestrian crowd flow and analyze movement process based on upstream number of pedestrians and average walking speed. The simulated results are calibrated with video observation data in a baseball stadium to verify the model precision. Statistical results have verified that the proposed pedestrian diffusion model could accurately describe pedestrian macromovement behavior within the margin of error.

  10. An open-access software platform for modeling turbulent heat and moisture fluxes as well as surface soil moisture from the Synergy of VNIR/TIR EO Data and a Land Biosphere Model

    Science.gov (United States)

    Petropoulos, George; Anagnostopoulos, Vasileios

    2015-04-01

    Today, in the face of climate change, it has been recognised by the global scientific community as a topic requiring further attention and investigation. Use of simulation process models combined with Earth Observation (EO) data provides a promising direction towards deriving accurately spatiotemporal estimates of key parameters characterising land surface interactions such as latent (LE) and sensible (H) heat fluxes as well as soil surface moisture (SSM). Herein a software tool developed in Java for deriving regional estimates of LE and H fluxes (sensible and latent heat) as well as surface soil moisture from the implementation of the so-called "triangle" method is presented. The method is based on a contextual interpretation of a satellite-derived scatterplot of land surface temperature (Ts) versus a Fractional Vegetation Cover (Fr) combined with a land biosphere model. The tool offers a graphical user interface (GUI) to the user, with the aim to allow customisation of the noise removal of the dataset. Upper and lower edges of the trapezoid in the Fr versus normalized Ts diagram are automatically derived and visualised. The user can also enter various parameters to the SimSphere engine through a convenient form and visualisation of trapezoid matching for various simulation scenarios is also provided. Computationally it can handle one million scatter points with acceptable lag in the user interface. It is also multi-core friendly by using Java 8 parallel streams for conversions and prediction. The predictor training and histogram computation are the main serialisation bottlenecks. In contrast to other methods the trapezoid derivation and matching is automatic requiring little more than a customisation of noise removal and scenario definition. The tool is written in Java 8 and Java FX 8 for best performance, reduced maintenance and easy interaction. The practical usefulness of the software tool is demonstrated using a variety of examples exploiting EO data from

  11. A Conceptual Approach to Assimilating Remote Sensing Data to Improve Soil Moisture Profile Estimates in a Surface Flux/Hydrology Model. Part 1; Overview

    Science.gov (United States)

    Crosson, William L.; Laymon, Charles A.; Inguva, Ramarao; Schamschula, Marius; Caulfield, John

    1998-01-01

    advantage of radar is its much higher resolution than passive microwave systems, but it is currently hampered by surface roughness effects and the lack of a good algorithm based on a single frequency and single polarization. In addition, its repeat frequency is generally low (about 40 days). In the meantime, two new radiometers offer some hope for remote sensing of soil moisture from space. The Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI), launched in November 1997, possesses a 10.65 GHz channel and the Advanced Microwave Scanning Radiometer (AMSR) on both the ADEOS-11 and Earth Observing System AM-1 platforms to be launched in 1999 possesses a 6.9 GHz channel. Aside from issues about interference from vegetation, the coarse resolution of these data will provide considerable challenges pertaining to their application. The resolution of TMI is about 45 km and that of AMSR is about 70 km. These resolutions are grossly inconsistent with the scale of soil moisture processes and the spatial variability of factors that control soil moisture. Scale disparities such as these are forcing us to rethink how we assimilate data of various scales in hydrologic models. Of particular interest is how to assimilate soil moisture data by reconciling the scale disparity between what we can expect from present and future remote sensing measurements of soil moisture and modeling soil moisture processes. It is because of this disparity between the resolution of space-based sensors and the scale of data needed for capturing the spatial variability of soil moisture and related properties that remote sensing of soil moisture has not met with more widespread success. Within a single footprint of current sensors at the wavelengths optimal for this application, in most cases there is enormous heterogeneity in soil moisture created by differences in landcover, soils and topography, as well as variability in antecedent precipitation. It is difficult to interpret the meaning of 'mean

  12. Infiltration-soil moisture redistribution under natural conditions: experimental evidence as a guideline for realizing simulation models

    Directory of Open Access Journals (Sweden)

    R. Morbidelli

    2011-06-01

    Full Text Available The evolution in time, t, of the experimental soil moisture vertical profile under natural conditions is investigated in order to address the corresponding simulation modelling. The measurements were conducted in a plot with a bare silty loam soil. The soil water content, θ, was continuously monitored at different depths, z, using a Time Domain Reflectometry (TDR system. For each profile four buriable three-rod waveguides were inserted horizontally at different depths (5, 15, 25 and 35 cm. In addition, we used sensors of air temperature and relative humidity, wind speed, solar radiation, evaporation and rain as supports for the application of selected simulation models, as well as for the detection of elements leading to their improvement. The results indicate that, under natural conditions, very different trends of the θ(z,t function can be observed in the given fine-textured soil, where the formation of a sealing layer over the parent soil requires an adjustment of the simulation modelling commonly used for hydrological applications. In particular, because of the considerable variations in the shape of the moisture content vertical profile as a function of time, a generalization of the existing models should incorporate a representation of the variability in time of the saturated hydraulic conductivity of the uppermost soil. This conclusion is supported by the fact that the observed shape of θ(z can be appropriately reproduced by adopting this approach, however the observed rainfall rate and the occurrence of freeze-thaw cycles with high soil moisture contents have to be explicitly incorporated.

  13. Infiltration-soil moisture redistribution under natural conditions: experimental evidence as a guideline for realizing simulation models

    Directory of Open Access Journals (Sweden)

    R. Morbidelli

    2011-09-01

    Full Text Available The evolution in time, t, of the experimental soil moisture vertical profile under natural conditions is investigated in order to address the corresponding simulation modelling. The measurements were conducted in a plot with a bare silty loam soil. The soil water content, θ, was continuously monitored at different depths, z, using a Time Domain Reflectometry (TDR system. Four buriable three-rod waveguides were inserted horizontally at different depths (5, 15, 25 and 35 cm. In addition, we used sensors of air temperature and relative humidity, wind speed, solar radiation, evaporation and rain as supports for the application of selected simulation models, as well as for the detection of elements leading to their improvement. The results indicate that, under natural conditions, very different trends of the θ(z, t function can be observed in the given fine-textured soil, where the formation of a sealing layer over the parent soil requires an adjustment of the simulation modelling commonly used for hydrological applications. In particular, because of the considerable variations in the shape of the moisture content vertical profile as a function of time, a generalization of the existing models should incorporate a first approximation of the variability in time of the saturated hydraulic conductivity, K1s, of the uppermost soil. This conclusion is supported by the fact that the observed shape of θ(z, t can be appropriately reproduced by adopting the proposed approach with K1s kept constant during each rainfall event but considered variable from event to event, however the observed rainfall rate and the occurrence of freeze-thaw cycles with high soil moisture contents have to be explicitly incorporated in a functional form for K1s(t.

  14. Physically-based modeling of topographic effects on spatial evapotranspiration and soil moisture patterns in complex terrain

    Directory of Open Access Journals (Sweden)

    M. Liu

    2011-07-01

    Full Text Available Simulation with the Soil Water Atmosphere Plant (SWAP model is performed to quantify the spatial variability of evapotranspiration (ET and soil moisture content (SMC caused by topography-induced spatial wind and radiation differences. The field scale SWAP model is applied in a distributed way, i.e. for each grid, assuming linear groundwater table, identical boundary conditions and no lateral flow. Input of spatial wind and solar radiation are obtained with the adapted r.sun model and the meso-scale METRAS PC model based on physical mechanisms respectively. Both potential and actual ET, as well as the individual components of evaporation and transpiration are calculated by the model. The numerical experiments are conducted for grids at two different resolutions (100 m and 1000 m to evaluate the scale effects. At fine scale, both solar radiation and wind have a strong effect on spatial ET/SMC pattern, whereas at coarse scale, the wind effect dominates. The results show a strong spatial and temporal intra-catchment variability in daily/annual total ET and less variability in soil moisture. The spatial variability in ET is associated with a difference in total amount of runoff generated, which may lead to a significant consequence in catchment water balance, snowmelt and rainfall-runoff generation processes.

  15. Comprehensive Assessment of Land Surface, Snow, and Soil Moisture-Climate Feedbacks by Multi-model Experiments of Land Surface Models under LS3MIP

    Science.gov (United States)

    Oki, T.; Kim, H.; Hurk, B. V. D.; Krinner, G.; Derksen, C.; Seneviratne, S. I.

    2015-12-01

    The solid and liquid water stored at the land surface has a large influence on the regional climate, its variability and its predictability, including effects on the energy and carbon cycles. Notably, snow and soil moisture affect surface radiation and flux partitioning properties, moisture storage and land surface memory. The Land surface, snow and soil moisture model inter-comparison project (LS3MIP) experiments address together the following objectives: an evaluation of the current state of land processes including surface fluxes, snow cover and soil moisture representation in CMIP6 DECK runs (LMIP-protoDECK) a multi-model estimation of the long-term terrestrial energy/water/carbon cycles, using the surface modules of CMIP6 models under observation constrained historical (land reanalysis) and projected future (impact assessment) conditions considering land use/land cover changes. (LMIP) an assessment of the role of snow and soil moisture feedbacks in the regional response to altered climate forcings, focusing on controls of climate extremes, water availability and high-latitude climate in historical and future scenario runs (LFMIP) an assessment of the contribution of land surface processes to the current and future predictability of regional temperature/precipitation patterns. (LFMIP) These LS3MIP outcomes will contribute to the improvement of climate change projections by reducing the systematic biases from the land surface component of climate models, and a better representation of feedback mechanisms related to snow and soil moisture in climate models. Further, LS3MIP will enable the assessment of probable historical changes in energy, water, and carbon cycles over land surfaces extending more than 100 years, including spatial variability and trends in global runoff, snow cover, and soil moisture that are hard to detect purely based on observations. LS3MIP will also enable the impact assessments of climate changes on hydrological regimes and available

  16. Process-based modeling of vegetation dynamics, snow, evapotranspiration and soil moisture patterns in an alpine catchment

    Science.gov (United States)

    Bertoldi, Giacomo; Della Chiesa, Stefano; Engel, Michael; Niedrist, Georg; Brenner, Johannes G.; Endrizzi, Stefano; Dall'Amico, Matteo; Cordano, Emanuele; Tappeiner, Ulrike; Rigon, Riccardo

    2014-05-01

    Mountain regions are particularly sensitive to climate change and at the same time they represent a key water resource not only locally but as well for lowland areas. Because of the complexity of mountain landscapes and the high climatic variability at a local scale, detailed quantification of key water budget components as snow cover, soil moisture and groundwater recharge is required. Therefore, there is a strong need to improve the capability of hydrological models to identify patterns in complex terrain (i.e. when variability of spatial characteristics counts), and to quantify changes of the water cycle components explicitly, considering interactions and feedbacks with climate and vegetation. Process-based hydrological models represent promising tools for addressing those needs. However, even if their inherent complexity sometimes limits their applicability for operational purpose, they offer great potential in terms of tools to test hypotheses, which can be verified in the field. GEOtop is a hydrological model that calculates the energy and mass exchanges between soil, vegetation, and atmosphere, accounting for land cover, water redistribution, snow processes, glacier mass budget and the effects of complex terrain and thus is one of the few models that was built with this complexity in mind. Recently, it has also been coupled with a dynamic vegetation model in order to simulate alpine grassland ecosystems. In this contribution, we want to present an application of the GEOtop model in simulating above ground biomass (Bag) production, evapotranspiration (ET), soil moisture (SM) and snow water equivalent (SWE) patterns for a catchment of about 100 km2, located in the Venosta/Vinschgau valley in the European Alps. Despite the Alps are one of the 'water towers of Europe', water scarcity issues can affect the region where the model is applied, and an intensive hydrological and ecological monitoring activity with ground observations and remote-sensing products has

  17. Modelling and Simulation for Train Movement Control Using Car-Following Strategy

    Institute of Scientific and Technical Information of China (English)

    LI Ke-Ping; GAO Zi-You; TANG Tao

    2011-01-01

    Based on optimal velocity car-following model, in this paper, we propose a new railway traffc model for describing the process of train movement control.In the proposed model, we give an improved form of the optimal velocity function Vopt, which is considered as the desired velocity function for train movement control under different control conditions.In order to test the proposed model, we simulate and anaiyze the trajectories of train movements,moreover, discuss the relationship curves between the train allowable velocity and the site of objective point in detail Analysis results indicate that the proposed model can well capture some realistic futures of train movement control.PACS numbers: 02.70.-c, 89.40.-a

  18. The impact of soil moisture on the spin up of 1-D Noah land surface model at a site in monsoonal region

    Science.gov (United States)

    Bhattacharya, A.; Mandal, M.

    2014-12-01

    Model spin-up is the process through which the model is adequately equilibrated to ensure balance between the mass fields and velocity fields. In this study, an offline 1-D Noah land surface model (LSM) has been used to investigate the impact of soil moisture on the model spin up at Kharagpur, India which is a site in monsoonal region. The model is integrated recursively for 3-years to assess its spin-up behavior. Several numerical experiments are performed to investigate the impact of initial soil moisture and subsequent dry or wet condition on model spin-up. These include simulations with different initial soil moisture content (observed soil moisture; dry soil; moderately wet soil; saturated soil), simulations initialized before different rain conditions (no rain; infrequent rain; continuous rain) and simulations initialized in different seasons (Winter, Spring, Summer/Pre-Monsoon, Monsoon and Autumn). It is noted that the model has significantly longer spin-up when initialized with very low initial soil moisture content than with higher soil moisture content. It is also seen that in general, simulations initialized just before a continuous rainfall event have the least spin-up time. In a region affected by the monsoon, such as Kharagpur, this observation is reinforced by the results from the simulations initialized in different seasons. It is seen that for monsoonal region, the model spin-up time is least for simulations initialized during Summer/Pre-monsoon. Model initialized during the Monsoon has a longer spin-up than that initialized in any other season. It appears that the model has shorter spin-up if it reaches the equilibrium state predominantly via drying process. It is also observed that the spin-up of offline 1-D Noah LSM may be as low as two months under quasi-equilibrium condition if the initial soil moisture content and time of start of simulations are chosen carefully.

  19. The perceptual trap: Experimental and modelling examples of soil moisture, hydraulic conductivity and response units in complex subsurface settings.

    Science.gov (United States)

    Jackisch, Conrad; Demand, Dominic; Allroggen, Niklas; Loritz, Ralf; Zehe, Erwin

    2017-04-01

    In order to discuss hypothesis testing in hydrology, the question of the solid foundation of such tests has to be answered. But how certain are we about our measurements of the components of the water balance and the states and dynamics of the complex systems? What implicit assumptions or bias are already embedded in our perception of the processes? How can we find light in the darkness of heterogeneity? We will contribute examples from experimental findings, modelling approaches and landscape analysis to the discussion. Example soil moisture and the soil continuum: The definition of soil moisture as fraction of water in the porous medium assumes locally well-mixed conditions. Moreover, a unique relation of soil water retention presumes instant local thermodynamic equilibrium in the pore water arrangement. We will show findings from soil moisture responses to precipitation events, from irrigation experiments, and from a model study of initial infiltration velocities. The results highlight, that the implicit assumption relating soil moisture state dynamics with actual soil water flow is biased towards the slow end of the actual velocity distribution and rather blind for preferential flow acting in a very small proportion of the pore space. Moreover, we highlight the assumption of a well-defined continuum during the extrapolation of point-scale measurements and why spatially and temporally continuous observation techniques of soil water states are essential for advancing our understanding and development of subsurface process theories. Example hydraulic conductivity: Hydraulic conductivity lies at the heart of hydrological research and modelling. Its values can range across several orders of magnitude at a single site alone. Yet, we often consider it a crisp, effective parameter. We have conducted measurements of soil hydraulic conductivity in the lab and in the field. Moreover, we assessed infiltration capacity and conducted plot-scale irrigation experiments to

  20. Analysis and modelling of the temporal stability of throughfall and near-surface soil moisture at the plot scale in the Italian pre-Alps

    Science.gov (United States)

    Zuecco, Giulia; van Meerveld, Ilja; Penna, Daniele; Hopp, Luisa; Borga, Marco

    2016-04-01

    Understanding the spatial and temporal variation in soil moisture at different scales is crucial for hydrological sciences. In forested areas, spatial patterns in throughfall and vegetation characteristics are expected to control soil moisture variability. However, few studies have focused on the influence of throughfall spatial patterns on near-surface soil moisture. Therefore, this study aimed to: i) investigate the relation between the spatial patterns of throughfall and near-surface soil moisture at the plot scale for a forested hillslope, ii) compare the temporal stability of throughfall and soil moisture with canopy characteristics, and iii) assess the controls on the correlation between throughfall and soil moisture temporal stability by means of a dynamic soil moisture model. Throughfall and soil moisture measurements were taken in a 500 m2 experimental plot on the hillslope of a densely forested catchment (Ressi) in the Italian pre-Alps between April 2013 and March 2014. The main tree species in the plot are beech and chestnut. The median diameter at breast height of the trees in the plot is 4 cm (range 1-61 cm). Fifty buckets (collecting area: 556 cm2; capacity: 162 mm) were randomly distributed in the plot for throughfall measurements, while a bucket was also installed in a nearby open area (approximately 150 m from the experimental plot) to collect rainfall. Volumetric soil moisture content was measured at 50 points, about 30 cm upslope of each bucket, at two depths (0-7 and 0-12 cm) before and after 23 rainfall events (7.7 mm to 156 mm) using portable TDR (Time Domain Reflectivity) probes. Canopy openness and leaf area index (LAI) were determined from hemispherical pictures at each bucket. For the measured events throughfall and soil moisture spatial patterns were not significantly or only weakly correlated, likely due to the lateral and vertical redistribution of water in the soil profile during the 2-36 hour period between the end of the rainfall

  1. A generalized mathematical model to determine the turning movement counts at

    Directory of Open Access Journals (Sweden)

    Al-Sayed Ahmed Al-Sobky

    2014-09-01

    Full Text Available Traffic turning movement counts at roundabouts is one of the key inputs required for roundabout assessment, control and management. Traditionally, a direct counting is conducted to track a vehicle from entering through circulation until exiting. This counting may be difficult and costly due to the size of roundabout, the vision obstacles, and the continuous traffic flow. Many researchers tried to avoid the tracking problem by counting only at entries and exits, then estimating the movements based on historical data which unfortunately affect the results. Other researchers reduced the tracking problem by counting some turning movements in addition to at entries and exits, then calculating mathematically the remaining movements. This approach is practical and accurate; however, it was applied on limited cases. In this paper, a generalized mathematical model was developed to calculate the most difficult movements based on the easiest movements determined based on the size of monitoring area. The developed model can be used to calculate the turning movements, including the u-turns, for roundabouts with any number of legs. The developed model was presented in O–D matrix forms to be practical and user-friendly. The model was validated against reference count data and the results were found to be satisfactory.

  2. Assimilation of SMOS-derived soil moisture in a fully integrated hydrological and soil-vegetation-atmosphere transfer model in Western Denmark

    DEFF Research Database (Denmark)

    Ridler, Marc-Etienne Francois; Madsen, Henrik; Stisen, Simon

    2014-01-01

    in Denmark. The objective is to determine if any additional gains can be achieved by SMOS surface soil moisture assimilation beyond the optimized model. A series of assimilation experiments were designed to (1) determine how effectively soil moisture corrections propagate downward in the soil column, (2...... cover classes. Assimilation also brought modest gains in R2 at 25 cm depth but slightly degraded the correlation at 50 cm depth. Assimilation overcorrected discharge peaks....

  3. Evaluation of moisture sources for the Central European summer flood of May/June 2013 based on regional climate model simulations

    OpenAIRE

    Kelemen, Fanni D.; Ludwig, Patrick; Reyers, Mark; Ulbrich, Sven; Pinto, Joaquim G.

    2016-01-01

    Heavy precipitation affected Central Europe in May/June 2013, triggering damaging floods both on the Danube and the Elbe rivers. Based on a modelling approach with COSMO-CLM, moisture fluxes, backward trajectories, cyclone tracks and precipitation fields are evaluated for the relevant time period 30 May–2 June 2013. We identify potential moisture sources and quantify their contribution to the flood event focusing on the Danube basin through sensitivity experiments: Control simulations are per...

  4. Automatic removal of eye movement artifacts from the EEG using ICA and the dipole model

    Institute of Scientific and Technical Information of China (English)

    Weidong Zhou; Jean Gotman

    2009-01-01

    12 patients were analyzed.The experimental results indicate that ICA with the dipole model is very efficient at automatically subtracting the eye movement artifacts,while retaining the EEG slow waves and making their interpretation easier.

  5. Inferring Land Surface Model Parameters for the Assimilation of Satellite-Based L-Band Brightness Temperature Observations into a Soil Moisture Analysis System

    Science.gov (United States)

    Reichle, Rolf H.; De Lannoy, Gabrielle J. M.

    2012-01-01

    The Soil Moisture and Ocean Salinity (SMOS) satellite mission provides global measurements of L-band brightness temperatures at horizontal and vertical polarization and a variety of incidence angles that are sensitive to moisture and temperature conditions in the top few centimeters of the soil. These L-band observations can therefore be assimilated into a land surface model to obtain surface and root zone soil moisture estimates. As part of the observation operator, such an assimilation system requires a radiative transfer model (RTM) that converts geophysical fields (including soil moisture and soil temperature) into modeled L-band brightness temperatures. At the global scale, the RTM parameters and the climatological soil moisture conditions are still poorly known. Using look-up tables from the literature to estimate the RTM parameters usually results in modeled L-band brightness temperatures that are strongly biased against the SMOS observations, with biases varying regionally and seasonally. Such biases must be addressed within the land data assimilation system. In this presentation, the estimation of the RTM parameters is discussed for the NASA GEOS-5 land data assimilation system, which is based on the ensemble Kalman filter (EnKF) and the Catchment land surface model. In the GEOS-5 land data assimilation system, soil moisture and brightness temperature biases are addressed in three stages. First, the global soil properties and soil hydraulic parameters that are used in the Catchment model were revised to minimize the bias in the modeled soil moisture, as verified against available in situ soil moisture measurements. Second, key parameters of the "tau-omega" RTM were calibrated prior to data assimilation using an objective function that minimizes the climatological differences between the modeled L-band brightness temperatures and the corresponding SMOS observations. Calibrated parameters include soil roughness parameters, vegetation structure parameters

  6. Evaluating the influence of antecedent soil moisture on variability of the North American Monsoon precipitation in the coupled MM5/VIC modeling system

    Directory of Open Access Journals (Sweden)

    Dennis P. Lettenmaier

    2009-11-01

    Full Text Available The influence of antecedent soil moisture on North American monsoon system (NAMS precipitation variability was explored using the MM5 mesoscale model coupled with the Variable Infiltration Capacity (VIC land surface model. Sensitivity experiments were performed with extreme wet and dry initial soil moisture conditions for both the 1984 wet monsoon year and the 1989 dry year. The MM5-VIC model reproduced the key features of NAMS in 1984 and 1989 especially over northwestern Mexico. Our modeling results indicate that the land surface has memory of the initial soil wetness prescribed at the onset of the monsoon that persists over most of the region well into the monsoon season (e.g. until August. However, in contrast to the classical thermal contrast concept, where wetter soils lead to cooler surface temperatures, less land-sea thermal contrast, weaker monsoon circulations and less precipitation, the coupled model consistently demonstrated a positive soil moisture – precipitation feedback. Specifically, anomalously wet pre-monsoon soil moisture always lead to enhanced monsoon precipitation, and the reverse was also true. Both the large-scale circulation change and local land-atmospheric interactions in response to pre-monsoon soil moisture anomalies play important roles in the coupled model’s positive soil moisture – monsoon precipitation feedback. However, the former may be sensitive to the strength and location of the thermal anomalies, thus leaving open the possibility of both positive and negative soil moisture – precipitation feedbacks. Furthermore, our use of a regional model with prescribed large-scale circulation at the model boundaries leaves open the possibility that the model behavior may, to some extent, reflect its limited ability to adjust its large-scale circulation to the regional thermal changes.

  7. Computational movement analysis

    CERN Document Server

    Laube, Patrick

    2014-01-01

    This SpringerBrief discusses the characteristics of spatiotemporal movement data, including uncertainty and scale. It investigates three core aspects of Computational Movement Analysis: Conceptual modeling of movement and movement spaces, spatiotemporal analysis methods aiming at a better understanding of movement processes (with a focus on data mining for movement patterns), and using decentralized spatial computing methods in movement analysis. The author presents Computational Movement Analysis as an interdisciplinary umbrella for analyzing movement processes with methods from a range of fi

  8. Analysis of Moisture, Oil, and Fatty Acid Composition of Olives by Near-Inferred Spectroscopy: Development and Validation Calibration Models.

    Science.gov (United States)

    Saha, Uttam; Jackson, Daniel

    2017-09-05

    Olive is a new, expanding crop in Georgia. Its oil content steadily increases with maturity, but eventually plateaus at the maximum when the olives should be promptly harvested avoiding over-ripening and quality degradation. This requires frequent testing. However, olive quality analysis by wet-chemistry is laborious, slow, and costly, whereas Near Infrared Reflectance Spectroscopy (NIRS) being precise, accurate, rapid, and cheap, could be suitable. We developed and validated NIRS calibration models for moisture, fresh-matter-oil (oil-FMO), dry-matter-oil (oil-DMO), and major fatty acids composition analyses. Of the12 models developed, the seven constituents such as moisture, oil-FMO, oil-DMO; and palmitic, palmitoleic, oleic and linoleic acids (representing 88-97% of the total fatty acids) had low standard errors and high coefficient of determinations (R(2) = 0.81-0.98; 1 ̶ VR = 0.74-0.86) for both calibration and cross validation. For these 9 constituents, predictions of an independent validation set yielded excellent agreement between the NIRS predicted values and the reference values with low standard error of prediction (SEP), low bias, high coefficient of determination (r(2) = 0.80-0.93), and high ratios of performance to deviation (RPD = SD/SEP; 2.21-3.85). Precise, accurate, and rapid analysis of fresh olives for moisture, oil, and major fatty acid composition can be done at a low cost using NIRS, meeting the analytical need of the industry. This article is protected by copyright. All rights reserved.

  9. Musculoskeletal Modeling of a Forward Lunge Movement:Implications for ACL Loading

    DEFF Research Database (Denmark)

    Alkjaer, T; Wieland, MR; Andersen, MS

    2010-01-01

    Context: The forward lunge is widely used among athletes for training and rehabilitation purposes. The forward lunge movement has also been suggested as a model to study functional adaptation to ACL rupture. Previous investigations indicate that the absence of the ACL influences the movement patt...... by the ACL. The forward lunge explored the muscle and reaction forces, which can be used for further examination of ACL injury mechanisms and prevention strategies by applying parameter and optimization studies to the model....

  10. Modelling of railway vehicle movement considering non-ideal geometry of wheels and rails

    Directory of Open Access Journals (Sweden)

    Jandora R.

    2007-11-01

    Full Text Available A model of railway vehicle movement is presented. This model takes into account arbitrary shape of wheel and rails. Therefore models of contact of surfaces of arbitrary geometry are built in. The contact forces are found with possibility of choice from methods of rolling contact mechanics. The shape irregularities cause vibrations, therefore a model of track and its rails, sleepers and ballast is incorporated and also the vehicle model includes vibration-damping elements. Overall it makes a complete model of the vehicle movement with focus on the wear prediction and vibrations due to the corrugation.

  11. Analysis of surface and root-zone soil moisture dynamics with ERS scatterometer and the hydrometeorological model SAFRAN-ISBA-MODCOU at Grand Morin watershed (France

    Directory of Open Access Journals (Sweden)

    T. Paris Anguela

    2008-12-01

    Full Text Available Spatial and temporal variations of soil moisture strongly affect flooding, erosion, solute transport and vegetation productivity. Its characterization, offers an avenue to improve our understanding of complex land surface-atmosphere interactions. In this paper, soil moisture dynamics at soil surface (first centimeters and root-zone (up to 1.5 m depth are investigated at three spatial scales: local scale (field measurements, 8×8 km2 (hydrological model and 25×25 km2 scale (ERS scatterometer in a French watershed. This study points out the quality of surface and root-zone soil moisture data for SIM model and ERS scatterometer for a three year period. Surface soil moisture is highly variable because is more influenced by atmospheric conditions (rain, wind and solar radiation, and presents RMSE up to 0.08 m3 m−3. On the other hand, root-zone moisture presents lower variability with small RMSE (between 0.02 and 0.06 m3 m−3. These results will contribute to satellite and model verification of moisture, but also to better application of radar data for data assimilation in future.

  12. Analysis of surface and root-zone soil moisture dynamics with ERS scatterometer and the hydrometeorological model SAFRAN-ISBA-MODCOU at Grand Morin watershed (France

    Directory of Open Access Journals (Sweden)

    T. Paris Anguela

    2008-07-01

    Full Text Available Spatial and temporal variations of soil moisture strongly affect flooding, erosion, solute transport and vegetation productivity. Its characterization, offers an avenue to improve our understanding of complex land surface–atmosphere interactions. In this paper, soil moisture dynamics at soil surface (first centimeters and root-zone (up to 1.5 m depth are investigated at three spatial scales: local scale (field measurements, 8×8 km2 (hydrological model and 25×25 km2 scale (ERS scatterometer in a French watershed. This study points out the quality of surface and root-zone soil moisture data for SIM model and ERS scatterometer for a three year period. Surface soil moisture is highly variable because is more influenced by atmospheric conditions (rain, wind and solar radiation, and presents RMS errors up to 0.08 m3 m−3. On the other hand, root-zone moisture presents lower variability with small RMS errors (between 0.02 and 0.06 m3 m-3. These results will contribute to satellite and model verification of moisture, but also to better application of radar data for data assimilation in future.

  13. Ferns, mosses and liverworts as model systems for light-mediated chloroplast movements.

    Science.gov (United States)

    Suetsugu, Noriyuki; Higa, Takeshi; Wada, Masamitsu

    2016-11-17

    Light-induced chloroplast movement is found in most plant species, including algae and land plants. In land plants with multiple small chloroplasts, under weak light conditions, the chloroplasts move towards the light and accumulate on the periclinal cell walls to efficiently perceive light for photosynthesis (the accumulation response). Under strong light conditions, chloroplasts escape from light to avoid photodamage (the avoidance response). In most plant species, blue light induces chloroplast movement, and phototropin receptor kinases are the blue light receptors. Molecular mechanisms for photoreceptors, signal transduction and chloroplast motility systems are being studied using the model plant Arabidopsis thaliana. However, to further understand the molecular mechanisms and evolutionary history of chloroplast movement in green plants, analyses using other plant systems are required. Here, we review recent works on chloroplast movement in green algae, liverwort, mosses and ferns that provide new insights on chloroplast movement.

  14. Effects of Pronunciation Practice System Based on Personalized CG Animations of Mouth Movement Model

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2012-06-01

    Full Text Available Pronunciation practice system based on personalized Computer Graphics: CG animation of mouth movement model is proposed. The system enables a learner to practice pronunciation by looking at personalized CG animations of mouth movement model , and allows him/her to compare them with his/her own mouth movements. In order to evaluate the effectiveness of the system by using personalized CG animation of mouth movement model, Japanese vowel and consonant sounds were read by 8 infants before and after practicing with the proposed system, and their pronunciations were examined. Remarkable improvement on their pronunciations is confirmed through a comparison to their pronunciation without the proposed system based on identification test by subjective basis.

  15. A Hidden Markov Movement Model for rapidly identifying behavioral states from animal tracks

    DEFF Research Database (Denmark)

    Whoriskey, Kim; Auger-Méthé, Marie; Albertsen, Christoffer Moesgaard

    2017-01-01

    1. Electronic telemetry is frequently used to document animal movement through time. Methods that can identify underlying behaviors driving specific movement patterns can help us understand how and why animals use available space, thereby aiding conservation and management efforts. For aquatic....... 2. We developed a new Hidden Markov Model (HMM) for identifying behavioral states from animal tracks with negligible error, which we called the Hidden Markov Movement Model (HMMM). We implemented as the basis for the HMMM the process equation of the DCRWS, but we used the method of maximum...... animal tracking data with significant measurement error, a Bayesian state-space model called the first-Difference Correlated Random Walk with Switching (DCRWS) has often been used for this purpose. However, for aquatic animals, highly accurate tracking data of animal movement are now becoming more common...

  16. Model-Based Synthesis of Visual Speech Movements from 3D Video

    Directory of Open Access Journals (Sweden)

    James D. Edge

    2009-01-01

    Full Text Available We describe a method for the synthesis of visual speech movements using a hybrid unit selection/model-based approach. Speech lip movements are captured using a 3D stereo face capture system and split up into phonetic units. A dynamic parameterisation of this data is constructed which maintains the relationship between lip shapes and velocities; within this parameterisation a model of how lips move is built and is used in the animation of visual speech movements from speech audio input. The mapping from audio parameters to lip movements is disambiguated by selecting only the most similar stored phonetic units to the target utterance during synthesis. By combining properties of model-based synthesis (e.g., HMMs, neural nets with unit selection we improve the quality of our speech synthesis.

  17. Impact of the initial specification of moisture and vertical motion on precipitation forecasts with a mesoscale model Implications for a satellite mesoscale data base

    Science.gov (United States)

    Mlynczak, Pamela E.; Houghton, David D.; Diak, George R.

    1986-01-01

    Using a numerical mesoscale model, four simulations were performed to determine the effects of suppressing the initial mesoscale information in the moisture and wind fields on the precipitation forecasts. The simulations included a control forecast 12-h simulation that began at 1200 GMT March 1982 and three experiment simulations with modifications to the moisture and vertical motion fields incorporated at 1800 GMT. The forecasts from 1800 GMT were compared to the second half of the control forecast. It was found that, compared to the control forecast, suppression of the moisture and/or wind initial field(s) produces a drier forecast. However, the characteristics of the precipitation forecasts of the experiments were not different enough to conclude that either mesoscale moisture or mesoscale vertical velocity at the initial time are more important for producing a forecast closer to that of the control.

  18. An action potential-driven model of soleus muscle activation dynamics for locomotor-like movements

    Science.gov (United States)

    Kim, Hojeong; Sandercock, Thomas G.; Heckman, C. J.

    2015-08-01

    Objective. The goal of this study was to develop a physiologically plausible, computationally robust model for muscle activation dynamics (A(t)) under physiologically relevant excitation and movement. Approach. The interaction of excitation and movement on A(t) was investigated comparing the force production between a cat soleus muscle and its Hill-type model. For capturing A(t) under excitation and movement variation, a modular modeling framework was proposed comprising of three compartments: (1) spikes-to-[Ca2+]; (2) [Ca2+]-to-A; and (3) A-to-force transformation. The individual signal transformations were modeled based on physiological factors so that the parameter values could be separately determined for individual modules directly based on experimental data. Main results. The strong dependency of A(t) on excitation frequency and muscle length was found during both isometric and dynamically-moving contractions. The identified dependencies of A(t) under the static and dynamic conditions could be incorporated in the modular modeling framework by modulating the model parameters as a function of movement input. The new modeling approach was also applicable to cat soleus muscles producing waveforms independent of those used to set the model parameters. Significance. This study provides a modeling framework for spike-driven muscle responses during movement, that is suitable not only for insights into molecular mechanisms underlying muscle behaviors but also for large scale simulations.

  19. Hillslope sediment and soil carbon transport: can we model their movement?

    Science.gov (United States)

    Hancock, Greg; Kunkel, Veikko; Dever, Chris; Braggins, Matthew; Willgoose, Garry

    2016-04-01

    Quantifying and predicting the movement of hillslope sediment and soil organic carbon (SOC) is of huge scientific, agronomic and economic benefit. In particular, the movement and fate of SOC has attracted considerable recent attention. However, the reliable modelling and prediction of sediment and SOC movement has proved elusive. Here we examine the movement of sediment and SOC along a grazing hillslope in south-eastern Australia. The slope is linear, uniformly managed and has consistent vegetation (grassland). We quantify sediment and SOC transport using the environmental tracer 137-Ceasium. However, here we collect field samples using the conventional soil cores but also shallow samples to quantify the dynamics of the near surface. We also model the movement of sediment and SOC using a numerically based soil erosion and landscape evolution model. Our results show that the hillslope is erosional which is supported by field observation. However, there was no relationship between SOC and 137-Caesium suggesting that SOC and their movement and fate are not related. Significant relationships were observed between soil texture and SOC for the near surface but not for the deeper cores suggesting any movement and fate of SOC is more controlled by soil particle size at the near surface. The SIBERIA sediment transport model was calibrated and run for the site. Comparing the field derived erosion and SOC data with model prediction found no significant relationship. However, the numerical model was able to predict the cyclic pattern of 137-Ceasium and SOC as well as overall trends. Our findings demonstrate that the movement and fate of sediment and SOC is complex.

  20. Evaluation of moisture sources for the Central European summer flood of May/June 2013 based on regional climate model simulations

    Directory of Open Access Journals (Sweden)

    Fanni D. Kelemen

    2016-02-01

    Full Text Available Heavy precipitation affected Central Europe in May/June 2013, triggering damaging floods both on the Danube and the Elbe rivers. Based on a modelling approach with COSMO-CLM, moisture fluxes, backward trajectories, cyclone tracks and precipitation fields are evaluated for the relevant time period 30 May–2 June 2013. We identify potential moisture sources and quantify their contribution to the flood event focusing on the Danube basin through sensitivity experiments: Control simulations are performed with undisturbed ERA-Interim boundary conditions, while multiple sensitivity experiments are driven with modified evaporation characteristics over selected marine and land areas. Two relevant cyclones are identified both in reanalysis and in our simulations, which moved counter-clockwise in a retrograde path from Southeastern Europe over Eastern Europe towards the northern slopes of the Alps. The control simulations represent the synoptic evolution of the event reasonably well. The evolution of the precipitation event in the control simulations shows some differences in terms of its spatial and temporal characteristics compared to observations. The main precipitation event can be separated into two phases concerning the moisture sources. Our modelling results provide evidence that the two main sources contributing to the event were the continental evapotranspiration (moisture recycling; both phases and the North Atlantic Ocean (first phase only. The Mediterranean Sea played only a minor role as a moisture source. This study confirms the importance of continental moisture recycling for heavy precipitation events over Central Europe during the summer half year.

  1. A Tropical Atmosphere Model with Moisture: Global Well-posedness and Relaxation Limit

    CERN Document Server

    Li, Jinkai

    2015-01-01

    In this paper, we consider a nonlinear interaction system between the barotropic mode and the first baroclinic mode of the tropical atmosphere with moisture; that was derived in [Frierson, D.M.W.; Majda, A.J.; Pauluis, O.M.: Dynamics of precipitation fronts in the tropical atmosphere: a novel relaxation limit, Commum. Math. Sci., 2 (2004), 591-626.] We establish the global existence and uniqueness of strong solutions to this system, with initial data in $H^1$, for each fixed convective adjustment relaxation time parameter $\\varepsilon>0$. Moreover, if the initial data enjoy slightly more regularity than $H^1$, then the unique strong solution depends continuously on the initial data. Furthermore, by establishing several appropriate $\\varepsilon$-independent estimates, we prove that the system converges to a limiting system, as the relaxation time parameter $\\varepsilon$ tends to zero, with convergence rate of the order $O(\\sqrt\\varepsilon)$. Moreover, the limiting system has a unique global strong solution, fo...

  2. Evaluating the strength of the land-atmosphere moisture feedback in Earth system models using satellite observations

    Science.gov (United States)

    Levine, Paul A.; Randerson, James T.; Swenson, Sean C.; Lawrence, David M.

    2016-12-01

    The relationship between terrestrial water storage (TWS) and atmospheric processes has important implications for predictability of climatic extremes and projection of future climate change. In places where moisture availability limits evapotranspiration (ET), variability in TWS has the potential to influence surface energy fluxes and atmospheric conditions. Where atmospheric conditions, in turn, influence moisture availability, a full feedback loop exists. Here we developed a novel approach for measuring the strength of both components of this feedback loop, i.e., the forcing of the atmosphere by variability in TWS and the response of TWS to atmospheric variability, using satellite observations of TWS, precipitation, solar radiation, and vapor pressure deficit during 2002-2014. Our approach defines metrics to quantify the relationship between TWS anomalies and climate globally on a seasonal to interannual timescale. Metrics derived from the satellite data were used to evaluate the strength of the feedback loop in 38 members of the Community Earth System Model (CESM) Large Ensemble (LENS) and in six models that contributed simulations to phase 5 of the Coupled Model Intercomparison Project (CMIP5). We found that both forcing and response limbs of the feedback loop in LENS were stronger than in the satellite observations in tropical and temperate regions. Feedbacks in the selected CMIP5 models were not as strong as those found in LENS, but were still generally stronger than those estimated from the satellite measurements. Consistent with previous studies conducted across different spatial and temporal scales, our analysis suggests that models may overestimate the strength of the feedbacks between the land surface and the atmosphere. We describe several possible mechanisms that may contribute to this bias, and discuss pathways through which models may overestimate ET or overestimate the sensitivity of ET to TWS.

  3. Land Surface Model and Particle Swarm Optimization Algorithm Based on the Model-Optimization Method for Improving Soil Moisture Simulation in a Semi-Arid Region.

    Directory of Open Access Journals (Sweden)

    Qidong Yang

    Full Text Available Improving the capability of land-surface process models to simulate soil moisture assists in better understanding the atmosphere-land interaction. In semi-arid regions, due to limited near-surface observational data and large errors in large-scale parameters obtained by the remote sensing method, there exist uncertainties in land surface parameters, which can cause large offsets between the simulated results of land-surface process models and the observational data for the soil moisture. In this study, observational data from the Semi-Arid Climate Observatory and Laboratory (SACOL station in the semi-arid loess plateau of China were divided into three datasets: summer, autumn, and summer-autumn. By combing the particle swarm optimization (PSO algorithm and the land-surface process model SHAW (Simultaneous Heat and Water, the soil and vegetation parameters that are related to the soil moisture but difficult to obtain by observations are optimized using three datasets. On this basis, the SHAW model was run with the optimized parameters to simulate the characteristics of the land-surface process in the semi-arid loess plateau. Simultaneously, the default SHAW model was run with the same atmospheric forcing as a comparison test. Simulation results revealed the following: parameters optimized by the particle swarm optimization algorithm in all simulation tests improved simulations of the soil moisture and latent heat flux; differences between simulated results and observational data are clearly reduced, but simulation tests involving the adoption of optimized parameters cannot simultaneously improve the simulation results for the net radiation, sensible heat flux, and soil temperature. Optimized soil and vegetation parameters based on different datasets have the same order of magnitude but are not identical; soil parameters only vary to a small degree, but the variation range of vegetation parameters is large.

  4. Modeling white sturgeon movement in a reservoir: The effect of water quality and sturgeon density

    Science.gov (United States)

    Sullivan, A.B.; Jager, H.I.; Myers, R.

    2003-01-01

    We developed a movement model to examine the distribution and survival of white sturgeon (Acipenser transmontanus) in a reservoir subject to large spatial and temporal variation in dissolved oxygen and temperature. Temperature and dissolved oxygen were simulated by a CE-QUAL-W2 model of Brownlee Reservoir, Idaho for a typical wet, normal, and dry hydrologic year. We compared current water quality conditions to scenarios with reduced nutrient inputs to the reservoir. White sturgeon habitat quality was modeled as a function of temperature, dissolved oxygen and, in some cases, suitability for foraging and depth. We assigned a quality index to each cell along the bottom of the reservoir. The model simulated two aspects of daily movement. Advective movement simulated the tendency for animals to move toward areas with high habitat quality, and diffusion simulated density dependent movement away from areas with high sturgeon density in areas with non-lethal habitat conditions. Mortality resulted when sturgeon were unable to leave areas with lethal temperature or dissolved oxygen conditions. Water quality was highest in winter and early spring and lowest in mid to late summer. Limiting nutrient inputs reduced the area of Brownlee Reservoir with lethal conditions for sturgeon and raised the average habitat suitability throughout the reservoir. Without movement, simulated white sturgeon survival ranged between 45 and 89%. Allowing movement raised the predicted survival of sturgeon under all conditions to above 90% as sturgeon avoided areas with low habitat quality. ?? 2003 Elsevier B.V. All rights reserved.

  5. Spatio-Temporal Analysis of Model and Satellite Based Soil Moisture Estimations for Assessing Coupling Hot Spots in the Southern La Plata Basin

    Science.gov (United States)

    Bruscantini, C. A.; Karszenbaum, H.; Ruscica, R. C.; Spennemann, P.; Salvia, M.; Sorensson, A. A.; Grings, F. M.; Saulo, C.

    2015-12-01

    The southern La Plata Basin, located in southeastern South America (SESA), a region of great importance because of its hydrological characteristics, the fact that it has the largest population density and is one of the most productive regions in terms of agriculture, cattle raising and industry of the continent, has been identified as a strong hotspot between soil moisture (SM) and the atmosphere by different regional studies. Among them, Ruscica et al. (2014, Atmos. Sci. Let, Int. J. Climatol.), and Spennemann et al. (2015, Int. J. Climatol.) show, through different modeling approaches, the presence of strong soil moisture-precipitation and evapotranspiration interactions during austral summer in SESA, revealing similar hotspots. Nevertheless these studies have diverse limitations related to model assumptions and to vegetation parameterizations, as well as the lack of observational data for the evaluation of models performance (Ferguson and Wood, 2011, J. of Hydrometeorology). On the other hand, in the last decade several instruments on board satellites are providing soil moisture products globally and in a continuous way. A recent work by Grings et al. (2015, IEEE JSTARS, in press), done over the Pampas Plains in SESA showed characteristic soil moisture patterns that follow the Standardized Precipitation Index (SPI) under extreme wet and dry conditions In order to deepen and overcome some of the mentioned model limitations, this work adds satellite soil moisture and vegetation products in the spatio-temporal analysis of the regions of strong soil moisture-atmosphere interactions. The main objectives and related outcomes are: the verification of already identified regions where soil moisture anomalies may have an influence on subsequent precipitation, evapotranspiration and temperature anomalies, and the study of their seasonal characteristics and land cover influences.

  6. Video-based feedback combined with reflective enquiry – An interactive model for movement awareness among nursing students

    OpenAIRE

    Sofia Backåberg; Mikael Rask; Christina Gummesson; David Brunt

    2015-01-01

    The aim of this study is to describe an interactive model developed for movement awareness in a practical learning situation and to explore the use of video-based digital feedback and reflective enquiry in this model among nursing students. Sixteen students participated in individual interactive video sessions with a facilitator, who encouraged the students to reflect upon their own movements. Qualitative analysis showed that movement patterns were visualized, and that movement awareness and ...

  7. Application of a multistate model to estimate culvert effects on movement of small fishes

    Science.gov (United States)

    Norman, J.R.; Hagler, M.M.; Freeman, Mary C.; Freeman, B.J.

    2009-01-01

    While it is widely acknowledged that culverted road-stream crossings may impede fish passage, effects of culverts on movement of nongame and small-bodied fishes have not been extensively studied and studies generally have not accounted for spatial variation in capture probabilities. We estimated probabilities for upstream and downstream movement of small (30-120 mm standard length) benthic and water column fishes across stream reaches with and without culverts at four road-stream crossings over a 4-6-week period. Movement and reach-specific capture probabilities were estimated using multistate capture-recapture models. Although none of the culverts were complete barriers to passage, only a bottomless-box culvert appeared to permit unrestricted upstream and downstream movements by benthic fishes based on model estimates of movement probabilities. At two box culverts that were perched above the water surface at base flow, observed movements were limited to water column fishes and to intervals when runoff from storm events raised water levels above the perched level. Only a single fish was observed to move through a partially embedded pipe culvert. Estimates for probabilities of movement over distances equal to at least the length of one culvert were low (e.g., generally ???0.03, estimated for 1-2-week intervals) and had wide 95% confidence intervals as a consequence of few observed movements to nonadjacent reaches. Estimates of capture probabilities varied among reaches by a factor of 2 to over 10, illustrating the importance of accounting for spatially variable capture rates when estimating movement probabilities with capture-recapture data. Longer-term studies are needed to evaluate temporal variability in stream fish passage at culverts (e.g., in relation to streamflow variability) and to thereby better quantify the degree of population fragmentation caused by road-stream crossings with culverts. ?? American Fisheries Society 2009.

  8. A NEW CONCEPT OF MODELING NEEDS OF THE POPULATION IN THE LABOR MOVEMENT BY PUBLIC TRANSPORT

    Directory of Open Access Journals (Sweden)

    P. F. Ghorbachov

    2015-05-01

    Full Text Available In the paper, with the purpose of accounting a casual character of distribution of capacities of transport areas on labor movements in a matrix of correspondences, the interval concept of modeling the population needs in movements has been suggested when for transport calculations one uses not one variant of a matrix but borders of an interval of its possible values at the set area capacities.

  9. Self-Propelled Pedestrian Dynamics Model: Application to Passenger Movement and Infection Propagation in Airplanes

    CERN Document Server

    Namilae, S; Mubayi, A; Scotch, M; Pahle, R

    2016-01-01

    Reducing the number of contacts between passengers on an airplane can potentially curb the spread of infectious diseases. In this paper, a social force based pedestrian movement model is formulated and applied to evaluate the movement and contacts among passengers during boarding and deplaning of an airplane. Within the social force modeling framework, we introduce location dependence on the self-propelling momentum of pedestrian particles. The model parameters are varied over a large design space and the results are compared with experimental observations to validate the model. This model is then used to assess the different approaches to minimize passenger contacts during boarding and deplaning of airplanes. We find that smaller aircrafts are effective in reducing the contacts between passengers. Column wise deplaning and random boarding are found to be two strategies that reduced the number of contacts during passenger movement, and can potentially lower the likelihood of infection spread.

  10. Self-propelled pedestrian dynamics model: Application to passenger movement and infection propagation in airplanes

    Science.gov (United States)

    Namilae, S.; Srinivasan, A.; Mubayi, A.; Scotch, M.; Pahle, R.

    2017-01-01

    Reducing the number of contacts between passengers on an airplane can potentially curb the spread of infectious diseases. In this paper, a social force based pedestrian movement model is formulated and applied to evaluate the movement and contacts among passengers during boarding and deplaning of an airplane. Within the social force modeling framework, we introduce location dependence on the self-propelling momentum of pedestrian particles. The model parameters are varied over a large design space and the results are compared with experimental observations to validate the model. This model is then used to assess the different approaches to minimize passenger contacts during boarding and deplaning of airplanes. We find that smaller aircrafts are effective in reducing the contacts between passengers. Column wise deplaning and random boarding are found to be two strategies that reduced the number of contacts during passenger movement, and can potentially lower the likelihood of infection spread.

  11. Evaluation of moisture sources for the Central European summer flood of May/June 2013 based on regional climate model simulations

    Science.gov (United States)

    Kelemen, Fanni Dora; Ludwig, Patrick; Reyers, Mark; Ulbrich, Sven; Pinto, Joaquim G.

    2016-04-01

    Heavy precipitation affected Central Europe in May/June 2013, triggering damaging floods both on the Danube and the Elbe rivers. A modelling approach with COSMO-CLM is used for a detailed analysis of the evolution of the event. Moisture flux, backward trajectories, evaporation and cyclone track analysis are evaluated for the relevant time period 30 May to 2 June 2013. The aim is to identify potential moisture sources and to quantify their contribution to the flood event in the Danube basin. Control simulations with undisturbed ERA-Interim boundary conditions and sensitivity experiments with modified evaporation characteristics are performed to estimate the role of moisture evaporated from different marine and land areas. The simulated cyclone tracks and upper level flow are compared against reanalysis. Simulated precipitation amounts are validated against E-OBS precipitation data. Two relevant cyclones are identified, which moved counterclockwise in a retrograde path from Southeastern Europe over Eastern Europe towards the northern slopes of the Alps. The control simulations represent the cyclone characteristics and tracks reasonably well. The evolution of the precipitation event in the simulations shows some minor differences to the Reanalysis in terms of its spatial and temporal characteristics. Our sensitivity experiment results provide evidence that the two main sources contributing to the event were the continental evapotranspiration (moisture recycling) and the North Atlantic Ocean. The Mediterranean Sea played only a minor role as a moisture source. This study confirms the importance of continental moisture recycling for heavy precipitation events over Central Europe during the summer half year.

  12. Influences of the Indoor Environment on Heat, Air and Moisture Conditions in The Building Component: Boundary Conditions Modeling

    DEFF Research Database (Denmark)

    Steskens, Paul Wilhelmus Maria Hermanus; Rode, Carsten; Janssen, Hans

    2008-01-01

    used to investigate this influence. The research showed that the indoor environmental conditions and local airflow velocity have a relatively large influence on the predicted HAM conditions in a building component. The influence of the convective surface heat transfer coefficient on the HAM performance...... is not acceptable for the convective surface heat transfer coefficient. The study showed that the influence on the surface relative humidity is limited.......Current models to predict heat, air and moisture (HAM) conditions in building components assume uniform boundary conditions, both for the temperature and relative humidity of the air in an indoor space as well as for the surface transfer coefficients. Such models cannot accurately predict the HAM...

  13. Hybrid Modelling of Individual Movement and Collective Behaviour

    KAUST Repository

    Franz, Benjamin

    2013-01-01

    Mathematical models of dispersal in biological systems are often written in terms of partial differential equations (PDEs) which describe the time evolution of population-level variables (concentrations, densities). A more detailed modelling approach is given by individual-based (agent-based) models which describe the behaviour of each organism. In recent years, an intermediate modelling methodology - hybrid modelling - has been applied to a number of biological systems. These hybrid models couple an individual-based description of cells/animals with a PDE-model of their environment. In this chapter, we overview hybrid models in the literature with the focus on the mathematical challenges of this modelling approach. The detailed analysis is presented using the example of chemotaxis, where cells move according to extracellular chemicals that can be altered by the cells themselves. In this case, individual-based models of cells are coupled with PDEs for extracellular chemical signals. Travelling waves in these hybrid models are investigated. In particular, we show that in contrary to the PDEs, hybrid chemotaxis models only develop a transient travelling wave. © 2013 Springer-Verlag Berlin Heidelberg.

  14. Generalized Pareto for Pattern-Oriented Random Walk Modelling of Organisms' Movements.

    Directory of Open Access Journals (Sweden)

    Sophie Bertrand

    Full Text Available How organisms move and disperse is crucial to understand how population dynamics relates to the spatial heterogeneity of the environment. Random walk (RW models are typical tools to describe movement patterns. Whether Lévy or alternative RW better describes forager movements is keenly debated. We get around this issue using the Generalized Pareto Distribution (GPD. GPD includes as specific cases Normal, exponential and power law distributions, which underlie Brownian, Poisson-like and Lévy walks respectively. Whereas previous studies typically confronted a limited set of candidate models, GPD lets the most likely RW model emerge from the data. We illustrate the wide applicability of the method using GPS-tracked seabird foraging movements and fishing vessel movements tracked by Vessel Monitoring System (VMS, both collected in the Peruvian pelagic ecosystem. The two parameters from the fitted GPD, a scale and a shape parameter, provide a synoptic characterization of the observed movement in terms of characteristic scale and diffusive property. They reveal and quantify the variability, among species and individuals, of the spatial strategies selected by predators foraging on a common prey field. The GPD parameters constitute relevant metrics for (1 providing a synthetic and pattern-oriented description of movement, (2 using top predators as ecosystem indicators and (3 studying the variability of spatial behaviour among species or among individuals with different personalities.

  15. Generalized Pareto for Pattern-Oriented Random Walk Modelling of Organisms' Movements.

    Science.gov (United States)

    Bertrand, Sophie; Joo, Rocío; Fablet, Ronan

    2015-01-01

    How organisms move and disperse is crucial to understand how population dynamics relates to the spatial heterogeneity of the environment. Random walk (RW) models are typical tools to describe movement patterns. Whether Lévy or alternative RW better describes forager movements is keenly debated. We get around this issue using the Generalized Pareto Distribution (GPD). GPD includes as specific cases Normal, exponential and power law distributions, which underlie Brownian, Poisson-like and Lévy walks respectively. Whereas previous studies typically confronted a limited set of candidate models, GPD lets the most likely RW model emerge from the data. We illustrate the wide applicability of the method using GPS-tracked seabird foraging movements and fishing vessel movements tracked by Vessel Monitoring System (VMS), both collected in the Peruvian pelagic ecosystem. The two parameters from the fitted GPD, a scale and a shape parameter, provide a synoptic characterization of the observed movement in terms of characteristic scale and diffusive property. They reveal and quantify the variability, among species and individuals, of the spatial strategies selected by predators foraging on a common prey field. The GPD parameters constitute relevant metrics for (1) providing a synthetic and pattern-oriented description of movement, (2) using top predators as ecosystem indicators and (3) studying the variability of spatial behaviour among species or among individuals with different personalities.

  16. Configuration of the relationship of soil moistures for vertical soil profiles on a steep hillslope using a vector time series model

    Science.gov (United States)

    Kim, Sanghyun; Sun, Hanna; Jung, Sungwon

    2011-03-01

    SummaryVariation in soil moisture content throughout soil profiles during several sequential rainfalls represents the internal hydrological response on a hillslope scale. A multiplex TDR system has been operating on a mountainous hillslope to obtain the time series of soil moisture along two transects in the study area. The soil moisture modeling conducted in this study highlights our understanding of the inter-relationships between soil moistures at identical spatial locations, but at different depths. A sequential procedure was used for the time series modeling to delineate an appropriate model for application to all monitoring points. The feedback relationship of soil wetness between two different depths was expressed with the proposed vector autoregressive model. Based on the successful modeling of 31 coupled soil water histories, the vertical distributions of the stochastic model throughout the study area were obtained. The distribution of the delineated models implied a spatial distribution of the hydrological processes, such as vertical infiltration for the upper soil layers and some of the lower soil layers (38 out of 62 models), lateral redistribution and subsurface flow over bedrock mostly for the lower soil layers (24 out of 62 models) on the steep hillslope. With the use of the resultant models, applications were proposed to improve the data acquisition system, i.e. gap filling for missing data and limited prediction for an ungauged location.

  17. Linking soil moisture balance and source-responsive models to estimate diffuse and preferential components of groundwater recharge

    Science.gov (United States)

    Cuthbert, M.O.; Mackay, R.; Nimmo, J.R.

    2012-01-01

    Results are presented of a detailed study into the vadose zone and shallow water table hydrodynamics of a field site in Shropshire, UK. A conceptual model is developed and tested using a range of numerical models, including a modified soil moisture balance model (SMBM) for estimating groundwater recharge in the presence of both diffuse and preferential flow components. Tensiometry reveals that the loamy sand topsoil wets up via macropore flow and subsequent redistribution of moisture into the soil matrix. Recharge does not occur until near-positive pressures are achieved at the top of the sandy glaciofluvial outwash material that underlies the topsoil, about 1 m above the water table. Once this occurs, very rapid water table rises follow. This threshold behaviour is attributed to the vertical discontinuity in the macropore system due to seasonal ploughing of the topsoil, and a lower permeability plough/iron pan restricting matrix flow between the topsoil and the lower outwash deposits. Although the wetting process in the topsoil is complex, a SMBM is shown to be effective in predicting the initiation of preferential flow from the base of the topsoil into the lower outwash horizon. The rapidity of the response at the water table and a water table rise during the summer period while flow gradients in the unsaturated profile were upward suggest that preferential flow is also occurring within the outwash deposits below the topsoil. A variation of the source-responsive model proposed by Nimmo (2010) is shown to reproduce the observed water table dynamics well in the lower outwash horizon when linked to a SMBM that quantifies the potential recharge from the topsoil. The results reveal new insights into preferential flow processes in cultivated soils and provide a useful and practical approach to accounting for preferential flow in studies of groundwater recharge estimation.

  18. Linking soil moisture balance and source-responsive models to estimate diffuse and preferential components of groundwater recharge

    Directory of Open Access Journals (Sweden)

    M. O. Cuthbert

    2013-03-01

    Full Text Available Results are presented of a detailed study into the vadose zone and shallow water table hydrodynamics of a field site in Shropshire, UK. A conceptual model is presented and tested using a range of numerical models, including a modified soil moisture balance model (SMBM for estimating groundwater recharge in the presence of both diffuse and preferential flow components. Tensiometry reveals that the loamy sand topsoil wets up via preferential flow and subsequent redistribution of moisture into the soil matrix. Recharge does not occur until near-positive pressures are achieved at the top of the sandy glaciofluvial outwash material that underlies the topsoil, about 1 m above the water table. Once this occurs, very rapid water table rises follow. This threshold behaviour is attributed to the vertical discontinuity in preferential flow pathways due to seasonal ploughing of the topsoil and to a lower permeability plough/iron pan restricting matrix flow between the topsoil and the lower outwash deposits. Although the wetting process in the topsoil is complex, a SMBM is shown to be effective in predicting the initiation of preferential flow from the base of the topsoil into the lower outwash horizon. The rapidity of the response at the water table and a water table rise during the summer period while flow gradients in the unsaturated profile were upward suggest that preferential flow is also occurring within the outwash deposits below the topsoil. A variation of the source-responsive model proposed by Nimmo (2010 is shown to reproduce the observed water table dynamics well in the lower outwash horizon when linked to a SMBM that quantifies the potential recharge from the topsoil. The results reveal new insights into preferential flow processes in cultivated soils and provide a useful and practical approach to accounting for preferential flow in studies of groundwater recharge estimation.

  19. Electrical models of excitation-contraction coupling and charge movement in skeletal muscle.

    Science.gov (United States)

    Mathias, R T; Levis, R A; Eisenberg, R S

    1980-07-01

    The consequences of ionic current flow from the T system to the sarcoplasmic reticulum (SR) of skeletal muscle are examined. The Appendix analyzes a simple model in which the conductance gx, linking T system and SR, is in series with a parallel resistor and capacitor having fixed values. The conductance gx is supposed to increase rapidly with depolarization and to decrease slowly with repolarization. Nonlinear transient currents computed from this model have some of the properties of gating currents produced by intramembrane charge movement. In particular, the integral of the transient current upon depolarization approximates that upon repolarization. Thus, equality of nonlinear charge movement can occur without intramembrane charge movement. A more complicated model is used in the text to fit the structure of skeletal muscle and other properties of its charge movement. Rectification is introduced into gx and the membrane conductance of the terminal cisternae to give asymmetry in the time-course of the transient currents and saturation in the curve relating charge movement to depolarization, respectively. The more complex model fits experimental data quite well if the longitudinal tubules of the sarcoplasmic reticulum are isolated from the terminal cisternae by a substantial resistance and if calcium release from the terminal cisternae is, for the most part, electrically silent. Specific experimental tests of the model are proposed, and the implications for excitation-contraction coupling are discussed.

  20. The punctum fixum-punctum mobile model: a neuromuscular principle for efficient movement generation?

    Directory of Open Access Journals (Sweden)

    Christoph von Laßberg

    Full Text Available According to the "punctum fixum-punctum mobile model" that was introduced in prior studies, for generation of the most effective intentional acceleration of a body part the intersegmental neuromuscular onset succession has to spread successively from the rotation axis (punctum fixum toward the body part that shall be accelerated (punctum mobile. The aim of the present study was to investigate whether this principle is, indeed, fundamental for any kind of efficient rotational accelerations in general, independent of the kind of movements, type of rotational axis, the current body position, or movement direction. Neuromuscular onset succession was captured by surface electromyography of relevant muscles of the anterior and posterior muscle chain in 16 high-level gymnasts during intentional accelerating movement phases while performing 18 different gymnastics elements (in various body positions to forward and backward, performed on high bar, parallel bars, rings and trampoline, as well as during non-sport specific pivot movements around the longitudinal axis. The succession patterns to generate the acceleration phases during these movements were described and statistically evaluated based on the onset time difference between the muscles of the corresponding muscle chain. In all the analyzed movement phases, the results clearly support the hypothesized succession pattern from punctum fixum to punctum mobile. This principle was further underlined by the finding that the succession patterns do change their direction running through the body when the rotational axis (punctum fixum has been changed (e.g., high bar or rings [hands] vs. floor or trampoline [feet]. The findings improve our understanding of intersegmental neuromuscular coordination patterns to generate intentional movements most efficiently. This could help to develop more specific methods to facilitate such patterns in particular contexts, thus allowing for shorter motor learning

  1. A tropical atmosphere model with moisture: global well-posedness and relaxation limit

    Science.gov (United States)

    Li, Jinkai; Titi, Edriss S.

    2016-09-01

    In this paper, we consider a nonlinear interaction system between the barotropic mode and the first baroclinic mode of the tropical atmosphere with moisture, which was derived in Frierson et al (2004 Commum. Math. Sci. 2 591-626). We establish the global existence and uniqueness of strong solutions to this system, with initial data in H 1, for each fixed convective adjustment relaxation time parameter \\varepsilon >0 . Moreover, if the initial data possess slightly more regularity than H 1, then the unique strong solution depends continuously on the initial data. Furthermore, by establishing several appropriate ɛ-independent estimates, we prove that the system converges to a limiting system as the relaxation time parameter ɛ tends to zero, with a convergence rate of the order O≤ft(\\sqrt{\\varepsilon}\\right) . Moreover, the limiting system has a unique global strong solution for any initial data in H 1 and such a unique strong solution depends continuously on the initial data if the initial data posses slightly more regularity than H 1. Notably, this solves the viscous version of an open problem proposed in the above mentioned paper of Frierson, Majda and Pauluis.

  2. LS3MIP (v1.0) contribution to CMIP6: the Land Surface, Snow and Soil moisture Model Intercomparison Project - aims, setup and expected outcome

    Science.gov (United States)

    van den Hurk, Bart; Kim, Hyungjun; Krinner, Gerhard; Seneviratne, Sonia I.; Derksen, Chris; Oki, Taikan; Douville, Hervé; Colin, Jeanne; Ducharne, Agnès; Cheruy, Frederique; Viovy, Nicholas; Puma, Michael J.; Wada, Yoshihide; Li, Weiping; Jia, Binghao; Alessandri, Andrea; Lawrence, Dave M.; Weedon, Graham P.; Ellis, Richard; Hagemann, Stefan; Mao, Jiafu; Flanner, Mark G.; Zampieri, Matteo; Materia, Stefano; Law, Rachel M.; Sheffield, Justin

    2016-08-01

    The Land Surface, Snow and Soil Moisture Model Intercomparison Project (LS3MIP) is designed to provide a comprehensive assessment of land surface, snow and soil moisture feedbacks on climate variability and climate change, and to diagnose systematic biases in the land modules of current Earth system models (ESMs). The solid and liquid water stored at the land surface has a large influence on the regional climate, its variability and predictability, including effects on the energy, water and carbon cycles. Notably, snow and soil moisture affect surface radiation and flux partitioning properties, moisture storage and land surface memory. They both strongly affect atmospheric conditions, in particular surface air temperature and precipitation, but also large-scale circulation patterns. However, models show divergent responses and representations of these feedbacks as well as systematic biases in the underlying processes. LS3MIP will provide the means to quantify the associated uncertainties and better constrain climate change projections, which is of particular interest for highly vulnerable regions (densely populated areas, agricultural regions, the Arctic, semi-arid and other sensitive terrestrial ecosystems). The experiments are subdivided in two components, the first addressing systematic land biases in offline mode ("LMIP", building upon the 3rd phase of Global Soil Wetness Project; GSWP3) and the second addressing land feedbacks attributed to soil moisture and snow in an integrated framework ("LFMIP", building upon the GLACE-CMIP blueprint).

  3. LS3MIP (v1.0) Contribution to CMIP6: The Land Surface, Snow and Soil Moisture Model Intercomparison Project Aims, Setup and Expected Outcome.

    Science.gov (United States)

    Van Den Hurk, Bart; Kim, Hyungjun; Krinner, Gerhard; Seneviratne, Sonia I.; Derksen, Chris; Oki, Taikan; Douville, Herve; Colin, Jeanne; Ducharne, Agnes; Cheruy, Frederique; Viovy, Nicholas; Puma, Michael J.; Wada, Yoshide; Li, Weiping; Jia, Binghao; Alessandri, Andrea; Lawrence, Dave M.; Weedon, Graham P.; Ellis, Richard; Hagemann, Stefan

    2016-01-01

    The Land Surface, Snow and Soil Moisture Model Intercomparison Project (LS3MIP) is designed to provide a comprehensive assessment of land surface, snow, and soil moisture feedbacks on climate variability and climate change, and to diagnose systematic biases in the land modules of current Earth System Models (ESMs). The solid and liquid water stored at the land surface has a large influence on the regional climate, its variability and predictability, including effects on the energy, water and carbon cycles. Notably, snow and soil moisture affect surface radiation and flux partitioning properties, moisture storage and land surface memory. They both strongly affect atmospheric conditions, in particular surface air temperature and precipitation, but also large-scale circulation patterns. However, models show divergent responses and representations of these feedbacks as well as systematic biases in the underlying processes. LS3MIP will provide the means to quantify the associated uncertainties and better constrain climate change projections, which is of particular interest for highly vulnerable regions (densely populated areas, agricultural regions, the Arctic, semi-arid and other sensitive terrestrial ecosystems).The experiments are subdivided in two components, the first addressing systematic land biases in offline mode (LMIP, building upon the 3rd phase of Global Soil Wetness Project; GSWP3) and the second addressing land feedbacks attributed to soil moisture and snow in an integrated framework (LFMIP, building upon the GLACE-CMIP blueprint).

  4. Fuzzy Deductive Inference Scheme Application in Solving the Problem of Modelling Movements of the Hand Prosthesis

    Directory of Open Access Journals (Sweden)

    Bozhenyuk Alexander

    2015-12-01

    Full Text Available The decision-making model with basic fuzzy rule modus ponens is suggested in this paper to control the hand prosthesis. The hand movements are described by angles of finger and wrist flexion. Electromyogram (EMG of hand muscles was used as a source of the input data. Software was developed to implement the decision-making model with fuzzy rule modus ponens. In particular, the software receives EMG data, executes calculations and visualises the output data. The key advantage of the model is smoothness of output data changes; this way a maximum approach to natural hand movements is reached.

  5. Modeling the Movement of Beach Alluvia in the Alongshore Direction

    Directory of Open Access Journals (Sweden)

    Elena V. Bondareva

    2014-06-01

    Full Text Available The authors have worked out a design model for the dynamics of a mixed-composition beach in the vicinity of transverse structures. The model uses a modified formula for calculating alluvia, which is based on modified energy dependencies. The authors provide an algorithm for performing these calculations.

  6. THE USE OF AN ARTIFICIAL NEURAL NETWORK FOR MODELING THE MOISTURE ABSORPTION AND THICKNESS SWELLING OF ORIENTED STRAND BOARD

    Directory of Open Access Journals (Sweden)

    Şükrü Özşahin

    2012-01-01

    Full Text Available In this study, an artificial neural network (ANN approach was employed for modeling the moisture absorption (MA and thickness swelling (TS properties of oriented strand board (OSB in various applications. A series of ANN models were developed for the analysis and prediction of correlations between processing parameters and MA and TS of OSB. An ANN model was found for modeling the effects of OSB treatment variables on the MA and TS. The required data for training and testing of the model were obtained from the experimental results of Salay (2010. In designing this model, the MA and TS of the OSB were determined using OSB treatment variables, including board layup type, resin type, application rate of resin, and wax content. When experimental data and results obtained from the ANN were compared by regression analysis using Matlab, it was determined that both groups of data (test and train were consistent. It was demonstrated that the well-trained feed forward and back propagation multilayer ANN model is a powerful and sufficient tool for the prediction of MA and TS; therefore, by using ANN outputs, satisfactory results can be estimated, rather than measured and hence time and cost are reduced in all the required experimental activities.

  7. Assimilating the Cosmic-Ray Soil Moisture Observing System Measurements for Land Surface Hydrologic Model Parameter Estimation Using the Ensemble Kalman Filter

    Science.gov (United States)

    Xiao, D.; Shi, Y.; Li, L.

    2015-12-01

    Parameter estimation is generally required for land surface models (LSMs) and hydrologic models to reproduce observed water and energy fluxes in different watersheds. Using soil moisture observations for parameter estimation in addition to discharge and land surface temperature observations can improve the prediction of land surface and subsurface processes. Due to their representativity, point measurements cannot capture the watershed-scale soil moisture conditions and may lead to notable bias in watershed soil moisture predictions if used for model calibration. The intermediate-scale cosmic-ray soil moisture observing system (COSMOS) provides average soil water content measurement over a footprint of 0.34 m2 and depths up to 50 cm, and may provide better calibration data for low-order watersheds. In this study, we will test using COSMOS observations for Flux-PIHM parameter and state estimation via the ensemble Kalman filter (EnKF). Flux-PIHM is a physically-based land surface hydrologic model that couples the Penn State Integrated Hydrologic Model (PIHM) with the Noah land surface model. Synthetic data experiments will be performed at the Shale Hills watershed (area: 0.08 km2, smaller than COSMOS footprint) and the Garner Run watershed (1.34 km2, larger than COSMOS footprint) in the Shale Hills Susquehanna Critical Zone Observatory in central Pennsylvania. COSMOS observations will be assimilated into Flux-PIHM using the EnKF, in addition to discharge and land surface temperature (LST) observations. The accuracy of EnKF estimated parameters and water and energy flux predictions will be evaluated. In addition, the results will be compared with assimilating point soil moisture measurement (in addition to discharge and LST), to assess the effects of using different scales of soil moisture observations for parameter estimation. The results at Shale Hills and Garner Run will be compared to test whether performance of COSMOS data assimilation is affected by the size of

  8. An assessment of six muscle spindle models for predicting sensory information during human wrist movements.

    Directory of Open Access Journals (Sweden)

    Puja eMalik

    2016-01-01

    Full Text Available Background: The muscle spindle is an important sensory organ for proprioceptive information, yet there have been few attempts to use Shannon information theory to quantify the capacity of human muscle spindles to encode sensory input.Methods: Computer simulations linked kinematics, to biomechanics, to six muscle spindle models that generated predictions of firing rate. The predicted firing rates were compared to firing rates of human muscle spindles recorded during a step-tracking (center-out task to validate their use. The models were then used to predict firing rates during random movements with statistical properties matched to the ergonomics of human wrist movements. The data were analyzed for entropy and mutual information.Results: Three of the six models produced predictions that approximated the firing rate of human spindles during the step-tracking task. For simulated random movements these models predicted mean rates of 16.0±4.1 imp/s (mean±sd, peak firing rates <50 imp/s and zero firing rate during an average of 25% of the movement. The average entropy of the neural response was 4.1±0.3 bits and is an estimate of the maximum information that could be carried by muscles spindles during ecologically valid movements. The information about tendon displacement preserved in the neural response was 0.10±0.05 bits per symbol; whereas 1.25±0.30 bits per symbol of velocity input were preserved in the neural response of the spindle models.Conclusions: Muscle spindle models, originally based on cat experiments, have predictive value for modeling responses of human muscle spindles with minimal parameter optimization. These models predict more than 10-fold more velocity over length information encoding during ecologically valid movements. These results establish theoretical parameters for developing neuroprostheses for proprioceptive function.

  9. A multivariate mixed model system for wood specific gravity and moisture content of planted loblolly pine stands in the southern United States

    Science.gov (United States)

    Finto Antony; Laurence R. Schimleck; Alex Clark; Richard F. Daniels

    2012-01-01

    Specific gravity (SG) and moisture content (MC) both have a strong influence on the quantity and quality of wood fiber. We proposed a multivariate mixed model system to model the two properties simultaneously. Disk SG and MC at different height levels were measured from 3 trees in 135 stands across the natural range of loblolly pine and the stand level values were used...

  10. Sensitivity of high-temperature weather to initial soil moisture: a case study using the WRF model

    Science.gov (United States)

    Zeng, X.-M.; Wang, B.; Zhang, Y.; Song, S.; Huang, X.; Zheng, Y.; Chen, C.; Wang, G.

    2014-09-01

    Using a succession of 24 h Weather Research and Forecasting model (WRF) simulations, we investigate the sensitivity to initial soil moisture of a short-range high-temperature weather event that occurred in late July 2003 in East China. The initial soil moisture (SMOIS) in the Noah land surface scheme is adjusted (relative to the control run, CTL) for four groups of simulations: DRY25 (-25%), DRY50 (-50%), WET25 (+25%) and WET50 (+50%). Ten 24 h integrations are performed in each group. We focus on 2 m surface air temperature (SAT) greater than 35 °C (the threshold of "high-temperature" events in China) at 06:00 UTC (roughly 14:00 LT in the study domain) to analyse the occurrence of the high-temperature event. The 10-day mean results show that the 06:00 UTC SAT (SAT06) is sensitive to the SMOIS change; specifically, SAT06 exhibits an apparent increase with the SMOIS decrease (e.g. compared with CTL, DRY25 generally results in a 1 °C SAT06 increase over the land surface of East China), areas with 35 °C or higher SAT06 are the most affected, and the simulations are more sensitive to the SMOIS decrease than to the SMOIS increase, which suggests that hot weather can be amplified under low soil moisture conditions. Regarding the mechanism underlying the extremely high SAT06, sensible heat flux has been shown to directly heat the lower atmosphere, and latent heat flux has been found to be more sensitive to the SMOIS change, resulting in an overall increase in surface net radiation due to the increased greenhouse effect (e.g. with the SMOIS increase from DRY25 to CTL, the 10-day mean net radiation increases by 5 W m-2). Additionally, due to the unique and dynamic nature of the western Pacific subtropical high, negative feedback occurs between the regional atmospheric circulation and the air temperature in the lower atmosphere while positive feedback occurs in the mid-troposphere. Using a method based on an analogous temperature relationship, a detailed analysis of the

  11. Sensitivity of high-temperature weather to initial soil moisture: a case study with the WRF model

    Science.gov (United States)

    Zeng, X.-M.; Wang, B.; Zhang, Y.; Song, S.; Huang, X.; Zheng, Y.; Chen, C.; Wang, G.

    2014-05-01

    Using the Weather Research and Forecasting model (WRF), we investigate the sensitivity of simulated short-range high-temperature weather to initial soil moisture for the East China extremely hot event in late July 2003 via a succession of 24 h simulations. The initial soil moisture (SMOIS) in the Noah land surface scheme is prescribed for five groups of designed simulations, i.e., relative to the control run (CTL), SMOIS is changed by -25, -50, +25 and +50% in the DRY25, DRY50, WET25 and WET50 groups, respectively, with ten 24 h-long integrations performed in each group. We focus on above-35 °C (standard of so-called "high-temperature" event in China) 2 m surface air temperature (SAT) at 06:00 UTC (roughly 12:00 LT in the study domain) to analyze the occurrence of the high-temperature event. Ten-day mean results show that the 06:00 UTC SAT (SAT06) is sensitive to the SMOIS change, i.e., SAT06 exhibits an apparent rising with the SMOIS decrease (e.g., compared with CTL, DRY25 results in a 1 °C SAT06 rising in general over land surface of East China), areas with above-35 °C SAT06 are most affected, and the simulations are found to be more sensitive to the SMOIS decrease than to the SMOIS increase, suggesting that hot weather can be amplified under low soil moisture conditions. With regard to the mechanism of influencing the extreme high SAT06, sensible heat flux shows to directly heat the lower atmosphere, latent heat flux is found to be more sensitive to the SMOIS change and results in the overall increase of surface net radiation due to the increased greenhouse effect (e.g., with the SMOIS increase of 25% from DRY25 to CTL, the ten-day mean net radiation is increased by 5 W m-2), and a negative (positive) feedback is found between regional atmospheric circulation and air temperature in the lower atmosphere (mid-troposphere) due to the unique dynamic nature of the western Pacific subtropical high. Using a method based on an analogous temperature relationship, a

  12. Automated quantitative gait analysis in animal models of movement disorders

    Directory of Open Access Journals (Sweden)

    Vandeputte Caroline

    2010-08-01

    Full Text Available Abstract Background Accurate and reproducible behavioral tests in animal models are of major importance in the development and evaluation of new therapies for central nervous system disease. In this study we investigated for the first time gait parameters of rat models for Parkinson's disease (PD, Huntington's disease (HD and stroke using the Catwalk method, a novel automated gait analysis test. Static and dynamic gait parameters were measured in all animal models, and these data were compared to readouts of established behavioral tests, such as the cylinder test in the PD and stroke rats and the rotarod tests for the HD group. Results Hemiparkinsonian rats were generated by unilateral injection of the neurotoxin 6-hydroxydopamine in the striatum or in the medial forebrain bundle. For Huntington's disease, a transgenic rat model expressing a truncated huntingtin fragment with multiple CAG repeats was used. Thirdly, a stroke model was generated by a photothrombotic induced infarct in the right sensorimotor cortex. We found that multiple gait parameters were significantly altered in all three disease models compared to their respective controls. Behavioural deficits could be efficiently measured using the cylinder test in the PD and stroke animals, and in the case of the PD model, the deficits in gait essentially confirmed results obtained by the cylinder test. However, in the HD model and the stroke model the Catwalk analysis proved more sensitive than the rotarod test and also added new and more detailed information on specific gait parameters. Conclusion The automated quantitative gait analysis test may be a useful tool to study both motor impairment and recovery associated with various neurological motor disorders.

  13. Mechanical and thermal hypersensitivities associated with orthodontic tooth movement: a behavioral rat model for orthodontic tooth movement-induced pain.

    Science.gov (United States)

    Sood, Mandeep; Bhatt, Poolak; Sessle, Barry J

    2015-01-01

    To test whether orofacial mechanical and thermal hypersensitivities occur in rats during orthodontic tooth movement (OTM). Sprague-Dawley rats (140 to 160 g) were divided into an experimental (E) group (n =7), with an active orthodontic spring placed in the right side of their mouth, and a sham (S) group (n = 7), with an inactive orthodontic spring. Mechanical sensitivity was tested preoperatively (1 day before attaching the orthodontic spring) and postoperatively (1 hour, 3 hours, 6 hours, days 1 to 7, day 14, day 21, and day 28 after orthodontic spring attachment) on the cheek, upper lip, and maxillary incisor labial gingiva bilaterally by recording the threshold for a head withdrawal response evoked by von Frey filaments. Thermal sensitivity was also tested preoperatively and postoperatively on the cheek bilaterally by applying a noxious thermal stimulus and measuring head withdrawal response duration, response score, and response percentile rate. Statistical analyses involved a mixed-model repeated-measures analysis of variance (MMRM ANOVA). The mechanical and thermal sensitivities at all bilateral sites were significantly increased (P pain model correlates with the time course of OTM-induced pain in humans and suggests that OTM-induced mechanical and thermal hypersensitivities may be useful measures of OTM-induced pain.

  14. The Sherborne Developmental Movement (SDM) Teaching Model for Pre-Service Teachers

    Science.gov (United States)

    Hen, Meirav; Walter, Ofra

    2012-01-01

    Previously, the Sherborne Developmental Movement (SDM) has been found to contribute to the development of emotional competencies in higher education. This study presents and evaluates a teaching model based on SDM for the development of emotional competencies in teacher education. The study examined the contributions of this model to the increase…

  15. The Sherborne Developmental Movement (SDM) Teaching Model for Pre-Service Teachers

    Science.gov (United States)

    Hen, Meirav; Walter, Ofra

    2012-01-01

    Previously, the Sherborne Developmental Movement (SDM) has been found to contribute to the development of emotional competencies in higher education. This study presents and evaluates a teaching model based on SDM for the development of emotional competencies in teacher education. The study examined the contributions of this model to the increase…

  16. A spatially distributed model of pesticide movement in Dutch macroporous soils

    NARCIS (Netherlands)

    Tiktak, A.; Hendriks, R.F.A.; Boesten, J.J.T.I.; Linden, van der A.M.A.

    2012-01-01

    In the Netherlands, a spatially distributed version of the pesticide fate model PEARL is routinely used to assess the leaching potential of pesticides to groundwater. Recently, the model was modified to simulate the movement of pesticides to surface water. The peak concentration is considered to be

  17. Musculoskeletal Modeling of a Forward Lunge Movement:Implications for ACL Loading

    DEFF Research Database (Denmark)

    Alkjaer, T; Wieland, MR; Andersen, MS

    2010-01-01

    5 20 years). Interventions: Three-dimensional coordinates of skin-mounted markers were obtained via five video cameras. The subject performed a forward lunge on a force plate, targeting a knee flexion angle of 906. A model of the lunge movement was developed using the AnyBody Modeling System...

  18. An enhanced beam model for glued laminated structures that takes moisture, mechano-sorption and time effects into account

    DEFF Research Database (Denmark)

    Ormarsson, Sigurdur; Steinnes, Jan Roar

    2014-01-01

    There is a need of more advanced analysis for studying how the long-term behaviour of glued laminated timber structures is affected by creep and by cyclic variations in climate. A beam theory is presented able to simulate the overall hygro-mechanical and visco-elastic behaviour of (inhomogeneous)...... that occurs to have a significant effect on deformations, section forces and stress distributions within the frame structures that were studied.......) glulam structures. Two frame structures subjected to both mechanical and cyclic environmental loading are analysed to illustrate the advantages the model involved can provide. The results indicate clearly both the (discontinuous) inhomogeneity of the glulam products and the variable moisture-load action...

  19. Decoding finger movements from ECoG signals using switching linear models

    Directory of Open Access Journals (Sweden)

    Remi eFlamary

    2012-03-01

    Full Text Available One of the most interesting challenges in ECoG-based Brain-Machine Interface is movement prediction. Being able to perform such a prediction paves the way to high-degree precision command for a machine such as a robotic arm or robotic hands. As a witness of the BCI community increasing interest towards such a problem, the fourth BCI Competition provides a dataset which aim is to predict individual finger movements from ECog signals. The difficulty of the problem relies on the fact that there is no simple relation between ECoG signals and finger movements. We propose in this paper, to estimate and decode these finger flexions using switching models controlled by an hidden state. Switching models can integrate prior knowledge about the decoding problem and helps in predicting fine and precise movements. Our model is thus based on a first block which estimates which finger is moving and anotherblock which, knowing which finger is moving, predicts the movements of allother fingers. Numerical results that have been submitted to the Competition show that the model yields high decoding performances when the hidden state is well estimated. This approach achieved the second place in the BCI competition with a correlation measure between real and predictedmovements of 0.42.

  20. Fuzzy Computing Model of Activity Recognition on WSN Movement Data for Ubiquitous Healthcare Measurement.

    Science.gov (United States)

    Chiang, Shu-Yin; Kan, Yao-Chiang; Chen, Yun-Shan; Tu, Ying-Ching; Lin, Hsueh-Chun

    2016-12-03

    Ubiquitous health care (UHC) is beneficial for patients to ensure they complete therapeutic exercises by self-management at home. We designed a fuzzy computing model that enables recognizing assigned movements in UHC with privacy. The movements are measured by the self-developed body motion sensor, which combines both accelerometer and gyroscope chips to make an inertial sensing node compliant with a wireless sensor network (WSN). The fuzzy logic process was studied to calculate the sensor signals that would entail necessary features of static postures and dynamic motions. Combinations of the features were studied and the proper feature sets were chosen with compatible fuzzy rules. Then, a fuzzy inference system (FIS) can be generated to recognize the assigned movements based on the rules. We thus implemented both fuzzy and adaptive neuro-fuzzy inference systems in the model to distinguish static and dynamic movements. The proposed model can effectively reach the recognition scope of the assigned activity. Furthermore, two exercises of upper-limb flexion in physical therapy were applied for the model in which the recognition rate can stand for the passing rate of the assigned motions. Finally, a web-based interface was developed to help remotely measure movement in physical therapy for UHC.

  1. Fuzzy Computing Model of Activity Recognition on WSN Movement Data for Ubiquitous Healthcare Measurement

    Science.gov (United States)

    Chiang, Shu-Yin; Kan, Yao-Chiang; Chen, Yun-Shan; Tu, Ying-Ching; Lin, Hsueh-Chun

    2016-01-01

    Ubiquitous health care (UHC) is beneficial for patients to ensure they complete therapeutic exercises by self-management at home. We designed a fuzzy computing model that enables recognizing assigned movements in UHC with privacy. The movements are measured by the self-developed body motion sensor, which combines both accelerometer and gyroscope chips to make an inertial sensing node compliant with a wireless sensor network (WSN). The fuzzy logic process was studied to calculate the sensor signals that would entail necessary features of static postures and dynamic motions. Combinations of the features were studied and the proper feature sets were chosen with compatible fuzzy rules. Then, a fuzzy inference system (FIS) can be generated to recognize the assigned movements based on the rules. We thus implemented both fuzzy and adaptive neuro-fuzzy inference systems in the model to distinguish static and dynamic movements. The proposed model can effectively reach the recognition scope of the assigned activity. Furthermore, two exercises of upper-limb flexion in physical therapy were applied for the model in which the recognition rate can stand for the passing rate of the assigned motions. Finally, a web-based interface was developed to help remotely measure movement in physical therapy for UHC. PMID:27918482

  2. Fuzzy Computing Model of Activity Recognition on WSN Movement Data for Ubiquitous Healthcare Measurement

    Directory of Open Access Journals (Sweden)

    Shu-Yin Chiang

    2016-12-01

    Full Text Available Ubiquitous health care (UHC is beneficial for patients to ensure they complete therapeutic exercises by self-management at home. We designed a fuzzy computing model that enables recognizing assigned movements in UHC with privacy. The movements are measured by the self-developed body motion sensor, which combines both accelerometer and gyroscope chips to make an inertial sensing node compliant with a wireless sensor network (WSN. The fuzzy logic process was studied to calculate the sensor signals that would entail necessary features of static postures and dynamic motions. Combinations of the features were studied and the proper feature sets were chosen with compatible fuzzy rules. Then, a fuzzy inference system (FIS can be generated to recognize the assigned movements based on the rules. We thus implemented both fuzzy and adaptive neuro-fuzzy inference systems in the model to distinguish static and dynamic movements. The proposed model can effectively reach the recognition scope of the assigned activity. Furthermore, two exercises of upper-limb flexion in physical therapy were applied for the model in which the recognition rate can stand for the passing rate of the assigned motions. Finally, a web-based interface was developed to help remotely measure movement in physical therapy for UHC.

  3. Physically-based modifications to the Sacramento Soil Moisture Accounting model. Part A: Modeling the effects of frozen ground on the runoff generation process

    Science.gov (United States)

    Koren, Victor; Smith, Michael; Cui, Zhengtao

    2014-11-01

    This paper presents the first of two physically-based modifications to a widely-used and well-validated hydrologic precipitation-runoff model. Here, we modify the Sacramento Soil Moisture Accounting (SAC-SMA) model to include a physically-based representation of the effects of freezing and thawing soil on the runoff generation process. This model is called the SAC-SMA Heat Transfer model (SAC-HT). The frozen ground physics are taken from the Noah land surface model which serves as the land surface component of several National Center for Environmental Prediction (NCEP) numerical weather prediction models. SAC-HT requires a boundary condition of the soil temperature at the bottom of the soil column (a climatic annual air temperature is typically used, and parameters derived from readily available soil texture data). A noteworthy feature of SAC-HT is that the frozen ground component needs no parameter calibration. SAC-HT was tested at 11 sites in the U.S. for soil temperature, one site in Russia for soil temperature and soil moisture, eight basins in the upper Midwest for the effects of frozen-ground on streamflow, and one location for frost depth. High correlation coefficients for simulated soil temperature at three depths at 11 stations were achieved. Multi-year simulations of soil moisture and soil temperature agreed very well at the Valdai, Russia test location. In eight basins affected by seasonally frozen soil in the upper Midwest, SAC-HT provided improved streamflow simulations compared to SAC-SMA when both models used a priori parameters. Further improvement was gained through calibration of the non-frozen ground a priori parameters. Frost depth computed by SAC-HT compared well with observed values in the Root River basin in Minnesota.

  4. An intercomparison of available soil moisture estimates from thermal infrared and passive microwave remote sensing and land surface modeling

    Science.gov (United States)

    Hain, Christopher R.; Crow, Wade T.; Mecikalski, John R.; Anderson, Martha C.; Holmes, Thomas

    2011-08-01

    Remotely sensed soil moisture studies have mainly focused on retrievals using active and passive microwave (MW) sensors, which provide measurements that are directly related to soil moisture (SM). MW sensors have obvious advantages such as the ability to retrieve through nonprecipitating cloud cover which provides shorter repeat cycles. However, MW sensors offer coarse spatial resolution and suffer from reduced retrieval skill over moderate to dense vegetation. A unique avenue for filling these information gaps is to exploit the retrieval of SM from thermal infrared (TIR) observations, which can provide SM information under vegetation cover and at significantly higher resolutions than MW. Previously, an intercomparison of TIR-based and MW-based SM has not been investigated in the literature. Here a series of analyses are proposed to study relationships between SM products during a multiyear period (2003-2008) from a passive MW retrieval (AMSR-E), a TIR based model (ALEXI), and a land surface model (Noah) over the continental United States. The three analyses used in this study include (1) a spatial anomaly correlation analysis, (2) a temporal correlation analysis, and (3) a triple collocation error estimation technique. In general, the intercomparison shows that the TIR and MW methods provide complementary information about the current SM state. TIR can provide SM information over moderate to dense vegetation, a large information gap in current MW methods, while serving as an additional independent source of SM information over low to moderate vegetation. The complementary nature of SM information from MW and TIR sensors implies a potential for integration within an advanced SM data assimilation system.

  5. Advanced statistical methods for eye movement analysis and modeling: a gentle introduction

    CERN Document Server

    Boccignone, Giuseppe

    2015-01-01

    In this Chapter we show that by considering eye movements, and in particular, the resulting sequence of gaze shifts, a stochastic process, a wide variety of tools become available for analyses and modelling beyond conventional statistical methods. Such tools encompass random walk analyses and more complex techniques borrowed from the pattern recognition and machine learning fields. After a brief, though critical, probabilistic tour of current computational models of eye movements and visual attention, we lay down the basis for gaze shift pattern analysis. To this end, the concepts of Markov Processes, the Wiener process and related random walks within the Gaussian framework of the Central Limit Theorem will be introduced. Then, we will deliberately violate fundamental assumptions of the Central Limit Theorem to elicit a larger perspective, rooted in statistical physics, for analysing and modelling eye movements in terms of anomalous, non-Gaussian, random walks and modern foraging theory. Eventually, by resort...

  6. Inter-comparison of hydrological model simulations with dense time series of SAR-derived soil moisture maps

    Science.gov (United States)

    Iacobellis, V.; Gioia, A.; Milella, P.; Satalino, G.; Balenzano, A.; Mattia, F.

    2012-04-01

    Over the last years, a vast number of experimental and theoretical studies has widely demonstrated the sensitivity of SAR data to soil moisture content, however, operational services integrating SAR measurements into land process models are not yet available. Important progresses in this field are expected, on the one hand, from SAR missions characterized by a short revisiting time, such as the COSMO-SkyMed or the forthcoming Sentinel-1 and ALOS-2 missions, on the other hand, from a strong effort in implementing hydrological models able to reproduce the dynamic of soil moisture content of the top layer (5 cm depth) of soil. With this latter purpose, we used the DREAM model [Manfreda et al., 2005], realized in a GIS-based approach, that explicitly takes into account the spatial heterogeneity of hydrological processes. The DREAM model carries out continuous hydrological simulations using the daily and the hourly scales. The distinctive feature of the model, which consists of evaluating the lateral flow through a water content redistribution weighted by the topographic index, was preserved. The latter provided the basis for the nested implementation of the Richard equation which has been used for evaluating vertical flows in the top soil layer (5cm).The Richard routine exploits the numerical solution proposed by Simunek et al. [2009] and runs, for each cell of the river basin, in a sub-module of 60 minutes with a vertical (i.e. depth) and temporal resolution of 1 cm and 1 s, respectively. The model was applied to the portion of the Celone at Foggia San Severo river basin downstream the San Giusto Dam, which is a tributary of the Candelaro river, in Puglia region (Southern Italy). Over this area quasi-dense time series of ALOS/PALSAR ScanSAR WB1 and COSMO-SkyMedStripMap images were acquired in 2007 and 2010, respectively. The SAR data have been used to derive time-series of soil moisture maps by means of the SMOSAR software developed for Sentinel-1 data [Balenzano et

  7. MODELLING THE CONSTRAINTS OF SPATIAL ENVIRONMENT IN FAUNA MOVEMENT SIMULATIONS: COMPARISON OF A BOUNDARIES ACCURATE FUNCTION AND A COST FUNCTION

    OpenAIRE

    Jolivet, L.; Cohen, M.; Ruas, A.

    2015-01-01

    Landscape influences fauna movement at different levels, from habitat selection to choices of movements' direction. Our goal is to provide a development frame in order to test simulation functions for animal's movement. We describe our approach for such simulations and we compare two types of functions to calculate trajectories. To do so, we first modelled the role of landscape elements to differentiate between elements that facilitate movements and the ones being hindrances. Different influe...

  8. The influence of soil type, vegetation cover and soil moisture on spin up behaviour of a land surface model in a monsoonal region

    Science.gov (United States)

    Bhattacharya, Anwesha; Mandal, Manabottam

    2015-04-01

    Model spin-up is the process through which the model is adequately equilibrated to ensure balance between the mass fields and velocity fields. In this study, an offline one dimensional Noah land surface model is integrated recursively for three years to assess its spin-up behavior at different sites over the Indian Monsoon domain. Several numerical experiments are performed to investigate the impact of soil category, vegetation cover, initial soil moisture and subsequent dry or wet condition on model spin-up. These include simulations with the dominant soil and vegetation covers of this region, different initial soil moisture content (observed soil moisture; dry soil; moderately wet soil; saturated soil), simulations initialized at different rain conditions (no rain; infrequent rain; continuous rain) and different seasons (Winter, Spring, Summer/Pre-Monsoon, Monsoon and Autumn). It is seen that the spin-up behavior of the model depends on the soil type and vegetation cover with soil characteristics having the larger influence. Over India, the model has the longest spin-up in the case of simulations with loamy soil covered with mixed-shrub. It is noted that the model has a significantly longer spin-up when initialized with very low initial soil moisture content than with higher soil moisture content. It is also seen that in general, simulations initialized just before a continuous rainfall event have the least spin-up time. This observation is reinforced by the results from the simulations initialized in different seasons. It is seen that for monsoonal region, the model spin-up time is least for simulations initialized just before the Monsoon. Model initialized during the Monsoon rain episodes has a longer spin-up than that initialized in any other season. Furthermore, it is seen that the model has a shorter spin-up if it reaches the equilibrium state predominantly via drying process and could be as low as two months under quasi-equilibrium condition depending on

  9. Stochastic particle based models for suspended particle movement in surface flows

    Institute of Scientific and Technical Information of China (English)

    Christina W.TSAI; Chuanjian MAN; Jungsun OH

    2014-01-01

    Modeling of suspended sediment particle movement in surface water can be achieved by stochastic particle tracking model approaches. In this paper, different mathematical forms of particle tracking models are introduced to describe particle movement under various flow conditions, i.e., the stochastic diffusion process, stochastic jump process, and stochastic jump diffusion process. While the stochastic diffusion process can be used to represent the stochastic movement of suspended particles in turbulent flows, the stochastic jump and the stochastic jump diffusion processes can be used to describe suspended particle movement in the occurrences of a sequence of extreme flows. An extreme flow herein is defined as a hydrologic flow event or a hydrodynamic flow phenomenon with a low probability of occurrence and a high impact on its ambient flow environment. In this paper, the suspended sediment particle is assumed to immediately follow the extreme flows in the jump process (i.e. the time lag between the flow particle and the sediment particle in extreme flows is considered negligible). In the proposed particle tracking models, a random term mainly caused by fluid eddy motions is modeled as a Wiener process, while the random occurrences of a sequence of extreme flows can be modeled as a Poisson process. The frequency of occurrence of the extreme flows in the proposed particle tracking model can be explicitly accounted for by the Poisson process when evaluating particle movement. The ensemble mean and variance of particle trajectory can be obtained from the proposed stochastic models via simulations. The ensemble mean and variance of particle velocity are verified with available data. Applicability of the proposed stochastic particle tracking models for sediment transport modeling is also discussed.

  10. Quantitative model prediction of the combined effect of moisture content and temperature on purple mudstone decay in south-western China

    Science.gov (United States)

    Zhang, Dan; Chen, Anqiang; Zhao, Jixia; Lu, Chuanhao; Liu, Gangcai

    2017-10-01

    Rock decay is mainly the result of the combined effects of moisture content and temperature, but little is known about the quantitative relationship between these variables and the rate of rock decay. In this study we develop quantitative calculation models of rock decay rate under laboratory conditions and validate the efficiency of these models by comparing the predicted rock decay mass and that measured for rock exposed in the field. Rainfall and temperature data in the field were standardised to a dimensionless moisture content and temperature variables, respectively, and then the predicted rock decay mass was calculated by the models. The measured rock decay mass was determined by manual sieving. Based on our previously determined relationship between a single factor (moisture content or temperature) and the rate of rock decay in the laboratory, power function models are developed. Results show that the rock decay mass calculated by the model was comparable with field data, with averaged relative errors of 1.53%, 9.00% and 11.82% for the Tuodian group (J3t), Matoushan group (K2m) and Lufeng group (J1l), respectively, which are mainly due to inaccurate transformation of field rainfall into the rock moisture content and artificial disturbance when the samples were sieved in the field. Our results show that the developed models based on laboratory-derived rates can accurately predict the decay rates of mudstones exposed in the field.

  11. Physically-based modeling of topographic effects on spatial evapotranspiration and soil moisture patterns through radiation and wind

    Directory of Open Access Journals (Sweden)

    M. Liu

    2012-02-01

    Full Text Available In this paper, simulations with the Soil Water Atmosphere Plant (SWAP model are performed to quantify the spatial variability of both potential and actual evapotranspiration (ET, and soil moisture content (SMC caused by topography-induced spatial wind and radiation differences. To obtain the spatially distributed ET/SMC patterns, the field scale SWAP model is applied in a distributed way for both pointwise and catchment wide simulations. An adapted radiation model from r.sun and the physically-based meso-scale wind model METRAS PC are applied to obtain the spatial radiation and wind patterns respectively, which show significant spatial variation and correlation with aspect and elevation respectively. Such topographic dependences and spatial variations further propagate to ET/SMC. A strong spatial, seasonal-dependent, scale-relevant intra-catchment variability in daily/annual ET and less variability in SMC can be observed from the numerical experiments. The study concludes that topography has a significant effect on ET/SMC in the humid region where ET is a energy limited rather than water availability limited process. It affects the spatial runoff generation through spatial radiation and wind, therefore should be applied to inform hydrological model development. In addition, the methodology used in the study can serve as a general method for physically-based ET estimation for data sparse regions.

  12. Consistently modeling the same movement strategy is more important than model skill level in observational learning contexts.

    Science.gov (United States)

    Buchanan, John J; Dean, Noah

    2014-02-01

    The experiment undertaken was designed to elucidate the impact of model skill level on observational learning processes. The task was bimanual circle tracing with a 90° relative phase lead of one hand over the other hand. Observer groups watched videos of either an instruction model, a discovery model, or a skilled model. The instruction and skilled model always performed the task with the same movement strategy, the right-arm traced clockwise and the left-arm counterclockwise around circle templates with the right-arm leading. The discovery model used several movement strategies (tracing-direction/hand-lead) during practice. Observation of the instruction and skilled model provided a significant benefit compared to the discovery model when performing the 90° relative phase pattern in a post-observation test. The observers of the discovery model had significant room for improvement and benefited from post-observation practice of the 90° pattern. The benefit of a model is found in the consistency with which that model uses the same movement strategy, and not within the skill level of the model. It is the consistency in strategy modeled that allows observers to develop an abstract perceptual representation of the task that can be implemented into a coordinated action. Theoretically, the results show that movement strategy information (relative motion direction, hand lead) and relative phase information can be detected through visual perception processes and be successfully mapped to outgoing motor commands within an observational learning context.

  13. A biobehavioral model of weight loss associated with meditative movement practice among breast cancer survivors

    Directory of Open Access Journals (Sweden)

    Linda K Larkey

    2014-12-01

    Full Text Available Women with breast cancer often experience weight gain during and after treatment, significantly increasing risk for recurrence as well as all-cause mortality. Based on a growing body of evidence, meditative movement practices may be effective for weight management. First, we describe the effects of stress on factors associated with weight gain for breast cancer survivors. Then, a model is proposed that utilizes existing evidence to suggest how meditative movement supports behavioral, psychological, and neurohormonal changes that may explain weight loss. Application of the model suggests how a novel “mindful-body-wisdom” approach may work to help reduce weight for this at-risk group.

  14. Referee comment on Velocity-Based Terrain Coefficients for Time-Based Models of Human Movement

    Directory of Open Access Journals (Sweden)

    Irmela Herzog

    2017-06-01

    Full Text Available In many archaeological studies assessing the impact of topography on past human movement, only weak arguments without validation for the weights assigned to different terrain features are given. Therefore a study presenting terrain coefficients relying on sound tests is most welcome though the range of applications in archaeological modelling is limited. This article is a referee comment for de Gruchy, M., Caswell, E and Edwards, J. 2017 Velocity-Based Terrain Coefficients for Time-Based Models of Human Movement, Internet Archaeology.

  15. Whisker movements reveal spatial attention: a unified computational model of active sensing control in the rat.

    Science.gov (United States)

    Mitchinson, Ben; Prescott, Tony J

    2013-01-01

    Spatial attention is most often investigated in the visual modality through measurement of eye movements, with primates, including humans, a widely-studied model. Its study in laboratory rodents, such as mice and rats, requires different techniques, owing to the lack of a visual fovea and the particular ethological relevance of orienting movements of the snout and the whiskers in these animals. In recent years, several reliable relationships have been observed between environmental and behavioural variables and movements of the whiskers, but the function of these responses, as well as how they integrate, remains unclear. Here, we propose a unifying abstract model of whisker movement control that has as its key variable the region of space that is the animal's current focus of attention, and demonstrate, using computer-simulated behavioral experiments, that the model is consistent with a broad range of experimental observations. A core hypothesis is that the rat explicitly decodes the location in space of whisker contacts and that this representation is used to regulate whisker drive signals. This proposition stands in contrast to earlier proposals that the modulation of whisker movement during exploration is mediated primarily by reflex loops. We go on to argue that the superior colliculus is a candidate neural substrate for the siting of a head-centred map guiding whisker movement, in analogy to current models of visual attention. The proposed model has the potential to offer a more complete understanding of whisker control as well as to highlight the potential of the rodent and its whiskers as a tool for the study of mammalian attention.

  16. Incorporating an enzymatic model of effects of temperature, moisture, and substrate supply on soil respiration into an ecosystem model for two forests of northeastern USA

    Science.gov (United States)

    Sihi, Debjani; Davidson, Eric; Chen, Min; Savage, Kathleen; Richardson, Andrew; Keenan, Trevor; Hollinger, David

    2017-04-01

    Soils represent the largest terrestrial carbon (C) pool, and microbial decomposition of soil organic matter (SOM) to carbon dioxide, also called heterotrophic respiration (Rh), is an important component of the global C cycle. Temperature sensitivity of Rh is often represented with a simple Q10 function in ecosystem models and earth system models (ESMs), sometimes accompanied by an empirical soil moisture modifier. More explicit representation of the effects of soil moisture, substrate supply, and their interactions with temperature has been proposed to disentangle the confounding factors of apparent temperature sensitivity of SOM decomposition and improve performance of ecosystem models and ESMs. The objective of this work was to incorporate into an ecosystem model a more mechanistic, but still parsimonious, model of environmental factors controlling Rh. The Dual Arrhenius and Michaelis-Menten (DAMM) model simulates Rh using Michaelis-Menten, Arrhenius, and diffusion functions. Soil moisture affects Rh and its apparent temperature sensitivity in DAMM by regulating the diffusion of oxygen and soluble carbon substrates to the enzymatic reaction site. However, in its current configuration, DAMM depends on assumptions or inputs from other models regarding soil C inputs. Here we merged the DAMM soil flux model with a parsimonious ecosystem flux model, FöBAAR (Forest Biomass, Assimilation, Allocation and Respiration) by replacing FöBAAR's algorithms for Rh with those of DAMM. Classical root trenching experiments provided data to partition soil CO2 efflux into Rh (trenched plot) and root respiration (untrenched minus trenched plots). We used three years of high-frequency soil flux data from automated soil chambers (trenched and untrenched plots) and landscape-scale ecosystem fluxes from eddy covariance towers from two mid-latitude forests (Harvard Forest, MA and Howland Forest, ME) of northeastern USA to develop and validate the merged model and to quantify the

  17. Improving Soil Moisture and Temperature Profile and Surface Turbulent Fluxes Estimations in Irrigated Field by Assimilating Multi-source Data into Land Surface Model

    Science.gov (United States)

    Chen, Weijing; Huang, Chunlin; Shen, Huanfeng; Wang, Weizhen

    2016-04-01

    The optimal estimation of hydrothermal conditions in irrigation field is restricted by the deficiency of accurate irrigation information (when and how much to irrigate). However, the accurate estimation of soil moisture and temperature profile and surface turbulent fluxes are crucial to agriculture and water management in irrigated field. In the framework of land surface model, soil temperature is a function of soil moisture - subsurface moisture influences the heat conductivity at the interface of layers and the heat storage in different layers. In addition, soil temperature determines the phase of soil water content with the transformation between frozen and unfrozen. Furthermore, surface temperature affects the partitioning of incoming radiant energy into ground (sensible and latent heat flux), as a consequence changes the delivery of soil moisture and temperature. Given the internal positive interaction lying in these variables, we attempt to retrieve the accurate estimation of soil moisture and temperature profile via assimilating the observations from the surface under unknown irrigation. To resolve the input uncertainty of imprecise irrigation quantity, original EnKS is implemented with inflation and localization (referred to as ESIL) aiming at solving the underestimation of the background error matrix and the extension of observation information from the top soil to the bottom. EnKS applied in this study includes the states in different time points which tightly connect with adjacent ones. However, this kind of relationship gradually vanishes along with the increase of time interval. Thus, the localization is also employed to readjust temporal scale impact between states and filter out redundant or invalid correlation. Considering the parameter uncertainty which easily causes the systematic deviation of model states, two parallel filters are designed to recursively estimate both states and parameters. The study area consists of irrigated farmland and is

  18. Comparison of NOAA-CREST Soil Moisture Measurements with SMOS Products

    Science.gov (United States)

    Norouzi, H.; Forbes, A.

    2014-12-01

    In October 2014, the Soil Moisture Active and Passive mission (SMAP) will launch into a near-polar and sun- synchronous orbit. SMAP includes the first 3 KM resolution product, by both radar and radiometer sensors which will transmit useful information concentrating on the global measurements of soil moisture and freeze/thaw cycles. NOAA- CREST (National Oceanic and Atmospheric Administration- Cooperative Remote Sensing Science and Technology) deploys a series of in-situ devices into the soil, and an L-BAND Radiometer close to the site ground at the Cary Institute in Millbrook, NY. The site is important for future validation of SMAP mission. Comparing mathematical and ground based remote sensing of soil moisture is beneficial to ensure the accuracy of the measurements. The focus of this research is to analyze and compare soil moisture from ESA- SMOS (Europe Space Agency- Soil Moisture Ocean Salinity) mission and the Cary Institute's soil moisture measurements within the same time period, and location. In the interest of establishing superb authentication; comparing SMOS and ground measurements will justify the accuracy of the newly launch satellite. Discrepancies can be found between field point measurement and relatively large footprint of SMOS, which affects comparison and validation. Several techniques and statistical methods will provide a more meaningful comparison to analyze soil moisture data. The results of this project will help to provide a useful method to compare the NOAA-CREST soil moisture measurements and SMAP measurements. In conclusion, the SMAP advance technology will provide more accurate feedback for modeling numerical weather and climate models. Keywords: Soil Moisture, Precipitation, CREST-SMART, Cary Institute, In-situ, Remote Sensors Accurate Soil Moisture Data, Millbrook, N.Y., CATDS, Hydrology is the branch of science concerning properties of earth's water especially its movement in relation to land. SMOS MIRAS, SMAP, Sensors (Underground)

  19. Data-driven modeling of hydroclimatic trends and soil moisture: Multi-scale data integration and decision support

    Science.gov (United States)

    Coopersmith, Evan Joseph

    regime curve data and facilitate the development of cluster-specific algorithms. Given the desire to enable intelligent decision-making at any location, this classification system is developed in a manner that will allow for classification anywhere in the U.S., even in an ungauged basin. Daily time series data from 428 catchments in the MOPEX database are analyzed to produce an empirical classification tree, partitioning the United States into regions of hydroclimatic similarity. In constructing a classification tree based upon 55 years of data, it is important to recognize the non-stationary nature of climate data. The shifts in climatic regimes will cause certain locations to shift their ultimate position within the classification tree, requiring decision-makers to alter land usage, farming practices, and equipment needs, and algorithms to adjust accordingly. This work adapts the classification model to address the issue of regime shifts over larger temporal scales and suggests how land-usage and farming protocol may vary from hydroclimatic shifts in decades to come. Finally, the generalizability of the hydroclimatic classification system is tested with a physically-based soil moisture model calibrated at several locations throughout the continental United States. The soil moisture model is calibrated at a given site and then applied with the same parameters at other sites within and outside the same hydroclimatic class. The model's performance deteriorates minimally if the calibration and validation location are within the same hydroclimatic class, but deteriorates significantly if the calibration and validates sites are located in different hydroclimatic classes. These soil moisture estimates at the field scale are then further refined by the introduction of LiDAR elevation data, distinguishing faster-drying peaks and ridges from slower-drying valleys. The inclusion of LiDAR enabled multiple locations within the same field to be predicted accurately despite non

  20. A new teaching model for demonstrating the movement of the extraocular muscles.

    Science.gov (United States)

    Iwanaga, Joe; Refsland, Jason; Iovino, Lee; Holley, Gary; Laws, Tyler; Oskouian, Rod J; Tubbs, R Shane

    2017-09-01

    The extraocular muscles consist of the superior, inferior, lateral, and medial rectus muscles and the superior and inferior oblique muscles. This study aimed to create a new teaching model for demonstrating the function of the extraocular muscles. A coronal section of the head was prepared and sutures attached to the levator palpebral superioris muscle and six extraocular muscles. Tension was placed on each muscle from a posterior approach and movement of the eye documented from an anterior view. All movements were clearly seen less than that of the inferior rectus muscle. To our knowledge, this is the first cadaveric teaching model for demonstrating the movements of the extraocular muscles. Clin. Anat. 30:733-735, 2017. © 2017Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  1. Model for the movement and distribution of fish in a body of water

    Energy Technology Data Exchange (ETDEWEB)

    DeAngelis, D.L.

    1978-06-01

    A Monte Carlo mathematical model tracks the movement of fish in a body of water (e.g., a pond or reservoir) which is represented by a two-dimensional grid. For the case of a long, narrow reservoir, depth and length along the reservoir are the logical choices for coordinate axes. In the model, it is assumed that the movement of fish is influenced by gradients of temperature and dissolved oxygen, as well as food availability and habitat preference. The fish takes one spatial ''step'' at a time, the direction being randomly selected, but also biased by the above factors. In trial simulations, a large number of simulated fish were allowed to distribute themselves in a hypothetical body of water. Assuming only temperature was influencing the movements of the fish, the resultant distributions are compared with experimental data on temperature preferences.

  2. Development and validation of a 3-D model to predict knee joint loading during dynamic movement.

    Science.gov (United States)

    McLean, S G; Su, A; van den Bogert, A J

    2003-12-01

    The purpose of this study was to develop a subject-specific 3-D model of the lower extremity to predict neuromuscular control effects on 3-D knee joint loading during movements that can potentially cause injury to the anterior cruciate ligament (ACL) in the knee. The simulation consisted of a forward dynamic 3-D musculoskeletal model of the lower extremity, scaled to represent a specific subject. Inputs of the model were the initial position and velocity of the skeletal elements, and the muscle stimulation patterns. Outputs of the model were movement and ground reaction forces, as well as resultant 3-D forces and moments acting across the knee joint. An optimization method was established to find muscle stimulation patterns that best reproduced the subject's movement and ground reaction forces during a sidestepping task. The optimized model produced movements and forces that were generally within one standard deviation of the measured subject data. Resultant knee joint loading variables extracted from the optimized model were comparable to those reported in the literature. The ability of the model to successfully predict the subject's response to altered initial conditions was quantified and found acceptable for use of the model to investigate the effect of altered neuromuscular control on knee joint loading during sidestepping. Monte Carlo simulations (N = 100,000) using randomly perturbed initial kinematic conditions, based on the subject's variability, resulted in peak anterior force, valgus torque and internal torque values of 378 N, 94 Nm and 71 Nm, respectively, large enough to cause ACL rupture. We conclude that the procedures described in this paper were successful in creating valid simulations of normal movement, and in simulating injuries that are caused by perturbed neuromuscular control.

  3. Soil moisture and root water uptake in climate models. Research Programme Climate Changes Spatial Planning

    NARCIS (Netherlands)

    Dam, van J.C.; Metselaar, K.; Wipfler, E.L.; Feddes, R.A.; Meijgaard, van E.; Hurk, van den B.

    2011-01-01

    More accurate simulation of the energy and water balance near the Earth surface is important to improve the performance of regional climate models. We used a detailed ecohydrological model to rank the importance of vegetation and soil factors with respect to evapotranspiration modeling. The results

  4. Soil moisture and root water uptake in climate models. Research Programme Climate Changes Spatial Planning

    NARCIS (Netherlands)

    Dam, van J.C.; Metselaar, K.; Wipfler, E.L.; Feddes, R.A.; Meijgaard, van E.; Hurk, van den B.

    2011-01-01

    More accurate simulation of the energy and water balance near the Earth surface is important to improve the performance of regional climate models. We used a detailed ecohydrological model to rank the importance of vegetation and soil factors with respect to evapotranspiration modeling. The results

  5. Moisture conditions in buildings

    DEFF Research Database (Denmark)

    Rode, Carsten

    2012-01-01

    Growth of mould requires the presence of moisture at a certain high level. In a heated indoor environment such moisture levels occur only if there is a reason for the moisture supply. Such moisture can come from the use of the building, because of malfunctioning constructions, or it can be the re......Growth of mould requires the presence of moisture at a certain high level. In a heated indoor environment such moisture levels occur only if there is a reason for the moisture supply. Such moisture can come from the use of the building, because of malfunctioning constructions, or it can...

  6. A computational model for aperture control in reach-to-grasp movement based on predictive variability

    Directory of Open Access Journals (Sweden)

    Naohiro eTakemura

    2015-12-01

    Full Text Available In human reach-to-grasp movement, visual occlusion of a target object leads to a larger peak grip aperture compared to conditions where online vision is available. However, no previous computational and neural network models for reach-to-grasp movement explain the mechanism of this effect. We simulated the effect of online vision on the reach-to-grasp movement by proposing a computational control model based on the hypothesis that the grip aperture is controlled to compensate for both motor variability and sensory uncertainty. In this model, the aperture is formed to achieve a target aperture size that is sufficiently large to accommodate the actual target; it also includes a margin to ensure proper grasping despite sensory and motor variability. To this end, the model considers: i the variability of the grip aperture, which is predicted by the Kalman filter, and ii the uncertainty of the object size, which is affected by visual noise. Using this model, we simulated experiments in which the effect of the duration of visual occlusion was investigated. The simulation replicated the experimental result wherein the peak grip aperture increased when the target object was occluded, especially in the early phase of the movement. Both predicted motor variability and sensory uncertainty play important roles in the online visuomotor process responsible for grip aperture control.

  7. Continuum modelling of pedestrian flows - Part 2: Sensitivity analysis featuring crowd movement phenomena

    Science.gov (United States)

    Duives, Dorine C.; Daamen, Winnie; Hoogendoorn, Serge P.

    2016-04-01

    In recent years numerous pedestrian simulation tools have been developed that can support crowd managers and government officials in their tasks. New technologies to monitor pedestrian flows are in dire need of models that allow for rapid state-estimation. Many contemporary pedestrian simulation tools model the movements of pedestrians at a microscopic level, which does not provide an exact solution. Macroscopic models capture the fundamental characteristics of the traffic state at a more aggregate level, and generally have a closed form solution which is necessary for rapid state estimation for traffic management purposes. This contribution presents a next step in the calibration and validation of the macroscopic continuum model detailed in Hoogendoorn et al. (2014). The influence of global and local route choice on the development of crowd movement phenomena, such as dissipation, lane-formation and stripe-formation, is studied. This study shows that most self-organization phenomena and behavioural trends only develop under very specific conditions, and as such can only be simulated using specific parameter sets. Moreover, all crowd movement phenomena can be reproduced by means of the continuum model using one parameter set. This study concludes that the incorporation of local route choice behaviour and the balancing of the aptitude of pedestrians with respect to their own class and other classes are both essential in the correct prediction of crowd movement dynamics.

  8. Skin moisturization mechanisms: new data.

    Science.gov (United States)

    Bonté, F

    2011-05-01

    The main function of the skin is to protect the body against exogenous substances and excessive water loss. The skin barrier is located in the outermost layer of the skin, called the stratum corneum, which is composed of corneocytes, originating from the keratinocytes differentiation process, embedded in organized complex lipid domains. Moisturizing of the skin is recognized as the first anti-aging skin care. Skin moisturization is essential for its appearance, protection, complexion, softness and the reinforcement of its barrier properties against deleterious and exogenous environmental factors. The intrinsic water binding capacity of skin is not only due to the complex natural moisturizing factor present in corneocytes, but also to hyaluronic acid and a regulated water transport within the skin. Recent data shows that the water movements between the cells at the different levels of the epidermis are due to dedicated water and glycerol transport proteins named aquaporins. Their role in the skin moisturization is completed by corneodesmosomes and tight junctions. Water and pH are now shown to be of prime importance in the regulation of the epidermal enzymes linked to corneocytes desquamation and lipid synthesis. Furthermore, the level of moisturization of the skin is important in its protection against repeated exposure to various irritant agents or phenomena such as very frequent washing with strong tensioactive materials.

  9. Predictions of rainfall-runoff response and soil moisture dynamics in a microscale catchment using the CREW model

    Science.gov (United States)

    Lee, H.; Zehe, E.; Sivapalan, M.

    2007-02-01

    .e., water retention curve) and hydraulic conductivity-saturation relationships for the unsaturated zone. Closure relations for concentrated overland flow and saturated overland flow were derived using both theoretical arguments and simpler process models. In addition to these, to complete the specification of the REW scale balance equations, a relationship for the saturated area fraction as a function of saturated zone depth was derived for an assumed topography on the basis of TOPMODEL assumptions. These relationships were used to complete the specification of all of the REW-scale governing equations (mass and momentum balance equations, closure and geometric relations) for the Weiherbach catchment, which are then employed for constructing a numerical watershed model, named the Cooperative Community Catchment model based on the Representative Elementary Watershed approach (CREW). CREW is then used to carry out sensitivity analyses with respect to various combinations of climate, soil, vegetation and topographies, in order to test the reasonableness of the derived closure relations in the context of the complete catchment response, including interacting processes. These sensitivity analyses demonstrated that the adopted closure relations do indeed produce mostly reasonable results, and can therefore be a good basis for more careful and rigorous search for appropriate closure relations in the future. Three tests are designed to assess CREW as a large scale model for Weiherbach catchment. The first test compares CREW with distributed model CATFLOW by looking at predicted soil moisture dynamics for artificially designed initial and boundary conditions. The second test is designed to see the applicabilities of the parameter values extracted from the upscaling procedures in terms of their ability to reproduce observed hydrographs within the CREW modeling framework. The final test compares simulated soil moisture time series predicted by CREW with observed ones as a way of

  10. Predictions of rainfall-runoff response and soil moisture dynamics in a microscale catchment using the CREW model

    Directory of Open Access Journals (Sweden)

    H. Lee

    2007-01-01

    pressure-saturation (i.e., water retention curve and hydraulic conductivity-saturation relationships for the unsaturated zone. Closure relations for concentrated overland flow and saturated overland flow were derived using both theoretical arguments and simpler process models. In addition to these, to complete the specification of the REW scale balance equations, a relationship for the saturated area fraction as a function of saturated zone depth was derived for an assumed topography on the basis of TOPMODEL assumptions. These relationships were used to complete the specification of all of the REW-scale governing equations (mass and momentum balance equations, closure and geometric relations for the Weiherbach catchment, which are then employed for constructing a numerical watershed model, named the Cooperative Community Catchment model based on the Representative Elementary Watershed approach (CREW. CREW is then used to carry out sensitivity analyses with respect to various combinations of climate, soil, vegetation and topographies, in order to test the reasonableness of the derived closure relations in the context of the complete catchment response, including interacting processes. These sensitivity analyses demonstrated that the adopted closure relations do indeed produce mostly reasonable results, and can therefore be a good basis for more careful and rigorous search for appropriate closure relations in the future. Three tests are designed to assess CREW as a large scale model for Weiherbach catchment. The first test compares CREW with distributed model CATFLOW by looking at predicted soil moisture dynamics for artificially designed initial and boundary conditions. The second test is designed to see the applicabilities of the parameter values extracted from the upscaling procedures in terms of their ability to reproduce observed hydrographs within the CREW modeling framework. The final test compares simulated soil moisture time series predicted by CREW with observed

  11. Finite-elements numerical model of the current-sheet movement and shaping in coaxial discharges

    Energy Technology Data Exchange (ETDEWEB)

    Casanova, Federico [CNEA-CONICET and Universidad Nacional del Centro, 7000 Tandil (Argentina); Moreno, Cesar [INFIP-PLADEMA, Universidad de Buenos Aires, 1428 Buenos Aires (Argentina); Clausse, Alejandro [CNEA-CONICET and Universidad Nacional del Centro, 7000 Tandil (Argentina)

    2005-08-01

    The movement and shaping of the current sheath in coaxial plasma guns is numerically modelled by means of a dynamic finite-elements representation. Numerical instabilities are avoided by a reshaping algorithm applied during the tracking of the current sheath acceleration. Improving upon older versions of the algorithm, the present model includes a delay model to treat the dielectric breakdown. Comparison against experimental measurements showed very good performances in representing the arrival times of the shock front at different filling pressures.

  12. DETERMINED MODEL FOR COORDINATED REGULATION OF MOTOR TRANSPORT MOVEMENT ON HIGHWAY

    Directory of Open Access Journals (Sweden)

    V. P. Ivanov

    2011-01-01

    Full Text Available The paper examines certain parameters of a determined model and its response to changes in these parameters. The determined model for bidirectional movement has been developed in the paper. The paper contains proposals for an optimization of the developed model which are intended for reduction of motor vehicle delays in front of an in-traffic light stop line along the main highway direction.

  13. Satellite observed preferential states in soil moisture

    Science.gov (United States)

    Vilasa, Luis U.; De Jeu, Richard A. M.; Dolman, Han A. J.; Wang, Guojie

    2013-04-01

    This study presents observational evidence for the existence of preferential states in soil moisture content. Recently there has been much debate about the existence, location and explanations for preferential states in soil moisture. A number of studies have provided evidence either in support or against the hypothesis of a positive feedback mechanism between soil moisture and subsequent precipitation in certain regions. Researchers who support the hypothesis that preferential states in soil moisture holds information about land atmosphere feedback base their theory on the impact of soil moisture on the evaporation process. Evaporation recycles moisture to the atmosphere and soil moisture has a direct impact on the supply part of this process but also on the partitioning of the available energy for evaporation. According to this theory, the existence of soil moisture bimodality can be used as an indication of possible land-atmosphere feedbacks, to be compared with model simulations of soil moisture feedbacks. On the other hand, other researchers argue that seasonality in the meteorological conditions in combination with the non-linearity of soil moisture response alone can induce bimodality. In this study we estimate the soil moisture bimodality at a global scale as derived from the recently available 30+ year ESA Climate Change Initative satellite soil moisture dataset. An Expectation-Maximization iterative algorithm is used to find the best Gaussian Mixture Model, pursuing the highest likelihood for soil moisture bimodality. With this approach we mapped the regions where bi-modal probability distribution of soil moisture appears for each month for the period between 1979-2010. These bimodality areas are analyzed and compared to maps of model simulations of soil moisture feedbacks. The areas where more than one preferential state exists compare surprisingly well with the map of land-atmosphere coupling strength from model simulations. This approach might

  14. An inter-comparison of soil moisture data products from satellite remote sensing and a land surface model

    Science.gov (United States)

    Fang, Li; Hain, Christopher R.; Zhan, Xiwu; Anderson, Martha C.

    2016-06-01

    Significant advances have been achieved in generating soil moisture (SM) products from satellite remote sensing and/or land surface modeling with reasonably good accuracy in recent years. However, the discrepancies among the different SM data products can be considerably large, which hampers their usage in various applications. The bias of one SM product from another is well recognized in the literature. Bias estimation and spatial correction methods have been documented for assimilating satellite SM product into land surface and hydrologic models. Nevertheless, understanding the characteristics of each of these SM data products is required for many applications where the most accurate data products are desirable. This study inter-compares five SM data products from three different sources with each other, and evaluates them against in situ SM measurements over 14-year period from 2000 to 2013. Specifically, three microwave (MW) satellite based data sets provided by ESA's Climate Change Initiative (CCI) (CCI-merged, -active and -passive products), one thermal infrared (TIR) satellite based product (ALEXI), and the Noah land surface model (LSM) simulations. The in-situ SM measurements are collected from the North American Soil Moisture Database (NASMD), which involves more than 600 ground sites from a variety of networks. They are used to evaluate the accuracies of these five SM data products. In general, each of the five SM products is capable of capturing the dry/wet patterns over the study period. However, the absolute SM values among the five products vary significantly. SM simulations from Noah LSM are more stable relative to the satellite-based products. All TIR and MW satellite based products are relatively noisier than the Noah LSM simulations. Even though MW satellite based SM retrievals have been predominantly used in the past years, SM retrievals of the ALEXI model based on TIR satellite observations demonstrate skills equivalent to all the MW satellite

  15. Combining satellite radar altimetry, SAR surface soil moisture and GRACE total storage changes for model calibration and validation in a large ungauged catchment

    DEFF Research Database (Denmark)

    Milzow, Christian; Krogh, Pernille Engelbredt; Bauer-Gottwein, Peter

    2010-01-01

    hundred meters; and (iii) Temporal changes of the Earth’s gravity field recorded by the Gravity Recovery and Climate Experiment (GRACE) caused by total water storage changes in the catchment. The SSM data are compared to simulated moisture conditions in the top soil layer. They cannot be used for model...

  16. The efficacy of different moisturizers on barrier recovery in hairless mice evaluated by non-invasive bioengineering methods. A model to select the potentially most effective product

    DEFF Research Database (Denmark)

    Mørtz, Charlotte G; Andersen, Klaus Ejner; Halkier-Sørensen, L

    1997-01-01

    Moisturizers (emollients) are used frequently on normal and diseased skin. However, only few studies have examined their effects in dynamic situations and in more clinically relevant settings. We evaluated the effect of 4 commonly used products in a hairless mice model after acute skin barrier...

  17. The efficacy of different moisturizers on barrier recovery in hairless mice evaluated by non-invasive bioengineering methods. A model to select the potentially most effective product

    DEFF Research Database (Denmark)

    Mørtz, Charlotte G; Andersen, Klaus Ejner; Halkier-Sørensen, L

    1997-01-01

    Moisturizers (emollients) are used frequently on normal and diseased skin. However, only few studies have examined their effects in dynamic situations and in more clinically relevant settings. We evaluated the effect of 4 commonly used products in a hairless mice model after acute skin barrier pe...

  18. Confidence interval estimation for an empirical model quantifying the effect of soil moisture and plant development on soybean (Glycine max (L.) Merr.) leaf conductance

    Science.gov (United States)

    In this work, we address uncertainty analysis for a model, presented in a companion paper, quantifying the effect of soil moisture and plant development on soybean (Glycine max (L.) Merr.) leaf conductance. To achieve this we present several methods for confidence interval estimation. Estimation ...

  19. Non-destructive and rapid prediction of moisture content in red pepper (Capsicum annuum L.) powder using near-infrared spectroscopy and a partial least squares regression model

    Science.gov (United States)

    Purpose: The aim of this study was to develop a technique for the non-destructive and rapid prediction of the moisture content in red pepper powder using near-infrared (NIR) spectroscopy and a partial least squares regression (PLSR) model. Methods: Three red pepper powder products were separated in...

  20. Passive microwave soil moisture research

    Science.gov (United States)

    Schmugge, T.; Oneill, P. E.; Wang, J. R.

    1986-01-01

    During the four years of the AgRISTARS Program, significant progress was made in quantifying the capabilities of microwave sensors for the remote sensing of soil moisture. In this paper, a discussion is provided of the results of numerous field and aircraft experiments, analysis of spacecraft data, and modeling activities which examined the various noise factors such as roughness and vegetation that affect the interpretability of microwave emission measurements. While determining that a 21-cm wavelength radiometer was the best single sensor for soil moisture research, these studies demonstrated that a multisensor approach will provide more accurate soil moisture information for a wider range of naturally occurring conditions.

  1. Integrating batch marks and radio tags to estimate the size of a closed population with a movement model.

    Science.gov (United States)

    Schwarz, Carl James; Cope, Scott; Fratton, Glenda

    2013-12-01

    Movement models require individually identifiable marks to estimate the movement rates among strata. But they are relatively expensive to apply and monitor. Batch marks can be readily applied, but individual animal movements cannot be identified. We describe a method to estimate population size in a stratified population when movement takes place among strata and animals are marked with a combination of batch and individually identifiable tags. A hierarchical model with Bayesian inference is developed that pools information across segments on the detection efficiency based on radio-tagged fish and also uses the movement of the radio-tagged fish to impute the movement of the batch-marked fish to provide estimates of the population size on a segment and river level. The batch marks provide important information to help estimate the movement rates, but contribute little to the overall estimate of the population size. In this case, the approximate equal catchability among strata in either sample obviates the need for stratification.

  2. Conveying clinical reasoning based on visual observation via eye-movement modelling examples

    NARCIS (Netherlands)

    Jarodzka, Halszka; Balslev, Thomas; Holmqvist, Kenneth; Nyström, Marcus; Scheiter, Katharina; Gerjets, Peter; Eika, Berit

    2012-01-01

    Jarodzka, H., Balslev, T., Holmqvist, K., Nyström, M., Scheiter, K., Gerjets, P., & Eika, B. (2012). Conveying clinical reasoning based on visual observation via eye-movement modelling examples. Instructional Science, 40(5), 813-827. doi:10.1007/s11251-012-9218-5

  3. Conveying clinical reasoning based on visual observation via eye-movement modelling examples

    NARCIS (Netherlands)

    Jarodzka, Halszka; Balslev, Thomas; Holmqvist, Kenneth; Nyström, Marcus; Scheiter, Katharina; Gerjets, Peter; Eika, Berit

    2012-01-01

    Jarodzka, H., Balslev, T., Holmqvist, K., Nyström, M., Scheiter, K., Gerjets, P., & Eika, B. (2012). Conveying clinical reasoning based on visual observation via eye-movement modelling examples. Instructional Science, 40(5), 813-827. doi:10.1007/s11251-012-9218-5

  4. Muscle, the motor of movement: properties in function, experiment and modelling

    NARCIS (Netherlands)

    Huijing, Peter A.

    1998-01-01

    The purpose of this paper is to review exemplary aspects of different views of skeletal muscle characteristics. A classical view of muscle characteristics plays a very important role in modelling of muscles and movement. However, it often also pervades concepts on which our understanding of muscle f

  5. Active controlled muscles in numerical model of human arm for movement in two degrees of freedom

    NARCIS (Netherlands)

    Budziszewski, P.; Nunen, E. van; Mordaka, J.K.; Kȩdzior, K.

    2008-01-01

    This paper describes the development of numerical model of human upper extremity able to perform movements and stabilization tasks in two degrees of freedom as a result of muscle activation controlled by a PID-based controller. These tasks are defined by functions of specified angle for every degree

  6. Creating a Double-Spring Model to Teach Chromosome Movement during Mitosis & Meiosis

    Science.gov (United States)

    Luo, Peigao

    2012-01-01

    The comprehension of chromosome movement during mitosis and meiosis is essential for understanding genetic transmission, but students often find this process difficult to grasp in a classroom setting. I propose a "double-spring model" that incorporates a physical demonstration and can be used as a teaching tool to help students understand this…

  7. Creating a Double-Spring Model to Teach Chromosome Movement during Mitosis & Meiosis

    Science.gov (United States)

    Luo, Peigao

    2012-01-01

    The comprehension of chromosome movement during mitosis and meiosis is essential for understanding genetic transmission, but students often find this process difficult to grasp in a classroom setting. I propose a "double-spring model" that incorporates a physical demonstration and can be used as a teaching tool to help students understand this…

  8. Model for on-line moisture-content control during solid-state fermentation

    NARCIS (Netherlands)

    Nagel, F.J.J.I.; Tramper, J.; Bakker, M.S.N.; Rinzema, A.

    2001-01-01

    In this study we describe a model that estimates the extracellular (nonfungal) and overall water contents of wheat grains during solid-state fermentation (SSF) with Aspergillus oryzae, using on-line measurements of oxygen, carbon dioxide, and water vapor in the gas phase. The model uses elemental ba

  9. Groundwater-soil moisture-climate interactions: lessons from idealized model experiments with forced water table depth

    Science.gov (United States)

    Ducharne, Agnès; Lo, Min-Hui; Decharme, Bertrand; Wang, Fuxing; Cheruy, Frédérique; Ghattas, Josefine; Chien, Rong-You; lan, Chia-Wei; Colin, Jeanne; Tyteca, Sophie

    2016-04-01

    Groundwater (GW) constitutes by far the largest volume of liquid freshwater on Earth. The most active part is soil moisture (SM), recognized as a key variable of land/atmosphere interactions, especially in so-called transition zones, where/when SM varies between wet and dry values. But GW can also be stored in deeper reservoirs than soils, in particular unconfined aquifer systems, in which the saturated part is called the water table (WT). The latter is characterized by slow and mostly horizontal water flows towards the river network, with well-known buffering effects on streamflow variability. Where/when the WT is shallow enough, it can also sustain SM by means of capillary rise, thus increase evapotranspiration (ET), with potential impact on the climate system (including temperatures and precipitation). The large residence time of GW may also increase the Earth system's memory, with consequences on the persistence of extreme events, hydro-climatic predictability, and anthropogenic climate change, particularly the magnitude of regional warming. Here, our main goal is to explore the potential impacts of the water table depth (WTD) on historical climate through idealized model analyses. To this end, we force three state-of-the art land surface models (LSMs), namely CLM, ORCHIDEE, and SURFEX, with prescribed WTDs ranging from 0.5 to 10 m. The LSMs are run either off-line or coupled to their parent climate model, following LMIP/AMIP-like protocols for intercomparability. Within this framework, we want to assess the sensitivity of ET and the simulated climate to the WTD in a systematic way. In particular, we will identify and compare the patterns of the critical WTD, defined as the deepest one to achieve a significant change in ET. To this end, we estimate derivatives of ET with respect to WTD, which tell how the sensitivity of ET to a unit change in WTD evolves with WTD. In each grid-point, these derivatives can be used to define the critical WTD, given a threshold ET

  10. A Conceptual Approach to Assimilating Remote Sensing Data to Improve Soil Moisture Profile Estimates in a Surface Flux/Hydrology Model. 2; Aggregation

    Science.gov (United States)

    Schamschula, Marius; Crosson, William L.; Inguva, Ramarao; Yates, Thomas; Laymen, Charles A.; Caulfield, John

    1998-01-01

    This is a follow up on the preceding presentation by Crosson. The grid size for remote microwave measurements is much coarser than the hydrological model computational grids. To validate the hydrological models with measurements we propose mechanisms to aggregate the hydrological model outputs for soil moisture to allow comparison with measurements. Weighted neighborhood averaging methods are proposed to facilitate the comparison. We will also discuss such complications as misalignment, rotation and other distortions introduced by a generalized sensor image.

  11. Multi-objective calibration of a hydrologic model using spatially distributed remotely sensed/in-situ soil moisture

    Science.gov (United States)

    Rajib, Mohammad Adnan; Merwade, Venkatesh; Yu, Zhiqiang

    2016-05-01

    The objective of this study is to evaluate the relative potential of spatially distributed surface and root zone soil moisture estimates in calibration of Soil and Water Assessment Tool (SWAT) toward improving its hydrologic predictability with reduced equifinality. The Upper Wabash and Cedar Creek, two agriculture-dominated watersheds in Indiana, USA are considered as test beds to implement this multi-objective SWAT calibration. The proposed calibration approach is performed using remotely sensed Advanced Microwave Scanning Radiometer-Earth Observing System surface soil moisture (∼1 cm top soil) estimates (NASA's Aqua daily level-3 gridded land surface product-version 2) in sub-basin/HRU level together with observed streamflow data at the watershed's outlet. Although application of remote sensing data in calibration improves surface soil moisture simulation, other hydrologic components such as streamflow, evapotranspiration (ET) and deeper layer moisture content in SWAT remain less affected. An extension of this approach to apply root zone soil moisture estimates from limited field sensor data showed considerable improvement in the simulation of root zone moisture content and streamflow with corresponding observed data. Difference in relative sensitivity of parameters and reduced extent of uncertainty are also evident from the proposed method, especially for parameters related to the subsurface hydrologic processes. Regardless, precise representation of vertical soil moisture stratification at different layers is difficult with current SWAT ET depletion mechanism. While the results from this study show that root zone soil moisture can play a major role in SWAT calibration, more studies including various soil moisture data products are necessary to validate the proposed approach.

  12. Modelling non-Euclidean movement and landscape connectivity in highly structured ecological networks

    Science.gov (United States)

    Sutherland, Christopher; Fuller, Angela K.; Royle, J. Andrew

    2015-01-01

    Movement is influenced by landscape structure, configuration and geometry, but measuring distance as perceived by animals poses technical and logistical challenges. Instead, movement is typically measured using Euclidean distance, irrespective of location or landscape structure, or is based on arbitrary cost surfaces. A recently proposed extension of spatial capture-recapture (SCR) models resolves this issue using spatial encounter histories of individuals to calculate least-cost paths (ecological distance: Ecology, 94, 2013, 287) thereby relaxing the Euclidean assumption. We evaluate the consequences of not accounting for movement heterogeneity when estimating abundance in highly structured landscapes, and demonstrate the value of this approach for estimating biologically realistic space-use patterns and landscape connectivity.

  13. Impulse processing: a dynamical systems model of incremental eye movements in the visual world paradigm.

    Science.gov (United States)

    Kukona, Anuenue; Tabor, Whitney

    2011-08-01

    The Visual World Paradigm (VWP) presents listeners with a challenging problem: They must integrate two disparate signals, the spoken language and the visual context, in support of action (e.g., complex movements of the eyes across a scene). We present Impulse Processing, a dynamical systems approach to incremental eye movements in the visual world that suggests a framework for integrating language, vision, and action generally. Our approach assumes that impulses driven by the language and the visual context impinge minutely on a dynamical landscape of attractors corresponding to the potential eye-movement behaviors of the system. We test three unique predictions of our approach in an empirical study in the VWP, and describe an implementation in an artificial neural network. We discuss the Impulse Processing framework in relation to other models of the VWP.

  14. Impulse process