Author: Swapan RoyPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Simulation of Spatial and Temporal Variability of Soil Moisture Using the Simultaneous Heat And Water (SHAW) Model
Author: Swapan RoySimulation of Spatial and Temporal Variability of Soil Moisture Using Swatre Model, and Geostatistical Procedures
Author: Suria Darma TariganModeling the Spatial and Temporal Distribution of Soil Moisture at Watershed Scales Using Remote Sensing and GIS
Author: PJ. StarksPublisher:
ISBN:
Category : Geographic information systems (GIS)
Languages : en
Pages : 17
Book Description
Soil water content (2v) is of fundamental importance in meteorology, agriculture, and hydrology, among other scientific disciplines. In hydrology, 2v partitions rainfall into runoff and infiltration, thus impacting surface and groundwater recharge, flood forecasting, and flow routing modeling. Measurement of 2v at a point is straightforward, but point measurements are inadequate for watershed hydrology due to variability of soil properties, land cover, and meteorological inputs over space. Passive microwave remote sensing systems have been successfully used to provide regional estimates of surface 2v (0-5 cm surface layer) at the spatial resolution of the sensor. To extend these data to other depths and scales, a two-layer soil water budget model was used to combine remotely sensed estimates of 2v and spatial information on land cover, soil type and meteorological inputs to predict root zone 2v over a 611 km2 watershed. A GIS was used to pre-process and geo-register spatial data sets for input into the soil water budget model, and analyze the results.
Transactions of the ASAE.
Author: American Society of Agricultural EngineersPublisher:
ISBN:
Category : Agricultural engineering
Languages : en
Pages : 412
Book Description
Spatial and Temporal Modeling of Soil Moisture Using Remote Sensing
Author: Scott D. LindseyPublisher:
ISBN:
Category : Hydrologic models
Languages : en
Pages : 410
Book Description
A Model for the Diurnal Variation of Simultaneous Heat and Water Transport in a Soil Profile with an Evaporating Bare Surface and Hysteresis
Author: Chu-Hui ChenComputer Simulation of Soil-water Dynamics
Author: Daniel HillelPublisher:
ISBN:
Category : Computers
Languages : en
Pages : 222
Book Description
Fundamental principles of modeling and simulation; Isothermal evaporation of soil water under fluctuating evaporativity, including the role of hysteresis; Non-isothermal evaporation of soil water, including the effect of surface reflectivity; Water dynamics and storage in fallow soils as affected by soil texture and profile layering; Hydrology of a sloping field, including surface runoff and groundwater flow; Moisture extraction by root systems, and the concurrent movement of water and salt in the soil profiles.
1992 Fall Meeting
Author: Analysis of Large Scale Spatial Variability of Soil Moisture Using a Geostatistical Method
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 22
Book Description
Spatial and temporal soil moisture dynamics are critically needed to improve the parameterization for hydrological and meteorological modeling processes. This study evaluates the statistical spatial structure of large-scale observed and simulated estimates of soil moisture under pre- and post-precipitation event conditions. This large scale variability is a crucial in calibration and validation of large-scale satellite based data assimilation systems. Spatial analysis using geostatistical approaches was used to validate modeled soil moisture by the Agriculture Meteorological (AGRMET) model using in situ measurements of soil moisture from a state-wide environmental monitoring network (Oklahoma Mesonet). The results show that AGRMET data produces larger spatial decorrelation compared to in situ based soil moisture data. The precipitation storms drive the soil moisture spatial structures at large scale, found smaller decorrelation length after precipitation. This study also evaluates the geostatistical approach for mitigation for quality control issues within in situ soil moisture network to estimates at soil moisture at unsampled stations.
Spatiotemporal Variability of Hydrologic Response
Author: Aldrich Edra CastilloPublisher:
ISBN:
Category :
Languages : en
Pages : 189
Book Description
Basin hydrologic response pertains to the partitioning of precipitation into stream-flow, evapotranspiration, and change in storage. The ability to explain or predict the response has many applications e.g. flood forecasting, water budget studies, and design of hydrological observing systems. However, explaining the response is challenging because it is the combined manifestation of many complex and interrelated factors that naturally vary in space and time, and act over a variety of scales. A possible key is better understanding of the space-time dynamics of the hydrologic state variable - the soil moisture field. This thesis uses the distributed hydrologic model MOBIDIC that uses a single soil layer with dual compartments: a capillary and a gravity reservoir composed of small, and large pores, respectively. Mass and energy fluxes are simultaneously solved using simple linear equations. These make the model computationally efficient. To improve soil moisture simulations, some model modifications were introduced. MOBIDICs ability to simulate the magnitude range and dynamics of soil moisture at the local scale is found comparable with a benchmark model that uses non-linear soil physics relations. We derive an entropy-based dimensionless measure of hydrologic complexity H which measures the distance of a given soil moisture spatial probability distribution from two limiting cases. Using 8 test basins with area of 10°-103 km2 and representing semiarid, temperate, and humid climates, it is shown that H effectively tracks the evolution of soil moisture distribution, and captures the interplay between vertical and lateral fluxes. Furthermore, we investigate the relationship of W with observable basin attributes and traditional measures of hydrologic response. Clear and logical relationships emerge only after grouping basins based on similarity. For example, in the semiarid basins, H increases with catchment area, infiltration ratio and baseflow index. For basins of similar size, H is highest in temperate climate, consistent with soil moisture being double-bounded so its variability peaks at intermediate conditions. Finally, although not explicitly coded in MOBIDIC, hysteresis is evident in the discharge-storage plots. It emerges from the use of a dual-pore soil structure that captures the threshold behavior of runoff. R- helps in understanding the mechanisms involved.