Scaling effects on modeled surface energy-balance components using the NOAH-OSU land surface model   总被引：3，自引：0，他引：3  

V. Sridhar  Ronald L. Elliott  Fei Chen 《Journal of Hydrology》2003,280(1-4):105-123

As surface exchange processes are highly non-linear and heterogeneous in space and time, it is important to know the appropriate scale for the reasonable prediction of these exchange processes. For example, the explicit representation of surface variability has been vital in predicting mesoscale weather events such as late-afternoon thunderstorms initiated by latent heat exchanges in mid-latitude regions of the continental United States. This study was undertaken to examine the effects of different spatial scales of input data on modeled fluxes, so as to better understand the resolution needed for accurate modeling. A statistical procedure was followed to select two cells from the Southern Great Plains 1997 hydrology experiment region, each 20 km×20 km, representing the most homogeneous and the most heterogeneous surface conditions (based on soil and vegetation) within the study region. The NOAH-OSU (Oregon State University) Land Surface Model (LSM) was employed to estimate surface energy fluxes. Three scales of study (200 m, 2 and 20 km) were considered in order to investigate the impacts of the aggregation of input data, especially soil and vegetation inputs, on the model output. Model results of net radiation and latent, sensible and ground heat fluxes were compared for the three scales. For the heterogeneous area, the model output at the 20-km resolution showed some differences when compared with the 200-m and 2-km resolutions. This was more pronounced in latent heat (12% decrease), sensible heat (22% increase), and ground heat flux (44% increase) estimation than in net radiation. The scaling effects were much less for the relatively homogeneous land area with 5% increase in sensible heat and 4% decrease in ground heat flux estimation. All of the model outputs for the 2- and 20-km resolutions were in close agreement. The results suggested that, for this study region, soils and vegetation input resolution of about 2 km should be chosen for realistic modeling of surface exchange processes. This resolution was sufficient to capture the effects of sub-grid scale heterogeneity, while avoiding the data and computational difficulties associated with higher spatial resolutions.  相似文献   

Ecology of River Basins     

V. S. Korshunova  N. M. Novikova 《Water Resources》2003,30(5):589-590

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Hydrogeological Zoning of the Central Minusinsk Basin by the Conditions of Formation of Fresh Groundwater Resources     

Rasskazov  N. M.  Kulagina  T. A.  Kuskovski  V. S. 《Water Resources》2003,30(3):246-251

A detailed hydrogeological zoning of the central part of the Minusinsk artesian basin is performed. Local basins confined to smaller plicated structures, as well as hydrogeological massifs of local scale, are recognized within large block structures. Direction of subsurface streams and their role in the formation of groundwater resources and composition are discussed. Forecast resources of fresh groundwater are estimated for every recognized structure.  相似文献   

Water Quality of Small Rivers in the Zone of Influence of Gold-Mining Facilities in Krasnoyarsk Region     

Shchur  L. A.  Bazhina  L. V.  Volkova  N. I.  Trofimova  M. A. 《Water Resources》2003,30(1):72-80

Environmental and sanitary estimation of small-river water quality is made in the zone of influence of gold-mining facilities in Krasnoyarsk Region. The estimates are based on data on the hydrochemical regime and the characteristics of phytoplankton, microphyto-periphyton, macrozoobenthos, and ichthyofauna collected during the vegetation period of 2000.  相似文献   

Long-Term Prediction of Water Quality in Marine Water Areas     

Zemlyanaya  N. V.  Lyakhov  V. N. 《Water Resources》2003,30(4):445-452

Random walk approach is used to develop a model for long-term prediction of water quality in shallow marine waters. The model allows one to simulate variations in hydrological situations, reactive solutes, interaction between solutes and liquid and solid boundaries. The model application is illustrated by calculations for Amur Bay. Calculations using the long-term prediction model has not found a stationary state in the pollution level. The velocities of seaward motion of pollution front and the rates of increase in the concentration of a nonreactive solute are given.  相似文献   

Seismic Wave Field in the Vicinity of Caustics and Higher-Order Travel Time Derivatives     

Goldin  S.V.  Duchkov  A.A. 《Studia Geophysica et Geodaetica》2003,47(3):521-544

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Modeling Lake Ladoga Zoobenthos and Studying Its Role in Phosphorus Exchange at the Water–Bed Interface     

Astrakhantsev  G. P.  Minina  T. R.  Petrova  N. A.  Poloskov  V. N.  Rukhovets  L. A. 《Water Resources》2003,30(2):209-220

A zoobenthos submodel is included in an ecosystem model. The new model is used to assess the role of zoobenthos in the phosphorus exchange at the water–bed interface, in particular, the phosphorus cycle in the water body ecosystem is described more accurately. The calculated zoobenthos distribution over the bed of a lake can be used in modeling the lake ichthyocenoses.  相似文献   

Comparison of Brewer spectrophotometer ultraviolet data from similar latitudes in the Northern and Southern Hemisphere     

M. G. Kimlin  J. M. Sabburg  A. V. Parisi  R. S. Meltzer 《Journal of Atmospheric and Solar》2003,65(16-18):1401-1410

This paper presents UV data recorded over 12 months in 2000/2001 at a southern hemisphere (Toowoomba) and similar latitude northern hemisphere (BigBend and Everglades) sites using Brewer Spectrophotometers. The peak daily erythemally weighted UV (DUV) at the Toowoomba site was 8.8% and 25% higher compared to that at the BigBend and Everglades sites, respectively. The Everglades site exposures are lower than the BigBend site exposures in summer and spring. This may be due to the higher cloud cover for the Everglades site. The summer DUV values between Toowoomba and BigBend are similar. In spring, the average DUV value is the greatest at BigBend compared to the other two sites. Results indicate that variability between the measurement sites is due to varying cloud and ozone, and possibly due to aerosol and airmass differences of each region. Of these different site-specific local atmospheric conditions, cloud was the main contributor to the differences in UV between the sites.  相似文献   

Structural Analysis of Time Series of Maximum Spring Levels of Natural Waters     

Pedan  V. V. 《Water Resources》2003,30(6):632-639

Observational data from two gauges in Poltava oblast are used to analyze the amplitude and phase–frequency characteristics of spectral decompositions of series containing maximum spring levels of subsoil and surface waters in successive 32-year-long intervals. The similarity and the regular evolution of the spectral characteristics for both gauges, which were confirmed by similar variations in the regime-forming factors (meteorological and heliosynoptic), opens up new avenues for modeling and prediction of maximum spring levels.  相似文献   

Cyclic tests on large‐scale models of existing bridge piers with rectangular hollow cross‐section     

A. V. Pinto  J. Molina  G. Tsionis 《地震工程与结构动力学》2003,32(13):1995-2012

Cyclic tests on two large‐scale models of existing bridge piers with rectangular hollow cross‐section were performed in the ELSA laboratory. The prototype structure is an existing reinforced concrete highway bridge constructed in Austria in 1975. The piers presented several seismic deficiencies and consequently they showed poor hysteretic behaviour and limited deformation capacity as well as undesirable failure modes that do not comply with the requirements of modern codes for seismic‐resistant structures. Experimental data are compared to numerical and empirical predictions. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献