The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The purpose of this paper is to find the variation of pollutant concentration field and its impact on water intake of the Fen River entrance into Yellow River. A 2-D water hydrodynamic and quality model was used to simulate flow and variation of the pollutant concentration field. There will be a backwater in tributaries when the water in Yellow River flow into Fen River. The COD concentration decreased...
This paper presents a numerical method to simulate the 2D tidal flow and water quality under the orthogonal curvilinear coordinates. In order to overcome the computational difficulties in natural rivers, such as the complicated boundary figures, the great disparity between length and width of computational domain, etc., orthogonal boundary-fitted grid is used, the irregular domain in physical plane...
In this paper, the Yellow River flow of some typical bends in Ningxia Reach is numerically simulated using a three-dimensional turbulent model, namely Reynolds stress equation model. Numerical results of vertical mean velocity, main velocity and secondary flow on some cross-sections are obtained. In addition, circulation flow in some cross-sections and back flow are computed and analyzed. Good consistencies...
Simulation of soil salinity is the basis for effective control of salinization and utilization of regional salinization lands. This paper was to simulate dynamic of soil salinity with pedo-transfer functions (PTFs) and geographic information system (GIS) technology based on facile variables in Yellow River Delta. Simulating models were derived from field observation data of soil salinity, EC and water...
Evapotranspiration (ET) is one of the most important land surface processes for terrestrial ecosystems because it strongly relates to both the energy balance and the mass balance of these ecosystems. Though there are many ground based approaches to estimate ET, it is still a challenge to estimate ET by remote sensing for most applications. A methodology was proposed to calculate regional actual ET...
With steep slopes, high mountains, concentrated rainfalls and frequent rainstorms, the agricultural production and economic development of the Wen County, the southernmost county, also heavily damaged by 5.12 Earthquake, of Gansu Province in northwest China, are gravely constrained by serious soil erosion. To make effective soil and water conservation measures, quantitative evaluation of soil erosion...
To minimize the damage resulting from oil spill accidents, it is necessary to respond quickly with an appropriate strategy. Accurately forecasting the behavior of the spilled oil is crucial for a successful recovery operation and protection of marine resources. Therefore, the numerical modeling and simulation of the spilled oil at sea plays an important role in the oil spill response and contingency...
The conceptual hydrogeological model of the study area is generalized according to the hydrogeological conditions, and then the numerical model of groundwater flow is built by MODFLOW-2000. Under current condition of groundwater exploitation, the groundwater flow field in the year 2018 of the study area is forecasted. The result shows the groundwater level will decrease in the river valley of Jixi...
This paper presents a numerical method to simulate the 2D tidal flow and water quality under the orthogonal curvilinear coordinates. In order to overcome the computational difficulties in natural rivers, such as the complicated boundary figures, the great disparity between length and width of computational domain, etc., orthogonal boundary-fitted grid is used, the irregular domain in physical plane...
GIS-based soil erosion model is one key tool in physical geography. This paper tried to use EROMAT (the erosion management tool) in Loess Plateau of China. The result indicate: (1) the model efficiency coefficient (ME) was low for the Chinese Loess Plateau, which had close relationships with the local special topographic features; (2) the value of ME had scale effect, it decreased with the study area...
Allowing for catchment hydrological effect due to spatial variability of precipitation and underlying topography, the catchment is divided into a number of basic units of concentration flow within only one channel link by the method of natural divide. The basic unit of concentration flow is regarded as a V-shaped structure, and a distributed watershed concentration flow model is built on a series...
A hydrodynamic model (MOCOE) is used in tidal current and wave calculations in the Yamen River, which is one of the eight estuaries of the Pearl River. The method of combining curvilinear orthogonal coordinates in the horizontal direction with Sigma mapping coordinates in the vertical direction is used in calculation of the tidal current. In order to consider the nonlinear effect of waves and the...
The fundamental of neural network and its application are introduced firstly. Then the main factors which affect the runoff and the sediment transport volume in the problems of the water and sediment fluxes in the Yellow River Mouth during the flood and non-flood period are analyzed. Furthermore, the BP model is set up by using the program in the toolbox of the neural network under the environment...
It is well known that no uniform prediction approaches were obtained regarding ground water level, though the neural network and some other so-called artificial intelligence methods consistently provide the smallest uncertainty and different medians warranting further research on their abilities. In the present paper, the lower reaches of Tarim River is taken as the study area, a grey correlation...
The Princeton Ocean Model (POM) is a three-dimensional baroclinic ocean model based on the original equations, using a sigma coordinate in the vertical coordinate to deal with significant topographical variability, and has been widely used for estuary and coastal ocean simulation. Wetting and drying is a common and important phenomenon of the coastal ocean, and the process could not be simulated by...
The central place theory is the classical theory in the urban geography field as well as the rank-size rule. The Zipf's law is the important practical formula to describe the rank-size rule, but there are still some problems when the Zipf's formula is used in urban system's size distribution, such as experiential discussions more than theoretical studies and the theoretical values far different from...
The Three Gorges Reservoir is a typical channel reservoir in the Changjiang River, China. Dynamic storage can preferably reflect the true situation of water storage for the discharge flowing into reservoir, so it's one of the important parameters of the water balance's calculation, runoff forecast and reservoir operation for a channel reservoir. Combining the GIS technology with the hydrodynamic method,...
For the purpose of hydrological process simulation in cold and arid regions, the authors brought out the Vertically-mixed runoff model with Grid-based Water Storage Capacity(GWSC-VMR) on the base of the spatial distributed model of water storage capacity. In GWSC-VMR, factors such as topography, vegetation, soil and meteorology were taken into account. GWSC-VMR included canopy interception module,...
Taking the Northern Slope of the Tianshan Mountains (NSTM) as the study area, we investigated into the oases LUCC and information entropy change by using RS, GIS and statistical model. The results showed that, (1) Establishing mathematical models of the range, speed and trend index of LUCC, especially the model of LUCC trend and state, the state and trend of oasis LUCC can be deeply researched. Meanwhile,...
The vegetation restoring model district lies in the southeast of Honghu Lake which is interlinked with the Yangtze River through the river course. Based on the field investigation and test, this paper applies the fuzzy mathematical principle and uses five parameters to assess the water quality of the model district. Inferring from the fuzzy concept, which is more objective comparing with other assessment...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.