• 全国中文核心期刊
  • 中国科技核心期刊
  • 美国工程索引(EI)收录期刊

1994 Vol. 5, No. 1

Display Method:
Astronomical Factor for the Occurrence of the Extraorchary Flood along the Yaugtze Huaihe Rivers During Early Summer,1991─The Bursts of Solar Proton Flares
Zhou Shurong
1994, 5(1): 1-8.
Abstract:
The relationship between anomalous circulation in the Northern hemisphere and a series of solar proton flares occurred before the severe floods along the Yangtze-Huaihe Rivers during early summer, 1991 is researched. The results indicate that the continuous bursts of the large proton flares on solar disk is believed to be an important astronomical factor for the occurrence of the floods. The solar proton flares may trigger or intensify the process of the southward shift of cold air from polar vortex, the eastward shift of the low southwest jet flows and the west-hor-thward shift of the subtropical high in the west Pacific. Due to the frequent meeting of the cold and hot airflow along the middle-lower reaches of Yangtze River and Huaihe Rivers, it formed frequent processes of the heavy and heaviest rainfalls and then lead to the extraordinary flood along the Yangtze-Huaihe Rivers during early summer, 1991.
Velocity Spatial Variability and its Effect on Solute Transport in Field Unsaturated Soil
Yang Jinzhong, Ye Zitong
1994, 5(1): 9-17.
Abstract:
In this paper, the spatial variability of solute transport velocity is analyzed based on the unsaturated solute transport experiment in a field. The lognormal distribution function of the velocity and then the effective dispersivity are obtained. The mean concentration and variance are calculated by using convective equation and convective-dispersive equation with the resulted stochastic velocity and the classical convective-dispersive equation. The calculated result is in fairly agreement with the experimental data. It is shown that the concentration variance is proportional to concentration gradient and inverse proportional to the local dispersivitv. The maximum concentration variance is near the concentration front.
Preliminary Analysis of the Statistical Characteristic for Regional Drought
Song Huizhu, Zhang Shifa
1994, 5(1): 18-25.
Abstract:
The paper deals with mainly regional drought characteristics, including large river basin, region and state wide drought characteristics. According to regional drought indexes and degrees, which is calculated and determined in this paper, the stage-property and continuity of the drought. events for different centuries in the past. over 500 years is studied. The simultaneous possibility of the drought events in various regions are evaluated. The drought area-duration distribution cuves during 1470~1979 and the extreme drought regime of selected 12 years is analysed statistically.
Estimates Water Balance of Paleolake Qinghai in Stable Wet and Warm Period of Holoceue
Qin Boqiang
1994, 5(1): 26-27.
Abstract:
Lake Qinghai is the largest one in China, which is located in the semiarid region of Tibet-Qinghai plateau with an enclosed drainage basin. In early middle Holocene (about 6000~7200 a. B. P.), there was a high lake level approximately 45m above present. The research on the palynology around the lake exposed the climatic characteristics from vegetation coverage is wetter and warmer than that of present, namely the atmospheric temperature is about 4℃ over modernday. By the aid of various information supplied by palynology, sedimentary, morphology and chronology, we try to establish the paleolake water budget. The conclusion has been reached that the precipitation,evaporation and runoff in paleolake region is 32.0%, 14.0% and 67.0% larger than the present respectively.
Numerical Simulation of Internal Waves in Lake Fuxian
Jiang Jiahu, Yang Xichen, Wang Xianchen
1994, 5(1): 28-39.
Abstract:
A numerical integral model of two-dimensional stratification is proposed in accordance with the features of Lake Fuxian. The model is used to study some characteristics of internal waves and epilimnion as well as hypolimnion currents in the lake. Computed results show that the internal waves rotate counterclockwise with a period of 42.5 hours in the case of nonrotational wind, that two layers of horizontal cyclic gyres, which rotate in opposite directions, exist in the northen part of Lake Fuxian in the case of rotational wind, and that the counterclockwise cyclic gyres in-the upper layer of the lake are mainly caused by rotational wind, etc. The simulated results agree well with observed facts.
Modeling of Groundwater Quantity and Quality in Jiamusi City
Zhu Xueyu, Sun Kerang
1994, 5(1): 40-49.
Abstract:
Jiamusi is an industrial city in north-east of Heilongjiang Province. Groundwater is the main source for water supply m this city. Two-dimensional mathematical models for groundwater resources and quality with their field applications in Jiamusi City were presented in this paper. The groundwater resource model was approached by a finite element method (FEM) and groundwater resource in this district was evaluated with the established model. The groundwater quality model was solved by a characteristic finite element method (CFEM). Numerical dispersion and oscillation were effectively reduced by using this method. Additionally, a simple but effective method was used to determine the serial number of the element where moving particle located, which is very important for the application of CFEM. The future distribution of contaminant concentrations in this area was predicted in the end of this paper.
Application of Analytical Finite Element Method to an Optimum Solution of Groundwater Management Model
Chen Yusun
1994, 5(1): 50-57.
Abstract:
In order to imporved such disadvatages as the matrix, applied in the embedding method, requires large memory for storage, and as the global optimum solution can not be guaranteed in response matrix method, here an integral unsteady response matrix of the whole region, derived by the analytical FEM, is proposed as a constraint condition, embeddling into the linear programming model. Since the later can express the behavior of the drawdown in the whole domain, it can be found that the method, given in this paper, will facilitate optimal development and management of ground water resources.
A Nonlinear Model for Optimizing Irrigation Schedule under a Limited Water Supply
Guo Zonglou
1994, 5(1): 58-63.
Abstract:
This paper aims to reseach the irrigation schedule with water-saving and a good harvest. Firstly, the measurement of water-saving irrigation has been researched by means of studing the characteristics of the soil water movement and evapotranspiration in the root zone of crops, and then a nonlinear model for optimizing irrigation schedule of crops under partially meeting the water demand hash been constructed. In the model, the relationship between yield and water demand of crops has been involved, and the characteristics of soil water in the root zone of crops has been considered as well. Finally, a case study has been carried out and satisfactory results have been obtained.
Primary Studies of Flood and Waterlogging Damages Using Remote Sensing in Jianghan plain
Yu Guangming
1994, 5(1): 64-70.
Abstract:
In this paper, the research scheme of flood and waterlogging damage is suggested by using remote sensing and geographical information system, and its contents are as following:(1)evaluation of the resources and the information processing; (2) analysis on mechanism and loss of the damage;(3) forecast of the damage and strategic decision for prevention and cure of the damage. In this scheme, the basic functions of technical system are:(I)image and data handling;(2) extraction and analysis of the basic information; (3) loss analysis model and forecast model. As a part of this study, a series of our experiments are also introduced.
Experiment Study of River Flood Control Information System for Remote Sensing System of Flood Control
Wei Wenqiu, Chen Xiuwan
1994, 5(1): 71-77.
Abstract:
This paper decribes a experiment study of river flood control information system (FCIS) for remote sensing system of flood control. Through a methodological study of input, output, and processing of graph and remotely sensed image, the microcomputer-based system is established by using a compiler method mixed DBASE-Ⅲ with FORTRAN,BASIC and C.The functions of FCIS include data storage, updating,retrivial,display,mapping; graph and imagc input/output, save/load, edit and processing.
A Survey of Flood Impact
Chen Yongbai, Fang Zhiyun
1994, 5(1): 78-84.
Abstract:
Flooding is one of most severe natural disasters. Its impacts involve many aspects of natural and social systems. There are some limitations related to the flood impact assessments in the present. To overcome them, this paper will incorporate flood impacts intao a flood environmental system in a systematic way. Moreover, the potential effects of floods on natural ecology, social economics, and national policies, are reviewed, which will promoting advances of flood impact asse ssments, flood controt strategies and counter measures.
1994, 5(1): 85-86.
Abstract: