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IMPACT OF URBANIZATION ON STRUCTURE AND FUNCTION OF river system—Case Study of Shanghai,China

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Chinese Geographical Science 2006年第2期16卷 102-108页

作者： Philip JAMES Research Institute for the Built and Human Environment School of Environment and Life Sciences University of Salford Greater Manchester M5 4WT UK

Urbanization can affect the physical process of river growth, modify stream structure and further influence the functions of river system. Shanghai is one of the largest cities in the world, which is located in Changjiang (Yangtze) river Delta in China. Since the 1970s, the whole river system in Shanghai has been planned and managed by the Shanghai Water Authority. The primary management objectives in the last 30 years have been to enhance irrigation and flood-control. By using Horton-Strahler classification and Horton laws as a reference, a novel method of stream classification, in conjunction with the traditional and specially designed indicators, was applied to understanding the structure and functions of the river system in Shanghai. Correlation analysis was used to identify the interrelations among indicators. It was found that the impact of urbanization on the river system was significant although natural laws and physical characteristics marked a super-developed river system. There was an obvious correlation between the degree of urbanization and the abnormal values of some indicators. Urbanization impacts on river system such as branches engineered out, riverbank concreting and low diversity of river style were widely observed. Each indicator had distinct sensibility to urbanization so they could be used to describe different characteristics of urban river system. The function indicators were significantly related to structure indicators. Stream structure, described by fractal dimension and complexity of river system, was as important as water area ratio for maintaining river’s multi-function.

关键词： river system stream classification Horton law urbanization Shanghai

Urbanization effects on the river systems in the Bucharest City region(Romania)

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Ecosystem Health and Sustainability 2016年第11期2卷 20-38页

作者： Liliana Zaharia Gabriela Ioana-Toroimac Octavian Cocoş Florin Adrian Ghiţă Emanuel Mailat Faculty of Geography University of Bucharest1 Nicolae BălcescuSector 1Bucharest010041Romania Water Management system Ilfov-Bucureşti Argeş-Vedea Water BranchNational Administration“Romanian Waters”294 Splaiul IndependenţeiSector 6Bucharest060031Romania Argeş-Vedea Water Branch National Administration“Romanian Waters”6-8 Calea CâmpulungPiteştiArgeşCounty110147Romania

This article identifies and analyzes the effects of human pressures on the river systems,landscape,flow regime,and water quality in the Bucharest region,the largest urbanized area in *** analyses focused on four streams crossing the Bucharest region,namely the Dâmboviţa,Colentina,Argeş,and Sabar *** approach relied especially on three types of information:(1)spatial data;(2)hydrological data sets;and(3)water quality *** made a diachronic analysis of the available maps and ran classic statistical analysis of the data sets,as well as trend *** the same time,we compared the flows in natural(reconstituted)and modified(current)*** results showed that the stream system and its associated landscapes have considerably changed due to several engineering works(reservoirs,dams,channelization works,diversion canals,water intakes,etc.).Under these circumstances,the flow regime suffered changes that differed among the ***,the multiannual discharges of the Argeşand Dâmboviţa rivers did not exhibit significant changes,but only mitigated the monthly discharge *** the case of Sabar and Colentina,a significant increase of the annual and monthly discharges was identified,due to the water transferred from the neighboring *** quality worsened,especially on the lower courses of the Dâmboviţa and Argeşrivers,degrading the states and health of the aquatic ecosystems in the study region.

关键词： aquatic ecosystems Bucharest region ecological state ecosystem health engineering works flow regime river system Romania urbanization water quality

Stochastic evolution of hydraulic geometry relations in the lower Yellow river of China under environmental uncertainties

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International Journal of Sediment Research 2020年第4期35卷 328-346页

作者： Xiaolong Song Deyu Zhong Guangqian Wang Xiaonan Li State Key Laboratory of Hydro-science and Engineering Tsinghua University State Key Laboratory of Hydraulic Engintering Simulation and Safety Tianjin University Changjiang Survey PlanningDesign and Research Co.Ltd

Hydraulic geometry relations comprise a classic way to understand characteristics of a ***,environmental changes pose large uncertainties for the reliability of such *** the current study,on the basis of the ordinary differential equations(ODEs) formed through linear treatment of the deterministic power-law hydraulic geometry relations,a set of stochastic differential equations(SDEs)driven by Fractional white noise and Poisson noise are developed to simulate the historical dynamic probability distributions of typical hydraulic geometry variables such as slope,width,depth,and velocity with bankfull discharge variation over time in the lower Yellow river of *** group of possible stochastic average behaviors within the next 50 years are calculated under three different design incoming water-sediment conditions(including 300,600,and 800 million t of annual average sediment discharge).In each part of the lower reaches,after estimation of the SDE parameters using a nonparametric maximum likelihood estimation(MLE) method,the model is carefully examined using Monte Carlo simulation as compared with the deterministic control *** results of this comparison reveal the potential responses of hydraulic geometry characteristics to environmental disturbances,and the average trends mainly agree with the *** among the three different prediction results reveal the stochastic average solution generally is greater than the deterministic *** results also confirm the severe negative impacts that result from the condition of 300 million t of incoming sediment,thus,pointing out the need to raise the level of river evolution alert for the lower Yellow river of China in the ***,with the help of the stochastic computation,the stream power and hydraulic width/depth ratio could be representative of an effective systematic measure for river *** proposed stochastic approach is not only important to development in t

关键词： Hydraulic geometry relations Environmental uncertainties Stochastic differential equation Lower Yellow river river system

The inner circulation mechanism in sinking column formation in North China coal field ——A case study in Fengfeng mining areas

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Journal of Coal Science & Engineering(China) 2007年第1期13卷 32-36页

作者：王经明刘咸卫刘文生关永强王军现 Department of Safety Engineering North China Institute of Science ＆ Technology Beijing 101601 China Science and Development Section Fengfeng Group Co. Ltd Handan 056200 China

Sinking columns are one of the most hazardous geological structures in north Chine typed coal fields. To understand the sinking column formation, to judge if the columns are hazardous or not, the inner circle mechanism of groundwater in forming sinking columns in the relatively isolated areas was proposed according to the investigation on formation or distribution of sinking columns in some north China typed coal fields, such as Fengfeng, Xiangtai, Huaibei, Yangquan and so on. The heat generated by magma energized groundwater circulation and developed limestone karst in the relatively isolated areas. The CaCO3 solution accelerated by geothermal abnormality, the effect of high content of CO2 on dissolution and saturation of CaCO3 were discussed. Compared the forming conditions of the sinking columns developed in other coal mining areas in north China coal field, the paper deduced that the above factors collude karst development and sinking column formation, the columns in current geothermal areas are permeable and those in high coal rank areas or in paleo abnormally geothermal areas. The paper suggested that the sinking columns in the current abnormally geothermal areas were permeable, but those in the areas with high coal rank were not on contract.

关键词： sinking columns inner circulation geothermy river system coal ranks

Applying Downscaled Global Climate Model Data to a Groundwater Model of the Suwannee river Basin, Florida, USA

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American Journal of Climate Change 2016年第4期5卷 526-557页

作者： Eric Swain J. Hal Davis Caribbean-Florida Water Science Center U.S. Geological Survey Davie FL USA Retired US Geological Survey Davie FL USA

The application of Global Climate Model (GCM) output to a hydrologic model allows for comparisons between simulated recent and future conditions and provides insight into the dynamics of hydrology as it may be affected by climate change. A previously developed numerical model of the Suwannee river Basin, Florida, USA, was modified and calibrated to represent transient conditions. A simulation of recent conditions was developed for the 372-month period 1970-2000 and was compared with a simulation of future conditions for a similar-length period 2039-2069, which uses downscaled GCM data. The MODFLOW groundwater-simulation code was used in both of these simulations, and two different MODFLOW boundary condition “packages” (river and Streamflow-Routing Packages) were used to represent interactions between surface-water and groundwater features. The hydrologic fluxes between the atmosphere and landscape for the simulation of future conditions were developed from dynamically downscaled precipitation and evapotranspiration (ET) data generated by the Community Climate system Model (CCSM). The downscaled precipitation data were interpolated for the Suwannee river model grid, and the downscaled ET data were used to develop potential ET and were interpolated to the grid. The future period has higher simulated rainfall (10.8 percent) and ET (4.5 percent) than the recent period. The higher future rainfall causes simulated groundwater levels to rise in areas where they are deep and have little ET in either the recent or future case. However, in areas where groundwater levels were originally near the surface, the greater future ET causes groundwater levels to become lower despite the higher projected rainfall. The general implication is that unsaturated zone depth could be more spatially uniform in the future and vegetation that requires a range of conditions (substantially wetter or drier than average) could be detrimentally affected. This vegetation would include wetland species,

关键词： Groundwater Climate Model river system Downscaling

Self-organization Mechanism during the Bedform Process

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Tsinghua Science and Technology 1997年第3期2卷 8-12,22页

作者：杨铁笙杨桦杨美卿 Department of Hydraulic and Hydropower Engineering Tsinghua University Beijing 100084

This paper investigates the functional and morphological self organization phenomena that occur during the bedform process in river systems. The fluvial process has architecturally functional self organization actions that serve to self adjust the river regime. The bedform (or sand waves) process is part of the functional self organization at the middle level of the geometrical scale. By increasing the resistance of the mobile bed and simultaneously decreasing the capacity carrying sediment, the bedform serves to self adjust the river system. The morphological self organization of the bedform process is the basis for the functional self organization. The concept of the water sand interaction region is suggested, and a nonlinear model is constructed to describe the complex interaction among water flow, bed load transport, and local bed deformation, i e , the sand waves. A numerical simulation was developed based upon this model. The primary results show that the model is able to repeat many important phenomena in the bedform process, especially the critical phase transition. 

关键词： river system bedform self organization nonlinearity critical phase transition feedback

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