Impacts of Urbanization on River Systems in the Taihu Region, China

River systems are valuable to human beings; meanwhile, they are intensively influenced by human activities, especially urbanization. In this study, based on the data derived from topographic maps and remote sensing images, the temporal and spatial change of river system geomorphology in the Taihu Region over the past 50 years was investigated in conjunction with urbanization. Results demonstrated that the number of river systems decreased drastically, that the morphology of river channels changed into wider and straighter and that the structure of river network tended to simplify in the Taihu Region in recent 50 years. Meanwhile, the changes in river density, the water surface ratio, the river development coefficient, the main river area length ratio and the box dimension in the rapid urbanization period were much greater than those in the slow urbanization period, but the decrease of river sinuosity in the slow urbanization period was more intense. Moreover, the spatial differences of the changes in the river development coefficient were the largest, and the changes in the river indicators in the low-urbanized regions were the most intense. In addition, the changes in the water surface ratio had the closest correlation with urbanization, and the relational degrees between population urbanization and the changes in river systems were the largest. The results can provide a reliable basis to determine reasonable management and conservation strategies of river systems in the Taihu Region.

[1]  Mark Cable Rains,et al.  Hydrological Connectivity Between Headwater Streams and Downstream Waters: How Science Can Inform Policy 1 , 2007 .

[2]  R. Rosso,et al.  On the fractal dimension of stream networks , 1989 .

[3]  S. Zucker,et al.  Evaluating the fractal dimension of profiles. , 1989, Physical review. A, General physics.

[4]  Janet Hooke,et al.  Human impacts on fluvial systems in the Mediterranean region (Invited paper for Binghamton Symposium , 2006 .

[5]  J. Heffernan,et al.  Morphological characteristics of urban water bodies: mechanisms of change and implications for ecosystem function. , 2014, Ecological applications : a publication of the Ecological Society of America.

[6]  R. Dong,et al.  Impacts of urbanisation on river systems and their functions in Yanggong River watershed of Lijiang City , 2011 .

[7]  Ronghua Ma,et al.  Two-decade reconstruction of algal blooms in China's Lake Taihu. , 2009, Environmental science & technology.

[8]  A. Chin.  Urban transformation of river landscapes in a global context , 2006 .

[9]  Xu Jintao,et al.  Impacts of urbanization on hydrology in the Yangtze River Delta, China. , 2010, Water science and technology : a journal of the International Association on Water Pollution Research.

[10]  Heung Wong,et al.  Change-point analysis of hydrological time series using grey relational method , 2006 .

[11]  H. Vijith,et al.  Factors influencing the sinuosity of Pannagon River, Kottayam, Kerala, India: An assessment using remote sensing and GIS , 2008, Environmental monitoring and assessment.

[12]  M. Barbour,et al.  Rapid bioassessment protocols for use in streams and wadeable rivers: periphyton , 1999 .

[13]  C. Sparrow.  The Fractal Geometry of Nature , 1984 .

[14]  D. Sear,et al.  Environmental change in river channels: a neglected element. Towards geomorphological typologies, standards and monitoring. , 2003, The Science of the total environment.

[15]  C. Revenga,et al.  Fragmentation and Flow Regulation of the World's Large River Systems , 2005, Science.

[16]  R. Bailey,et al.  Buried streams: Uncovering a potential threat to aquatic ecosystems , 2013 .

[17]  R. Stone.  Ecology. China aims to turn tide against toxic lake pollution. , 2011, Science.

[18]  J. Poesen,et al.  River channel response to short-term human-induced change in landscape connectivity in Andean ecosystems , 2005 .

[19]  E. W. Lane.  The Importance of Fluvial Morphology in Hydraulic Engineering , 1955 .

[20]  Nick Reynard,et al.  Hydrological analysis for water level projections in Taihu Lake, China , 2013 .

[21]  Boqiang Qin,et al.  Environmental issues of Lake Taihu, China , 2007, Hydrobiologia.

[22]  Karmeshu.  Demographic Models of Urbanization , 1988 .

[23]  Jian Wang,et al.  Taihu Lake, lower Yangtze drainage basin: evolution, sedimentation rate and the sea level , 2001 .

[24]  Yang Kai.  Stream Structure Characteristics and Its Urbanization Responses to Tidal River System , 2004 .

[25]  Wenhua Yuan,et al.  Impact of urbanization on structure and function of river system , 2006 .

[26]  P. Groffman,et al.  The urban stream syndrome: current knowledge and the search for a cure , 2005, Journal of the North American Benthological Society.

[27]  A. N. Strahler.  Hypsometric (area-altitude) analysis of erosional topography. , 1952 .

[28]  J. Ward.  RIVERINE LANDSCAPES: BIODIVERSITY PATTERNS, DISTURBANCE REGIMES, AND AQUATIC CONSERVATION , 1998 .

[29]  B. Mandelbrot.  Fractal Geometry of Nature , 1984 .

[30]  J. Karr.  Defining and measuring river health , 1999 .

[31]  M. Antrop.  Landscape change and the urbanization process in Europe , 2004 .

[32]  Ping Xue-liang,et al.  Grey System Theory and Its Applications in Engineering , 2003 .

[33]  A. Roy,et al.  Urbanization affects the extent and hydrologic permanence of headwater streams in a midwestern US metropolitan area , 2009, Journal of the North American Benthological Society.

[34]  Zhongyuan Chen,et al.  Yangtze Delta, China: Taihu lake-level variation since the 1950s, response to sea-level rise and human impact , 1999 .

[35]  P. James,et al.  Impact of urbanization on structure and function of river system - case study of Shanghai, China , 2006 .

[36]  T. Anderson.  View from the river. , 2007, The practising midwife.

[37]  R. O'Neill,et al.  The value of the world's ecosystem services and natural capital , 1997, Nature.

[38]  A. Elmore,et al.  Disappearing headwaters: patterns of stream burial due to urbanization , 2008 .

[39]  K. Gregory.  The human role in changing river channels , 2006 .

[40]  B. Maheshwari,et al.  River health assessment in peri-urban landscapes: an application of multivariate analysis to identify the key variables. , 2011, Water research.

[41]  Barry T. Hart,et al.  Development and testing of an Index of Stream Condition for waterway management in Australia , 1999 .

[42]  Haixia Zhao,et al.  Spatial correlations between urbanization and river water pollution in the heavily polluted area of Taihu Lake Basin, China , 2013, Journal of Geographical Sciences.

[43]  Yuan Zhang,et al.  Identifying Major Factors Affecting Groundwater Change in the North China Plain with Grey Relational Analysis , 2014 .

[44]  Mary C. Freeman,et al.  Hydrologic Connectivity and the Contribution of Stream Headwaters to Ecological Integrity at Regional Scales 1 , 2007 .

[45]  B. Gu,et al.  Assessment of ecosystem health during the past 40 years for Lake Taihu in the Yangtze River Delta, China , 2011, Limnology.

[46]  D. Montgomery,et al.  Urbanization impacts upon catchment hydrology and gully development using mutli‐temporal digital elevation data analysis , 2010 .

[47]  Stephen J. Burges,et al.  REVIVING URBAN STREAMS: LAND USE, HYDROLOGY, BIOLOGY, AND HUMAN BEHAVIOR 1 , 2004 .