Integrated utilization of
Remote Sensing and GIS in Shashi's urban general planning
Chen Jun, Qiu
Zhaoyue Wuhan Technical University of Surveying and Mapping Wuhan, China Abstract Since 1986, remote sensing and geographic information system (GIS) techniques have been used by the authors to assist urban planning and management in Hubei Province, China. This paper described the methodology and practices of integrated utilized of multidate airphotos, satellite imagery and GIS in Shashi's urban general planning. Introduction Urban general planning is based various types of data (including physical environment, resource distribution, urban landuse and utility, socio-economic development etc) and comprehensive analysis. As far as the basic urban data is concerned , not only quantitative composition and geographic distribution of the relevant urban phenomena in different scales are required, but also the changing characteristics or dynamic process of some phenomena are needed. On the other hand, a large number of facts and /or extensive calculations need to be processed for the simulation of physical situations by means of mathematic methods, for the systemato-logical and synthetic analysis, comparison and selection of alternative plans. In order to meet with these requirements, remote sensing and GIS techniques have been used by the authors to support urban general planning in the middle sized cities in Hubei Province, China. In the urban general planning of Shashi, sequential airphotos and satellite imagery are used to collect more complete, accurate, reliable basic urban data, and GIS is used to assist urban environmental quality accessment, traffic volume forecast and analysis, socio-economic development forecast. Comprehensive survey of basic urban data using Remote Sensing methods As we may see from Table 1, the large-scale air photos taken in March 1989 were used for collecting the basic urban data in urban construction area, planning area, as well as in some specific zones. TM and MSS imageries were used mainly to collect basic data in regional scale and to study some specific phenomena in the planning area, Sequential airphotos and satellite imageries were used for urban change (or expansion) analysis, urban landuse plan implementation checking, river and lake change analysis. Table 1. The airphotos and satelite imagesries
used in Shashi's urban planning
Table 2. Basic urban data collection by integrated utilization of remote sensing and auxiliary data.
As far as the technical scheme is concerned, the 1:10,000 air orthophotos and 1: 100,000 satellite and 1:100,000 satellite mosaic were firstly made. The whole planning area was then divided into 135 geographic units according to the spatial homogeneity, natural borders and the existing administrative boundaries. Further study of the geometric and spectral characteristics of urban objects or phenomena were carried out with the help of all available auxiliary data. On the basis of the work, the basic urban data listed in Table 2 were collected. And the intermediate and final results were provdied to urban general planning in the forms of series of thematic maps, alpha-numeric data tables, analytic reports, or data bases.. GIS-Based Urban Quantitive analysis
Fuzzy weighting method was used for multifactor synthetic accessment. Suppose k factors be selected. with their weights w1, w2,.... wk, p ranks are classified for each factor. Let x1, x2,.... xk be the values of a given evaluation unit, the subordiance degree of xi to the jth rank of the ith factor is defined as: xijl,x iju are respectively the low limit and upper limit of the jth rank of the ith factor. In this way, fuzzy subordinace degree matrix R was created for k factors and p ranks, and the fuzzy set of class St was determined as follows: The evaluation unit in consideration was assigned to the class corresponding to the maximum of s1, S2,..., Sp. On the basic of traffic survey and geographic analysis, the planning area was divided into 42 traffic zones. The existing traffic volume was firstly analyzed to obtain O-D distribution, time variation of traffic volume for certain road segments, traffic generation between basic traffic zones in different mode (by bicycle, by vehicle or on foot). Then the so-called "four-steps" pattern was used to forecast the trip and goods volume in the planned years. As far as the trip volume forecast is concerned, the total trip volume and the volumes for different trip purposes were calculated according to the average trip volume per person and the future population. The generated and attracted trip volume were simulated by EVANS model, Tij=KiLjOiDjf(dij)
------------------(3) where Tij is the volume between the ith and jth traffic zones dij is the distance between the ith and jth traffic zones. Oi is the traffic volume generated by the ith traffic zone. Dj is the traffice volume attracted by the jth traffic zone: f(dij)=dij Then the traffic volume was classified into different mode (by bicycle, by vehicle or on foot), and the relevant traffic volume was assigned to the temporary road network using shortest path algorithm. Goods volume forecast was related to the non-agricultural, existing and planned urban landuse, category of enterprises etc. Similarly, the EVANS model was used for forecasting the generated and attracted goods volume of each traffic zone. The resulted traffic volume was assigned to the temporary road network. The diagnosis, evaluation and adjustment were then followed to optimize the road network and its relevant plan. An optimal equilibrium model was used for forecasting the industrial structure and industrial output values of Shashi in 1995, 2000 and 2010. The objective selected was to maximize the final social product and minimize the quantity of wasted water, gas and solid waste. Energy resources and raw materials. Labor resources etc were selected, after a detailed study, as the other constraints in the model. And the urban population production was carried out according to the discrete differential model. The integrated utilization of remote sensing and GIS technology in Shashi urban general planning made it possible to provide with urban authority and urban planners, in a rather short time more complete, accurate and reliable basic data and to perform more comprehensive and efficient quantitative analysis, simulation and optimization. Reference
|