Urban land-use planning using Geographical Information System and Analytical Hierarchy Process : case study Dhaka city

anglais. Urban land-use planning, which is a useful tool for the sustainable development of a city, is a complex decision making process. However, the modern GIS technologies facilitate such complex jobs in two ways – (i) GIS allows to work with large numbr of datasets, (ii) a number of methods, techniques or models could be embeded in GIS for land-use suitability analysis. Analytical Hierarchy Process (AHP), which is a kind of Multi-Criteria Decision Making (MCDM) technique, could be used for urban land-use planning with support of GIS technology. The aim of this thesis is preparing urban land-use planning using GIS and AHP, where the case study is Dhaka city. Dhaka, which is one of the fastest growing mega cities in the world and is the capital city of Bangladesh, is facing acute pressure of increasing population and unplanned urbanization, despite, a number of planning interventions have been taken for the planned development of the city. Recent Detail Area Planning (DAP) for Dhaka city was a cumbersome job but brought little benefits. DAP primarily prepared a land-use plan at city scale using GIS technology. Although huge resources and times were used to build the GIS database, it had promlems on (i) specifying data requirements, (ii) ensuring quality database (having topological rules, elimination of sliver polygons etc.) and (iii) using the database for spatial analysis in view to make better planning decision. In this connection, this thesis tried to conceptualize a model to build geographical database for urban land-use planning to address first two problems and applied GIS-based AHP technique for more sophisticated analysis (problem-iii). After literature review and selection of the study area (Group-E of DAP), the study set a number of criteria through sharing experts’ opinions. Based on those criteria the collected GIS data was transformed into the Geodatabase, where the geodatabase was conceptualized using Unified Modelling Language (UML). Five experts’ opinions were shared and further literature reviews were done for calculating Eigen Values using AHP methodological operations. The Eigen Values show the degree of priority of the criteria. Using Eigen Values, raster criterion maps were prepared from data available in the geodatabase. These criterion maps were overlaid to develop a composite map which was later classified to prepare suitability map. The research result shows that highly suitable area (13%) should be used for urban residential zone; moderately suitable area (35%) should be designated as mixed use zone; low suitable area (42%) should be reserved for agricultural use and open spaces; and not suitable area (10%) should be protected from any types of activities except agriculture. The research approached an urban land-use planning at a regional scale. The research results were also validated with Detail Area Plan of Dhaka Metropolitan Development Plan package in some order. Such validation concludes that Geographical Information System based Analytical Hierarchy Process can be applied successfully for preparing urban land-use planning at the regional level.

anglais. Dhaka, the capital city of Bangladesh, is one of the fastest growing mega cities in the world. The city is facing acute pressure of increasing population and unplanned urbanization. Since 1959 a number of planning mechanisms have been formulated to promote planned growth of the city. But the city never experienced planned development. Current state of city development is quite unsustainable in nature. Urban land-use planning is a useful mechanism for sustainable city development. At the same time, land-use planning is a complex decision making process as such planning approach encompasses a number of socio-economic, physical and environmental criteria. Modern Geographical Information System (GIS) technology is very much helpful to incorporate these criteria and allow improved decision making process to prepare sustainable planning. Different Multi-Criteria Decision Making Models (MCDM), like, Analytical Hierarchy Model (AHP), can be applied fruitfully with the support of GIS to ease the complex decision making process of spatial planning, e.g., land-use planning. So, the aim of the thesis is to prepare urban land-use planning using GIS and AHP in context of Dhaka city. The thesis used both primary and secondary data. Experts’ opinions were shared to select the criteria for land-use planning and to fix the level of preferences of each criterion. The objective of selecting criteria and their level of preferences were to identify the suitability of areas for residential, industrial, commercial development and for protecting agricultural land. In this purpose, AHP technique was used so that the criteria can be selected easily in hierarchy order, the preferences level can be fixed with consistency and finally, the suitability of land-use can be ranked using GIS. The ranking of suitability allow deciding which land is more suitable for which category of development or for which development control. The research result shows that – The Highly Suitable areas are featured by vacant land, high elevation, no earthquake risk, and well connected with utilities and community services. Hard urban development can be promoted in these areas. These areas should be used for urban residential areas to facilitate new housing development. Moderately Suitable areas are featured by rural homestead, vacant land, existing residential use, high elevation, minimum earthquake risk, close to market places and connected with utilities and community services. These areas have been proposed as mixed-use area. This mixed-use area has potentiality of housing, commercial and industrial development. Low Suitable areas are predominated by agricultural and low lying flood flow zones. These areas should be free from major development. The lands here are close to fault lines. So, the places are also prone to earthquake risk. Here development controlling mechanism is earnest necessary. Agricultural lands should be protected as Bangladesh is facing acute shortages of agricultural land. However, as these areas fall within the Greater Dhaka Metropolitan Area jurisdiction, so, some parcels of land in these areas could be used for sports grounds, parks and other recreational open spaces as a requirement of city’s civic amenities. The Not Suitable areas are featured by agricultural uses, restricted areas (e.g. military camp) and high earthquake risk. Any type of use other than agriculture should be protected in these areas.