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GIS as tools for monitoring the urban development in metropolitan region: A case of Llang Valley Region, Peninsular Malaysia 3.0 Generating Development Scenarios In the planning evaluation process, it is important to have several alternatives, in which various factors such as the cost-benefit and the socio-economic characteristics have to be taken into account (Yaakup, 1991). In the past, the number of alternative planning scenarios was rather limited due to the difficulties in producing them. This is mainly due to the time consuming procedures of creating scenarios as well as the evaluation that follows. Policy-makers, like most decision-makers, face the difficult task of evaluating and examining the impact of various resource allocations. In the past, the evaluation process appeared to be quite static and limited. Having prepared the evaluation model, the operation can be accomplished within a much shorter time frame by computer processing of the data and computer mapping of the results. Despite the proliferation of advanced equipment and software in GIS technology, there are still many constraints on the use of GIS in urban and regional planning, which limit their effective application. As pointed out by Scholten and Padding (1990), GIS systems are not advanced enough for mainstream urban policy making because of the rather limited possibilities for analysis built into them and are also rarely user-friendly. As such, they could be positively terrifying for ordinary citizens who would like to use data they contain in making informed responses to government policies. A filter between their professional use and their use as public information system is clearly required. Hence, there is a need to integrate existing analytical techniques and GIS packages by adding modeling software directly into such GIS software or developing easy to use interfaces with already developed planning models (Openshaws, 1987; Worral, 1989; Harris, 1990; Brail, 1990). The Use of What-If? Planning Support System ‘What if?’ is a planning support system which incorporates procedures for conducting land suitability analysis, projecting future land use demands, and allocating the projected demands to the most suitable locations. The use of What if? is found to be relatively easy as it requires only a minimum set of data apart from a simple data structure to enable the programme to react with the GIS. It is specifically designed to provide an easy and rational model for urban development process. Generally, it projects future land use patterns by balancing the supply of, and demand for, land suitable for different uses at different locations. Alternative visions for an area’s future can be explored by defining alternative suitability, growth and allocation scenarios. For instance, a “Trend” scenario could determine the effects of continuing current development policies, an “Environmental Protection” scenario might consider the impact of policies that severely limit growth in scenic areas and on land that is most suitable for agricultural uses, and a “Build out” scenario would reveal the implications of allowing growth to continue until it reached permitted density levels for all developable parcels in the study area. The system allows users to create alternative development scenarios and determine the likely impacts of alternate public policy choices on future land use patterns and associated population and employment trends. As stressed by Klosterman (2001), the What if? planning support system however, does not attempt to predict future conditions exactly. Instead, it is an explicitly policy-oriented planning tool that can be used to determine ‘what would happen if’ clearly defined policy choices are made and assumptions concerning the future prove to be correct. It dose this by explicitly identifying alternative policy choices, allowing users to choose between these alternatives and determine their likely effects on the area being studied. Through preparation of a range of alternative scenario-based forecasts, a range of potential futures can in turn be revealed instead of adopting the unrealistic goal of producing a single “exact” prediction of the future due to the limitations of planners’ knowledge, information and resources. Policy choices that can be considered in the model include the staged expansion of public infrastructure and the implementation of land use plans or zoning ordinances, while assumptions for the future that can be considered include future population and employment trends, assumed household characteristics, and anticipated development densities. Integrated Land Use Assessment The dynamic nature of planning and monitoring of development in Klang Valley region needs for a continuous evaluation and analysis of the current environment as well as the carrying capacity for future development. Planners should be able to identify and make adjustments to deriving factors as well as evaluation criteria to develop scenarios for generating alternatives to support the decision makers. The choice of deriving factors should include land resources such as agricultural land suitability, suitability for land development and environmental sensitive areas as well as land capacity to cater for development such as the terrain map and public amenities, utilities and infrastructure based on availability of land for development. Figure 6 shows the model developed and implemented for integrated land use assessment of Klang Valley. The model was first applied for the district of Gombak to evaluate the result. Data on Gombak (a district on the northern part of Klang Valley) was interrogated to generate alternative planning scenarios of ‘potential areas for development’ as well as ‘areas for conservation’. Gombak is 72688.16 hectares in area, of which half its land use is considered ecological, and some parts has not been fully developed. For generating the scenarios, the GIS layers involved were identified to include the current land use, suitability factors, land use control, infrastructure allocation control, growth trend and administrative boundary, as well as other related information. Apart from that, the suitability factors and scores, factor weights, factor types and ratings as well as land use conversion were earlier defined for the suitability analysis. Figure 7 illustrates the four alternative scenarios derived from the analysis of potential areas for development based on categories of suitability.  Figure 6: Model for Integrated Land Use Assessment of Klang Valley Region |