The Kinta Valley is an area of karst in the north-western part of Peninsular Malaysia. Over 30 years of uncontrolled land use and development has led to significant changes in topography and geomorphology, such as the appearance of sinkholes. In this paper, geospatial techniques were utilized to the task of evaluating sinkholes susceptibility map using a spatial multi criteria evaluation approach (SMCE). Sinkhole location and a spatial database were applied to calculate eight inherent causative factors for limestone instability namely: lithology, structure (lineament), soil cover, slope, land use mining, urban area features, ponds and rivers. The preparation of the sinkhole geohazard map involved summing the weighted values for each hazard element, which permits the construction of geohazard model; the results of the analysis were validated using the previous actual sinkholes locations in the study area. The spatial distribution of sinkholes occurrence, urban development, faults distribution and ex-mining ponds are factors that are directly responsible for all sinkholes subsidence hazards. Further, the resulting geo-hazard map shows that 93% of recent sinkholes occur in areas where the model flags as "high" and "very high" potential hazard, located in the urbanized part of the valley, while less-developed areas to the west and southwest suffered less sinkhole development. The results can be used for hazard prevention and land-use planning.

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Limestone bedrock topography has complex phenomena and highly relief subsurface topography due to the presence of karstic features. Geotechnical and environmental problems arise whenever foundations are established on the surface of the limestone bedrock or within the overburden soils. Geographical information system (GIS) and remote sensing are emerging as powerful techniques widely applicable in natural resources management to detect land use changes and devise strategies based on these changes. The study focuses on using aerial photography for the detection of changes and effects of mining on geomorphology, especially the use of sequential images that allows to detect changes taken place from time to time, by using. Volumetric Surface Movement Spatiotemporal Data Model (VSMSDM) application has been employed to create karst terrain surface movements and visualized 3D information in the Virtual Geographical Information Systems (VGIS). VSMSDM application was implemented by developing prototype of visualization system using with integrated time in the TIN structure. The data have been collected from aerial photography in 1981 and 2004, and the results displayed that the proposed data model is able to view the changing in karst topography to detect significant landscapes and landforms changes.

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