Land suitability assessment for urban built-up development of a city in the Eastern Himalayan foothills: a study towards urban sustainability

In order to achieve the socio-environmental sustainability, it is important to identify the suitable zone for urban built-up land (UBL) development. Hence, this study has elucidated the most suitable sites for sustainable urban growth in Siliguri Municipal Corporation (SMC) area based on ten most significant influential factors and their subcriteria. Different geophysical data, official data, and open street data were used to assess the land suitability for future urban growth by integrating multi-criteria decision-making (MCDM) techniques and different geo-statistical models, namely multi-influence factor, frequency ratio, weights of evidence, and evidential believe function. Based on the land suitability assessment (LSA) outcomes, four different zones were identified such as zone of very high suitability zone, high suitability zone, moderately suitable zone, and low suitable zone. The findings of this study revealed that the 1/3rd of the area in SMC, especially in the central-western part has observed as low suitability for sustainable urban development, whereas moderately suitable areas (32-36%) are composed of well-connected regions and 13-24% area has been noticed as the high to very high suitable zone for sustainable urban development. The outcome of the selected models has been validated (> 80%) by the receiver operating characteristics (ROC) curve after checking multi-collinearity and variance inflation factors (VIF). Still, the northernmost and eastern parts of the SMC region have a high proportionality of new residential and built-up area sites that can be utilised as second-degree suitable land for future sustainable urban development. Consequently, the identification of proper site suitability will be helpful for urban planner to reshaping the urban landscape as sustainable urban future.