Search

The importance in studying issues like heat waves, urban heat islands, and polluted air, is on the rise in the perspective of global warming. One effective method to mitigate the hot climate in urban areas is by harnessing the cooling effect of rivers. This study aims to examine the impact of the Krishna River on its surrounding urban environment by utilizing geospatial techniques in identifying and analysing the surface temperature and urban morphology data. Additionally, it seeks to explore the potential of rivers in cooling urban areas using linear regression models. The findings of this study indicate the following key points. Initially, it is noteworthy that aqueous entities possess a cooling impact on the adjacent environment. The maximum range of this cooling influence is observable at 2,000 m, while the most favourable distance is at 1200–1400 m. Since the stretch of the river in the study area was divided with a barrage as upstream and downstream, the river cooling effect is clear in the upstream side as it contains water when compared to the downstream side with dry sand. The findings indicate a correlation between elevation in the Normalised Difference Vegetation Index and a reduction in Land Surface Temperature (LST), as evidenced by negative correlation. Moreover, an elevation in the Built-Up Index results in reduction in Land Surface Temperature (LST) values. With regards to the Sky View Factor, it is generally observed that higher values are associated with elevated Land Surface Temperature (LST), except in regions where air circulation is enhanced, leading to a reduction in temperatures. The results give the view over possibility of measures that can be itaken to sustain the urban environment and reduce the impact of the heat island effect. Examples include increasing the amount of urban vegetation and reducing the density of buildings. The findings of this study provide important empirical facts and instructive examples to support the efforts of urban planning and development organizations in improving the urban environment and creating sustainable urban habitats.

Floods are a natural calamity that causes loss of human life and destruction of property. They are caused by riverine, coastal and storm surges, cyclones, and tsunami waves. The primary causes of urban floods are an unusual rise in quantum of rainfall, extreme man-made changes in land-use–land-cover patterns, and consequent detrimental hydrological impacts. There are different methods available for flood estimation like rational formulae and empirical methods for approximate estimation of flood peak discharge, but they cannot be applied widely, and their application is confined to a particular region. The current study first discusses the causes of urban floods and then assesses the appropriate flood modeling methods that can be effectively used for urban catchments. Flood modeling methods deployed internationally and nationally in major- and medium-sized cities are discussed, and the research gap is identified. The advantages and demerits of each method are analyzed, and the parameters involved are also identified. An integrated modeling approach is chosen for this case study. In India, only coastal megacities have been considered for flood modeling studies thus far. There have been no research studies conducted on medium-sized urban catchment areas using an integrated modeling approach. Therefore, the present article reviews all the features of a novel integrated flood modeling approach which can be adopted for a medium-sized dendritic pattern ungauged urban catchment area.