Shankha Pratim Bhattacharya

Bio: Shankha Pratim Bhattacharya is an academic researcher from Indian Institute of Technology Kharagpur. The author has contributed to research in topics: Vulnerability assessment & Air quality index. The author has an hindex of 1, co-authored 6 publications receiving 5 citations.

The accessibility of urban neighborhoods when buildings collapse due to an earthquake

Abstract: Local or neighborhood roads form the bulk of urban road network and are responsible for the last mile connectivity. They are highly vulnerable to earthquake-like hazards, causing road closures of magnitude ranging from small traffic diversions to isolation of entire neighborhoods. Such disruptions impede the emergency response, and significantly affect the post-disaster recovery. Hence their design, construction, and maintenance are of utmost importance for efficient working of transportation systems. In this article, we study the accessibility of local roads based on intrinsic and extrinsic determinants of vulnerability with a focus on Indian cities. The methodology divides the road network into two components. The first one is the inaccessible stretch of the road network due to its width (Intrinsic Vulnerability), and the second one is the accessible stretch of the road network prone to road closures due to collapsed buildings (Extrinsic vulnerability). Then a three-step framework, namely road network inventory development, building vulnerability assessment, and road closure analysis, is proposed for vulnerability assessment. For this purpose, 77 km of road network and 612 buildings are studied in three selected wards of Siliguri Municipal Corporation (Seismic zone IV). A comparative analysis between the wards for the change in accessibility levels before and after an earthquake is done. The results are measures of inaccessibility in the road network, which are also visualized as isolated streets on the maps. The proposed framework aides an urban planner and an emergency manager to identify the vulnerable parts of road network and take necessary mitigative measures.

Rapid Visual Screening method for vertically irregular buildings based on Seismic Vulnerability Indicator

Abstract: Seismic vulnerability assessment of a large group of buildings can prove to be extremely difficult as it requires huge amount of time and resources. Rapid Visual Screening (RVS) alleviates this problem by classifying buildings into different classes of vulnerability thereby limiting the need for detailed analysis only to a few selected vulnerability classes. RVS survey of five G+1 houses were conducted using Arya et al. method, Sinha et al. method, Jain et al. method, FEMA Level 1 and FEMA Level 2 method. The lack of details regarding irregularities resulted in the same RVS score for buildings with significantly different configurations. This renders the RVS procedure difficult to be used for comparison. This paper provides a qualitative comparison of seismic vulnerability among vertically irregular buildings in terms of mass, geometric and stiffness irregularity through Rapid Visual Screening. 3D Response spectrum analysis of reinforced concrete buildings have been done using STAAD Pro software and Seismic Vulnerability Indicator (SVI) values are calculated for comparison of seismic vulnerabilities with respect to vertical irregularities. Mass irregularity near the mid height of building or stiffness irregularity below the mid height of building is found to be more critical among the possible locations of irregularity. Elevation asymmetry above mid height is found to decrease the seismic vulnerability of a building. Presence of stiffness irregularity is found to be significantly more critical than mass or geometric irregularity.

Analyzing the Impact of Temporal Landcover Changes on the Runoff Component of a Catchment Using Geospatial Techniques

Abstract: Globally, the issue of urbanization has been a matter of concern over the past few decades. Unplanned urban growth alters the natural drainage pattern and the water cycle, consequently, giving rise...

Sustainable cities and communities

Abstract: Today, more than half the world’s population live in cities. By 2030, it is projected that 6 in 10 people will be urban dwellers. Despite numerous planning challenges, cities offer more efficient economies of scale on many levels, including the provision of goods, services and transportation. With sound, risk-informed planning and management, cities can become incubators for innovation and growth and drivers of sustainable development.

A decomposition-based heuristic for a multicrew coordinated road restoration problem

Abstract: Natural disasters disrupt the connectivity of road networks by blocking road segments, which impedes efficient distribution of relief materials to the affected area. We study the problem of finding coordinated paths for clearing teams so that the connectivity of the road network is regained in the shortest time. We provide an efficient novel heuristic algorithm for this problem. In our algorithm, the problem is first pre-processed to define a binary problem to generate initial solutions, and then several rich and problem-specific neighborhood search moves are applied to improve the derived initial solutions. We provide several analytical results which facilitate the design of our algorithm. The performance of our proposed algorithm is assessed by different numerical experiments, and a comparison with existing algorithms from the literature using instances from Istanbul road networks. The results demonstrate that our algorithm performs notably better, both in terms of speed, and proximity to optimal solution.

A GIS-Based System for Spatial-Temporal Availability Evaluation of the Open Spaces Used as Emergency Shelters: The Case of Victoria, British Columbia, Canada

Abstract: Canadian emergency management planners have historically ignored the self-motivated evacuation procedures of people who cannot initially choose the safest evacuation areas In densely developed urban areas, open spaces can be seen as ideal evacuation areas and should thus be included in shelter planning In this study, the public open spaces in Great Victoria were selected as the study area and evaluated using GIS technologies A multi-criteria TOPSIS evaluation model was used to conduct comprehensive quantitative evaluations of the open spaces’ safety, accessibility, and availability Through hybrid process, service area, and POI aggregation coupling analyses, a model is created that provides an overall evaluation at the district level In addition to providing a model for evaluating open spaces as emergency shelters, applicable to most Canadian cities, this study emphasizes the importance and disadvantages of open space emergency shelters in Canada, which have heretofore been ignored by decision makers In Great Victoria, we found that the distribution of open spaces does not match the dynamics of the population distribution, meaning that through inadequate preparation some districts lack a safe evacuation place—this in an area where people are at high risk of earthquake disasters and their subsequent effects