Investigating the potential of integrated urban greening strategies for reducing outdoor thermal stresses: a case of asymmetrical configuration in the tropical city of Bhopal.

In Indian cities where streets are the only affordable outdoor public space, pedestrians are always exposed to extreme heat related health risk. However, it's a challenge to reduce heat stress in existing streets characterized by asymmetrical urban configuration. Integrating vegetation without reconstituting the original orientation and geometry is one of the feasible ways to alleviate stress. Therefore, current study focuses to analyse the heat stress reduction potential of urban greenery strategy in asymmetrical urban configuration from spatiotemporal perspective. It initiates with the selection of commercial streets in extreme hot climate with an on-site measurement of its climatic and morphological attributes. Furthermore, it leads to the classification and prioritizing of street's sections linked to hot-spots determined by varied sky view factor and asymmetrical aspect ratio. Finally, an Envi-Met model with iterated scenarios at the building and street levels is developed, incorporating three strategies (trees, grass, green-walls). The impact of heat related health risk is quantified using a thermal index Universal Thermal Climate Index along with air temperature and mean radiant temperature. The results suggested that due to asymmetricity a fixed strategy would not be applicable across the street. The highest reduction was observed by trees in asymmetrical sections while lowest was recorded by green-wall. However, it would be worthwhile to adopt green-wall along with dense tree's (leaf area density, 0.3) in order to reduce the heat stress in deeper sections. The evidence-based integration of Urban greenery can assist planners and designers in mitigating extreme heat stress in similar complex urban environment.

Nature-Based Resilience: Experiences of Five Cities from South Asia.

As in many other parts of the world, the urban areas of the South Asian region are increasingly expanding. While cities today are the heart of commercial, technological and social development, they are also vulnerable to a variety of natural and anthropogenic threats. The complex urban infrastructure, and the ever-expanding population in cities, exacerbate the impacts of climate change and increase the risk of natural hazards. Throughout history, various hydrological disasters including floods, tidal surges, and droughts, and non-hydrological disasters such as earthquakes, landslides, and storms have led to catastrophic social, economic and environmental impacts in numerous South Asian cities. Disaster risk reduction is therefore central to ensure sustainability in urban areas. Although Nature-based Solutions (NbS) are identified as a promising strategy to reduce risk and increase resilience, there appears to be a lack of evidence-based approaches. NbS are measures that can be practiced to obtain benefits of nature for the environmental and community development through conserving, managing, and restoring ecosystems. Against this backdrop, the South Asian cities provide opportunities to evaluate capacities for achieving Nature-based Resilience (NbR) through NbS. This study documents insights from five cities of five different countries of the South Asian region which are subjected to a wide array of disasters: Barishal (Bangladesh), Phuentsholing (Bhutan), Gurugram (India), Kathmandu (Nepal), and Colombo (Sri Lanka). The primary objective of this study is to provide evidence on how NbS are being practiced. Thus, some success stories in cities under consideration are highlighted: restoration of natural canals through integrated development plans and community participation (Barishal), concepts of Gross National Happiness (GNH) and minimal nature interventions (Phuentsholing), "Greening cities'' including eco-corridors, vegetation belts, biodiversity parks (Gurugram), proper land use planning aims at different disasters (Kathmandu), and wetland restoration and management with multiple benefits (Colombo). These cases could therefore, act as a "proxy" for learning from each other to prepare for and recover from future disasters while building NbR.

Impact of ganga canal on thermal comfort in the city of Roorkee, India.

The rise in urban air temperature has forced the researchers to look for nature-based solutions to resolve the problem sustainably. Urban waterbody plays a multidimensional role in the well-being of the city by catering to its economical, ecological, and socio-cultural needs. It can offer a potential solution for urban heat attenuation, but its effect on outdoor thermal comfort is contentious in humid subtropical climate. This study investigates the thermal impact of waterbody on its surroundings in humid subtropical climate by adopting a human centric approach. Waterbody impact on ambient air temperature, PET, and UTCI are evaluated and compared for a better understanding of its thermal impact on nearby surroundings. This study employs a CFD-based simulation model Envi-met for microclimate analysis. The results show that a dynamic waterbody lowers the ambient air temperature during daytime in summer of its nearby surroundings in humid subtropical climate. Maximum cooling is observed in open mid-rise LCZ where the cooling impact range is 140 m with the amplitude of 2.59 °C and compact low-rise LCZ exhibits minimum cooling of the identified LCZs with the cooling impact ending 24 m from waterbody edge with amplitude being 0.131 °C in the study area. Air temperature, UTCI, and PET do reflect the same trend when moving away from the waterbody in large low-rise LCZ, but it decreases drastically in open mid-rise LCZ and is non-existent in compact low-rise. This result provides an insight on the impact of waterbody on thermal comfort in its surroundings in humid subtropical climate, thus assisting urban planners and designers in making context-specific holistic decision.

Ecosystem-centric business continuity planning (eco-centric BCP): A post COVID19 new normal.

This article views the COVID-19 pandemic as an opportunity leading to a significant reduction in pollution levels, clean waters in rivers, improved visibility, and other tangible benefit to humanity and the environment. In Post-COVID scenario, to restore the margins and regain the lost production, industries are likely to increase their production leading to a quantum jump in the pollution levels. Having precedence of such a scenario in 2008-09, this article looks at what are the possible avenues to engage the city government and business houses through an a new normal ECO-BCP concept for long term sustainability. All economic stimulus needs to be tied down with the stringent reduction in the emission norms. The Ten Principles for the Eco-centric BCP guide the reopening of MSMEs after lockdown period called to check the spread of the COVID-19 pandemic. The Eco-centric BCP model will help the MSMEs to adopt the new-normal business strategies to align with the country-specific commitments to SDGs, SFDRR and Paris declaration.