An assessment of WRF-urban schemes in simulating local meteorology for heat stress analysis in a tropical sub-Saharan African city, Lagos, Nigeria.

Megacities, such as Lagos, Nigeria, face significant challenges due to rapid urbanization and climate change, resulting in a higher intensity of the urban heat island effect, coupled with high population density, making the city fall under the category of moderate to high heat stress/risk. Despite this, very few studies have analyzed the urban impact on heat stress over the coastal city, albeit with poor resolution data. In this study, we assessed the performance of an integrated high-resolution WRF-urban scheme driven by the readily available urban canopy information of the local climate zone (LCZ) to simulate local meteorological data for analyzing the spatiotemporal pattern of heat stress over the megacity. Our results show that the WRF-BEP scheme outperformed the other evaluated urban schemes, reducing the normalized root mean squared error by 25%. Furthermore, using humidex, we found a generally high incidence of intense discomfort in highly urbanized areas and noted the significant influence of urban morphology on the pattern of heat stress, particularly at night due to the combined effect of urban warming and higher relative humidity. The most socioeconomically disadvantaged urban areas, LCZ7, were most affected, with "hot" heat stress conditions observed over 90% of the time. However, during the afternoon, we found reduced heat stress in the core urban areas which might be due to the shading effect and/or cold air advection. Our findings would be relevant in the development of the urgently needed climate/heat adaptation plans for the city and other sub-Saharan African cities.

A health data led approach for assessing potential health benefits of green and blue spaces: Lessons from an Irish case study.

Research producing evidence-based information on the health benefits of green and blue spaces often has within its design, the potential for inherent or implicit bias which can unconsciously orient the outcomes of such studies towards preconceived hypothesis. Many studies are situated in proximity to specific or generic green and blue spaces (hence, constituting a green or blue space led approach), others are conducted due to availability of green and blue space data (hence, applying a green or blue space data led approach), while other studies are shaped by particular interests in the association of particular health conditions with presence of, or engagements with green or blue spaces (hence, adopting a health or health status led approach). In order to tackle this bias and develop a more objective research design for studying associations between human health outcomes and green and blue spaces, this paper discussed the features of a methodological framework suitable for that purpose after an initial, year-long, exploratory Irish study. The innovative approach explored by this study (i.e., the health-data led approach) first identifies sample sites with good and poor health outcomes from available health data (using data clustering techniques) before examining the potential role of the presence of, or engagement with green and blue spaces in creating such health outcomes. By doing so, we argue that some of the bias associated with the other three listed methods can be reduced and even eliminated. Finally, we infer that the principles and paradigm adopted by the health data led approach can be applicable and effective in analyzing other sustainability problems beyond associations between human health outcomes and green and blue spaces (e.g., health, energy, food, income, environment and climate inequality and justice etc.). The possibility of this is also discussed within this paper.

Combining expert and crowd-sourced training data to map urban form and functions for the continental US.

Although continental urban areas are relatively small, they are major drivers of environmental change at local, regional and global scales. Moreover, they are especially vulnerable to these changes owing to the concentration of population and their exposure to a range of hydro-meteorological hazards, emphasizing the need for spatially detailed information on urbanized landscapes. These data need to be consistent in content and scale and provide a holistic description of urban layouts to address different user needs. Here, we map the continental United States into Local Climate Zone (LCZ) types at a 100 m spatial resolution using expert and crowd-sourced information. There are 10 urban LCZ types, each associated with a set of relevant variables such that the map represents a valuable database of urban properties. These data are benchmarked against continental-wide existing and novel geographic databases on urban form. We anticipate the dataset provided here will be useful for researchers and practitioners to assess how the configuration, size, and shape of cities impact the important human and environmental outcomes.

Integrated urban hydrometeorological, climate and environmental services: Concept, methodology and key messages.

Integrated Urban hydrometeorological, climate and environmental Services (IUS) is a World Meteorological Organization (WMO) initiative to aid development of science-based services to support safe, healthy, resilient and climate friendly cities. Guidance for Integrated Urban Hydrometeorological, Climate and Environmental Services (Volume I) has been developed with the intent to provide an overview of the concept, methods and good practices for producing and providing these services to respond to urban hazards across a range of time scales (weather to climate). This involves combining (dense) heterogeneous observation networks, high-resolution forecasts, multi-hazard early warning systems and climate services to assist cities in setting and implementing mitigation and adaptation strategies for the management and building of resilient and sustainable cities. IUS includes research, evaluation and delivery with a wide participation from city governments, national hydrometeorological services, international organizations, universities, research institutions and private sector stakeholders. An overview of the IUS concept with key messages, examples of good practice and recommendations are provided. The research community will play an important role to: identify critical research challenges; develop impact forecasts and warnings; promote and deliver IUS internationally, and; support national and local communities in the implementation of IUS thereby contributing to the United Nations' Sustainable Development Goals at all scales.

Mapping Europe into local climate zones.

Cities are major drivers of environmental change at all scales and are especially at risk from the ensuing effects, which include poor air quality, flooding and heat waves. Typically, these issues are studied on a city-by-city basis owing to the spatial complexity of built landscapes, local topography and emission patterns. However, to ensure knowledge sharing and to integrate local-scale processes with regional and global scale modelling initiatives, there is a pressing need for a world-wide database on cities that is suited for environmental studies. In this paper we present a European database that has a particular focus on characterising urbanised landscapes. It has been derived using tools and techniques developed as part of the World Urban Database and Access Portal Tools (WUDAPT) project, which has the goal of acquiring and disseminating climate-relevant information on cities worldwide. The European map is the first major step toward creating a global database on cities that can be integrated with existing topographic and natural land-cover databases to support modelling initiatives.

An inventory of trees in Dublin city centre.

While urban areas are often considered to be comprised chiefly of artificial surfaces, they can contain a substantial portion of green space and a great diversity of natural habitats. These spaces include public parks, private gardens and street trees, all of which can provide valuable environmental services, such as improved air quality. Trees play a particular role in cities as they are often placed along roadsides and in the median strip of busy streets. As such they regulate access to sunshine, restrict airflow, provide shelter, scavenge air pollutants and manage noise at the street level. A tree planting policy can be an important part of a broader environmental strategy aimed at improving the quality of life in urban areas but this requires up-to-date knowledge of the current tree stock, which does not exist for Dublin. This article presents an inventory of trees in Dublin's city centre, defined as the area between the Grand and Royal canals. The results show that there are over 10,000 trees in the study area representing a density of 684 trees km-2 or one tree to approximately every 50 residents of the city centre. The tree canopy extent when in full foliage was nearly 1 km2 in extent or 6% of the study area. A more detailed analysis of those trees planted along streets shows little species variation but clear distinction in the sizes of trees, which is indicative of the age of planting. These data are used to estimate the carbon stored in Dublin's trees.