Urban imperviousness effects on summer surface temperatures nearby residential buildings in different urban zones of Parma

Rapid and unplanned urban growth is responsible for the continuous conversion of green or generally natural spaces into artificial surfaces. The high degree of imperviousness modifies the urban microclimate and no studies have quantified its influence on the surface temperature (ST) nearby residential building. This topic represents the aim of this study carried out during summer in different urban zones (densely urbanized or park/rural areas) of Parma (Northern Italy). Daytime and nighttime ASTER images, the local urban cartography and the Italian imperviousness databases were used. A reproducible/replicable framework was implemented named "Building Thermal Functional Area" (BTFA) useful to lead building-proxy thermal analyses by using remote sensing data. For each residential building (n = 8898), the BTFA was assessed and the correspondent ASTER-LST value (ST_BTFA) and the imperviousness density were calculated. Both daytime and nighttime ST_BTFA significantly (p < 0.001) increased when high levels of imperviousness density surrounded the residential buildings. These relationships were mostly consistent during daytime and in densely urbanized areas. ST_BTFA differences between urban and park/rural areas were higher during nighttime (above 1 °C) than daytime (about 0.5 °C). These results could help to identify "urban thermal Hot-Spots" that would benefit most from mitigation actions

Interaction of urban heating and local winds during the calm intermonsoon seasons in the tropics.

Rapid urbanization of cities has greatly modified the thermal and dynamic profile in the urban boundary layer. This paper attempts to study the interaction of urban heating and the local topographic-induced flow circulation for a tropical coastal city, Greater Kuala Lumpur, in Malaysia. The role of sea-and-valley-breeze-orientated synoptic flow (SBOS) on the interaction is determined by comparing two intermonsoon periods. A state-of-the-art numerical model, Advanced Research Weather Research and Forecasting model, is used to identify the influence of urbanization through modification of urban surfaces. The model reasonably reproduces the vertical sounding data and near-surface weather parameters. The diurnal urban heating pattern is attributed to three predominant factors: (i) weak under calm and clear-sky condition (morning heating), (ii) weak under larger atmospheric moisture content (late afternoon convection), and (iii) largest (1.4°C) due to differential cooling rate of urban and rural surface at night. The interaction of urban thermals and upper level SBOS affects the effect of urbanization on local circulation during the day. The urban thermals reduce the weak opposing SBOS (2 m s−1) suppresses the vertical lifting of urban thermals and decelerates the sea breeze front. It is discovered that the interaction of urban heating and topographic-induced flow is interdependent while the synoptic flow plays a critical role in modifying both factors, respectively

Planning For The Future: Framework Towards Achieving Co-benefits Through Beneficial Management Practices In The Credit Valley Watershed, Ontario

As the population increases, development pressures, especially in large urban centers, have created a lot of stress on ecosystems, and the ecosystem functions and services that they provide. Issues such as loss of wetland and paving over pervious surfaces has led to increased runoff, low infiltration rates and degradation of the quality of source and non-point source water. Roads, parking lots and other forms of impervious cover are the most significant contributors to stormwater runoff. Effective stormwater management is therefore crucial in such urbanized areas. Low Impact Development (LID) is an innovative stormwater management design philosophy and approach that is closely modeled after nature. Its main goal is to manage rainfall at the source using uniformly distributed, decentralized units such as permeable pavement, bioswales and green roofs. . The principle of LID is to mimic a site's pre-development hydrology by using design techniques that infiltrate, filter, store, evaporate and detain runoff close to the source. The term 'Green Infrastructure' is also used when referring to LID. LID can be used individually or incorporated into conventional stormwater management systems to achieve maximum benefits. Human health and well-being are fundamentally dependent on the services provided by the ecosystems that surround us. The field of ecohealth attempts to make this connection and use it to improve public health, promote resilient communities, and create more sustainable environments. This paper attempts to analyze the connections between three selected Low Impact Development and its effects on the ecosystem services that ultimately affect the health and wellbeing of humans in the Credit River watershed in Southern Ontario, Canada. Ecohealth theories developed by the Millennium Ecosystem Assessment (MEA) (2005; 2003) and the cascade model of ecosystem services (Haines-Young & Potschin, 2010; Braat & de Groot, 2012; Potschin & Haines-Young, 2010) were used to help develop and illustrate the concepts and relationships being researched

Diurnal variation of amplified canopy urban heat island in Beijing megacity during heat wave periods: Roles of mountain-valley circulation and urban morphology

In the context of global warming and rapid urbanization, heat waves (HW) are becoming more frequent, which is amplifying canopy urban heat island (CUHI) via various driving mechanisms. While the roles of local circulation and urban morphology remain unclear in the synergistic interaction between HW and CUHI. By utilizing the data from high-density automatic weather stations in the Beijing megacity, this article explored spatiotemporal patterns of the interactions between HW and CUHI. The average daily CUHII during HW periods exhibited a significant increase of 59.33 % compared to the non-heat wave (NHW) periods. Mountain-valley breeze significantly modulated the spatiotemporal patterns of CUHI intensity (CUHII). In particular, on an urban scale, the turning mountain-valley breeze caused horizontal transport of heat inner-city, resulting in the north-south asymmetric pattern of urban excess warming during HW periods. On a street scale, the amplified CHUII was closely associated with urban morphology in the inner city, especially for the vertical characteristics of buildings. During the mountain breeze phase, the amplification of CUHII in the high-rise street zone was significantly stronger than that in the low-rise street zone. During the valley breeze phase, the amplification of CUHII in high-rise street zones exhibits weaker effects in the afternoon compared to the low-rise street areas, while demonstrating stronger amplification during the nighttime. Our findings provide scientific insight to understand the driving mechanisms of urban excess warming and mitigating the escalating risks associated with extreme high-temperature events over megacities in the transitional zone of mountains and plains

Land cover impacts towards thermal variation in the Kuala Lumpur City.

Physical geography and urban characteristics influence the urban climate conditions. Built-up areas, green urban parks, forest reserves, streets and terrain constitute the climatic interactions within urban areas. These have led to the variation of the urban climate condition throughout the world. Thus, in studying urban climate, the impacts of these factors are crucial to be examined. This study aims to examine the effects of six important factors, namely built-up areas, green covers, terrain elevation, building volume, surface roughness and land use type, which contribute to the variation of the urban climate condition within the Kuala Lumpur City. In this study, the effects of the six factors (urban parameters) towards the air surface temperature variation were statistically tested. Using the Weather Research and Forecasting (WRF) model and the remote sensing technique, the data needed for the analyses were extracted. The Geographical Information System (GIS) was employed as the analysis platform during the study. Based on the Spearman’s rho and Mann-Whitney U tests, it was identified that the six urban parameters and the air surface temperature variation are correlated. The further investigation conducted using the Kruskall-Wallis test has identified that only five of the urban parameters showed significant effects toward the air surface temperature variation, which are built-up areas, green covers, terrain elevation, building volume and surface roughness while the land use type was excluded. The findings of this study are very crucial as a pioneer research to integrate the urban climatic information in the urban planning decision making in tropical cities like Kuala Lumpur

Numerical study of the interaction between oasis and urban areas within an arid mountains-desert system in Xinjiang, China

The rapid oasis expansion and urbanization that occurred in Xinjiang province (China) in the last decades have greatly modified the land surface energy balance and influenced the local circulation under the arid mountains-plain background system. In this study, we first evaluated the ALARO regional climate model coupled to the land surface scheme SURFEX at 4 km resolution using 53 national climatological stations and 5 automatic weather stations. We found that the model correctly simulates daily and hourly variation of 2 m temperature and relative humidity. A 4-day clear sky period has been chosen to study both local atmospheric circulations and their mutual interaction. Observations and simulations both show that a low-level divergence over oasis appears between 19:00 and 21:00 Beijing Time when the background mountain-plain wind system is weak. The model simulates a synergistic interaction between the oasis-desert breeze and urban-rural breeze from 16:00 until 22:00 with a maximum effect at 20:00 when the downdraft over oasis (updraft over urban) areas increases by 0.8 (0.4) Pa/s. The results show that the oasis expansion decreases the nocturnal urban heat island in the city of Urumqi by 0.8 degrees C, while the impact of urban expansion on the oasis cold island is negligible

Monitoring the effects of vegetation cover losses on land surface temperature dynamics using geospatial approach in Rajshahi City, Bangladesh

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Characterization of the UHI in Zaragoza (Spain) using a quality-controlled hourly sensor-based urban climate network

The study of the urban heat island (UHI) is of great importance in the context of climate change, where increasingly frequent and intense extreme thermal events will generate lethal effects in cities. In this work, we characterize the UHI of the urban area of Zaragoza (Spain) using a thermohygrometric network of hourly observatories composed of 21 sensors, from March 2015 to February 2021. Due to the diversity of urban spaces and the high volume of information (˜ 995, 000 observations), we performed an exhaustive quality control. Incorporating a synoptic analysis to better identify atmospheric situations not recorded by sensors. The results indicate that 1.6% of observations are removed, mainly due to outliers and hourly variability. We demonstrate that the UHI displays the classical center-periphery pattern with intensity values around 2 °C, but with variations due to the urban structure. We also observe seasonal UHI variations that intensify, especially in winter and autumn nights. Finally, this characterization confirms the differences in UHI intensity are due to their structural and climatic characteristics, which can ultimately guide the logical urban planning design of Zaragoza, and other Mediterranean-like cities with a similar urban environment

Impacts of Land Cover Change on Urban Heat Island (UHI) in Denver from 1985 to 2020

Rapid urbanization due to land use and land cover change has become one of the major problems in the fastest-growing cities during the past few decades. Land surface temperature has changed dramatically due to urban expansion, and it is a major driver of urban eco-environmental change. Increasing temperature leads to the Urban Heat Island (UHI) problem in rapidly growing cities like Denver, contributing to global warming at multiple scales. UHI study is significant to monitor and mitigate the urban heat islandrelated problem in the study area Denver. Satellite remote sensing analysis ready data (ARD) with 30 m resolution based on Landsat 4,5,7 and 8 were acquired for nine dates that correspond to summer, fall, and winter seasons in 1985, 2000, and 2020. Land cover change dynamics were derived using Land Change Monitoring Assessment and Projection (LCMAP) developed land cover classes, and land surface temperature (LST) has been extracted from seasonal and annual surface temperature data. Land cover data analysis observed changes within seven primary land cover classes; for instance, study area has gained 13% of developed land cover but lost a significant percentage of cropland from 1985 to 2020. The relationship between land cover and surface temperature has been explored by linear regression analysis using normalized difference vegetation index (NDVI) and LST. NDVI was taken as the explanatory variable, and LST was taken as a dependent variable to show the correlation between land cover and LST. Investigation of the correlation between NDVI and LST found that seasonal variability, spatiotemporal variations, and other underlying factors affect their relationship. Seasonal and annual Urban Heat Island intensity (UHII) distribution and variation have been investigated. The results found that the mean annual UHII in 2020 was 1°C which was greater than the mean UHII in 1985 and 2000. The UHII distribution was consistent in the central part of the city, and the scattered distribution of UHII was examined in non-urban extent over the past three decades. The methodology of this study can be a framework for future research on cities with a similar climate to Denver, and this can also help for sustainable urban planning and a better ecological environment