Urban Change Research Articles

Numerical simulation study on the effect of underground drainage pipe network in typical urban flood

Rapid urbanization and climate change have heightened urban flood risks. An in-depth examination of the underground drainage pipe network’s effect on urban flood inundation can enhance urban stormwater management and mitigate disaster risks. This study presents a full hydrodynamic urban flood model (FHUM) coupling the pipe transport module of the Storm Water Management Model (SWMM) with a shallow water model. Based on unstructured grid cells, runoff yield and confluence calculations are carried out to effectively separate the underground drainage pipe network from other factors. The model is applied to Minzhi Area and Haidian Island to quantitatively assess the influence of the underground drainage system on urban flooding. Results indicate that FHUM performs well, accurately reflecting the process from rainfall to inundation. The underground drainage pipe network reduces surface inundation in the study area and improves the city’s stormwater drainage capacity. With increasing rainstorm intensity, the impact of the pipe network does not exhibit a consistent trend. During heavy rainstorms, the pipe network consistently plays a significant and stable role, particularly in reducing high inundation depths. However, attention should be paid to the potential flood risk transfer associated with using pipe networks in urban flood management. This work provides a scientific basis for urban stormwater management, holding significant importance in improving flood control and disaster reduction capabilities.

Measuring Urban and Landscape Change Due to Sea Level Rise: Case Studies in Southeastern USA

As a consequence of global climate change, sea level rise (SLR) presents notable risks to both urban and natural areas located near coastlines. For developing effective strategies to mitigate and adapt to these risks, it is essential to evaluate the potential impacts of SLR in coastal areas. While substantial research has been conducted on mapping the broad-scale impacts of SLR based on scenarios of Global Mean Sea Level (GMSL), consideration of regional scenarios, systematic classification, and distinct stages of SLR have been largely overlooked. This gap is significant because SLR impacts vary by region and by the level of SLR, so adaptations, planning, and decision-making must be adapted to local conditions. This paper aims to precisely identify the landscape and urban morphology changes caused by the impact of SLR for each foot of elevation increase based on remote sensing technologies, focusing on St. Johns County, Florida, and Chatham County, Georgia. These two counties are both situated along the southeastern coastline of the United States but with completely different urban forms due to distinct historical and cultural developments. Regional forecasting SLR scenarios covering the period from 2020 to 2100 were utilized to assess the landscape transformation and urban changes, incorporating selected landscape and urban metrics to calculate quantitative data for facilitating comparative analyses. This study investigated gradual alterations in urban morphology and green infrastructure both individually and in combination with the effect on wetlands due to SLR. The mapping outcomes of this research were generated by employing comprehensive remote sensing data. The findings of this research indicated that, when the sea level rose to 3 feet, the wetlands would experience notable alterations, and the level of fragmentation in urban built areas would progressively increase, causing most of the metric data to exhibit a pronounced decline or increase.

A Trial of Urban Area Change Detection by Open Satellite Data Platform

A Trial of Urban Area Change Detection by Open Satellite Data Platform

Landscape and meteorological variables associated with Aedes aegypti and Aedes albopictus mosquito infestation in two southeastern USA coastal cities.

Aedes transmitted arboviral human cases are increasing worldwide and spreading to new areas of the United States of America (USA). These diseases continue to re-emerge likely due to changes in vector ecology, urbanization, human migration, and larger range of climatic suitability. Recent shifts in landscape and weather variables are predicted to impact the habitat patterns of urban mosquitoes such as Aedes aegypti and Aedes albopictus. Miami (FL) is in the tropical zone and an established hotspot for arboviruses, while Charleston (SC) is in the humid subtropical zone and newly vulnerable. Although these coastal cities have distinct climates, both have hot summers. To understand mosquito infestation in both cities and potentiate our surveillance effort, we performed egg collections in the warmest season. We applied remote sensing with land-use cover and weather variation to identify mosquito infestation patterns. Our study found predominant occurrence of Ae. aegypti and, to a lesser extent, Ae. albopictus in both cities. We detected statistically significant positive and negative associations between entomological indicators and most weather variables in combined data from both cities. For all entomological indices, weekly wind speed and relative humidity were significantly positively associated, while precipitation and maximum temperature were significantly negatively associated. Aedes egg abundance was significantly positively associated with open land in Charleston but was negatively associated with vegetation cover in combined data. There is a clear need for further observational studies to determine the impact of climate change on Ae. aegypti and Ae. albopictus infestation in the Southeastern region of the USA.

Environmental pollution effect on honey bees and their derived products: a comprehensive analysis

AbstractSeveral factors, including environmental degradation, air pollution, intense urbanization, excessive agriculture, and climate change, endanger the well-being of animals and plants. One of the major issues with an increasingly negative impact is agricultural contamination with pesticides and antibiotics. Seed coatings with neonicotinoid insecticides used as a protective layer against pests are shown to exceed the permissible limits in most cases. Neonicotinoid compounds bind to nicotinic acetylcholine receptors, therefore affecting the honey bees’ brain. Heavy metals in higher concentrations are lethal for honey bees, and the residue in bee products might pose a threat to human health. Highly effective acaricides used to treat Varroa destructor infestations in honey bee colonies have negative effects on honey bee reproduction, olfaction, and honey production. Furthermore, amitraz and fluvalinate are mostly found in the highest amounts and lead to decreased honey production and reduced colony reproduction, along with decreased learning ability and memory. However, scientific studies have shown that honey bees act as a reliable bio-indicator of environmental pollution. In response to the growing demand for bee products, the effects of adulteration and improper storage conditions have gotten worse and represent a new risk factor. In light of the shifting global economy, it is important to analyze consumer expectations and adjust manufacturing accordingly. By ensuring the manufacture of high-quality, traceable products devoid of drug residues, consumers will be better protected from subsequent health problems. This review’s objectives are based on the necessity of identifying the risks associated with honey bees and bee products. Graphical abstract

Seasonal mosquito (Diptera: Culicidae) dynamics and the influence of environmental variables in a land use gradient from Yucatan, Mexico

Mosquito-borne diseases constitute a significant global impact on public and animal health. Climatic variables are recognized as major drivers in the mosquitoes’ life history, principally rainfall and temperature, which directly influence mosquito abundance. Likewise, urbanization changes environmental conditions, and understanding how environmental variables and urbanization influence mosquito dynamics is crucial for the integrated management of mosquito-borne diseases, especially in the context of climate change. In this study, our aim was to observe the effect of temperature, rainfall, and the percentage of impervious surface on the abundance of mosquito species over a temporal scale of one complete year of fortnightly samplings, spanning from June 2021 to June 2022 in Yucatan, Mexico. We selected nine localities along an urbanization gradient (three natural, three rural, and three urban) from Mérida City to Reserva de la Biosfera Ría Celestún. Using BG-traps, mosquitoes were collected biweekly at each locality. Additionally, we estimated the percentage of impervious surface. Daily data of the maximum, mean and minimum temperatures, diurnal temperature range and rainfall were accumulated weekly. We calculated the accumulated quantities of temperatures and rainfall and lagged from one to four weeks before sampling for each locality. Generalized linear mixed models were then performed to study the influence of environmental variables and percentage of impervious surfaces on each of the 15 most abundant species. A total of 131,525 mosquitoes belonging to 11 genera and 49 species were sampled with BG-Sentinel traps baited with BG-lure and dry ice. The most frequently significative variable is the accumulated precipitation four weeks before the sampling. We observed a positive relationship between Cx. quinquefasciatus and Cx. thriambus with the diurnal temperature range. For Ae. aegypti, we observed a positive relationship with minimum temperature. Conversely, the percentage of impervious surface serves as a proxy of anthropogenic influence and helped us to distinguishing species exhibiting habitat preference for urban and rural environments, versus those preferring natural habitats. Our results characterize the species-specific effects of environmental variables (temperature, rainfall and impervious surface) on mosquito abundance.

Sustainable development in Mekong Delta, Vietnam: designing resilient cities based on landscape ecological principles

ABSTRACT Mekong Delta cities are increasingly degrading as a result of urbanization, flood control, and climate change. These cities are increasingly vulnerable to flooding, and current flood control measures are not only inappropriate but also exacerbate the impacts of climate change and urbanization. A flood-resilient city is a solution; however, applying this idea to the actual urban environment through exposure to flood risk is not effective for long-term, sustainable development. This research evaluates landscape structure, changes in land use, and changes in economic, social, and cultural structure, thereby proposing rules for sustainable urban development planning. In addition, this research also suggests a comprehensive functional space plan for Cao Lanh City. This city plays a role as a case study that helps clarify the proposed rules for sustainable urban development planning for Mekong Delta cities in Vietnam.

Efficient multi-scale network for semantic segmentation of fine-resolution remotely sensed images

Abstract Semantic segmentation of remote sensing urban scene images has diverse practical applications, including land cover mapping, urban change detection, environmental protection, and economic evaluation. However, classical semantic segmentation networks encounter challenges such as inadequate utilization of multi-scale semantic information and imprecise edge target segmentation in high-resolution remote sensing images. In response, this article introduces an efficient multi-scale network (EMNet) tailored for semantic segmentation of common features in remote sensing images. To address these challenges, EMNet integrates several key components. Firstly, the efficient atrous spatial pyramid pooling module is employed to enhance the relevance of multi-scale targets, facilitating improved extraction and processing of context information across different scales. Secondly, the efficient multi-scale attention mechanism and multi-scale jump connections are utilized to fuse semantic features from various levels, thereby achieving precise segmentation boundaries and accurate position information. Finally, an encoder-decoder structure is incorporated to refine the segmentation results. The effectiveness of the proposed network is validated through experiments conducted on the publicly available DroneDeploy image dataset and Potsdam dataset. Results indicate that EMNet achieves impressive performance metrics, with mean intersection over union (MIoU), mean precision (MPrecision), and mean recall (MRecall) reaching 75.99%, 86.76%, and 85.07%, respectively. Comparative analysis demonstrates that the network proposed in this article outperforms current mainstream semantic segmentation networks on both the DroneDeploy and Potsdam dataset.

Strategies for promoting and preserving urban landscape identity through public participation amidst urban renewal changes: The case of Kisumu City, Kenya

Strategies for promoting and preserving urban landscape identity through public participation amidst urban renewal changes: The case of Kisumu City, Kenya

Drought Monitoring due to Climate Change in Urban and Sub Urban Area

Drought Monitoring due to Climate Change in Urban and Sub Urban Area

The relationship between urbanization, energy consumption, economic growth, and carbon dioxide emissions in middle eastern countries: Saudi Arabia, Jordan and Egypt

The Middle East region is a strategic driver of the global economy. However, ensuring environmental sustainability in the context of rapid urban and economic changes remains a major challenge for most Middle Eastern countries. Although researchers have widely examined factors affecting carbon dioxide emissions (CO2), little attention has been paid to the Middle Eastern countries. This study uses an ARDL model to examine the nexus between urbanization, energy consumption, economic growth, and CO2 emissions for three Middle Eastern countries, (Saudi Arabia, Egypt and Jordan) based on panel data for the period from 1990 to 2023. Findings reveal that urbanization has had no significant impact on CO2 emissions in Egypt; this is not in line with the findings for Saudi Arabia and Jordan, where urbanization has reduced CO2 emissions in the long- and short-run, indicating that urban policies are well matched with environmental goals in both countries. However, empirical results indicate that energy consumption has had a positive effect on CO2 emissions in the long- and short-run in all three countries and economic growth has also had a positive impact on CO2 emissions. The fact that economic growth has been unable to mitigate CO2 emissions indicates a mismatch between economic policies and environmental goals. This article suggests a series of valuable insights for policymakers to reduce CO2 emissions.

Six‐decade trend in minute‐scale short‐duration intense precipitation in Beijing and its association with urbanization

AbstractUnderstanding the characteristics of minute‐scale short‐duration intense rainfall and its possible link with urbanization is valuable for addressing urban climate change and evaluating biases in high‐resolution historical precipitation data series. This study analyses the long‐term trends of rainy‐season minute‐scale intense rainfall events at different continuous time periods based on precipitation data from 20 national meteorological stations in the Beijing area covering the period from 1961 to 2021. This study shows that during the whole period analysed, the number of events of intense rainfall lasting 15 min or longer decreased, while the number of shorter‐duration events and the accumulated precipitation increased. The frequency and amount of minute‐scale intense rainfall recorded by urban stations are generally higher than those recorded by rural stations in terms of climatological means. The signal of the urbanization effect in minute‐scale precipitation changes is detectable, with the contribution of urbanization to the trends in average precipitation of 30‐min intense rainfall being 68.8%, whereas the contributions with respect to the frequency of 20‐ and 30‐min intense rainfall and the maximum precipitation of intense rainfall with a duration of 45 min reach 100%. The results of the analysis can provide reference for understanding long‐term changes in short‐duration rainfall and the possibility that they are driven by local anthropogenic activity, as well as bias in the minute‐scale precipitation data series of urban observation sites when they are used in studies of large‐scale intense precipitation changes.

Experimental study on the hydraulic performance of nonwoven geotextile efficiency of sustainable drainage system

Abstract Globally, the frequency of record-breaking rainfall events has greatly risen. As a result, surface water urban flooding is becoming a bigger concern. SUDS are increasingly being used in many metropolitan areas to reduce peak surface runoff and pollutants by utilizing various designed open water structures, such as infiltration basins. Urbanization and climate change have resulted in an increase in catchment runoff, often exceeding the designed capacity of sewer systems. The purpose of this research is to study the performance of nonwoven geotextile in subsurface drainage beds to improve the efficiency of infiltration rate compared to existing drainage system. This research proposes to create a subsurface drainage bed consisting of gravel, sand, and nonwoven geotextile to act as an alternative compared to existing drainage system. This module will be run by conducting an experiment to study the characteristics of subsurface drainage bed, effects of rainfall intensity and the relationship of infiltration rate on various rainfall intensity will be studied. In conclusion, in this study, nonwoven geotextile with a thickness of 5 mm (Condition B) significantly improved infiltration rates, reducing surface runoff by up to 30 % compared to Condition A and Condition across varying rainfall intensities.

Effect of street trees shade on perceived thermal comfort in a south temperate climate: The sidewalks of Montevideo (Uruguay)

The use of vegetation in cities is one of the most promising strategies for urban climate change adaptation and mitigation. Tree shade influences heat storage from surfaces reducing long wave radiation emission which directly affects people. People 's heat perception depends more on insolation and the temperature of surrounding objects than on air temperature itself. There is a need for analyzes that include the combined effects of physical and human variables on thermal comfort, as well as location-based studies to address its climatic and social conditions. In order to compare the effect of the trees on microenvironmental temperature and perceived thermal comfort, we measured physical parameters and performed structured interviews on three downtown streets of Montevideo, Uruguay, which had sections with and without trees on four dates during the summer. Generally, people surveyed under both treatments stated they did not feel fully comfortable due to summer heat, but the proportion of people who stated feeling in thermal comfort under tree shade was more than double than the unshaded sections.The seasonal ARIMA analysis supported that the tree shade reduced the microenvironmental temperature by its effect on radiant temperature. By using a statistical decision tree methodology that combines all the variables in the same analysis, we found a greater impact of physical variables than personal variables on people's thermal comfort and thermal preferences. We also identified gender as a significant variable that affects people's thermal preferences, where 46.4 % of females preferred a slightly colder environment.

Numerical Studies on the Influence of Building Morphology on Urban Canopy Wind Speed

AbstractBuildings increase the urban surface roughness and reduce near‐surface wind speeds in the urban canopy due to the drag effect. Urban heat storage and other effects cause urban warming as well, which decreases the urban boundary layer stability and enhances the turbulence exchange between upper and lower layer. As upper momentum is transported downward, the wind speed of urban canopy increases. Quantitative descriptions of these mechanisms are still lacking currently. This paper presents high‐resolution numerical simulation results of a mega city, Shanghai, China from 2016 to 2020 using the building effect parameterization in WRF (WRF‐BEP) with urban morphological parameters. The dynamic and thermal effects of building morphology on urban canopy wind speed were separated and their quantitative expression functions were given. The results indicate that the influence of building morphology on urban canopy wind speed is mainly dynamic resulting in a wind speed attenuation of approximately 50% and nearly constant. The thermal effect of building morphology on urban canopy wind speed increases with the urban heat island intensity, and the thermal effect could increase urban canopy wind speed by about 30% under the condition of strong urban heat island. The relative contributions of the dynamic and thermal effects of building morphology to urban canopy wind speed change with the wind speed. As wind speed increases, the contribution of the thermal effect of building morphology to urban canopy wind speed gradually decreases. This paper provides a quantitative relationship between the urban canopy wind speed variation and urban morphology, as well as urban heat island intensity.

Spatio-Temporal Analysis of Vegetation Index Change on Land Surface Temperature in Yogyakarta Special Region Using MODIS Imagery (2000-2023)

Yogyakarta has become a province renowned for its abundance of tourist destinations and learning opportunities for students from all over Indonesia. Temperature and vegetation density are key factors contributing to comfort in both academic pursuits and recreational activities. This study utilizes NDVI (Normalized Difference Vegetation Index) and LST (Land Surface Temperature) to determine these crucial parameters. MODIS imagery serves as a vital data source for analyzing NDVI and LST. The aim of this research is to comprehend the environmental dynamics of DIY (Yogyakarta Special Region) by exploring the relationship between NDVI and LST. Through the Pearson correlation method, the relationship between these variables is deeply evaluated. The analysis reveals a significant correlation between changes in NDVI and LST, indicating a complex interaction between vegetation and land surface temperature. However, these significant findings have minimal impact on Yogyakarta City and Sleman, which serve as the focal points of community activities in Yogyakarta. These changes can be attributed to various factors, including changes in land use, urbanization, and climate variability, which show weak correlation values when associated with vegetation. Another finding is that Yogyakarta City exhibits the most distinct response in vegetation density and surface temperature compared to the surrounding four cities. This is attributed to Yogyakarta City being the administrative center and economic hub of DIY. These findings provide a deeper understanding of the environment's response to these factors in DIY. By employing spatial and temporal analysis, this study offers valuable insights for climate change mitigation efforts and adaptation to the evolving environmental dynamics.

Use of Digital Technology to Calculate Water Footprints for Different Daily Use Items

Water security is a global concern for utilities due to urbanization and climate change. Although water utilities are directly affected by climate change, greenhouse gas emissions are also a result of their activities. Urban water cycles are becoming more sustainable as a result of the efficient operations of utilities made possible by digital technologies. Nonetheless, there is still a dearth of research on the global advancement of digital water transformation. Here, we report on the findings of an online survey that 64 utilities from 28 countries participated in to learn more about the digital transformation's effects on the water utility industry, its drivers, and the main technologies that make it possible. We discovered that the water distribution system serves as the gateway for additional digital technology adoption throughout the entire urban water cycle. In addition, the main forces behind the adoption of technology are economic gains, governmental regulations, and hydroclimatic conditions. We identify areas for future research aimed at improving our understanding of the role that company culture, consumer involvement, and regulations play in effective digital transformation, based on the survey results.

Inaccessible and Unaffordable? The State of Water and Sanitation Services in Nairobi, Kenya

As the limited water resources become increasingly stressed by factors such as rapid urbanization, population growth, and climate change, the need for sustainable urban water management is more important than in the past decades. A large part of the world’s population still lacks access to clean water and sanitation, making achieving Sustainable Development Goals a challenge. Water is an indispensable resource and plays an important role in ensuring the achievement of Sustainable Development Goals. Therefore, there is a need to prioritize research on the availability, affordability, and access of water resources to promote sustainable water resource management. In this study, we reviewed academic articles and published reports from various institutions and organizations to assess water sources, infrastructure, coverage, accessibility, and affordability of water and sanitation services in Nairobi County. The study identified Nairobi’s main water sources as municipal water, primarily from surface water and groundwater. However, the capacities of the water sources, treatment plants, and wastewater treatment plants were found to be insufficient, resulting in water shortages in most parts of the city.Most of the infrastructures were also found to be insufficient and old, contributing to water distribution inefficiencies, frequent leakages, and pipe bursts which hampers water reliability. The study suggests prioritizing the water and sanitation sector in government budgets to increase infrastructure development investments and funding. Appropriate wastewater treatment methods should also be adopted and implemented to enable wastewater to meet water consumption standards and be potentially integrated into supply systems.

Assessing the Impact of Urban Expansion on Forest Cover using LULC Maps, NDVI, and NDBI: A Case Study of Kathmandu District

Rapid urbanization poses significant challenges to the delicate balance between urban development and environmental conservation. This study investigates the impact of urban expansion on forest cover in the Kathmandu District, employing a comprehensive approach that integrates Land Use/Land Cover (LULC) maps, Normalized Difference Vegetation Index (NDVI), and Normalized Difference Built-Up Index (NDBI). The aim of the study area is to provide insights into the dynamic interplay between urban growth and its consequences on the region's ecological landscape. LULC maps derived from remote sensing data offer a spatially explicit representation of land-use changes over time, enabling the identification of areas where urbanization has encroached upon forest area. The NDVI, a vegetation health indicator, serves as a quantitative measure of changes in the density and health of vegetation cover, aiding in the assessment of ecological impacts. Complementing this, the NDBI highlights intensity of built-up areas, allowing for a nuanced understanding of the urbanization process. This study employs NDBI and NDVI to dynamically assess urban growth and land use cover change, enhancing analytical accuracy. Findings reveal a substantial 89.9 km² increase in built- up areas between 2013 and 2016, coupled with a minor 18.4 km² increase between 2016 and 2021, reflecting continuous urban expansion driven by population growth and development initiatives. Concurrently, forest area marginally increased by 2.3 km² in 2016, suggesting reforestation and conservation efforts, yet a subsequent 23.5 km² decline by 2021, due to deforestation, urban encroachment, and natural disasters such as wildfires. Notably, vacant land decreased by 92.3 km² in 2016, absorbed by built- up areas and forest expansion, underscoring the urgent need for spatial planning to accommodate the growing population and its evolving needs.

Ecological effects of land use and land cover changes on lakes in urban environments

AbstractUrban lakes confront significant threats due to changes in land use and land cover (LULC) resulting from urbanization and subsequent climate change. This review discusses the intricate effects of the urban heat island phenomenon on lakes, specifically attributed to LULC changes. Utilizing the Scopus and Web of Science databases, this study gathers the most pertinent earlier research in the LULC and water bodies. This study systematically categorizes variables into five distinct groups and scrutinizes the drivers, parameters, tools, and management strategies influencing the LULC dynamics on lakes. A research gap is identified in understanding the conjoined impacts of LULC and urban heat island effects within urban lake environments. The review further investigates diverse ways in which LULC impacts lakes, intersecting with multiple United Nations sustainable development goals (SDGs), notably SDGs 6, 11, 13, and 15. Consequently, this review serves as a valuable contribution to the understanding of LULC to provide substantial benefits to the urban climate research toward meeting SDGs.