scholarly journals Standardized Green View Index and Quantification of Different Metrics of Urban Green Vegetation

2020 ◽  
Vol 12 (18) ◽  
pp. 7434 ◽  
Author(s):  
Yusuke Kumakoshi ◽  
Sau Yee Chan ◽  
Hideki Koizumi ◽  
Xiaojiang Li ◽  
Yuji Yoshimura
Keyword(s):  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Urban Landscapes ◽  
Site Location ◽  
Urban Green ◽  
Urban Greenery ◽  
Geographical Scale ◽  
Green Vegetation ◽  
Block Level ◽  
The City

Urban greenery is considered an important factor in sustainable development and people’s quality of life in the city. To account for urban green vegetation, Green View Index (GVI), which captures the visibility of greenery at street level, has been used. However, as GVI is point-based estimation, when aggregated at an area-level by mean or median, it is sensitive to the location of sampled sites, overweighing the values of densely located sites. To make estimation at area-level more robust, this study aims to (1) propose an improved indicator of greenery visibility (standardized GVI; sGVI), and (2) quantify the relation between sGVI and other green metrics. Experiment on an hypothetical setting confirmed that bias from site location can be mitigated by sGVI. Furthermore, comparing sGVI and Normalized Difference Vegetation Index (NDVI) at the city block level in Yokohama city, Japan, we found that sGVI captures the presence of vegetation better in the city center, whereas NDVI is better at capturing vegetation in parks and forests, principally due to the different viewpoints (eye-level perception and top-down eyesight). These tools provide a foundation for accessing the effect of vegetation in urban landscapes in a more robust matter, enabling comparison on any arbitrary geographical scale.

scholarly journals Mapping Public Urban Green Spaces Based on OpenStreetMap and Sentinel-2 Imagery Using Belief Functions

2021 ◽  
Vol 10 (4) ◽  
pp. 251
Author(s):  
Christina Ludwig ◽  
Robert Hecht ◽  
Sven Lautenbach ◽  
Martin Schorcht ◽  
Alexander Zipf
Keyword(s):  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Open Data ◽  
Green Spaces ◽  
Data Sets ◽  
Urban Green ◽  
Urban Green Spaces ◽  
Urban Quality Of Life ◽  
Shafer Theory ◽  
Sentinel 2

Public urban green spaces are important for the urban quality of life. Still, comprehensive open data sets on urban green spaces are not available for most cities. As open and globally available data sets, the potential of Sentinel-2 satellite imagery and OpenStreetMap (OSM) data for urban green space mapping is high but limited due to their respective uncertainties. Sentinel-2 imagery cannot distinguish public from private green spaces and its spatial resolution of 10 m fails to capture fine-grained urban structures, while in OSM green spaces are not mapped consistently and with the same level of completeness everywhere. To address these limitations, we propose to fuse these data sets under explicit consideration of their uncertainties. The Sentinel-2 derived Normalized Difference Vegetation Index was fused with OSM data using the Dempster–Shafer theory to enhance the detection of small vegetated areas. The distinction between public and private green spaces was achieved using a Bayesian hierarchical model and OSM data. The analysis was performed based on land use parcels derived from OSM data and tested for the city of Dresden, Germany. The overall accuracy of the final map of public urban green spaces was 95% and was mainly influenced by the uncertainty of the public accessibility model.

scholarly journals Seasonal Variations of Daytime Land Surface Temperature and Their Underlying Drivers over Wuhan, China

2021 ◽  
Vol 13 (2) ◽  
pp. 323
Author(s):  
Liang Chen ◽  
Xuelei Wang ◽  
Xiaobin Cai ◽  
Chao Yang ◽  
Xiaorong Lu
Keyword(s):  
Surface Temperature ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Maximum Temperature ◽  
Maximum Temperature Difference ◽  
Rapid Urbanization ◽  
The Impact ◽  
The City

Rapid urbanization greatly alters land surface vegetation cover and heat distribution, leading to the development of the urban heat island (UHI) effect and seriously affecting the healthy development of cities and the comfort of living. As an indicator of urban health and livability, monitoring the distribution of land surface temperature (LST) and discovering its main impacting factors are receiving increasing attention in the effort to develop cities more sustainably. In this study, we analyzed the spatial distribution patterns of LST of the city of Wuhan, China, from 2013 to 2019. We detected hot and cold poles in four seasons through clustering and outlier analysis (based on Anselin local Moran’s I) of LST. Furthermore, we introduced the geographical detector model to quantify the impact of six physical and socio-economic factors, including the digital elevation model (DEM), index-based built-up index (IBI), modified normalized difference water index (MNDWI), normalized difference vegetation index (NDVI), population, and Gross Domestic Product (GDP) on the LST distribution of Wuhan. Finally, to identify the influence of land cover on temperature, the LST of croplands, woodlands, grasslands, and built-up areas was analyzed. The results showed that low temperatures are mainly distributed over water and woodland areas, followed by grasslands; high temperatures are mainly concentrated over built-up areas. The maximum temperature difference between land covers occurs in spring and summer, while this difference can be ignored in winter. MNDWI, IBI, and NDVI are the key driving factors of the thermal values change in Wuhan, especially of their interaction. We found that the temperature of water area and urban green space (woodlands and grasslands) tends to be 5.4 °C and 2.6 °C lower than that of built-up areas. Our research results can contribute to the urban planning and urban greening of Wuhan and promote the healthy and sustainable development of the city.

scholarly journals Heat Islands in the city of San Francisco de Campeche: Detection and solution

2020 ◽  
pp. 16-20
Author(s):  
Román Alejandro Canul-Turriza ◽  
Francisco Javier Barrera-Lao ◽  
Gabriela Patricia Aldana Narváez
Keyword(s):  
Soil Temperature ◽  
San Francisco ◽  
Vegetation Cover ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Heat Islands ◽  
Mathematical Algorithm ◽  
Green Areas ◽  
Landsat 5 Tm ◽  
The City

This paper presents the identification of heat islands in the city of San Francisco de Campeche, period 1990 - 2020 and their relationship with changes in the vegetation cover areas. To identify the heat islands in the city, 6 Landsat 5 (TM), 7 (TM) and 8 (OIL) images were obtained from the USGS database (http://earthexplorer.usgs.gov/). In geographic information software, soil temperature was calculated from a mathematical algorithm applied to thermal infrared bands 6 and 10, in addition, the Normalized Difference Vegetation Index (NDVI) was calculated, in order to find a relationship between changes in temperature and vegetation cover. It was found that the green areas have reduced their surface by more than 50% and the soil temperature has increased up to 7 ° C

scholarly journals A Comparative Study of RGB and Multispectral Sensor-Based Cotton Canopy Cover Modelling Using Multi-Temporal UAS Data

2019 ◽  
Vol 11 (23) ◽  
pp. 2757 ◽  
Author(s):  
Akash Ashapure ◽  
Jinha Jung ◽  
Anjin Chang ◽  
Sungchan Oh ◽  
Murilo Maeda ◽  
...  
Keyword(s):  
Comparative Study ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Canopy Cover ◽  
Unmanned Aircraft ◽  
Estimation Methods ◽  
Green Vegetation ◽  
Multi Temporal ◽  
Rgb Images ◽  
Multispectral Sensors

This study presents a comparative study of multispectral and RGB (red, green, and blue) sensor-based cotton canopy cover modelling using multi-temporal unmanned aircraft systems (UAS) imagery. Additionally, a canopy cover model using an RGB sensor is proposed that combines an RGB-based vegetation index with morphological closing. The field experiment was established in 2017 and 2018, where the whole study area was divided into approximately 1 x 1 m size grids. Grid-wise percentage canopy cover was computed using both RGB and multispectral sensors over multiple flights during the growing season of the cotton crop. Initially, the normalized difference vegetation index (NDVI)-based canopy cover was estimated, and this was used as a reference for the comparison with RGB-based canopy cover estimations. To test the maximum achievable performance of RGB-based canopy cover estimation, a pixel-wise classification method was implemented. Later, four RGB-based canopy cover estimation methods were implemented using RGB images, namely Canopeo, the excessive greenness index, the modified red green vegetation index and the red green blue vegetation index. The performance of RGB-based canopy cover estimation was evaluated using NDVI-based canopy cover estimation. The multispectral sensor-based canopy cover model was considered to be a more stable and accurately estimating canopy cover model, whereas the RGB-based canopy cover model was very unstable and failed to identify canopy when cotton leaves changed color after canopy maturation. The application of a morphological closing operation after the thresholding significantly improved the RGB-based canopy cover modeling. The red green blue vegetation index turned out to be the most efficient vegetation index to extract canopy cover with very low average root mean square error (2.94% for the 2017 dataset and 2.82% for the 2018 dataset), with respect to multispectral sensor-based canopy cover estimation. The proposed canopy cover model provides an affordable alternate of the multispectral sensors which are more sensitive and expensive.

scholarly journals ОЦЕНКА УРОВНЯ ОЗЕЛЕНЕНИЯ ГОРОДА БИРОБИДЖАНА С ПРИМЕНЕНИЕМ МУЛЬТИСПЕКТРАЛЬНЫХ ДАННЫХ

2021 ◽  
Vol 13 (4) ◽  
Author(s):  
Д.М. Фетисов ◽  
Д.В. Жучков ◽  
М.В. Горюхин
Keyword(s):  
Green Infrastructure ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Multispectral Imaging ◽  
Natural Vegetation ◽  
Medium Size ◽  
Functional Zones ◽  
Functional Areas ◽  
The City ◽  
And Storage

The urban greenness distribution between functional areas of a medium-size city Birobidzhan was assessed. To this end, normalized difference vegetation index (NDVI) values were calculated based on Sentinel 2 multispectral imaging. Birobidzhan is characterized by a large scatter of NDVI values (from –0.5 to +1). Areas with high levels of greenery are prevalent. They are found in different types of functional zones, but are specific mainly to natural recreational, agricultural, and individual build-up zones as well as to special areas. The spatial distribution of green infrastructure is highly contrast. The downtown part as well as the industrial and storage zones feature a combination of built-up areas with dense woody vegetation, which is often represented by fragments of preserved natural vegetation. In addition, a feature of the contrast is that low level of tree greenness is characteristic for the built-up districts of the city. Thus, in the city of Birobidzhan, ecological functions are largely performed by the natural vegetation present in the natural recreational zones on 70% of the city's area.

scholarly journals ANÁLISE DA GESTÃO OCUPACIONAL EM MONTES CLAROS – MG: Impactos do uso do solo e suas consequências na temperatura de superfície

2020 ◽  
Vol 15 (01) ◽  
pp. 285-311
Author(s):  
Bruna Reis Pereira ◽  
Mariana Barreto Mees ◽  
Manoel Reinaldo Leite ◽  
Raul de Magalhães Filho
Keyword(s):  
Surface Temperature ◽  
Urban Space ◽  
Temperature Increase ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Urban Centers ◽  
Human Needs ◽  
Significant Temperature ◽  
Landsat 5 Tm ◽  
The City

O uso do solo é a atividade de uma sociedade por sobre uma superfície, este caracteriza-se conforme as individualidades conjugada aos padrões de necessidades humanas. Um dos impactos ambientais que deve ser considerado neste processo de apropriação é o comportamento térmico de superfície. Neste sentido, o presente trabalho, tendo como área de estudo o perímetro urbano de Montes Claros – MG, teve como objetivo analisar a ocupação do espaço urbano na cidade sob uma condição cronológica: 1990 a 2010. Por meio da análise de imagens de sensoriamento remoto (Landsat 5 TM) procurou-se verificar se o modelo de ocupação provocou problemas urbanos de natureza térmica. Os resultados mostraram, a partir da metodologia adotada, que regiões com decréscimo de NDVI (Índice de Vegetação por Diferença Normalizada) e grande adensamento de edificações tiveram significativos aumento de temperatura no período considerado, ratificando o problema de aumento de temperatura de superfície nos centros urbanos. Palavras-chave: Urbanização; temperatura de superfície; desenvolvimento urbano; Montes Claros.   ANALYSIS OF OCCUPATIONAL MANAGEMENT IN MONTES CLAROS - MG: Impacts of land use and its consequences on surface temperature Abstract The use of the soil is the activity of a society above a surface, this is characterized according to the individualities combined with the patterns of human needs. One of the environmental impacts that must be considered in this appropriation process is the surface thermal behavior. In this sense, the present study, having as its study area the urban perimeter of Montes Claros - MG, aimed to analyze the occupation of urban space in the city under a chronological condition: 1990 to 2010. Through the analysis of remote sensing images (Landsat 5 TM), it was verified that the occupation model caused urban problems of a thermal nature. The results showed that the regions with decreasing NDVI (Normalized Difference Vegetation Index) and high density of buildings had significant temperature increase in the period considered, confirming the problem of surface temperature increase in urban centers . Keywords: Urbanization; Surface temperature; urban Development; Montes Claros.   ANALYSE DES PROFESSIONNELLES GESTION MONTES CLAROS - MG: impacts de l'utilisation des terres et les conséquences de la température de surface Resumen Uso de la tierra es la actividad de una corporación sobre una superficie, este se caracteriza como individualidades combinados a los estándares de las necesidades humanas. Un impactos ambientales que deben ser considerados en este proceso de solución es la superficie comportamiento térmico. En este sentido, el presente trabajo, con el área de estudio del área urbana de Montes Claros - MG, tuvo como objetivo analizar la ocupación del espacio urbano en la ciudad bajo una condición cronológico: 1990 a 2010. Por medio del análisis de imágenes de teledetección (Landsat 5 TM) trató de verificar que el modelo de ocupación provocó problemas urbanos de la naturaleza térmica. Los resultados mostraron que a partir de la metodología utilizada, las regiones con la disminución de NDVI (índice de vegetación de diferencia normalizada) y de alta densidad de edificios tenían aumento significativo de la temperatura durante el periodo considerado, lo que confirma el problema aumento de la temperatura de superficie en los centros urbanos . Palavras chave: urbanización; temperatura de la superficie; desarrollo Urbano; Montes Claros.

scholarly journals The Utility of Sentinel-2 Spectral Data in Quantifying Above-Ground Carbon Stock in an Urban Reforested Landscape

2021 ◽  
Vol 13 (21) ◽  
pp. 4281
Author(s):  
Mthembeni Mngadi ◽  
John Odindi ◽  
Onisimo Mutanga
Keyword(s):  
Climate Change ◽  
Ecosystem Services ◽  
Spectral Data ◽  
Carbon Stock ◽  
Climate Change Mitigation ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Urban Landscapes ◽  
Change Mitigation ◽  
Sentinel 2

The transformation of the natural landscape into an impervious surface due to urbanization has often been considered an important driver of environmental change, affecting essential urban ecological processes and ecosystem services. Continuous forest degradation and deforestation due to urbanization have led to an increase in atmospheric carbon emissions, risks, and impacts associated with climate change within urban landscapes and beyond them. Hence, urban reforestation has become a reliable long-term alternative for carbon sink and climate change mitigation. However, there is an urgent need for spatially accurate and concise quantification of these forest carbon stocks in order to understand and effectively monitor the accumulation and progress on such ecosystem services. Hence, this study sought to examine the prospect of Sentinel-2 spectral data in quantifying carbon stock in a reforested urban landscape using the random forest ensemble. Results show that Sentinel-2 spectral data estimated reforested forest carbon stock to an RMSE between 0.378 and 0.466 t·ha−1 and R2 of 79.82 and 77.96% using calibration and validation datasets. Based on random forest variable selection and backward elimination approaches, the red-edge normalized difference vegetation index, enhanced vegetation index, modified simple ratio index, and normalized difference vegetation index were the best subset of predictor variables of carbon stock. These findings demonstrate the value and prospects of Sentinel-2 spectral data for predicting carbon stock in reforested urban landscapes. This information is critical for adopting informed management policies and plans for optimizing urban reforested landscapes carbon sequestration capacity and improving their climate change mitigation potential.

scholarly journals Ecological State Assessment of Urban Green Spaces Based on Remote Sensing Data. The Case of Aktobe City, Kazakhstan

2021 ◽  
Vol 12 (2) ◽  
pp. 83-92
Author(s):  
Aigul SERGEYEVA ◽  
Altynbek KHAMIT ◽  
Asima КOSHIM ◽  
Murat MAKHAMBETOV
Keyword(s):  
Remote Sensing ◽  
Vegetation Index ◽  
Integrated Approach ◽  
Ecological Condition ◽  
State Assessment ◽  
Green Spaces ◽  
Urban Green ◽  
Urban Green Spaces ◽  
Green Areas ◽  
The City

The rapid pace of urban development triggers complex problems mostly related to urban environment pollution, and shortcomings of city’s improvement. The modern city is characterized by the highest man-made pressure on the natural environment, the main problems being overcrowding, lack of open-access green areas, as well as the decrease of vegetation areas, fact that does not create comfortable living conditions for urban residents. At present, remote sensing methods are some of the priority tools used in vegetation state assessment, particularly, the calculation of vegetation index (NDVI). But often, obtaining the necessary information is limited only to the analysis of satellite data, without geobotanical field surveys, which considerably increase the reliability of the detected results. In addition, the definition of dependencies when using an integrated approach of different man-affected surfaces with a different type of overgrowth within the city remains insufficiently studied. The purpose of this study is to assess the ecological condition of the green area (parks and squares) in Aktobe city. A comprehensive processing of satellite images including the calculation of NDVI index, mapping of green areas and data statistical analysis, was carried out. We learned that the average value of NDVI for green spaces in Aktobe ranges from 0,11 µm to 0,47 µm, which allows for the categorization of planted areas by levels of photosynthetic activity, from “unsatisfactory” to “good”, yet, with 59% of them in an unsatisfactory condition. This means that the city is underdeveloped in terms of modern landscape and infrastructure. The obtained results make it possible to assess the current situation, determine the dynamics of urban green spaces and optimize spatial planning measures for green space management.

scholarly journals Applying Remote Sensing Technologies in Urban Landscapes of the Mediterranean

2020 ◽  
Vol 2 (1) ◽  
pp. 27-36
Author(s):  
Celestina M. G. Pedras ◽  
Helena Maria Fernandez ◽  
Rui Lança ◽  
Fernando Granja-Martins
Keyword(s):  
Mediterranean Climate ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Urban Landscape ◽  
Urban Landscapes ◽  
Climate Data ◽  
Water Requirements ◽  
The Mediterranean ◽  
Almost All

There has been increasing pressure on water resources in cities due to the proliferation of urban green areas. In the Mediterranean climate, only a small part of the plants’ water needs is supplied by rainfall during the winter months. Thus, in Algarve (Portugal) irrigation of the urban landscapes is required almost all year round. The aims of this study were to evaluate the maintenance of the urban landscapes of São Brás de Alportel (Algarve) during a year, based on the characterization of the vegetation of the urban gardens, the climate data, the analysis of the irrigation systems, the calculation of the plants water requirements and the normalized difference vegetation index (NDVI). By crossing all this information, it was possible to understand if the current maintenance level is the most suitable for sustainable irrigated urban landscapes. In most of the gardens, it was possible to establish a relationship between the gross irrigation water requirements and NDVI. In general, the NDVI allowed us to study the urban landscape, through the monthly observation of the differences in the appearance and development of the vegetation.

Developing City-Wide Hurricane Impact Maps using Real-Life Data on Infrastructure, Vegetation and Weather

2020 ◽  
pp. 036119812097271
Author(s):  
Mingyang Chen ◽  
Alican Karaer ◽  
Eren Erman Ozguven ◽  
Tarek Abichou ◽  
Reza Arghandeh ◽  
...  
Keyword(s):  
Geographical Information Systems ◽  
Vegetation Change ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Real Life ◽  
Google Earth ◽  
Geographical Information ◽  
Data Sets ◽  
Hurricane Impact ◽  
The City

Hurricanes affect thousands of people annually, with devastating consequences such as loss of life, vegetation and infrastructure. Vegetation losses such as downed trees and infrastructure disruptions such as toppled power lines often lead to roadway closures. These disruptions can be life threatening for the victims. Emergency officials, therefore, have been trying to find ways to alleviate such problems by identifying those locations that pose high risk in the aftermath of hurricanes. This paper proposes an integrated methodology that utilizes both Google Earth Engine (GEE) and geographical information systems (GIS). First, GEE is used to access Sentinel-2 satellite images and calculate the Normalized Difference Vegetation Index (NDVI) to investigate the vegetation change as a result of Hurricane Michael in the City of Tallahassee. Second, through the use of ArcGIS, data on wind speed, debris, roadway density and demographics are incorporated into the methodology in addition to the NDVI indices to assess the overall impact of the hurricane. As a result, city-wide hurricane impact maps are created using weighted indices created based on all these data sets. Findings indicate that the northeast side of the city was the worst affected because of the hurricane. This is a region where more seniors live, and such disruptions can lead to dramatic consequences because of the fragility of these seniors. Officials can pinpoint the identified critical locations for future improvements such as roadway geometry modification and landscaping justification.

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