scholarly journals Remote Sensing in Urban Forestry: Recent Applications and Future Directions

2019 ◽  
Vol 11 (10) ◽  
pp. 1144 ◽  
Author(s):  
Xun Li ◽  
Wendy Y. Chen ◽  
Giovanni Sanesi ◽  
Raffaele Lafortezza
Keyword(s):  
Remote Sensing ◽  
Data Processing ◽  
Urban Forest ◽  
Scale Effects ◽  
Urban Forestry ◽  
Urban Forests ◽  
Accurate Information ◽  
Multi Scale ◽  
Sensing Applications ◽  
Multi Temporal

Increasing recognition of the importance of urban forest ecosystem services calls for the sustainable management of urban forests, which requires timely and accurate information on the status, trends and interactions between socioeconomic and ecological processes pertaining to urban forests. In this regard, remote sensing, especially with its recent advances in sensors and data processing methods, has emerged as a premier and useful observational and analytical tool. This study summarises recent remote sensing applications in urban forestry from the perspective of three distinctive themes: multi-source, multi-temporal and multi-scale inputs. It reviews how different sources of remotely sensed data offer a fast, replicable and scalable way to quantify urban forest dynamics at varying spatiotemporal scales on a case-by-case basis. Combined optical imagery and LiDAR data results as the most promising among multi-source inputs; in addition, future efforts should focus on enhancing data processing efficiency. For long-term multi-temporal inputs, in the event satellite imagery is the only available data source, future work should improve haze-/cloud-removal techniques for enhancing image quality. Current attention given to multi-scale inputs remains limited; hence, future studies should be more aware of scale effects and cautiously draw conclusions.

scholarly journals Measuring Multi-Scale Urban Forest Carbon Flux Dynamics Using an Integrated Eddy Covariance Technique

2019 ◽  
Vol 11 (16) ◽  
pp. 4335 ◽  
Author(s):  
Kaidi Zhang ◽  
Yuan Gong ◽  
Francisco J. Escobedo ◽  
Rosvel Bracho ◽  
Xinzhong Zhang ◽  
...  
Keyword(s):  
Eddy Covariance ◽  
Green Infrastructure ◽  
Urban Forest ◽  
Scale Effects ◽  
Atmospheric Stability ◽  
Urban Forests ◽  
Co2 Flux ◽  
Forest Patches ◽  
Multi Scale ◽  
Co2 Dynamics

The multi-scale carbon-carbon dioxide (C-CO2) dynamics of subtropical urban forests and other green and grey infrastructure types were explored in an urbanized campus near Shanghai, China. We integrated eddy covariance (EC) C-CO2 flux measurements and the Agroscope Reckenholz-Tänikon footprint tool to analyze C-CO2 dynamics at the landscape-scale as well as in local-scale urban forest patches during one year. The approach measured the C-CO2 flux from different contributing areas depending on wind directions and atmospheric stability. Although the study landscape was a net carbon source (2.98 Mg C ha−1 yr−1), we found the mean CO2 flux in urban forest patches was −1.32 μmol m−2s−1, indicating that these patches function as a carbon sink with an annual carbon balance of −5.00 Mg C ha−1. These results indicate that urban forest patches and vegetation (i.e., green infrastructure) composition can be designed to maximize the sequestration of CO2. This novel integrated modeling approach can be used to facilitate the study of the multi-scale effects of urban forests and green infrastructure on CO2 and to establish low-carbon emitting planning and planting designs in the subtropics.

scholarly journals Beijing Resident’s Preferences of Ecosystem Services of Urban Forests

Forests ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 14
Author(s):  
Han Zhi-Ying ◽  
Youn Yeo-Chang
Keyword(s):  
Ecosystem Services ◽  
Air Quality ◽  
Fresh Water ◽  
Urban Forest ◽  
Urban Forestry ◽  
Urban Forests ◽  
Wildlife Habitat ◽  
Quality Regulation ◽  
Water Provision ◽  
Air Quality Regulation

This paper aims to investigate the Beijing resident’s preferences over various options of urban forest management strategies. The literature investigation and expert Delphi method were conducted to classify the ecosystem services of urban forests into six categories: (1) fresh water provision, (2) noise reduction, (3) moderation of extreme events, (4) air quality regulation, (5) species diversity and wildlife habitat, and (6) recreation and spiritual experience. To elicit the relative preferences to ecosystem service (hereafter referred to as ES) of Beijing residents, we employed the choice experiment method. The data were collected by interviews with questionnaires conducted in October 2017, and a total of 483 valid questionnaires were analyzed. The subjects of this experiment were residents older than 19 years old who have lived in Beijing for more than 1 year and have visited any one of the urban forests located in Beijing more than once during 2016. The results were as follows: Firstly, the air quality regulation ES was considered as the most important service for Beijing residents in terms of their choices of urban forest. In addition, Beijing residents regarded the fresh water provision ES as the second most important ES. Beijing residents were willing to pay up to 1.84% of the average monthly income of Chinese households annually to expand urban forest ecosystems in order to improve air quality. Secondly, apartment owners were willing to pay more municipality tax for forest ESs than residents who did not own an apartment. Thirdly, residents were more willing to pay for urban forest ESs as their income increases. The results indicated that Beijing residents were willing to pay more tax in support of urban forestry for air quality improvement. This research suggests that urban environmental policy makers in Beijing should pay more attention to the regulation function of forests (especially improving air quality) when designing and managing urban forests.

Multi-scale analysis of landslide occurrence and evolution using optical and radar time series

2020 ◽  
Author(s):  
Sigrid Roessner ◽  
Robert Behling ◽  
Mahdi Motagh ◽  
Hans Ulrich-wetzel
Keyword(s):  
Remote Sensing ◽  
Time Series ◽  
High Resolution ◽  
Intense Rainfall ◽  
Large Area ◽  
Landslide Occurrence ◽  
Multi Scale ◽  
Multi Temporal ◽  
Hazard And Risk

<p>Landslides represent a worldwide natural hazard and often occur as cascading effects related to triggering events, such as earthquakes and hydrometeorological extremes. Recent examples are the Kaikoura earthquake in New Zealand (November 2016), the Gorkha earthquake in Nepal (April/May 2015), and the Typhoon Morakot in Taiwan (August 2009) as well as less intense rainfall events persisting over unusually long periods of time as observed for Central Asia (spring 2017) and Iran (spring 2019). Each of these events has caused thousands of landslides that account substantially to the primary disaster’s impact. Moreover, their initial failure usually represents the onset of long-term progressing slope destabilization leading to multiple reactivations and thus to long-term increased hazard and risk. Therefore, regular systematic high-resolution monitoring of landslide prone regions is of key importance for characterization, understanding and modelling of spatiotemporal landslide evolution in the context of different triggering and predisposing settings. Because of the large extent of the affected areas of up to several ten thousands km<sup>2</sup>, the use of multi-temporal and multi-scale remote sensing methods is of key importance for large area process analysis. In this context, new opportunities have opened up with the increasing availability of satellite remote sensing data of suitable spatial and temporal resolution (Sentinels, Planet) as well as the advances in UAV based very high resolution monitoring and mapping.</p><p>During the last decade, we have been pursuing extensive methodological developments in remote sensing based time series analysis including optical and radar observations with the goal of performing large area and at the same time detailed spatiotemporal analysis of landslide prone regions. These developments include automated post-failure landslide detection and mapping as well as assessment of the kinematics of pre- and post-failure slope evolution.  Our combined optical and radar remote sensing approaches aim at an improved understanding of spatiotemporal dynamics and complexities related to evolution of landslide prone slopes at different spatial and temporal scales.  In this context, we additionally integrate UAV-based observation for deriving volumetric changes also related to globally available DEM products, such as SRTM and ALOS.  </p><p>We present results for selected settings comprising large area co-seismic landslide occurrence related to the Kaikoura 2016 and the Nepal 2015 earthquakes. For the latter one we also analyzed annual pre- and post-seismic monsoon related landslide activity contributing to a better understanding of the interplay between these main triggering factors. Moreover, we report on ten years of large area systematic landslide monitoring in Southern Kyrgyzstan resulting in a multi-temporal regional landslide inventory of so far unprecedented spatiotemporal detail and completeness forming the basis for further analysis of the obtained landslide concentration patterns. We also present first results of our analysis of landslides triggered by intense rainfall and flood events in spring of 2019 in the North of Iran. We conclude that in all cases, the obtained results are crucial for improved landslide prediction and reduction of future landslide impact. Thus, our methodological developments represent an important contribution towards improved hazard and risk assessment as well as rapid mapping and early warning</p>

A strategy for Canada's urban forests

2003 ◽  
Vol 79 (4) ◽  
pp. 785-789 ◽  
Author(s):  
W A Kenney
Keyword(s):  
Professional Development ◽  
Natural Environment ◽  
Urban Forest ◽  
Urban Forestry ◽  
Urban Forests ◽  
Economic Benefits ◽  
Community Action ◽  
Development Research ◽  
Intimate Contact ◽  
Conservation And Management

Urban forests are where 80% of Canadians live and work and, as such, represent their most intimate contact with their natural environment. The trees and woodlands in and around our cities and towns provide a broad range of environmental and socio-economic benefits to society. A recent survey in Ontario indicates that urbanites in that province not only consider their urban forests to be very important to them; they are also concerned about their conservation and management. A strategy for a collaborative, sustained, and nationally based effort to advance urban forestry in Canada is presented under the themes of community action, interdisciplinary relations, policy, professional development, research, and urban forests and planning. Key words: urban forest, strategy, community action, interdisciplinary relations, policy, professional development, research, planning.

scholarly journals Application of terrestrial laser scanning in forest inventory – an overview of selected issues

2020 ◽  
Vol 81 (4) ◽  
pp. 175-194
Author(s):  
Grzegorz Krok ◽  
Bartłomiej Kraszewski ◽  
Krzysztof Stereńczak
Keyword(s):  
Remote Sensing ◽  
Data Processing ◽  
Forest Inventory ◽  
Laser Scanning ◽  
Sustainable Forest Management ◽  
Forest Policy ◽  
Terrestrial Laser Scanning ◽  
Remote Sensing Data ◽  
Temperate Climate ◽  
Accurate Information

Abstract Precise determination of forest resources is one of the most important tasks in conducting sustainable forest management. Accurate information about the forest’s resources allows for a better planning of current and future management as well as conservation activities. Such precise information is needed by both, individual forest managers and for developing the national forest policy. In recent years, interest in the use of remote sensing in forest inventory has significantly increased. Remote sensing allows for non-invasive measurements and the automation of data processing. The most accurate source of remote sensing data at the level of the sample plot is terrestrial laser scanning (TLS). Its use in forest inventory has been studied for about two decades. This paper aims to introduce studies on state of the art TLS technology as well as provide an overview of research conducted in stands within the temperate climate zone. This article furthermore discusses issues such as TLS data acquisition, data processing and presents results for the estimation of tree biometric features.

scholarly journals Review on the Use of Remote Sensing for Urban Forest Monitoring

2016 ◽  
Vol 42 (6) ◽  
Author(s):  
Razieh Shojanoori ◽  
Helmi Shafri
Keyword(s):  
Remote Sensing ◽  
Urban Areas ◽  
Urban Forest ◽  
Urban Forests ◽  
Potential Method ◽  
Forest Monitoring ◽  
Species Discrimination ◽  
Imaging Method ◽  
Object Based ◽  
Crown Delineation

Urban forests are vital in urban areas because they clean the air, absorb water, and protect the environment from intense heat. Destruction of the urban forest by increased urbanization is a considerable threat to the ecosystem. Hence, urban planners must obtain and manage information about urban forests, but the complexity of urban areas has made these tasks difficult. With developments in remote-sensing technologies, the monitoring and detection of urban forests can be achieved without performing any field measurements. In this study, different remote-sensing imageries and various methods are evaluated to obtain urban forest information. This review demonstrates that very high resolution (VHR) satellite imagery, such as from WorldView-2, is the most efficient data that can be used to obtain urban forest information. The use of the combination of LiDAR data with VHR imagery increases the accuracy of information, particularly about tree crown delineation. Traditional pixel-based classification methods are not effectively applicable to obtain urban tree information because of significant spectral variability in urban areas. An object-based classification technique, which uses spatial, textural, and color information, can be a potential method to detect urban forest and tree species discrimination. The new VHR imaging method, which uses the object-based technique, is recommended to overcome limitations of collecting urban forest information.

scholarly journals Urban Forest Research in Malaysia: A Systematic Review

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 903
Author(s):  
Keeren Sundara Rajoo ◽  
Daljit Singh Karam ◽  
Arifin Abdu ◽  
Zamri Rosli ◽  
Geoffery James Gerusu
Keyword(s):  
Developing Countries ◽  
Urban Forest ◽  
Urban Forestry ◽  
Urban Forests ◽  
Global South ◽  
Forest Research ◽  
Research Gaps ◽  
Continuous Increase ◽  
The Past ◽  
Research Themes

Sustainable urban development is a major issue in developing countries, namely in environmental and social aspects. Urban forests have the potential to address these issues. Thus, it is not surprising that urban forest research is slowly gaining traction in these regions. However, there have been limited urban forest research reviews focusing on developing countries, especially tropical countries in the global south. Research reviews are vital in identifying the distribution of research themes, hence revealing research gaps and needs. Therefore, this review paper aims to provide a deep insight into the development of urban forest research in Malaysia in the past 20 years. The core purpose of this review is to analyze the distribution of research themes in Malaysia, thus identifying research gaps and needs in developing countries. A total of 43 articles were selected for this review, using the PRISMA framework. The distribution of research articles showed a continuous increase over time, especially for the past five years (2016 to 2021). The reviewed articles were categorized according to five emerging research themes in urban forestry. More than 41% of the reviewed articles fell under Theme 1 (the physicality of urban forests), with the majority being on biodiversity (n = 10). Theme 5 (the governance of urban forest) had the lowest research output (n = 3). Urban forestry research is slowly gaining prominence globally including the global south; however, there are obvious preferences in research focus, causing some research questions to be neglected. These research gaps are especially evident in four areas—soil science, ecophysiology, valuation (economics), and environmental justice. These research gaps should be addressed by the scientific community to ensure a thorough and complete research growth pertaining to urban forestry.

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