Guofan Shao

Purdue University West Lafayette | Purdue · Department of Forestry and Natural Resources

Tree species mapping from the individual crown to landscape scales provides crucial information on the diversity and richness of forest ecosystems, supporting major conservation decisions under ongoing climate change. With the emergence of Remote Piloted Aircraft (RPA), high spatial resolution datasets can be obtained and analyzed to inherently imp...

Context Landscape sensation is essential for the delivery of cultural ecosystem services (CESs), yet the pathways through which these services are delivered remain inadequately understood. Exploring how people obtain CESs from landscapes facilitates better understanding of the tradeoffs and synergies between ecosystem services and landscape sustain...

Scientific researchers are known for their demanding intellectual efforts and are particularly susceptible to mental health disorders. Urban green spaces (UGSs) are beneficial for people’s mental health, yet there is limited research on what types of UGSs and activities are effective for improving researchers’ mental health. Here, we investigate if...

Image segmentation using deep learning has become overwhelmingly widespread. However, routine model testing methods can encounter evaluation inconsistencies or bias, largely due to how accuracy metrics respond to variations in class share distribution. Here we address the effects of class imbalance on model performance evaluation and demonstrates a...

The measurement of forest structure has evolved steadily due to advances in technology, methodology, and theory. Such advances have greatly increased our capacity to describe key forest structural elements and resulted in a range of measurement approaches from traditional analog tools such as measurement tapes to highly derived and computationally...

Accurately estimating land-use demand is essential for urban models to predict the evolution of urban spatial morphology. Due to the uncertainties inherent in socioeconomic development, the accurate forecasting of urban land-use demand remains a daunting challenge. The present study proposes a modeling framework to determine the scaling relationshi...

Urban form, especially urban functional form, is an important consideration for urban planning, construction, and management. Recent progress in characterizing urban functional form makes it possible to quantify the relationship between urban functional form and urban carbon emissions. We used urban functional form data from 178 cities of China to...

Precise tree inventory plays a critical role in sustainable forest planting, restoration, and management. LiDAR-based individual tree detection algorithms often focus on finding individual treetops to discern tree positions. However, deliquescent tree forms (broad, flattened crowns) in deciduous forests can make these algorithms ineffective. In thi...

Current techniques of forest inventory rely on manual measurements and are slow and labor intensive. Recent developments in computer vision and depth sensing can produce accurate measurement data at significantly reduced time and labor costs. We developed the ForSense system to measure the diameters of trees at various points along the stem as well...

The rapid expansion of different types of urban land continues to erode natural and semi-natural ecological space and causes irreversible ecological damage to rapidly industrialized and urbanized areas. This work considers Quanzhou, a typical industrial and trade city in southeastern China as the research area and uses a Markov chain integrated int...

With the increased availability of unmanned aerial systems (UAS) imagery, digitalized forest inventory has gained prominence in recent years. This paper presents a methodology for automated measurement of tree height and crown area in two broadleaf tree plantations of different species and ages using two different UAS platforms. Using structure fro...

This paper introduces a detailed procedure to utilize the high temporal and spatial resolution capabilities of an unmanned aerial system (UAS) to document vegetation at regular intervals both before and after a planned disturbance, a key component in natural disturbance-based management (NDBM), which uses treatments such as harvest and prescribed b...

Forest canopy height model (CHM) is useful for analyzing forest stocking and its spatiotemporal variations. However, high-resolution CHM with regional coverage is commonly unavailable due to the high cost of LiDAR data acquisition and computational cost associated with data processing. We present a CHM generation method using U.S. Geological Survey...

Machine learning (ML) reproducibility needs to be informed with reliable evaluation measures. However, routine image classification is evaluated using metrics that are highly sensitive to class prevalence. Consequently, the reproducibility of ML models remains unclear due to class imbalance-induced noise. We suggest regularly using class imbalance-...

Accuracy assessment is essential in all image classification-related fields, ranging from molecular imaging to earth observation. However, existing accuracy metrics are too sensitive to class imbalance or lack explicit interpretations for assessing classification performance. Consequently, their scores may be misleading when they are applied to com...

The Karakoram-Himalayan (KH) region comprises high mountains across seven countries (i.e., China, Afghanistan, Pakistan, India, Nepal, Bhutan, and Myanmar) with a variety of management regimes and priorities and capacities for conservation. Currently, there is no comprehensive framework for assessing cooperation on protected areas (PAs) in the KH r...

Unmanned Aerial Systems (UAS) serve as an excellent remote-sensing platform to fulfill an aerial imagery data collection niche previously unattainable in forestry by satellites and manned aircraft. However, for UAS-derived data to be spatially representative, a precise network of ground control points (GCP) is often required, which can be tedious a...

Mapping surface water distribution and its dynamics over various environments with robust methods is essential for managing water resources and supporting water-related policy design. Thresholding Single Water Index image (TSWI) with threshold is a common way of using water index (WI) for mapping water for it is easy to use and could obtain accepta...

The COVID-19 pandemic caused drastic changes in human activities and nighttime light (NTL) at various scales, providing a unique opportunity for exploring the pattern of the extreme responses of human community. This study used daily NTL data to examine the spatial variations and temporal dynamics of human activities under the influence of COVID-19...

Compact development is one of the most effective solutions for sustainable urbanization under the rapid growth of the urban population. Great efforts have been made to measure urban physical compactness while limited attention has been paid to functional zoning of urban areas. Here, we introduce a novel index, called the functional compactness inde...

The utilization of urban green space (UGS) in a city contributes to people’s mental and physical health. Information on the perceptions and attitudes of people from landscape evaluation and preference studies serves as an important scientific basis for the planning and management of UGS. This study used eye tracking and an online questionnaire to i...

In recent years, with the development of society, the awareness of environmental protection for people has been increasing. While ports promote the economic development and employment levels of port cities, they also have a negative impact on the environment of port cities. The sustainability of port cities is increasingly valued. Port cities face...

Land use/land cover (LULC) pattern change due to human activity is one of the key components of regional and global climate change drivers. Urban green space plays a critical role in regulating urban thermal environment, and its cooling effect has received widespread attention in urban heat island (UHI) related studies. To fully understand the effe...

The Original article has been corrected.

Intense human activities and drastic land use changes in rapidly urbanized areas may cause serious water quality degradation. In this study, we explored the effects of land use on water quality from a landscape perspective. We took a rapidly urbanized area in Hangzhou City, China, as a case study, and collected stream water quality data and algae b...

The difficulty of obtaining reliable individual identification of animals has limited researcher’s ability to obtain quantitative data to address important ecological, behavioral and conservation questions. Traditional marking methods placed animals at undue risk. Machine learning approaches for identifying species through analysis of animal images...

The Normalized Difference Vegetation Index (NDVI), one of the earliest remote sensing analytical products used to simplify the complexities of multi-spectral imagery, is now the most popular index used for vegetation assessment. This popularity and widespread use relate to how an NDVI can be calculated with any multispectral sensor with a visible a...

The timely and accurate recognition of damage to buildings after destructive disasters is one of the most important post-event responses. Due to the complex and dangerous situations in affected areas, field surveys of post-disaster conditions are not always feasible. The use of satellite imagery for disaster assessment can overcome this problem. Ho...

The land use and land cover changes in rapidly urbanized regions is one of the main causes of water quality deterioration. However, due to the heterogeneity of urban land use patterns and spatial scale effects, a clear understanding of the relationships between land use and water quality remains elusive. The primary purpose of this study is to inve...

Forest inventorying is time-consuming and expensive. Recent research involving photogrammetry promises to reduce the cost of inventorying. Existing photogrammetry methods require substantial data-processing time, however. Our aim was to reduce data-acquisition and processing times while obtaining relatively accurate diameter estimates compared to m...

This special issue is the first systematic introduction to the progress of landsenses ecology and its applications since its formation in 2016. As a people-oriented, science-technology-based emerging discipline, landsenses ecology connects our physical senses with digital sensors, and balances the local and global considerations of ecosystem servic...

The downstream reach of the Three Gorges Dam (TGD) along the Yangtze River (1560 km) hosts numerous mid-channel bars (MCBs). MCBs dynamics are crucial to the river's hydrological processes and local ecological function. However, a systematic understanding of such dynamics and their linkage to TGD remains largely unknown. Using Landsat-image-extract...

This paper presents a concept of sustainable development from the perspective of ecosystem services and analyzes some existing problems in ecosystem service assessment. It also proposes the concepts of landsense, landsense creation (LC) and general landsenses ecology in order to expand the research and application of landsenses ecology, and discuss...

Information about urban built-up areas is important for urban planning and management. However, obtaining accurate information about urban built-up areas is a challenge. This study developed a general-purpose built-up area intelligent classification (BAIC) system that supports various types of data and classifiers. All of the steps in the BAIC were...

Highly suitable but limited ecological space continues to become one of the most critical constraints in the processes of urbanization due to extremely scarce land resources in urban areas. Urban cellular automata have become an effective tool for simulating the development of cities. However, the constraints in the current literature are establish...

Context Image classification is routine in a variety of disciplines, and analysts rely on accuracy metrics to evaluate the resulting maps. The most frequently used accuracy metric in Earth resource remote sensing is overall accuracy. However, the inherent properties of this accuracy metric make it inappropriate as the single metric for map assessme...

In our study, we collected 146 surface soil samples in Xiamen City and measured the concentrations of five heavy metals (Cr, Cu, Pb, Ni, and Zn) and one metalloid (As). Multivariate statistics, geostatistics and Random Forest methods were applied to identify the potential sources and spatial variation of the six elements. The results revealed that...

Rapid assessment of natural disasters is essential for disaster analysis and spatially explicit strategic decisions of post-disaster reconstruction but requires timely available data. The recent daily data of the National Polar-Orbiting Partnership Visible Infrared Imaging Radiometer Suite (NPP-VIIRS) day/night band (DNB) provide new opportunities...

Optical remote sensing (ORS) is a traditional remote‐sensing method. Contemporary ORS data are largely in digital formats and may consist of visible, near‐infrared (NIR), and shortwave infrared (SWIR) bands. ORS data can be characterized with radiometric, spatial, spectral, and temporal resolutions. Ground‐based, airborne, and spaceborne ORS system...

The downstream of the world’s largest Three Gorges Dam (TGD) along Yangtze River (1560 km) hosts numerous mid-channel bars (MCBs). The morphodynamics of these MCBs are crucial to the river’s hydrological processing, local ecological functioning, and socioeconomic development. However, a systematic understanding of such dynamics and their linkages t...

In recent years, intensified industrialization and rapid urbanization have accelerated the accumulation of trace metals in topsoils of the Golden Triangle of Southern Fujian Province in China. Trace metals can cause adverse impacts on ecosystems and human health. In order to assess the ecological and human health risks of trace metals in the Golden...

Delineation of individual deciduous trees with Light Detection and Ranging (LiDAR) data has long been sought for accurate forest inventory in temperate forests. Previous attempts mainly focused on high-density LiDAR data to obtain reliable delineation results, which may have limited applications due to the high cost and low availability of such dat...

Intensifying urbanization and rapid population growth in Fujian Province, China, has caused pollution of air and water resources; this has adversely impacted ecosystems and human health. China has recently begun pursuing a massive infrastructure and economic development strategy called the Belt and Road Initiative, which could potentially cause fur...

The landscape ecological risk (LER) in Xiamen City, China, from 1990 to 2030 was studied using an urban land use and land cover change (LUCC) model and LER analysis. The LUCC model was used to predict the LUCC of Xiamen from 2020 to 2030. We analyzed the characteristics of LUCC and landscape pattern changes and, finally, evaluated the effect of rap...

Excessive logging in China is the major cause of poor forest quality, degraded ecosystem functions, and near exhaustion of harvestable resources of the country's natural forests. An overall extended moratorium on logging in the country's natural forests has been launched since 2015, which is a suggested method for the gradual recovery of the struct...

Conservation programs that incentivize the increased provision of ecosystem services on private lands have become common policy instruments. The forgone revenues implied by these programs and the ecosystem services benefits they provide might be spatially heterogeneous. However, such programs are not always spatially targeted to maximize the return...

Urban sustainable development strategies are of great importance to rapidly urbanized countries such as China. One of the most challenging problems is how to coordinate urban spatial development with social efficiency and environmental protection, e.g., highly efficient low-carbon urban traffic. Despite broad research efforts with respect to the in...

Optical remote sensing (ORS) is a traditional remote sensing method. Contemporary ORS data are largely in digital formats and may consist of visible, near‐infrared, and shortwave infrared bands. ORS data can be characterized with radiometric, spatial, spectral, and temporal resolutions. Both airborne and spaceborne ORS systems are available for a v...

It is useful and challenging to analyze and select object features of very high resolution (VHR) remote sensing imagery. The overwhelming majority of existing feature selection methods always concatenate all of the features into a long feature vector and then select features from the vector, ignoring the homogeneity and heterogeneity of underlying...

The planning and construction of large-scale coal-fired power plants are important components of China’s future energy development strategy in response to global environmental problems, as proposed in China’s Twelfth Five-Year Plan for National Economic and Social Development. With the rapid socio-economic development, research and assessments of e...

Forest wildfires pose significant and growing threats to human safety, wildlife habitat, regional economies and global climate change. It is crucial that forest fires be subject to timely and accurate monitoring by forest fire managers and other stake-holders. Measurement by spaceborne equipment has become a practical and appealing method to monito...

Remote sensing has evolved from airborne to spaceborne since the 1960s. Recent advances in drone remote sensing represent a more flexible and affordable option. A variety of sensors are used to record both visible and invisible, such as infrared, parts of the spectrum of electromagnetic radiation. Depending on the number of spectral bands used, rem...

Earth observation satellites collect a variety of data relevant to a wide range of Earth resource topics, including Earth surface features and atmospheric conditions. Satellite data are collected, transmitted, stored, and analyzed in digital forms. Satellite data are characterized with spatial, spectral, radiometric, and temporal resolutions. A gen...

Urban ecological risk (UER) caused by rapid urbanization means potential threat to urban ecosystem structure, pattern and services. The scales of ecological risk assessment (ERA) have been expanded from individual organisms to watersheds and regions. The types of stressor range from chemical to physical, biological and natural events. However, the...

Features relevant to a thematic class, that is, class-specific features are beneficial to thematic information extraction. However, existing class-specific feature selection methods require abundant labelled samples, while sample labelling is always labour intensive and time consuming. Therefore, it is necessary to select class-specific features wi...

Semisupervised feature selection methods can improve classification performance and enhance model comprehensibility with few labeled objects. However, most of the existing methods require graph construction beforehand, and the resulting heavy computational cost may bring about the failure to accurately capture the local geometry of data. To overcom...

Urban cellular automata (CA) models are broadly used in quantitative analyses and predictions of urban land-use dynamics. However, most urban CA developed with neighborhood rules consider only a small neighborhood scope under a specific spatial resolution. Here, we quantify neighborhood effects in a relatively large cellular space and analyze their...

With the emerging problems of air pollution and urban heat island associated with urbanization, urban microclimatic spatial planning was attended unprecedentedly. Microclimatic spatial planning is proposed within the framework of landsenses ecology and its aim is to harmoniously integrate human with nature and specifically to improve the microclima...

This paper proposes the concepts and associated contents of landsenses ecology and mix-marching data, and explains the roles of the meliorization model and Internet of Things (IoT) in the landsenses ecology-based land-use planning, construction and management. It also analyses the importance and application approaches of mix-marching data. In the c...

Ecosystem management is to make adaptive management strategy based on full understanding the process of composition, structure and function of ecological system, and to restore or maintain ecosystem integrity and sustainability. Forest ecosystem management attempts to maintain forest ecosystem complex process, path and the interdependent relationsh...

The economic zone on the western bank of Taiwan Straits represents one of the key development regions for the future under the national development strategic planning. The sustainable development of the economic zone requires the improved our understanding of the current status of ecological landscapes and their changes in the past within the regio...

The presence of shadows in optical satellite images limits the application of remote-sensing technology. It is important to restore shadow radiance information for improving information extraction from remote-sensing images. Several shadow-restoration methods have been developed using complex statistical relationships between shadowed areas and the...