Shuanning Zheng

A neighbor decay cellular automata approach for simulating urban expansion based on particle swarm intelligence

Simulation and quantitative analysis of urban land use change are effective ways to investigate urban form evolution. Cellular Automata (CA) has been used as a convenient and useful tool for simulating urban land use change. However, the key issue for CA models is the definition of the transition rules, and a number of statistical or artificial intelligence methods may be used to obtain the optimal rules. Neighborhood configuration is a basic component of transition rules, and is characterized by a distance decay effect. However, many CA models do not consider the neighbor decay effect in cellular space. This paper presents a neighbor decay cellular automata model based on particle swarm optimization (PSO-NDCA). We used particle swarm optimization (PSO) to find transition rules and considered the decay effect of the cellular neighborhood. A negative power exponential function was used to compute the decay coefficient of the cellular neighborhood in the model. By calculating the cumulative differences between simulation results and the sample data, the PSO automatically searched for the optimal combination of parameters of the transition rules. Using Xiamen City as a case study, we simulated urban land use changes for the periods 1992–1997 and 2002–2007. Results showed that the PSO-NDCA model had a higher prediction accuracy for built-up land, and a higher overall accuracy and Kappa coefficient than the urban CA model based on particle swarm optimization. The study demonstrates that there exist optimal neighborhood decay coefficients in accordance with the regional characteristics of an area. Urban CA modelling should take into account the role of neighborhood decay.

Experimental mobile environmental monitoring and real-time analysis as an initial application of EIoT in town villages in China

Villages in China have been greatly impacted by the countrywide urbanisation process, and many of them have undergone transformation in landscape structure and rapid changes in environment. However, environmental monitoring in urbanising villages, or town villages, cannot be fully realised by the existing environmental monitoring infrastructure and resources. We intended to apply Environmental Internet of Things (EIoT) technology to fulfill this task, beginning with the development of a Mobile Meteorological Monitor (3M) consisting of an ultrasonic weather station, an industrial tablet PC, a foldable mountain bicycle and a series of accessories. The initial application of 3M in environmental monitoring for a town village indicates that the monitoring capability could be expanded to carry out the monitoring of other environmental variables, such as water quality, air pollution and noise pollution. By simultaneously employing multiple 3M units, it is possible to generate a spatiotemporal framework of monitoring data for landscape-level environmental analysis and modelling. Such an approach is economically affordable and scientifically reliable. The application of EIoT as it matures over time will revolutionise future environmental monitoring and governance.

Real-time measurement of wind environment comfort in urban areas by Environmental Internet of Things

Wind environment comfort (WEC) can have major impacts on people who use outdoor spaces within a city. WEC in urban areas is directly linked to the configuration of urban geometry, including street axes, building heights, and other attributes. Thus, it is valuable to provide an outdoor WEC measure at pedestrian level in as much detail and close to real time as possible. In this paper, a system for the real-time measurement of WEC (SRTM-WEC), one of the subsystems of Environmental Internet of Things (EIoT), was established to conduct real-time measurements of the WEC value in Pingtan Island, Fujian Province. Four layers were employed in the system to handle data measurement, synchronized data transfer, data manipulation, and application tasks. It was demonstrated that EIoT enabled the system to successfully perform real-time WEC measurement in urban area. Six favorable attributes obtained for the system include low cost, small size, ease of installation, low-cost operation, ease of retrofit in existing spaces, and independence from specific manufacturers.

Landsenses pattern design to mitigate gale conditions in the coastal city – a case study of Pingtan, China

ABSTRACT Due to the special geographic locations and multiple typhoons a year, the frequent strong winds bring great discomfort and danger to the daily lives of the urban residents in southeast coast of China. The strategic design of landsenses pattern on different scales can help reduce gale days in urban areas while delivering diverse additional benefits such as pollution control and biodiversity habitat protection. Although the greatest gale days are observed in cold and damp winters, there is comparatively little information available for land managers to determine an appropriate strategy for landsenses pattern design under these climatic conditions. We present a framework for prioritization and selection of landsenses pattern for gale day reductions. The framework is supported by examining the relationships between urban landsenses pattern evolution and gale day mitigation in the past, with which we used to develop implementation guidelines that maximize reductions of urban surface gale days. We focus particularly on quantifying the benefits of four types of landsenses: land-use patterns, urban road network, architectural patterns, and vertical greening systems (green walls and facades) and demonstrate how to apply the framework with a case study from Pingtan Island, China.

Risk assessment for effective prevention and management of forest fires in Lijiang City

Forest fires threaten natural resources and human lives in many areas of the world. A rational assessment of forest fire risk is critical to reduce fire damage that threatens the sustainability of forest resources and their services. This is particularly true in Lijiang City, an important world heritage site. We assessed the grades of forest fire risk in Lijiang City based on the concept of a fire life cycle, using the probability of ignition in the pre-forest fire period, the capacity for detection and emergency rescue in the mid-forest fire period, and forest fire damage in the post-forest fire period. We used the analytical hierarchy process to analyse data on the ecology, economy, cultural resources, humanities and topography of Lijiang City, and geographic information systems (GIS) as a platform to integrate multi-source data. The results strongly agree with the records of reported forest fires between 2000 and 2011. This assessment method could be used in cities with large areas forestland that contains important resources and settlements, but without sufficient fire-fighting capacity to prevent and fight forest fires.

Microclimatic spatial planning for Xianghe Segment of China’s Grand Canal

ABSTRACT 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 microclimate comfortable sensation for people from wind speed, temperature, humidity, etc. In this paper, we analyzed the current spatial pattern of the microclimate in Xianghe Segment of China’s Grand Canal (XSCGC) based on meteorological data, and a computational fluid dynamics (CFD) simulation of human comfort and microclimate expandability. Finally, spatial planning recommendations for XSCGC were proposed to suppress northeasterly winds and protect southwesterly winds, which helped divide the planning area into four functional land-use types to improve the livability and security of microclimate, including microclimate regulatory areas, development core areas, natural ventilation corridors areas, and development extension areas.

Urban ecological risk assessment management platform

ABSTRACT Due to rapid socioeconomic development in recent years, the influence of human activities on the urban ecosystem and environment is becoming more pronounced, causing increases in accumulated pollutants, resource consumption, and built-up land area. At this time, cities are facing complex ecological threats. We designed a platform to classify and assess the various types of ecological risks that cities and urban agglomerations may encounter. We used PHP to develop a web-based application, with nginx as the platform server, and MySQL to manage the background database. The platform provides users with a clearly structured, visual platform to manage ecological risk. By using this platform, users can quickly identify regional risk sources, find and describe risk factors, and predict possible consequences caused by these risks based on simulation modeling. The forecasting model and database can be synchronously updated and adjusted according to the actual situation. The visual web management platform and user security login system employ the MD5 encryption algorithm. The platform is designed to provide convenient, accurate, and scientific decision-making services for urban planning, construction, environmental protection, and other related areas.