Predicting Growth of City\u27s Built-up Land Based on Scenario Planning

In this paper, method of scenario planning is applied to the study of land use planning, putting forward a new approach to analyze future growth of city\u27s built-up land in the context of future uncertainty. By introducing economic and policy factors into land use system, a calculation model of urban built-up land is built based on the correlation between industries and land use. And using Chongqing Municipality from China as an example, we establish 6 different scenarios and simulate future development of city\u27s land use from 2015 to 2020 under each scenario. The results indicate that Chongqing will meet fast urban expansion according to current trend and is in urgent need to improve its land use efficiency which shows strongest effect in controlling city size

A Self-Adjusting Approach to Identify Hotspots

Hotspot identification or detection has been widely used in many fields; however the traditional grid-based approaches may incur some problems when dealing with point database. This article expands on three types of mismatch problems in grid-based approach and suggests a point-based approach may be more suitable. Inspired by the DBSCAN algorithm, a self-adjusting approach is then proposed for hotspot detection which overcomes the weakness of parameter sensitivity shared by most clustering approaches. Finally, the data of commercial points of interest of a city is used for demonstration

Urban Growth Boundaries of the Hangzhou Metropolitan Area Based on Ecosystem Service

The identification of urban growth boundaries (UGBs) as components of an ecologically liveable city is rather significant in urban space management. However, the evaluation of ecosystem service in establishing UGBs as reactions to protect open spaces and ecological sensitive area are largely ignored. Furthermore, the lack of scenario analysis for urban growth patterns has made it difficult to adjust planning existed. Accordingly, in this paper, we take Hangzhou metropolitan areas (HMA) as the study area, using Landsat TM image data, and established the UGBs for the HMA based on ecosystem service by the Green Infrastructure Assessment (GIA) model with scenario analysis. The results suggested that: 1) The risk of urban development in the northern and eastern areas of the central city is relatively low, while the southern, eastern and south-western areas need intensive protection; 2) In the model of ecological management, the erosion of ecological space has increased gradually and the regional ecological patterns in the fourth scenarios have faced great challenges; 3) UGBs for the HMA were identified as the view of development and ecological space complementarily

Progress in the Application of Chemometrics in the Field of Food Flavor

Flavor substances affect the sensory properties of food and consumer choices, and flavor substance analysis is crucial for improving food quality and developing new products. However, the vast amount of flavor substance data and inappropriate statistical analysis greatly limit the development of this field. Therefore, it is crucial to use new chemometrics methods, such as artificial intelligence algorithms, correctly and reasonably to obtain effective information in this field. In recent years, chemometrics methods have been widely applied in food research. In addition to dimensionality reduction, classification and regression methods, various neural network methods have also emerged in the field of food research. However, a summary of their reasonable application is lacking. Therefore, this article summarizes the statistical analysis methods available to study food flavor, including principal component analysis, linear discriminant analysis, linear regression methods such as partial least squares regression, and nonlinear methods such as fuzzy logic and artificial neural networks, explains their principles and provides application examples. This article aims to provide effective methods and ideas for further research on chemometrics in the field of food flavor

Analysis of Sensory Characteristics and Aroma-Active Substances of Milk from Different Farms Using Check-All-That-Apply and Gas Chromatography-Mass Spectrometry-Olfactometry

In this study, the check-all-that-apply (CATA) method, headspace solid phase microextraction (HS-SPME)-Arrow combined with gas chromatography-mass spectrometry (GC-MS) and gas chromatography-mass spectrometry-olfactometry (GC-MS-O) were used to analyze volatile flavor substances that affect the sensory differences among milk from four pastures. The results of the CATA questionnaire showed that milky aroma, creamy aroma, fragrant and sweet aroma, milky aroma, plastic odor, cooked odor and metallic odor were significantly different among the four milk samples (P < 0.05), and milk from pasture I were the most preferred by respondents, and the preference scores of milk from pastures III and IV were lower. Totally 14 aroma-active substances with an aroma intensity greater than or equal to 1 were obtained from the four milk samples through olfactometry. Using partial least squares regression analysis (PLSR), correlation analysis among sensory data, aroma-active substances and milk samples was conducted. The results showed that milky and creamy aroma from pasture I were prominent, which was strongly correlated with 2-heptanone, butanoic acid, decanoic acid, and hexanoic acid. Milk from pasture II showed a fragrant and sweet aroma, which may be related to the concentration of limonene. Milk from pasture III had prominent metallic, plastic, and milky odors, which may be related to 1-octene-3-alcohol. Milk from pasture IV had a cooked odor, which mainly came from hexanal and styrene

Exploring the Features of Sustainable Urban Form and the Factors that Provoke Shoppers towards Shopping Malls

This study examined various features of urban form, which promote sustainable development and provoke shoppers toward shopping malls. A field survey was conducted in shopping malls at Hangzhou, which is the capital city of the Zhejiang province, China. Structural equation modeling and a confirmatory factor analysis were used to measure the hypotheses. The results of this study showed that the built environment and entertainment completely mediated the relationship between ambiance and consumption, and they have a positive impact on the environment and shoppers. The built environment and entertainment are viewed as essential elements of physical and social sustainability. Real estate developers, urban planners, and shopping mall managers should consider the design features of urban form to meet sustainable development goals and to attract more shoppers. Testing these relationships via a mediating method is a novel contribution to the study of shopping malls

The Impact of High-Speed Rail on Economic Development: A County-Level Analysis

High-speed rail has an important impact on the location choices of enterprises and the labor force, which is reflected in a complex space–time process. Previous studies have been unable to show the change characteristics between enterprises and the labor force at the county level. Therefore, based on the new economic geography theory, we first constructed a theoretical analysis framework to explore high-speed railway’s impact on county economy development and then obtained the two economic subdivision factors’ impacts: industrial enterprises and secondary labor force. Then, based on the panel data of 1791 county units in China from 2003 to 2019, the study constructed a multi-period PSM-DID model to empirically explore high-speed rail’s impact on the county’s agglomeration of industrial enterprises and secondary labor force. The results show that high-speed rail has a long-term negative effect on the county area’s agglomeration of industrial enterprises. From the perspective of the labor force, high-speed rail has a long-term and continuous positive effect on the agglomeration of the secondary labor force in county units

Spatiotemporal dynamics and driving forces of cultivated land in China

Abstract It is important to study the temporal and spatial change characteristics and the decreasing trend in cultivated land in China in the past decades, analyze the core influencing factors of the cultivated land decrease, and understand the regularity and trend in the cultivated land change. This study has important guiding significance for ensuring food security in China and optimizing and adjusting the pattern of land spatial development and utilization. Based on the data of China’s urban cultivated land change from 1990 to 2022, this study analyzes the pattern of cultivated land protection and destruction in China from the perspective of the total cultivated land change, the increase and decrease evolution characteristics, and future trends and determines the main driving factors of cultivated land destruction in the process of urbanization. The results show the following: (1) The goal of the dynamic balance policy of cultivated land in China from 1990 to 2022 has been basically achieved, but regional differences still exist, which show a spatial pattern of planar contraction and belt growth. There is a new feature of a “southwest, northwest, and northeast” increase, while there is a “central” decrease. (2) Cultivated land has gradually shown a trend of growth rather than contraction, the cultivated land contraction shows a trend of crossing the “Hu–Huanyong Line” and moving westward, and the center of gravity of the cultivated land contraction has shifted to the periphery of the Chengdu–Chongqing area. The cultivated land growth shows a trend of moving southeast across the “Hu–Huanyong Line”, and developed provinces such as Guangdong, Fujian, and Zhejiang have gradually become the new centers of cultivated land growth. This coincides with the strict implementation of basic cultivated land protection policies in developed areas of China in recent years. (3) Factors such as the urban population size, economic level, agricultural scale, industrial structure, and other types of land scale have different degrees of impact on the destruction and restoration of cultivated land

Spatiotemporal Dynamic Characteristics and Causes of China’s Population Aging from 2000 to 2020

Aging involves the transformation of the population reproduction mode under the rapid development of the social economy. We studied population survey data based on the WorldPop population statistics website and used ArcGIS to construct a spatial database and implement spatial analysis methods. In this study, we analyzed the spatiotemporal evolution characteristics of population aging and its main influencing factors in counties of China, in order to provide a reference for the formulation of a national population development policy and the construction of a pension system. The results are as follows: ① The situation of population aging in China is becoming more serious, showing a point-line-area spatial pattern and two core–periphery aging patterns of high core–low periphery and low core–high periphery. ② The speed of population aging in China is characterized by rapid growth, large scale, and a high degree. Large areas of growing old before getting rich have emerged in the central and western regions. ③ The aging of the population has gradually spread to the northeast, southwest, northwest, and other regions. Influenced by factors such as population migration, population structure change, transportation facility construction, and geographic environment changes, a trend of aging that has spread across the Hu Huan-Yong line has appeared