Exploring the rules of cropland elevation uplift in China

Cropland elevation uplift(CLEU) has recently become a new challenge for agricultural modernization,food security,and sustainable cropland use in China.Uncovering the rules of CLEU is of great theoretical and practical significance for China’s sustainable agricultural development and rural revitalization strategy.However,existing studies lack in-depth disclosure of multi-scale CLEU evolution rules,making it difficult to support the formulation of specific cropland protection policies.We analyzed the spatio-temporal evolution and multiscale CLEU in China from 1980 to 2020 using the Lorenz curve,gravity center model,hotspot analysis,and cropland elevation spectrum.The results indicated that the center of gravity of cropland moved to the northeast from 1980 to 2000 and then shifted to the northwest.The spatial distribution of cropland became increasingly imbalanced from 1980 to 2000.The change hotspots clustered in the northwest and the northeast,whereas cold-spots were mainly in southeastern China.The average elevation of cropland increased by 17.38 m,and the elevation uplift rule in different regions differed evidently across scales.From 1980 to 2000,all provinces except Xinjiang,Inner Mongolia,Gansu,and Yunnan exhibited CLEU,with Qinghai,Tibet,Beijing,and Guangdong showing the most noticeable uplifting.The CLEU can alleviate the shortage of cropland to some extent.However,without a planning constraint,the CLEU will lead to the increase of ecological risk and food security risk.

High-Speed Rail Route and Regional Mobility with a Ras-ter-Based Decision Support System: The Texas Urban Triangle Case

This study addresses sustainable transportation in the Texas Urban Triangle at the regional scale. Its aim is to determine the most suitable corridor for new transport infrastructure by employing a spatial decision support system proposed in this project. The system is being tested through its application to a prototype corridor parallel to Interstate 35 between San Antonio and Austin. The basic research questions asked are spatial in nature, so accordingly the geographic information system is the primary method of data analysis. The overall modeling approach is devoted to answering the following questions: What are the considerations to support sustainable growth? What scale or type of infrastructure is necessary? And how to adequately model the transportation corridors to meet the demands and to sustain the living environment at the same time?

Content analysis of state hazard mitigation plans and their ability to address pandemics

Hazard mitigation plans address hazards such as earthquakes,hurricanes,landslides,tornados,flooding more explicitly than pandemics or other public health crises.This paper analyzes and identifies pandemic-related mitigation strategies in state-level hazard mitigation plans across the United States.This study identifies common and uncommon strategies that could be included in plan updates such as:use of personal protective equipment(PPE),self-isolation/quarantine,hygiene,restricted gatherings,vaccination,vulnerability assessment,economic consequences analysis,acknowledging the need to address pandemics,and referring Centers for Disease Control and Prevention(CDC)guidelines.The 54 statelevel plans are compared based on their inclusion of the nine strategies.Findings show that vaccination,self-isolation/quarantine,and vulnerability assessment are the strategies most listed in plans.Additional concerns made evident by the 2020 coronavirus pandemic,such as contact tracing,environmental impact,and public services,were limited across the plans.It was concluded that long-term mitigation strategies for reducing the risk and speed of spread such as identifying strategic locations for testing,vaccination,and quarantine should be devised and implemented.Pandemics should be included as a distinct class of hazards while formulating state hazard mitigation plans.Strategies for addressing the impact of long working hours on the mental health of healthcare workers should be explored.Economic and psychological impact of unavailability of essential public services,such as transport and groceries,should be investigated and strategies should be formulated in the mitigation plans accordingly.

城市地域地表温度-植被覆盖定量关系分析——以深圳市为例

地表温度-植被覆盖间的关系一直是城市热岛研究的热点之一,两者均为描述生态系统特征的重要参数。本文利用深圳市2004年的ETM+影像,基于遥感技术提取相关的下垫面类型、地表温度和植被覆盖等信息,探讨不同下垫面类型对地表温度-植被覆盖关系的影响,并结合分形维度计算方法,比较不同分辨率下地表温度、植被覆盖及其相关关系的变化。研究结果表明,植被覆盖程度与地表温度之间存在明显的负相关,并且在不同的植被覆盖程度下,地表温度-植被覆盖关系呈现分段线性关系。下垫面类型及其组合主要通过植被覆盖的分布对地表温度产生影响。而在不同空间分辨率下(30m至960m),地表温度和植被覆盖的空间变异程度均表现为先升后降,在120m的分辨率下,两者的相关程度达到最高。结果证实区域植被覆盖状况可直接影响辐射、热动力以及土壤水分等多种地表特征,从而导致地表温度分异等。

区域设计:景观规划设计与城市规划优秀传统的复兴

本文认为,当代区域设计起源于传统的区域规划。物质设计复兴和传统区域规划是当代区域设计的两个来源。区域设计致力于塑造区域的物质形态,它通过适宜地引导社区中居民点的布局规划一个区域的未来。作为适应增长的战略,区域设计提供了一个物质框架,用以决定或引导社区在区域中最有利的位置、功能、规模和相互关系。社区、联系通道和边缘区这三者是区域设计概念的支柱。区域设计致力于通过交通、通讯及其他联系方式将社区联接成为一个区域网络,但同时又保持这些社区的相对独立。

Analyzing Asymmetric City Connectivity by Toponym on Social Media in China

The connectedness between cities has become one of the most widely discussed topics in urban and regional research in the mobile and big data era. One problem identified is the asymmetric city connectivity, partially due to data availability. We present a data-driven approach based on location and toponym(place name) extracted from social media data, to assess the asymmetric connectivity between cities. The assumption is that a higher frequency of occurrences of the name of city i in posts located in city j would imply that the city i is more influential than other cities upon city j. In addition, we’ve developed a group of measurements such as the relatedness index, impact index, link strength index, dependence index, and structure similar index to characterize such interactions. This framework of connectivity measurements can also be used to support smart planning taking into account the evolving interplay among cities. The space-time structure of urban systems in China is examined as the case study.

Land-use planning in China:Past,present,and future

Under the framework of ecological civilisation,the formulation of territorial spatial planning(TSP) and improvement of spatial governance systems are of great practical significance.Since the founding of the People’s Republic of China,land-use planning(LUP) has experienced profound changes,and tremendous research efforts have been made in that field.However,systematic studies on LUP history are scarce.To bridge the existing gap,this study traced back to the emergence of LUP,described its practice stages,and analysed the evolution of its classification system and methods.Further,the three rounds of general LUP practice and the current TSP over the past 40 years of the reform and opening-up have been discussed.The evolution of LUP was found to be closely related to economic development and could be broadly divided into four stages.The development of land-use classification in China has been slow and can be divided into five stages according to the evolution of the land classification system and important historical events.The development of LUP methods can be divided into two stages,before and after 1978.Since the economic reform,China has successively conducted three rounds of general LUP under different institutional and policy backgrounds.Future development should aim to innovate the theories and methods of TSP with Chinese characteristics and promote the study of village planning and the construction of TSP systems to achieve rural revitalisation and ecological civilisation.

Valuing ecological resources through stakeholder participation

This paper presents a pilot effort to identify a methodology to more efficiently codify, quantify and illustrate the intrinsic values associated with ecological resources as expressed by stakeholders. Existing methodologies examine the value of ecological resources, but are often criticized for their monetary focus. These methods generally produce quasi-market values for non-market resources. The natural and cultural resources associated with a national park are analyzed in terms of the expressed values of active stakeholders to quantitatively produce multiple dimensions of value for each resource relative to all others. The resulting abstract and graphical value-space quantitatively reflects stakeholder participation, reflects non-market intrinsic value, and proactively contributes to environmental management and decision making.

Social and geographical disparities in Twitter use during Hurricane Harvey

Socialmedia such as Twitter is increasingly beingused as an effective platform to observe human behaviors in disastrous events.However,uneven social media use among different groups of population in different regions could lead to biased consequences and affect disaster resilience.This paper studies the Twitter use during 2017 Hurricane Harvey in 76 counties in Texas and Louisiana.We seek to answer a fundamental question:did socialgeographical disparities of Twitter use exist during the three phases of emergency management(preparedness,response,recovery)?We employed a Twitter data mining framework to process the data and calculate two indexes:Ratio and Sentiment.Regression analyses between the Ratio indexes and the social-geographical characteristics of the counties at the three phrases reveal significant social and geographical disparities in Twitter use during Hurricane Harvey.Communities with higher disasterrelated Twitter use in Harvey generally were communities having better social and geographical conditions.These results of Twitter use patterns can be used to compare with future similar studies to see whether the Twitter use disparities have increased or decreased.Future research is also needed to examine the effects of Twitter use disparities on disaster resilience and to test whether Twitter use can predict community resilience.

Revisiting the gravity laws of inter-city mobility in megacity regions

Inter-city mobility is one of the most important issues in the UN Sustainable Development Goals,as it is essential to access the regional labour market,goods and services,and to constrain the spread of infectious diseases.Although the gravity model has been proved to be an effective model to describe mobility among settlements,knowledge is still insufficient in regions where dozens of megacities interact closely and over 100 million people reside.In addition,the existing knowledge is limited to overall population mobility,while the difference in inter-city travel with different purposes is unexplored on such a large geographic scale.We revisited the gravity laws of inter-city mobility using the 2.12 billion trip chains recorded by 40.48 million mobile phone users’trajectories in the Jing-Jin-Ji Region,which contains China’s capital Beijing.Firstly,unlike previous studies,we found that non-commuting rather than commuting is the dominant type of inter-city mobility(89.3%).Noncommuting travellers have a travel distance 42.3%longer than commuting travellers.Secondly,we developed more accurate gravity models for the spatial distribution of inter-city commuting and non-commuting travel.We also found that inter-city mobility has a hierarchical structure,as the distribution of inter-city travel volume follows Zipf’s law.In particular,the hierarchy of non-commuting travel volume among the cities is more in line with an ideal Zipf distribution than commuting travel.Our findings contribute to new knowledge on basic inter-city mobility laws,and they have significant applications for regional policies on human mobility.

Using Micro-Level Data to Evaluate Infrastructure of the Walking Environment Around Bus Rapid Transit Stations:A Case Study of Xiamen,China

China has experienced rapid car-oriented suburbanization during the past decades and is facing emerging challenges such as traffic congestion,air pollution,and even health threats.Learning from North American cities,Chinese cities have started adopting and implementing a Transit-Oriented Development(TOD) strategy,which encourages the transit ridership and walking trips by creating a pedestrian-friendly urban environment.Although much research has examined the walking environment in various neighborhoods or communities,few existing studies have examined the walking environment around transit stations,especially using micro-level data,such as walking infrastructure variables.This research chooses several infrastructure variables that are critical for pedestrians to investigate the walking environment around stations of the Bus Rapid Transit(BRT) No.1 Line in Xiamen City,China.This study defines a half mile buffer centered on each station as the spatial unit of analysis.The Geographic Information System(GIS) and field audits are employed to measure the characteristics of the infrastructure for pedestrians in each spatial unit of analysis.The results of this analysis can help assess the existing conditions of the infrastructure for pedestrians in each station area,which might need to be added or improved.The findings will not only provide empirical support for improving TODs in Xiamen,but also offer a lesson on how areas around transit stations could be retrofitted to improve the pedestrian environment.

Urban vitality assessment at the neighborhood scale with geo-data:A review toward implementation

The number of urban vitality assessment studies is rising continuously,owing to the emergence of geographic data.The current literature focuses primarily on evaluation,rather than implementation,of urban vitality.Hence,a scoping review and research agenda are needed for urban vitality research to be more practical.This study aims to fill the research gap by exploring the content and methods of vitality assessment that can make urban vitality research more compatible with policy,planning,and design practice.We chose the neighborhood scale,which is the most practical initiative unit for vitality enhancement.We discovered that the gaps between the current research and practice primarily lie in the diversity of research subjects,the authenticity and comprehensiveness of vitality measurement,and the multi-domain of impact factor analysis.On this basis,we classified the following expandable aspects:(1) multi-type,multi-dimensional,multi-temporal,and implementation-adaptive vitality evaluation;(2) methods reflecting high-quality social interactions and the perceptions of vulnerable groups;(3) how design and urban management impacts vitality;and(4) the synergistic effects of multiple indicators on vitality.Overall,the research content and methodology presented in this paper can help neighborhood-scale vitality assessment to provide more meaningful insights for policy makers and practitioners.

Estimating long-term K-12 student homelessness after a catastrophic flood disaster

Despite efforts to end homelessness in the United States,student homelessness is gradually growing over the past decade.Homelessness creates physical and psychological disadvantages for students and often disrupts school access.Research suggests that students who experience prolonged dislocation and school disruption after a dis-aster are primarily from low-income households and under-resourced areas.This study develops a framework to predict post-disaster trajectories for kindergarten through high school(K-12)students faced with a major disaster;the framework includes an estimation on the households with children who recover and those who experience long-term homelessness.Using the National Center for Education Statistics school attendance boundaries,resi-dential housing inventory,and U.S.Census data,the framework first identifies students within school boundaries and links schools to students to housing.The framework then estimates dislocation induced by the disaster sce-nario and tracks the stage of post-disaster housing for each dislocated student.The recovery of dislocated students is predicted using a multi-state Markov chain model,which captures the sequences that households transition through the four stages of post-disaster housing(i.e.,emergency shelter,temporary shelter,temporary housing,and permanent housing)based on the social vulnerability of the household.Finally,the framework predicts the number of students experiencing long-term homelessness and maps the students back to their pre-disaster school.The proposed framework is exemplified for the case of Hurricane Matthew-induced flooding in Lumberton,North Carolina.Findings highlight the disparate outcomes households with children face after major disasters and can be used to aid decision-making to reduce future disaster impacts on students.

重探城市群地区跨城移动性的引力模型

跨城移动性是联合国可持续发展目标中的重要问题之一,与区域劳动力市场、商品和服务以及遏制传染病传播紧密相关.尽管引力模型已被证明是刻画地区间移动性的有效模型,但针对数十个大城市密切联系、人口过亿的巨型城市群地区,仍然缺乏进一步研究.此外,现有研究仅限于人口总体的移动性,而大地理尺度下城市间不同出行目的的模型差异尚未被研究.利用京津冀地区4018万手机用户记录的21.2亿条出行链,重新探索和优化了城市群跨城移动性的引力模型.首先,发现非通勤是城市间流动的主要类型,占89.3%,非通勤者的出行距离比通勤者长42.3%.其次,我们为城市间通勤和非通勤出行的空间分布分别开发了更精确的引力模型.我们还发现,城市间流动具有层次结构,因为城市间出行量的分布遵循Zipf定律.特别是,城市之间的非通勤出行比通勤出行更符合标准Zipf分布.本研究有利于提高对跨城移动性规律的认识,并对区域人口流动相关政策的制定具有重要应用价值.

Roof greening in major Chinese cities possibly afford a large potential carbon sink

China is experiencing accelerated urbanisation,with a large number of people moving from rural to urban areas[1].It has resulted in large losses in the net primary production(NPP),biodiversity and carbon stocks and an increase in environmental pollution and CO_(2)emissions[2–4].In 2015,196 countries signed the Paris Agreement and committed to setting long-term goals to jointly manage climate change and reduce their individual emissions,aiming to control the increase in global average temperature from the pre-industrial level to below 2℃and to curtail the temperature rise within 1.5℃till the end of the 21st century[5].China is bolstering its efforts to achieve the climate change mitigation goals and has announced a plan for achieving carbon neutrality by 2060[6].The carbon neutrality goal poses a challenge to the current policies promoting rapid urbanisation across China.

中国社会经济与环境协调发展的可持续减贫模式

过去几十年里,中国在贫困地区实施了大量的减贫措施,贫困地区的基础设施和居民的生活水平得到了极大地改善.中国的贫困地区与生态保护区和脆弱区高度重叠,而贫困地区社会经济发展与环境之间的协调关系仍然没有得到充分认识.本研究提出了一个包含社会经济和生态环境维度的区县水平指标体系,揭示了贫困地区社会经济和环境的时空变化模式,并评估了它们之间的协调发展关系.研究表明,2000-2020年,中国贫困地区社会经济和环境的协调发展指数得到了加强.同时,在社会经济指数以58.4%的增长率实现增长的同时,环境指数也有明显改善,增长率为19.6%.贫困地区在社会经济发展方面与非贫困地区仍然有较大差距,但贫困地区在环境指数方面表现较好.得益于中国的地理多样性,本文确定了有利有效性、持续性、周期性和有限有效性四种减贫模式,可以为世界其他地区在应对减贫和环境保护方面的挑战提供参考.