Evaluation of the SNOWPACK model’s metamorphism and microstructure in Canada: a case study

The snow thermodynamic multi-layer model SNOWPACK was developed to address the risk of avalanches by simulating the vertical properties of snow. Risk and stability assessments are based on the simulation of the vertical variability of snow microstructure, as well as on snow cohesion parameters. Previous research has shown systematic error in grain size simulations (equivalent optical grain size) over several areas in northern Canada. To quantify the simulated errors in snow grain size and uncertainties in stability, the snow specific surface area (SSA) was measured with a laser-based instrument. Optical grain size was retrieved to validate the optical equivalent grain radius from SNOWPACK. The two study plots are located in Glacier National Park, BC, and Jasper National Park, AB, Canada. Profiles for density and stratigraphic analysis were obtained as well as grain size profiles, combined with snow micropenetrometer (SMP) measurements. Density analysis showed good agreement with the simulated values (R² = 0.76). Optical grain size analysis showed systematic overestimation of the modeled values, in agreement with the current literature. The error in SSA evolution for a rounding environment was mostly constant, whereas error for conditions driven by a temperature gradient was linked to the size of the facetted grains.     

Long-term rates of sediment accumulation in the Tonle Sap,Cambodia: a threat to ecosystem health?

The Tonle Sap is an invaluable resource for the people of Cambodia, and is a globally significant ecological site. Much of the literature published on the environmental health and management of the lake suggests that its sustainability is threatened by accelerated rates of infilling related to unfettered land-use in the catchment. However, the evidence for supposedly increased sedimentation rates is confused and contradictory, and there have been very few studies that have attempted to actually measure the rate at which sediment is accumulating on the bed of the lake. This research measures long-term sedimentation rates in the Tonle Sap in an attempt to provide an empirically derived baseline against which more recent and allegedly accelerated sedimentation rates can be compared. Radiometric dating techniques (¹⁴C, ²¹⁰Pb, ¹³⁷Cs) reveal that sediment has been accumulating in the lake at an average long-term rate of less than 1 mm per year. There is a clear and consistent decline in the rate of sediment accumulation in the lake basin over time, with the highest rates recorded in the middle to early Holocene epoch. It is recommended that research be directed toward measuring changes in the morphology of the lake margin over time, rather than focus on changes in the bathymetry of the lake basins themselves, which are here shown to be effectively stable in terms of sediment accumulation.     

The impact of perceived urban human settlement quality on subjective well-being: A case study using urban health examination data in the Yangtze River Delta region北大核心CSCD

城市体检是促进中国城市人居环境高质量和提升城市居民幸福感的创新举措,但却很少有研究正面关注城市体检社会评价对居民福祉的影响。论文基于2021年住建部在长三角地区8个样本城市开展的大规模城市体检社会满意度调查数据,采用主成分分析和多元回归分析相结合方法,分别探讨了长三角地区居民的城市人居环境质量感知因子及其对居民幸福感的影响,并从以人为本视角提出长三角地区城市人居环境高质量发展策略。研究发现:(1)城市体检社会满意度评价指标共提取了7个城市人居环境感知评价主成分因子,分别命名为城市管理、城市活力、城市舒适、城市宜居、城市包容、城市安全和城市便利,累计贡献率达到66.767%。(2)城市人居环境感知评价因子均对长三角地区城市居民幸福感具有显著影响,但不同城市人居环境感知评价因子的影响方向却存在差异性。其中,城市管理、城市活力、城市舒适、城市宜居和城市包容等因子显著正向影响幸福感,城市安全和城市便利等因子显著负向影响幸福感。(3)不同城市规模居民幸福感的人居环境主导因子有所不同,同时不同户口和年龄居民幸福感的人居环境影响因素也有差异。研究结果对促进长三角地区城市居民幸福感提升和指导城市人居环境建设具有重要的决策参考作用。     

Land cover changes in the rural-urban interaction of Xi’an region using Landsat TM/ETM data

1 Introduction Urbanization process in Xi’an has been accelerated after the Chinese governmentimplemented the strategy ofW estern Region Developmentof China aboutfouryears ago,which has caused the loss offarm land in urban peripheralareas.W hatis more,ur…     

Spatial chromatic model in high-dimensional spaces and the uniqueness of chromatic code: a new perspective of geographic entity–space relationship

The abstraction, representation, and computation of entity–space relationship are keystones of geographic information science (GIS). The newly proposed spatial chromatic tessellation (SCT) provides a novel model to explore this relationship. SCT has demonstrated a variety of potential applications in GIS, such as reasoning spatial topology, point pattern analysis, and Voronoi diagrams. This study aims to theoretically investigate SCT by focusing on two aspects: (1) extending SCT to higher dimensional spaces. Results show that cells missing in lower dimensional spaces are hidden in higher dimensional spaces; (2) exploring the uniqueness of chromatic codes, particularly the chromatic codes of 2-cell and 3-cell clusters: their codes are proved to be unique. In a mathematical perspective, the observed phenomena from the above two aspects bring some new thoughts into the first law of geography and spatial heterogeneity. Based on these new understandings of entity–space relationship, SCT is replaced by spatial chromatic model (SCM) in which spaces are created by entities themselves rather than by partitioning the space preexisted. This makes a change from an absolute geographic space to a relative geographic space.     

A Road to Conflict: Stakeholder’s and Social Network Analysis of the Media Portrayals of a Social-Environmental Conflict in Bolivia

Society’s understanding of a conflict is mediated by information provided in mass media, for which researchers stress the importance of analyzing media portrays of stakeholders in a conflict. We analyze information from the Bolivian press regarding the construction of a road crossing the Isiboro-Sécure Indigenous Territory and National Park (TIPNIS). Using stakeholder’s and social network analyses, we explore stakeholder’s positions and alliances as represented in the media and contrast it with previous scholarly work. We found that some actors cited as central in scholar analyses of the conflict are largely absent in the media (e.g., private investors, conservationist sector) and that the media tend to present stakeholders as having more homogeneous positions than the academic literature does while also neglecting some important alliances in their account. The media also suggests that Indigenous communities are forging stronger alliances with urban sectors and civil society, alliances not stressed by researchers.     

The border as an engine for mobility and spatial integration: A study of commuting in a Swedish–Norwegian context

The purpose of the study was to analyse how cross-border commuting differed from intranational commuting in Sweden, and how cross-border mobilities affected spatial integration. The authors analysed patterns and spatial flows of cross-border commuting by comparing them with characteristics of intranational commuting. In the article, they explore the assumption that the border constitutes an ‘engine’ for work-related mobility, which affects processes of spatial integration in cross-border areas. The empirical material comprised data from surveys of commuting from the Swedish county of Värmland to Norway and commuting within Värmland. The findings showed that cross-border commuting shared common features with intranational commuting, including how the frequency of commuting was dependent on distance. The motives for commuting differed, and the reasons for working in Norway were economic rather than professional. In terms of spatial integration, cross-border commuting was mainly one-directional, from Sweden to Norway, while leisure mobility and migration tended to be in the opposite direction. The authors conclude that the border region is characterised by integration through specialisation, which involves a permanent state of ‘transient’ mobility. Thus, a win-win situation can be distinguished, in which the border serves as a resource and an ‘engine’ for cross-border integration, mobility and economic activities.     

Impact of radiations on the long-range correlation of soil moisture: A case study of the A’rou superstation in the Heihe River Basin

Journal of Geographical Sciences - Analyses of the soil moisture evolution trend and the influence of different types of radiation on soil moisture are of great significance to the simulation and...     

“Is there a bubble to burst?”-college students’ spatial perception of campus and the city,a case study of rhodes college in memphis,TN

ABSTRACT

This paper builds on the study of student geography by critically examining college students’ perceived space of a university campus and the surrounding urban space. Rhodes College is a liberal arts college situated in the city of Memphis. As a campus with a majority white population located in a predominately black city, Rhodes College exists within but often separate from the city. It serves as a perfect case study to investigate how the college students build relationships with the environment within and beyond the campus. By using mental mapping and focus groups, this research unpacks four spatialities that shape college students’ perception of the urban space: (in)activity space, (im)mobility, boundaries, and center. This research demonstrates that student geography can be gendered, classed and racialized. The perceived space is socially constructed, and is reinforced by the lived and material space. Finally, this paper provides implications to facilitate deeper connections between students, the campus, and the city.     

The role of visualisation in the choice of stationary non-separable space–time covariance functions: an application to air pollution data

Modelling spatio-temporal dependencies resulting from dynamic processes that evolve in both space and time is essential in many scientific fields. Spatio-temporal Kriging is one of the space–time procedures, which has progressed the most over the last few years. Kriging predictions strongly depend on the covariance function associated with the stochastic process under study. Therefore, the choice of such a covariance function, which is usually based on empirical covariance, is a core aspect in the prediction procedure. As the empirical covariance is not necessarily a permissible covariance function, it is necessary to fit a valid covariance model. Due to the complexity of these valid models in the spatio-temporal case, visualising them is of great help, at least when selecting the set of candidate models to represent the spatio-temporal dependencies suggested by the empirical covariogram. We focus on the visualisation of the most interesting stationary non-separable covariance functions and how they change as their main parameters take different values. We wrote a specialised code for visualisation purposes. In order to illustrate the usefulness of visualisation when choosing the appropriate non-separable spatio-temporal covariance model, we focus on an important pollution problem, namely the levels of carbon monoxide, in the city of Madrid, Spain.     

Geochemical processes in a Mediterranean Lake: a high-resolution study of the last 4,000 years in Zoñar Lake,southern Spain

High-resolution geochemical analysis of a 6-m-long sediment core from Zoñar Lake, southern Spain, provides a detailed characterization of major changes in lake and watershed processes during the last 4,000 years. Geochemical variables were used as paleolimnological indicators and complement Zoñar Lakes’s paleoenvironmental reconstruction based on sedimentological and biological proxies, which define periods of increasing allochthonous input to the lake and periods of dominant autochthonous sedimentation. Chemical ratios identify periods of endogenic carbonate formation (higher Ca/Al, Sr/Al and Ba/Al ratios), evaporite precipitation (higher S/Al, Sr/Al ratios), and anoxic conditions (higher Mo/Al, U/Th ratios and Eu anomaly). Higher productivity is marked by elevated organic carbon content and carbonate precipitation (Mg/Ca). Hydrological reconstruction for Zoñar Lake was based on sedimentological, mineralogical and biological proxies, and shows that lower lake levels are characterized by Sr-rich sediments (a brackish lake with aragonite) and S-rich sediments (a saline lake with gypsum), while higher lake levels are characterized by sediments enriched in elements associated with alumino-silicates (Al, K, Ti, Fe, trace and rare earth elements), reflecting fresher conditions. Geochemical indicators also mark periods of higher detrital input to the lake related to human activity in the watershed: (1) during the Iberian Roman Humid Period (650 BC–AD 300), around the onset of the Little Ice Age (AD 1400), during the relatively drier Post-Roman and Middle Ages (AD 800–1400), and over the last 50 years, due to mechanized farming practices. Heavy metal enrichment in the sediments (Cu and Ni) suggests intensification of human activities during the Iberian Roman Period, and the use of fertilizers during the last 50 years.     

Elite discourses of regional identity in a new regionalism development scheme: The case of the ‘Mountain Region’ in Norway

Norway's regional structure is under debate as questions about territorial boundaries, scale, scope of tasks and responsibilities, and decision-making structures have become an issue in Norwegian politics. This tendency of changing the scale of public action with regard to governmental structures, economic politics, welfare, and civic society has been termed ‘new regionalism’. New regionalism often comes under criticism of being too neo-liberalistic or too economically orientated, leaving in its wake debates of democratic accountability and the neglect of ‘soft factors’ (i.e. socio-culture, identity, consciousness, and participation). In this article the authors investigate whether new democratic or semi-democratic regional organisations as advocated by new regionalist schemes require identification amongst the local population in order to be successful and enduring governmental structures. Further, it is shown how too simplistic understandings of the social processes, and their inherent power aspects, involved in the implementation of the new regionalist development scheme ‘Mountain Region’ distort the undertaking. The authors find that a more complex relational and contextual understanding is in demand, one in which regionalisation is not only recognised as a process which diffuses across time-space, but also takes an asymmetrical place across society's social fabric, and one where ‘soft factors’ such as ‘regional identity’ are not sidestepped.     

Limnogeology in Brazil’s “forgotten wilderness”: a synthesis from the large floodplain lakes of the Pantanal

Sediment records from floodplain lakes have a large and commonly untapped potential for inferring wetland response to global change. The Brazilian Pantanal is a vast, seasonally inundated savanna floodplain system controlled by the flood pulse of the Upper Paraguay River. Little is known, however, about how floodplain lakes within the Pantanal act as sedimentary basins, or what influence hydroclimatic variables exert on limnogeological processes. This knowledge gap was addressed through an actualistic analysis of three large, shallow (<5 m) floodplain lakes in the western Pantanal: Lagoa Gaíva, Lagoa Mandioré and Baia Vermelha. The lakes are dilute (CO₃ ²⁻ > Si⁴⁺ > Ca²⁺), mildly alkaline, freshwater systems, the chemistries and morphometrics of which evolve with seasonal flooding. Lake sills are bathymetric shoals marked by siliciclastic fans and marsh vegetation. Flows at the sills likely undergo seasonal reversals with the changing stage of the Upper Paraguay River. Deposition in deeper waters, typically encountered in proximity to margin-coincident topography, is dominated by reduced silty-clays with abundant siliceous microfossils and organic matter. Stable isotopes of carbon and nitrogen, plus hydrogen index measured on bulk organic matter, suggest that contributions from algae (including cyanobacteria) and other C₃-vegetation dominate in these environments. The presence of lotic sponge spicules, together with patterns of terrigenous sand deposition and geochemical indicators of productivity, points to the importance of the flood pulse for sediment and nutrient delivery to the lakes. Flood-pulse plumes, waves and bioturbation likewise affect the continuity of sedimentation. Short-lived radioisotopes indicate rates of 0.11–0.24 cm year⁻¹ at sites of uninterrupted deposition. A conceptual facies model, developed from insights gained from modern seasonal processes, can be used to predict limnogeological change when the lakes become isolated on the floodplain or during intervals associated with a strengthened flood pulse. Amplification of the seasonal cycle over longer time scales suggests carbonate, sandy lowstand fan and terrestrial organic matter deposition during arid periods, whereas deposition of lotic sponges, mixed aquatic organic matter, and highstand deltas characterizes wet intervals. The results hold substantial value for interpreting paleolimnological records from floodplain lakes linked to large tropical rivers with annual flooding cycles.     

Spatial-temporal change in urban agricultural land use efficiency from the perspective of agricultural multi-functionality: A case study of the Xi’an metropolitan zone

The excessive expansion of urbanized areas has resulted in haphazard land utilization, immoderate consumption of superior agricultural land and water resources, significant fragmentation of agricultural landscape, and gradual deterioration of the agro-ecological environment. Combined, these factors cause poor land use efficiency. Under these circumstances, comprehensively assessing land use efficiency for urban agriculture is a key issue in land use research. Currently, evaluation methods for agricultural land use efficiency narrowly concentrate on aspects of economic input and output. However, urban agro-ecosystems can provide diverse economic, social, and ecological services and functions. In particular, the social and ecological services and functions originating from agricultural land, which have a higher value than economic services, play a significant role in ensuring regional social, ecological, and environmental security. However, recent research has rarely taken these benefits into consideration. Therefore, land use value has been greatly underestimated, which has resulted in mishandled and poor land use policies. In this study, we apply Landsat imagery and social and economic statistical data for the Xi’an metropolitan zone (XMZ) to investigate agricultural multi-functionality. We develop an evaluation framework for urban agricultural land use efficiency and identify agro-ecosystem services and functions as important outputs from agricultural land. The land use efficiency of urban agriculture is then evaluated using ecosystem services models, providing a mechanism for assessing spatial-temporal changes in land use efficiency in the XMZ from 1999 to 2015. Four important conclusions are reached from this analysis. First, the rapid urbanization and agricultural transformation from traditional cereal cultivation to modern urban agriculture has resulted in steadily increasing costs, outputs, and land use efficiency of urban agriculture. The total output value increased 41% and land use efficiency per hectare increased by 33.13% on average. Second, the spatial patterns of comprehensive output and land use efficiency were dominated by economic outputs from agricultural land. Areas near cities, which are dominated by orchard and arable land, provide more economic functions. These areas support and regulate services due to the transformation from extensive cereal production to intensive modern urban agriculture; therefore, they have higher output value and land use efficiency. In contrast, areas distant from cities, towns, and high traffic roads, namely, remote rural areas, provide more support and regulating services, but have relatively lower economic function due to inaccessibility to urban markets and slow agricultural transformation. Therefore, these areas have lower output value and land use efficiency. The spatial change in agricultural output and land use efficiency in urban areas is strongly dependent on the degree of urbanization and agricultural transformation. Third, the total output value and land use efficiency of urban agriculture measured with our approach are much higher than evaluations using traditional methods. However, the spatial patterns measured using the two approaches are in agreement. The evaluation framework integrates ecological services and economic and social functions into a comprehensive output from agricultural land. This approach is more methodical and accurate for evaluating the comprehensive efficiency of land use based on quantities and spatial scale because they are at the pixel scale. Finally, the evaluation results have important implications for enhancing current agricultural subsidies and even implementing ecological payment policies in China. Most importantly, they can be directly applied to agricultural transformation regulations, decision- making, and guidance for rational land utilization.     

Spatiotemporal evolution of urban theft crimes and mechanism in the context of regular COVID-19 pandemic prevention and control: A case study of Haining,Zhejiang北大核心CSCD

新冠疫情的爆发会对区域内犯罪数量产生显著影响。然而,常态化疫情防控是否显著改变了犯罪空间分布格局,仍然有待进一步的实证检验。论文选择始终采取常态化疫情防控措施的浙江海宁市中心城区,采用标准差椭圆、核密度估计方法,对2018年2月—2021年7月城市盗窃犯罪的时空格局演变特征及其机理进行研究。结果表明:(1)新冠疫情爆发后,研究区内盗窃犯罪月均数量较疫情前降幅达53%,并持续在100~200起之间波动,而其日内分布模式却没有明显变化;(2)2020年2月—2021年7月,研究区内盗窃犯罪热点较疫情前有明显减弱、减少,且其犯罪空间分布格局较为稳定;(3)针对疫情前的12个典型犯罪热点区域,其月均犯罪数量在疫情后的降幅在52%~78%之间,其分季度的时间演变模式存在明显差异;(4)根据日常活动理论和犯罪三角理论,常态化疫情防控中有7类具体措施可对各区域的犯罪产生较大影响。研究结果对于理解重大突发公共卫生事件下的犯罪空间演变规律和制定科学的犯罪防控策略均具有重要参考价值。     

The role of money in China’s urban production: the local property industry in Qujing,a fourth-tier city

What has made the urbanization of capital possible in China since the late 1990s? A major strand of literature in urban geography has pointed out land as the main trigger of urbanization. Scholars have highlighted the empowerment of local governments and their subsequent role in implementing China’s national urbanization objectives because of substantial revenues from the commodification of land. Other scholars have looked beyond the supply side, emphasizing the role of demand in stimulating urban development in China. In terms of demand, the speculative rationale of urban households aided land and property development during the 2000s, when property became a main alternative financial asset. However, this still raises the question of how urban production is financed. Based on a case study of the fourth-tier city of Qujing, in Yunnan province, this article investigates the financing of urban production from the perspective of the development industry. For the time being, little is known about how these companies finance their operations.     

Estimating the size and distribution of South Asian religious populations in Britain: is there an alternative to a religion question in the census?

This paper addresses the question of whether there is an alternative to asking a direct religious question in the 2001 Census through a systematic review of alternative methods of quantifying religious populations. After establishing the limited availability of direct information on religion, the paper considers the application of an inferential method for estimating religious populations based on data from the 1994 Fourth National Survey of Ethnic Minorities (NSEM). Except for the monoreligious Pakistani and Bangladeshi populations, evidence of substantial spatial variation in the association between ethnicity and religion severely limits application of the method below national level. Using the religiously diverse Indian population of outer London as a case study, the NSEM is investigated to see whether the incorporation of other ?predictors? of religion as weighting variables improves sensitivity of the method to this variation. In a second method, logistic regression is employed to develop predictive models of religious affiliation for application to census microdata. Based on these two applications, it was concluded that very little of the variation in the religious geography of Indians in outer London can be inferred from measured characteristics in the census. However, this does not necessarily imply support for inclusion of a religion question in the 2001 Census. It was suggested that it may be more appropriate and cost effective to define and solve the need for data locally.     

How to identify transitional geospace in mountainous areas? An approach using a transitional index from the perspective of coupled human and natural systems

The coupling of humans and nature differs in terms of distribution and intensity, thus producing a gradient of synthetic geographical environments. Within this variety of gradients, the transitional zone represents a complex space where dynamic processes and unstable conditions are observed. Based on the concepts of ecotone and transitional zone, we propose a conceptual framework for the transitional geospace of coupled human and natural systems and a quantitative identification method for the z...