An analysis of intra-event precipitation variability for the United States (1980–2010)

Hourly precipitation data were collected from 143 first-order US weather stations during the period from 1980 to 2009 to assess the internal distribution of precipitation events lasting at least three hours. A total of 46,595 individual precipitation events were identified and evaluated using the mean, standard deviation, skewness, kurtosis, and the number of peaks occurring within an event. Mean event duration is longest along the West and Northwest coasts, the Mid-South, the Mid-Atlantic, and the Northeast; while shorter-duration events are more frequent in the Rocky Mountains, the Southwest, and the Great Plains. Mean event precipitation and standard deviation are greatest along the Gulf Coast and decrease inland. Precipitation events are positively skewed, indicating that more precipitation tends to occur earlier in the event. The most positively-skewed events are also located in regions flanking the Gulf of Mexico, while less-skewed events are common in the Northwest and Rocky Mountain regions. Event kurtosis is negative throughout the entire USA, with the highest negative values generally west of the Front Range, where cyclonic development and transition produce more evenly distributed precipitation within storms. Intra-event precipitation maxima were also evaluated, with western Florida and the desert Southwest having the greatest number per event.     

An event-based methodology for climate change and human–environment research

Abductive causal eventism (ACE) is an analytical methodology based on a pragmatic view of research methods and explanation that places at the center of research inquiry the answering of ‘why’ questions about events, including human actions or environmental changes of interest. When used in human–environment research, the methodology entails constructing causal histories of interrelated social and/or biophysical events backward in time through a process of eliminative inference and reasoning from effects to causes, called abduction. ACE encourages an eclectic use of methods, models, and theoretical ideas. It fosters integrative, interdisciplinary analysis without being committed either to systems as ontological entities or to holistic analytical frameworks. By not privileging particular theories or explanatory factors in advance, ACE enables researchers to interrogate the plausibility of different causal influences, including local environmental changes that may be related to much wider changes in climate. Likewise, behaviors or practices that may be of value in light of anticipated environmental changes can be studied without their presuming to be caused by these changes or by changes in climate per se. Research on coastal mangrove planting for storm protection in the Philippines and upland tree planting in St. Lucia are used to illustrate these arguments.     

The spatial distribution of economic activity in Melbourne, 1971–2006

This paper reports an empirical analysis of the distribution of employment by industry in Melbourne and how this changes over time. Depending on the nature of the industry being considered, two main patterns of spatial behavior are found, population-related dispersion and centralization. A methodology for estimating the benefits of centralization is developed and applied. Centralization benefits are highest for business services and other high-level services, supporting the view that the benefits of concentrating in the central business district are related to knowledge creation and exchange. Other forces, such as competitive pressure, land prices, and colocation with other industries, play only a minor role in determining the spatial distribution of industries, at least at the spatial levels used here. The implications of these findings are discussed.     

An evaluation of void‐filling interpolation methods for SRTM data

The Digital Elevation Model that has been derived from the February 2000 Shuttle Radar Topography Mission (SRTM) has been one of the most important publicly available new spatial data sets in recent years. However, the ‘finished’ grade version of the data (also referred to as Version 2) still contains data voids (some 836,000 km²)—and other anomalies—that prevent immediate use in many applications. These voids can be filled using a range of interpolation algorithms in conjunction with other sources of elevation data, but there is little guidance on the most appropriate void‐filling method. This paper describes: (i) a method to fill voids using a variety of interpolators, (ii) a method to determine the most appropriate void‐filling algorithms using a classification of the voids based on their size and a typology of their surrounding terrain; and (iii) the classification of the most appropriate algorithm for each of the 3,339,913 voids in the SRTM data. Based on a sample of 1304 artificial but realistic voids across six terrain types and eight void size classes, we found that the choice of void‐filling algorithm is dependent on both the size and terrain type of the void. Contrary to some previous findings, the best methods can be generalised as: kriging or inverse distance weighting interpolation for small and medium size voids in relatively flat low‐lying areas; spline interpolation for small and medium‐sized voids in high‐altitude and dissected terrain; triangular irregular network or inverse distance weighting interpolation for large voids in very flat areas, and an advanced spline method (ANUDEM) for large voids in other terrains.     

An Analysis of the Commuting and Jobs–Housing Patterns of Older Adult Workers

Many researchers have explored the relationships between land use and transportation via the jobs–housing balance concept. This type of research involves the disaggregation of commuter groups to understand variances in the relationship between land use and transportation outcomes. Disaggregation by commuter age has not been considered, however. To address this gap, we analyze spatially and temporally disaggregate census data for five areas in Florida. Using several jobs–housing balance metrics we compare and contrast the outcomes of different commuter age groups, across different geographies, and over time (2002–2011). Generally, commutes vary more by region than they do by any age category of commuter. Most of the differences in the commute metrics among the older age group tend to depend on where those commuters live. The results also suggest that there are more efficient and less sprawling commuting landscapes for older workers located near other older workers.     

An overall consistent increase of global aridity in 1970–2018

Climate change is expected to introduce more water demand in the face of diminishing water supplies, intensifying the degree of aridity observed in terrestrial ecosystems in the 21st century. This study investigated spatiotemporal variability within global aridity index(AI) values from 1970–2018. The results revealed an overall drying trend(0.0016 yr-1, p<0.01), with humid and semi-humid regions experiencing more significant drying than other regions, including those classified as arid or sem...     

Searching for a new dynamic of industrialization and urbanization: anatomy of China’s characteristic town program

The characteristic town program is one of China’s latest industrialization and urbanization strategies. Originating in Zhejiang, characteristic towns are expected to serve as platforms for industrial upgrading and the promotion urbanization. This paper attempts to analyze the characteristic town program by examining the reasons behind the origination of characteristic towns, as well as elucidating the towns’ components. The paper argues that this exploratory local program has been leveraged into a national-level strategy because the primary idea underlying characteristic towns has been in accordance with several of China’s critical policies. Furthermore, the paper presents the challenges that the characteristic town program has encountered. The characteristic town program can be viewed as a new effort of entrepreneurial governments and a spatial fix for capital during the period of industrial upgrading. This paper helps us to better understand one of China’s explorations in searching for a new dynamic of industrialization and urbanization.     

An Improved Data-Driven Multiple Criteria Decision-Making Procedure for Spatial Modeling of Mineral Prospectivity: Adaption of Prediction–Area Plot and Logistic Functions

Natural Resources Research - Assigning realistic weights to targeting criteria in order to synthesize various geo-spatial datasets is one of the most important challenging tasks for mineral...     

An AHP–TOPSIS Predictive Model for District-Scale Mapping of Porphyry Cu–Au Potential: A Case Study from Salafchegan Area (Central Iran)

The Salafchegan area in central Iran is a greenfield region of high porphyry Cu–Au potential, for which a sound prospectivity model is required to guide mineral exploration. Satellite imagery, geological geochemical, geophysical, and mineral occurrence datasets of the area were used to run an innovative integration model for porphyry Cu–Au exploration. Five favorable multi-class evidence maps, representing diagnostic porphyry Cu–Au recognition criteria (intermediate igneous intrusive and sub-volcanic host rocks, structural controls, hydrothermal alterations, stream sediment Cu anomalies, magnetic signatures), were combined using analytic hierarchy process and technique for order preference by similarity to ideal solution to calculate a final map of porphyry Cu–Au potential in the Salafchegan area.     

An Investigation of the Use of Real-Time,Authentic Geospatial Data in the K–12 Classroom

Abstract

This article situates geospatial technologies as a constructivist tool in the K-12 classroom and examines student experiences with real-time authentic geospatial data provided through a hybrid adventure learning environment. Qualitative data from seven student focus groups demonstrate the effectiveness of using real-time authentic data, peer collaboration, and geospatial technologies in learning geography. We conclude with recommendations about geospatial technology curricula, geospatial lesson design, providing preservice teachers with geographic technological pedagogical content knowledge, and encouraging further research to investigate the impact, affordances, and pedagogical implications of geospatial technologies and data in the K–12 classroom.     

Space–time prism bounds of activity programs: a goal-directed search in multi-state supernetworks

Space–time prism (STP), which envelops the spatial and temporal opportunities for travel and activity participation within a time frame, is a fundamental concept in time geography. Despite many variants, STPs have been mostly modeled for one flexible activity between two anchor points. This study proposes a systemic approach to construct the STP bounds of activity programs that usually include various possible realizations of activity chains. To that effect, multi-state supernetworks are applied to represent the relevant path sets of multi-activity travel patterns. A goal-directed search method in multi-state supernetworks is developed to delineate the potential space–time path areas satisfying the space–time constraints. Particularly, the approximate lower and upper STP bounds are obtained by manipulating the goal-directed search procedure utilizing landmark-based triangular inequalities and spatial characteristics. The suggested approach can in an efficient fashion find the activity state dependent bounds of STP and potential path area. The formalism of goal-directed search through multi-state supernetworks addresses the fundamental shift from constructing STPs for single flexible activities to activity programs of flexible activity chains.     

Temporal and spatial analysis of vegetation fire activity in the circum-Arctic during 2001–2020

Vegetation fires become the concern worldwide due to their substantial impacts on climate and environment, and in particular in the circum-Arctic. Assessing vegetation fires and associated emissions and causes can improve understanding of fire regime and provide helpful information for vegetation fires solution. In this study, satellitebased vegetation fires and emissions during 2001–2020 were investigated and contributions of different types of fires were analyzed. Furthermore, climate anomalie...     

An Evaluation of an Object-Oriented Paradigm for Land Use/Land Cover Classification∗

Object-oriented image classification has tremendous potential to improve classification accuracies of land use and land cover (LULC), yet its benefits have only been minimally tested in peer-reviewed studies. We aim to quantify the benefits of an object-oriented method over a traditional pixel-based method for the mixed urban–suburban–agricultural landscape surrounding Gettysburg, Pennsylvania. To do so, we compared a traditional pixel-based classification using maximum likelihood to the object-oriented image classification paradigm embedded in eCognition Professional 4.0 software. This object-oriented paradigm has at least four components not typically used in pixel-based classification: (1) the segmentation procedure, (2) nearest neighbor classifier, (3) the integration of expert knowledge, and (4) feature space optimization. We evaluated each of these components individually to determine the source of any improvement in classification accuracy. We found that the combination of segmentation into image objects, the nearest neighbor classifier, and integration of expert knowledge yields substantially improved classification accuracy for the scene compared to a traditional pixel-based method. However, with the exception of feature space optimization, little or no improvement in classification accuracy is achieved by each of these strategies individually.     

Spatial patterns of subsistence extraction of forest products – An indirect approach for estimation of forest degradation in dry forest

Successful implementation of a forest based climate change mitigation mechanism such as REDD + depends on robust and available methods for measurement and estimation of forest degradation. Currently available methods are for application in single-hit degradation incidents in high density humid forests. However, it has been suggested that gradual degradation, especially in dry forests, is more widespread and that methods are needed for measuring and estimating associated emissions. We assess the applicability of an indirect remote sensing approach for monitoring forest degradation: infrastructure and other indicators of human activities are mapped and used for spatial prediction of degradation activities. For proxy variables we tested distance to forest edge, distance to roads, and population pressure calculated as the sum of inhabitants per pixel in the Landscan 2010 population raster dataset multiplied by an inverse power distance decay function. Wood extraction incidents were counted in 160 plots in two dry forests in Tanzania with infrastructural entry from one side only. We analyzed the spatial pattern of forest degradation as a function of the chosen proxy variables using zero inflated count models which allows for an excess of zero counts. A jack-knife bootstrap using 10,000 runs was applied to optimize the population distance decay function. We found that the impact of forest degradation is highest near high population concentration, above 1000 individuals. Furthermore, distance to nearest forest edge or road was a significant proxy for estimation of the number of wood extraction incidents (p < 0.001), where degradation incidents decreased with increasing distance to forest edge or road. At 3000 m from the forest edge towards the forest core the probability of wood extraction is 20% and dropping. The population distance decay function was found to have a steep decline indicating a relative small impact on forest degradation. Further, and perhaps larger, studies are needed to be able to recommend a distance decay function for general application in Tanzania. However, the results are useful for understanding spatial patterns of wood harvesting as a function of distance to nearest forest edge or road in dry Miombo woodland areas with average population pressure at 1685 ± 101 persons within a radius of 4000 m from the wood extraction sites.     

The Availability of Critical Minerals for China’s Renewable Energy Development: An Analysis of Physical Supply

Natural Resources Research - In the context of depletion of fossil energy and environmental impacts of its use, society has begun to develop vigorously renewable energy (RE). As a result, concerns...     

A first step towards a framework for presenting the location of confidential point data on maps—results of an empirical perceptual study

A common concern when working with health‐related data is that national standard guidelines are designed to preserve individual statistical information, usually recorded as text or in a spreadsheet format (‘statistical confidentiality’), but lack appropriate rules for visualizing this information on maps (‘spatial confidentiality’). Privacy rules to protect spatial confidentiality become more and more important, as governmental agencies increasingly incorporate Geographic Information Systems (GIS) as a tool for collecting, storing, analysing, and disseminating spatial information. The purpose of this paper is to propose the first step of a general framework for presenting the location of confidential point data on maps using empirical perceptual research. The overall objective is to identify geographic masking methods that preserve both the confidentiality of individual locations, and at the same time the essential visual characteristics of the original point pattern.