GIS and Crime Analysis

Spatial analysis of crime has gained increasing attention during the past thirty years, coupled with the growth of geographic information systems (GIS). Most crime analysis tasks are either carried out in a GIS environment or supported by a GIS. GIS is typically used as a tool for data management, data processing, data visualization, and data analysis for crime studies. Crime analysis normally involves the following elements: uncovering spatio-temporal patterns of crime distribution, such as crime hotspots; explaining these patterns and discerning major contributing factors based on multivariate regression modeling; predicting future crime patterns using machine learning and other predictive methods; developing crime prevention approaches based on historical and future crime patterns; and evaluating the effectiveness of crime prevention, to find out if crime is reduced in the targeted area and whether the nearby areas are affected by the intervention. It should be noted that crime analysis is inherently multidisciplinary, including but not limited to geography, criminology, computer science, statistics, urban planning, and sociology. Therefore, an effective crime analyst should be well trained in multiple disciplinary approaches. Any crime analysis that leads to real-world impact must rely on sound theories and effective methodologies. Many of the theories covered in this article are related to geography, criminology, and sociology. The methods are mostly influenced by GIS, spatial statistics, and artificial intelligence. Crime analysis also involves multiple stakeholders, including at least government agencies, universities, and private companies. Universities conduct basic and applied research, private companies convert the research to products, and government agencies provide funding for research and implement crime prevention strategies. In addition, crime analysis needs to pay close attention to potential issues related to ethics, privacy, confidentiality, and discrimination.

Environmental Electronic Sensing Systems

Although environmental measurement instrumentation has been utilized by human civilizations for thousands of years, the use of electronics to conduct measurements closely parallels the development of electrical theory from the 19th century to the present. Environmental electronic sensing systems have been created to automate measurement tasks that are difficult for humans to repeat in a precise and synchronous fashion or to measure phenomena that cannot be manually observed at scales ranging from the microscopic to the planetary. The collection and recording of data at regular timesteps enable inputs to mathematical models that provide predictions and forecasts of environmental processes; moreover, these models can be used to better understand planetary systems. Data measurements conducted at different scales can be subjected to statistical or scaling analysis to provide gridded data sets for application of mathematical models. Point measurements made at a single geographic location provide calibration or validation for satellite remote sensing data products. Measurements made by different sensors can be utilized along with sensor fusion algorithms to calculate indexes or gridded data sets. The sources in this article have been selected to provide an overview of the sensors and associated sensing systems that measure components of the environment on or near the surface of the Earth. Each first-level heading demarcates different environmental components. The final section of the article provides a selection of references pertaining to the engineering of sensor networks that are used to obtain areal measurements of environmental processes. Each section contains a series of subsections that divide the literature according to the type of sensor or measurement. An emphasis is placed on the selection of references that provide insight into the measurement physics of the sensor and the environmental physics of the phenomena being measured. Moreover, references are selected that provide schematic diagrams and engineering design considerations suitable for replication and development of new sensors. Papers on sensor calibration and error analysis as well as case studies are included for operational use and field deployment applications. Due to the numerous papers that have been published on environmental sensing systems, it is not possible to cite all available literature pertaining to a certain type of sensor. To close gaps in the literature and to provide ideas for students, instrument developers, engineers, and environmental scientists, overview papers are also provided in this article. These overview papers often present ideas in a succinct fashion and the associated sensor mathematics, design, and signal processing are provided in a manner to enhance pedagogical value.

Agricultural Meteorology/Climatology

Agricultural meteorology (also referred to as agrometeorology) is the study of the effects of weather on agriculture, while agricultural climatology (alternatively, agroclimatology) is concerned with the effects of climate on agriculture. These fields of study share many of the same goals, philosophies, approaches, and methods. As a consequence, disciplinary boundaries are indistinct, and the terms “agricultural meteorology” and “agrometeorology” are increasingly used interchangeably with “agricultural climatology” and “agroclimatology.” Agricultural meteorology/climatology is oftentimes considered a bridge between the physical and biological sciences, although this interdisciplinarity increasingly includes the social sciences. While most research has focused on the production of food staples (e.g., maize, rice, and wheat), agricultural meteorologists and climatologists also address the influence of weather and climate on specialty crops, animal husbandry, commercial forestry, and aquaculture. Management of agricultural pests and diseases is another major focus. Atmospheric and biophysical processes operating at a wide range of temporal and spatial scales—from seconds to centuries and from an individual leaf to a global agricultural system—are explored. Agricultural meteorologists and climatologists promote the sustainable management of agricultural resources and strive to improve the livelihoods of agricultural stakeholders. Both basic and applied research are conducted to further these goals, and agricultural meteorologists and climatologists are often involved in the development, delivery, and evaluation of agricultural services. These services range from decision support tools for daily agricultural operations to services focused on seasonal or longer-term planning. Observations of the atmosphere-plant-soil environment are central to research and applications in agricultural meteorology/climatology, as are empirical and process-based models. Agriculture is highly vulnerable to climate variability and change, and potential adaptation strategies are widely investigated. Mitigation is also a concern as many agriculture activities emit greenhouse gases or contribute to land cover change. As other entries in Oxford Bibliographies address the theoretical aspects of atmosphere-plant-soil interactions (see “Land-Atmosphere Interactions” by Geoffrey M. Henebry, Nathan J. Moore, and Jiquan Chen), this entry primarily focuses on the applications-based literature in agricultural meteorology/climatology. The intent is to draw on both classic and recent literature to illustrate the nature of the research questions and applications of concern to agricultural meteorologists and climatologists, the approaches they use to address these questions and concerns, and the types of agricultural services they provide.

Ethnonationalism

The term ethnonationalism (or ethno-nationalism) elicits understandings and forms of nationalism that regard ethnicity and ethnic ties as core components of conceptions and experiences of the “nation”. At the intersection of profound cultural, social, and political concerns, the study of ethnonationalism lends itself to a variety of interdisciplinary approaches across the full spectrum of the human and social sciences: from history and geography to international law, from anthropology to political science and international relations, from psychology and sociology to philosophy and ethics. Geographical approaches to ethnonational questions tend to privilege the spatiality of ethnonational identities and the territoriality of ethnic and national groups and political movements. They draw on the work of social and cultural geographers dedicated to issues of ethnicity and other identities as well as on the political and legal geographies of social movements, organizations, and institutions. Since the early 20th century, the study of ethnonationalism (or simply nationalism) has consistently been justified by the momentum of the topic at critical historical junctures. There was, first, the formation and management of large European multiethnic and multinational empires—principally the Austro-Hungarian dual monarchy, but also the Russian and Ottoman Empires—their role as sources of conflict and their ultimate demise in the wake of World War I. In the interwar period the redrawing of the political map of Europe in part along ethnic and national lines according to a proclaimed “right of peoples” to self-determination, but also the rise of fascism and national-socialism (Nazism), would justify continued interest in the “national question.” During the Cold War the independence of former European colonies in Asia and Africa motivated research in issues of ethnic, tribal, and national identities and allegiances and the political difficulties stemming from their interactions in the context of modern territorial statehood. The governance structure of the Soviet Union and its eventual collapse in the 1980s and 1990s and the resurgence of ethnic and national claims and conflicts in its aftermath and around the world of the post–Cold War era reinvigorated ethnonationalism research and scholarship in the late 20th and well into the 21st centuries. Simultaneously, some sociocultural and political effects of contemporary globalization and increased international migration may have generated newer brands of “ethno-national” movements in the form of reactionary, “nativist” and populist, often xenophobic and racist, always exclusionary identity politics in the more developed world—such as so-called “white nationalism” in the United States.

Human Geography and Islands

Work on islands has long played a critical role in the development of many academic disciplines that overlap and are intimately connected with the discipline of geography. Islands were central to Charles Darwin’s theory of evolution and have subsequently been for the development of ecological, sustainability, and resilience approaches that are prevalent in geography in the 2020s. Islanders were the focal points for Margaret Mead’s and Marylin Strathern’s developments of the discipline of anthropology, concerns for Indigenous geographies, and the counterpositioning of nonmodern reasoning to European or Western frameworks of reasoning. Islands and islanders have also long been a key focus for many who have critiqued the forces of colonialism, such as Édouard Glissant, Kamau Brathwaite, Sylvia Wynter, and Derek Walcott, whose work is extremely influential for Critical Black Geographies. More recently, engaging islands and islanders shaped Linda Tuhiwai Smith’s and Epeli Hau‘ofa’s influential reappraisal of how academic research itself can and should do better, reorienting toward more geographically appropriate Indigenous perspectives. What this is already telling us is that any bibliography compiled under the title of “Geography and Islands” needs to work beyond the boundaries of neatly defined academic disciplines. The focus is the geographical form, the island, and associated island cultures, and thus geographers who study islands regularly step outside fixed disciplines. Thus, this article presents a range of references that are categorized by way of key early-21st-century island themes and topics that will be of particular concern to geographers. Here, the decades since the late 20th century have seen the rise of a more distinct or focused field of academic inquiry, which has come to be known as “island studies.” The key characteristics of this field are its diversity, interdisciplinarity, openness, and extremely rapid growth—geographically, intellectually, and in the broad range of topics and subjects being engaged with in the 2020s. Back in the 1970s and 1980s, the term “island studies” did not have much purchase. In the 2020s, due to the strong repositioning of islands within broader concerns—such as human-nature relations, current developments in environmental and resilience approaches, the ongoing legacies and effects of colonialism, Indigenous geographies, migration patterns, mobilities and movements of humans and nonhumans, geopolitical tensions and strategies, and the Anthropocene, as just some examples—the figure of the island has moved considerably more to the center of many debates (and particularly those debates that concern geographers). This article therefore also reflects the sense of dynamism, as well as the interdisciplinary nature, of work with islands as an exponentially developing field of research.

Human Geographies of Outer Space

Human geographies of outer space encompass a burgeoning body of social science and humanities scholarship exploring the application of geographical perspectives, concepts, and approaches through the study of outer space, human–outer space relations, and space travel. Humanity’s engagement with outer space has everyday effects, spanning the way we act and interact with each other here on Earth—how we live with other species, and our imagined landscapes and futures. In the last decade or so, a growing number of geographers have explored these themes. However, the emergence of geographies of outer space must be understood as an innately interdisciplinary endeavor, inspired by, and inspiring, wider social science engagements with outer space. For this reason, in this guide work is included that has been published by geographers within and outside geography departments and centers, as well as those located in allied fields, particularly sociology, anthropology and organization studies. These interdisciplinary engagements are necessarily wide-ranging—in terms of their: (i) empirical objects of analyses, (ii) purpose, and (iii) theoretical influences. Empirical engagements encompass: off-world mining, astropolitics, space art, space tourism, astronomy, space-themed toys, moon landings, orbital work practices, space law and much more. In terms of purpose, although a great deal of published work consists of critiques of imperialist-nationalistic-capitalistic space activities and imaginaries, research has also increasingly sought to advance alternative, more socially inclusive visions of outer space. Geographies of outer space are also theoretically diverse, informed by David Harvey’s critique of capitalism through Gilles Deleuze and Félix Guattari’s concept of smooth/striated space to Peter Sloterdyk’s theorization of spaces of containment. However, despite this diversity, research remains predominately Western; this is despite the longstanding presence of Russian, Chinese, Japanese and Indian space hardware and millennia of non-Western cosmographies. While this focus may partly stem from the lack of availability of research materials, it remains a challengeable trend. Nonetheless, geographical studies of outer space have certainly explored critical questions of power that are mostly absent in popular and technoscientific framings of outer space—namely, whose interests and agendas do human activities in space serve? How can outer space help us understand how to live on Earth with other peoples and species? And what futures will space activities open up or close down? These questions open up new horizons of geographical inquiry, while also returning geography to its early cosmographical origins.

Postcolonialism

In the colonial period imperialism advanced in uneven ways across time and space globally. European exploration in the late 15th century first brought destructive, exploitative, and deadly changes to what became known as the Americas. The subjugation and elimination of Indigenous groups, which commenced during this period, created the conditions for accumulation by dispossession, enslavement (of both Indigenous groups and people stolen from Africa), plantation-style production systems, and the extraction of resources—the legacies of which still mark political, social, economic, and environmental landscapes today. Following rebellion and successful de jure (legal) independence from Europe in the late 1700s and early 1800s (starting with the radical uprising of enslaved peoples in Haiti), Western powers turned to new regions to regain such systems of control and resource extraction. In 1848, the Berlin Conference was held— also called the “Scramble for Africa,” where European powers divided the continent and created new sites of extraction. Such patterns followed in South and Southeast Asia as well as North Africa and Central Asia in the latter parts of the 19th century. As a result of these violent campaigns, there are very few places on the globe that did not sustain, at some point, a form of colonial-imperial relation. Independence movements were ongoing and by the end of the 20th century, de jure colonial control had all but disappeared. Decolonization had occurred and the global periphery entered the period of being postcolonial. Former British colonies were assembled into the Commonwealth, which changed relations from direct control and subjugation to allegiance to the Queen and for some, drastic changes in economic relations, (this had the effect of marginalizing Indigenous struggles in many of these places). Notwithstanding the legal separation of the colonies from imperial powers, de facto (in effect) colonial arrangements lingered and remain today, giving rise to a series of critiques and new ways of thinking about imperialism and the impact of colonialism, such as the theory of postcolonialism.

Geospatial Artificial Intelligence (GeoAI)

Nowadays, artificial intelligence (AI) is bringing tremendous new opportunities and challenges to geospatial research. Its fast development is powered by theoretical advancement, big data, computer hardware (e.g., the graphics processing unit, or GPU), and high-performance computing platforms that support the development, training, and deployment of AI models within a reasonable amount of time. Recent years have witnessed significant advances in geospatial artificial intelligence (GeoAI), which is the integration of geospatial studies and AI, especially machine learning and deep learning methods and the latest AI technologies in both academia and industry. GeoAI can be regarded as a study subject to develop intelligent computer programs to mimic the processes of human perception, spatial reasoning, and discovery about geographical phenomena and dynamics; to advance our knowledge; and to solve problems in human environmental systems and their interactions, with a focus on spatial contexts and roots in geography or geographic information science (GIScience). Thus, it would require the knowledge of AI theory, programming and computation practices as well as geographic domain knowledge to be competent in GeoAI research. There have already been increasingly collaborative GeoAI studies for GIScience, remote sensing, physical environment, and human society. It is a good time to provide a key reference list for educators, students, researchers, and practitioners to keep up with the latest GeoAI research topics. This bibliographical entry will first review the historical roots for AI in geography and GIScience and then list up to ten selective recent works with annotations that briefly describe their importance for each topic of interest in the GeoAI landscape, ranging from fundamental spatial representation learning to spatial predictions and to various advancements in cartography, earth observation, social sensing, and geospatial semantics.

Visualizations

Visualizations (i.e., thinking in images internally in the human mind) or externally expressing a concept via graphical means—such as documenting an observation in a hand-drawn or digital visuospatial sketch, or creating a visual output from data—have always been an integral part of scientific inquiry and communication. One might argue that the ‘graphy’ part of ‘geography’ refers to visually and spatially (i.e., visuospatially) documenting the world. For the vast majority of people, a significant part of human experience is shaped by sight, and the human visual system occupies a large chunk of human cognitive processing capacity. Given that, one can speculate that comprehension and communication through visuospatial means could be ‘second nature’ to people. There is ample evidence to support this line of thinking: As opposed to written words or a large list of numbers, visualizations allow us to see patterns and anomalies quickly, sometimes even at a glance. However, the power of visualizations depends on a number of factors including the details of their design, the abilities and background of the human viewing them, and the context in which a visualization is used. This power must also be critically viewed from an ethics perspective. These three factors are elaborated under various subsections. However, first, a fundamental question needs to be asked: Is visualization a product or a process? The word visualization is commonly used as a noun for a visual product (e.g., a map or a plot is a visualization). However, both mental and external visualizations are processes, and the term ‘visualization’ as it was introduced into scientific discourse refers to a process. The process aspect is important to remember, because this is viewed as a key factor that distinguishes using visualizations to explain what is already known versus exploring the unknown. With the latter activity, visualizing things becomes a part of the scientific inquiry as an active tool that helps build hypotheses and thus facilitate thinking and reasoning, in addition to explaining what is already known. Whether the goal is to explain or to explore, the design and use of visualizations needs to be intentional and not arbitrary. To create and read visualizations intentionally, a certain level of visual literacy built on design, technology, and knowledge of human visuospatial cognition is necessary. This manuscript identifies scholarly resources to help all scientists and aspiring scientists, especially those in spatial sciences, to build, refresh their knowledge of, and learn or teach about visualizations.

Geography and Empire

Geography has engaged in the study of empire since its early days as an academic discipline. Few disciplines have such a clear complicity with this political formation, that feeds on territorial growth through military power, and that limits political sovereignty in the peripheries. In fact, a temporal correspondence exists between the birth of modern geography and the emergence of a new phase of capitalist imperialism during the 1870s. Viewed as the queen of the imperial sciences over a century ago, geographies of empire have changed throughout time, reflecting the modifications in the discipline and the transformation in the nature of empires. During the late 19th and early 20th centuries, and under environmental determinism, geographical knowledge produced by the likes of Frederich Ratzel or Alfred Mackinder lent scientific credibility to ideologies of imperialism while, at the same time, they legitimized the scientific claims of geography as an academic discipline. Climatic and acclimatization studies and prerogatives were pivotal to construct moralistic considerations of both people and places. During the first half of the 20th century, geographies of empire were dominated, in part, by the regional tradition of French geographic inquiry, which cultivated a regional, zonal approach, while work with a focus on empire had a global and zonal tropicality architecture. Quantitative and neopositivist geography approaches in the second half of the 20th century had a less marked influence. Since the late 1980s, a concern for “empire” has returned to geography, and various subdisciplines have focused on the imperial genealogy of the discipline, the links between geography and empire, and the consequences of those links. A more critical engagement with the history of geography has provided contextual histories of global spatial practice and discourse over the past two centuries. The reconsideration of imperialism in view of postcolonial theory, tackling “historical amnesia,” has also promoted a new wave of studies. In a broad way we can be tempted today to make a division between geographical research, which participated in imperial development and maintenance, and geographical research “after Empire,” which aims to study and understand the past and present spatialities of empire.