Архив рубрики "Geography" (Page 2)
World map of the boreal forest climate

High-Latitude Climates (Group III)

By and large, the high-latitude climates are climates of the northern hemisphere, occupying the northern subarctic and arctic latitude zones. But they also extend southward into the midlatitude zone as far south as about the 47th parallel in eastern North America and eastern Asia. One of these, the ice sheet climate, is present in both hemispheres in the polar zones. The […]

World map of the moist continental climate

Midlatitude Climates (Group II)

The midlatitude climates almost fully occupy the land areas of the midlatitude zone and a large proportion of the subtropical latitude zone. They also extend into the subarctic latitude zone, along the western fringe of Europe, reaching to the 60th parallel. Unlike the lowlatitude climates, which are about equally distributed between northern and southern hemispheres, nearly all of the midlatitude climate area […]

World map of wet equatorial and monsoon and trade-wind coastal climates

Low-Latitude Climates (Group I)

The low-latitude climates lie for the most part between the Tropics of Cancer and Capricorn, occupying all of the equatorial zone (10° N to 10° S), most of the tropical zone (10–15° N and S), and part of the subtropical zone. The low-latitude climate regions include the equatorial trough of the intertropical convergence zone (ITCZ), the belt of tropical easterlies (northeast and […]

Climate groups and air-mass regions

Climate Classification

Mean monthly values of air temperature and precipitation can describe the climate of a weather station and its nearby region quite accurately. To study climates from a global viewpoint, climatologists classify these values into distinct climate types. This classification requires developing a set of rules to use in examining monthly temperature and precipitation values. By applying the rules, a climatologist can use […]

Precipitation on an idealized supercontinent

Temperature and Precipitation Regimes

Many parts of the world show distinctive patterns of monthly temperature and precipitation, usually related to latitude and location. These patterns are referred to as regimes of temperature and precipitation. TEMPERATURE REGIMES Figure 7.5 shows annual cycles of air temperature for different temperature regimes. The equatorial regime (Douala, Cameroon, 4° N) is uniformly very warm, with temperatures close to 27°C (81°F) […]

Climate controls

Factors Controlling Climate

Climate is the average weather of a region. The primary driving force for weather is the flow of solar energy received by the Earth and atmosphere. Because that energy flow varies on daily cycles with the planet’s rotation and on annual cycles with its revolution in orbit, temperature and precipitation also vary on daily and annual cycles. However, climate includes […]

The African Sahel

Drought in the African Sahel

One of the Earth’s more distinctive climates is the wetdry tropical climate . Here, the weather is largely dry for much of the year, but there is a rainy season of a few months duration in which most of the annual rainfall occurs. Precipitation during the wet season is quite variable, ranging from little or none to torrential rainfalls that produce […]

Global atmospheric transport of heat and moisture

Poleward Transport of Heat and Moisture

As we saw in Chapter 5, the general circulation of the atmosphere and oceans is driven by the difference in solar heating between low and high latitudes. This general circulation, combined with jet stream disturbances in the midlatitudes, serves to redistribute heat and moisture from the Equator to the poles in the process of poleward heat transport. Figure 6.30 shows the various mechanisms by which this […]

Intertropical rainfall measured by TRMM

The Tropical Rainfall Monitoring Mission

In November of 1997, NASA and the Japanese Space Agency launched a joint satellite mission with the goal of monitoring rainfall in the tropical and equatorial regions of the world—the Tropical Rainfall Monitoring Mission (TRMM). Its operational objective is to provide more information about where and when intertropical convective precipitation occurs, particularly over oceans, which are not monitored by weather stations and rain gauges. The mission is also designed […]

Typhoons Chaba and Aere

Tropical and Equatorial Weather Systems

So far, we have discussed weather systems of the midlatitudes and poleward. Weather systems of the tropical and equatorial zones show some basic differences from those of the midlatitudes. Upper-air winds are often weak, so air-mass movement is slow and gradual. Air masses are warm and moist, and different air masses tend to have similar characteristics, so fronts are not as clearly defined. Without the […]

Picture of an anticyclone

Midlatitude Anticyclones and Cyclones

Air masses are set in motion by wind systems—typically, masses of air moving in a spiral. Air can spiral inward and converge in a cyclone, or spiral outward and diverge in an anticyclone. Most types of cyclones and anticyclones are large features spanning hundreds to thousands of kilometers that move slowly across the Earth’s surface, bringing changes in the weather as […]

Global air masses and source regions

Air Masses

We know that the Earth’s atmosphere is in constant motion, driven by the planet’s rotation and its uneven heating by the Sun. The horizontal motion of the wind moves air from one place to another, allowing air to acquire characteristics of temperature and humidity in one region and then carry those characteristics into another region. In addition, as winds at the […]

Cloud Cover, Precipitation, and Global Warming

Clouds are so common we don’t think much about them. But they can have a large impact on climate. How would global climate be influenced by an increase in clouds and precipitation? Global temperatures have been rising over the last 20 years. Satellite data show a rise in temperature of the global ocean surface of about 1°C (1.8°F) over the past […]

Sea-surface temperatures in the western Atlantic

Ocean Circulation

Just as there is a circulation pattern to the atmosphere, there is also a circulation pattern to the oceans that it is driven by differences in density and pressure acting along with the Coriolis force. Pressure differences are created in the water when the ocean is heated unequally, because warm water is less dense than cold water. These pressure differences induce […]

Upper-air pressure gradient

Winds Aloft

We’ve looked at airflows at or near the Earth’s surface, including both local and global wind patterns. But how does air move at the higher levels of the troposphere? Like air near the surface, winds at upper levels of the atmosphere move in response to pressure gradients and are influenced by the Coriolis effect. How do pressure gradients arise at […]

Global surface winds on an ideal Earth

Global Wind and Pressure Patterns

For simplicity, let’s begin by looking at surface winds and pressure patterns on an ideal Earth that does not have oceans and continents, or seasons (Figure 5.16). Hadley cells are key to an understanding of the wind patterns on our ideal Earth. These form because the Equator is heated more strongly by the Sun than other places, creating thermal circulations. Air […]

The Coriolis effect

Cyclones and Anticyclones

THE CORIOLIS EFFECT We have seen that the pressure gradient force moves air from high pressure to low pressure. For sea and land breezes, which are local in nature, this pushes wind in about the same direction as the pressure gradient. But on global scales, the direction of air motion is more complicated. The difference is caused by the Earth’s rotation, through the Coriolis effect (Figure 5.13). The Coriolis effect […]

Measurement of wind

Local Wind Patterns

Wind is defined as air moving horizontally over the Earth’s surface. Air motions can also be vertical, but these are known by other terms, such as updrafts or downdrafts. Wind direction is identified by the direction from which the wind comes—a west wind blows from west to east, for example. Like all motion, the movement of wind is defined by its […]

Measuring atmospheric pressure

Atmospheric Pressure

We live at the bottom of a vast ocean of air—the Earth’s atmosphere. Like the water in the ocean, the air in the atmosphere is constantly pressing on the Earth’s surface beneath it and on everything that it surrounds. The atmosphere exerts pressure because gravity pulls the gas molecules of the air toward the Earth. Gravity is an attraction among all […]

La Niña and El Niño sea-surface temperatures

El Nino

At irregular intervals of about three to eight years, a remarkable disturbance of ocean and atmosphere occurs in the equatorial Pacific region—El Nino. Its name comes from Peruvian fishermen, who refer to the Corriente del Nino or the “Current of the Christ Child,” to describe an invasion of warm surface water once every few years around Christmas time that greatly depletes their […]

Air pollutant emissions and sources by weight, 2007

Air Quality

Most people living in or near urban areas have experienced air pollution first hand. Perhaps you’ve felt your eyes sting or your throat tickle as you drive an urban freeway. Or you’ve noticed black dust on window sills or window screens and realized that you are breathing in that dust as well. AIR POLLUTANTS Air pollution is largely the result […]

Tornadoes

A tornado is a small but intense vortex in which air spirals at tremendous speed. It is associated with thunderstorms spawned by fronts in the midlatitudes of North America. Tornadoes can also occur inside tropical cyclones (hurricanes). TORNADO CHARACTERISTICS A tornado, seen in Figure 4.32, appears as a dark funnel cloud hanging from the base of a dense cumulonimbus cloud. At […]

Stages in the development of an air-mass thunderstorm

Thunderstorms

A thunderstorm is any storm that produces thunder and lightning. At the same time, thunderstorms can also produce high winds, hail, and tornadoes. They are typically associated with cumulus clouds that indicate the presence of rising, unstable air. It is this rising motion that produces the characteristic rainfall and lightning that accompany thunderstorms. Thunderstorms can range from fairly isolated, short-lived storms, sometimes called […]

Types of Precipitation

Precipitation consists of liquid water drops and solid crystals that fall from the atmosphere and reach the ground. This precipitation can take several different forms. RAIN Rain is precipitation that reaches the ground as liquid water. Raindrops can form in warm clouds as liquid water, which through collisions can coalesce with other drops and grow large enough to fall to Earth. […]

Rain formation in warm clouds

Precipitation

FORMATION OF PRECIPITATION Clouds are the source of precipitation—the process that provides the fresh water essential for most forms of terrestrial life. Precipitation can form in two ways. In warm clouds, fine water droplets condense, collide, and coalesce into larger and larger droplets that can fall as rain. In colder clouds, ice crystals form and grow in a cloud that contains a mixture of […]

Earth from GOES-8

Observing Clouds from GOES

Some of the most familiar images of Earth acquired by satellite instruments are those of the Geostationary Operational Environmental Satellite (GOES) system. Images from the GOES series of satellites have been in constant use since 1974. The primary mission of the GOES series is to view cloud patterns and track weather systems by providing frequent images of the Earth from a consistent viewpoint in space provided by […]

Cloud condensation nuclei

Clouds

Clouds are frequent features of the atmosphere. Views of the Earth from space show that clouds cover about half of the Earth at any given time. Low clouds reflect solar energy, thus cooling the Earth–atmosphere system, while high clouds absorb outgoing longwave radiation, thus warming the Earth– atmosphere system. One of the most familiar roles of clouds, however, is in producing precipitation. Clouds […]

Adiabatic cooling and heating

The Adiabatic Process

What makes the water vapor in the air turn into liquid or solid particles that can fall to the Earth? The answer is that the air is naturally cooled. When air cools to the dew point, the air is saturated with water. Think about extracting water from a moist sponge. To release the water, you have to squeeze the sponge—that […]

Global specific humidity and temperature

Humidity

Blistering summer heat waves can be deadly, with the elderly and the ill at most risk. However, even healthy young people need to be careful, especially in hot, humid weather. High humidity slows the evaporation of perspiration from our bodies, reducing its cooling effect. Clearly, it is not only the temperature of the air that controls how hot weather affects us—the amount of water vapor in […]

Three states of water

Water in the Environment

In this chapter, we focus on water in the air, both as vapor and as liquid and solid water. Precipitation is the fall of liquid or solid water from the atmosphere that reaches the Earth’s land or ocean surface. It forms when moist air is cooled, causing water vapor to form liquid droplets or solid ice particles. If cooling is […]

Acid Deposition

Perhaps you’ve heard about acid rain killing fish and poisoning trees. Acid rain is part of the phenomenon of acid deposition. It’s made up of raindrops that have been acidified by air pollutants. Fossil fuel burning releases sulfur dioxide (SO2) and nitric oxide (NO2) into the air. The SO2 and NO2 readily combine with oxygen and water in the presence of […]

Factors affecting global warming and cooling

Global Warming and the Greenhouse Effect

The Earth is getting warmer. In February 2007, the Intergovernmental Panel on Climate Change (IPCC), a United Nations-sponsored group of more than 2000 scientists, issued a report saying that global warming is “unequivocal”. Is this recent warming an effect of human activity? In 1995 the IPCC concluded that human activity has probably caused climatic warming by increasing the concentration of greenhouse gases […]

Annual range of air temperature in Celsius degrees

World Patterns of Air Temperature

We have learned some important principles about air temperatures in this chapter. Surface type (urban or rural), elevation, latitude, daily and annual insolation cycles, and location (maritime or continental) can all influence air temperatures. Now let’s put all these together and see how they affect world air temperature patterns. First, we need a quick explanation of air temperature maps. Figure 3.21 shows a set of isotherms—lines connecting locations […]

Daily cycles of insolation, net radiation, and air temperature

Daily and Annual Cycles of Air Temperature

Let’s turn to how, and why, air temperatures vary around the world. Insolation from the Sun varies across the globe, depending on latitude and season. Net radiation at a given place is positive during the day, as the surface gains heat from the Sun’s rays. At night, the flow of incoming shortwave radiation stops, but the Earth continues to radiate longwave […]

A typical atmospheric temperature curve for a summer day in the midlatitudes

Temperature Structure of the Atmosphere

In general, the air is cooler at higher altitudes. Remember from Chapter 2 that most incoming solar radiation passes through the atmosphere and is absorbed by the Earth’s surface. The atmosphere is then warmed at the surface by latent and sensible heat flows. So it makes sense that, in general, air farther from the Earth’s surface will be cooler. We call […]

Wind chill conversion

Surface and Air Temperature

This chapter focuses on air temperature—that is, the temperature of the air as observed at 1.2 m (4 ft) above the ground surface. Air temperature conditions many aspects of human life, from the clothing we wear to the fuel costs we pay. Air temperature and air temperature cycles also act to select the plants and animals that make up the biological landscape of a region. […]

Increases in atmospheric carbon dioxide

Carbon Dioxide — On the Increase

One of the most important factors affecting air temperatures over the long run is the greenhouse effect, in which atmospheric gases absorb outgoing longwave radiation and reradiate a portion back to the surface. This makes surface temperatures warmer. Apart from water vapor, carbon dioxide gas plays the largest role in the greenhouse effect and CO2 concentration is increasing. In the centuries before […]

Global shortwave and longwave energy fluxes from CERES

CERES—Clouds and the Earth’s Radiant Energy System

The Earth’s global radiation balance is the primary determinant of long-term surface temperature, which is of great importance to life on Earth. Because this balance can be affected by human activities, such as converting forests to pasturelands or releasing greenhouse gases into the atmosphere, it is important to monitor the Earth’s radiation budget over time as accurately as possible. For nearly 20 years, NASA has studied the […]

Annual surface net radiation from pole to pole

Net Radiation, Latitude, and the Energy Balance

Although the energy budgets of the Earth’s surface and atmosphere are in balance overall, their budgets do not have to balance at each particular place on the Earth, nor do they have to balance at all times. At night, for example, there is no incoming radiation from the Sun, yet the Earth’s surface and atmosphere still emit out going radiation. Net […]

Fate of incoming solar radiation

The Global Energy System

Human activity around the globe has changed the planet’s surface cover and added carbon dioxide to the atmosphere. Have we irrevocably shifted the balance of energy flows? Is our Earth absorbing more solar energy and becoming warmer? Or is it absorbing less and becoming cooler? If we want to understand human impact on the Earth–atmosphere system, then we need to examine the […]

Sensible Heat and Latent Heat Transfer

The most familiar form of heat storage and transport is known as sensible heat—it’s what you feel when you touch a warm object. When we use a thermometer, we are measuring sensible heat. Sensible heat transfer moves heat from warmer to colder objects by conduction when they are in direct contact. Sensible heat is also transferred by convection when a fluid such as the atmosphere […]

Component gases of the lower atmosphere

Composition of the Atmosphere

The Earth is surrounded by air—a mixture of various gases that reaches up to a height of many kilometers. This envelope of air makes up our atmosphere (Figure 2.13). It is held in place by the Earth’s gravity. Almost all the atmosphere (97 percent) lies within 30 km (19 mi) of the Earth’s surface. The upper limit of the atmosphere is […]

The path of the Sun in the sky at 40° N latitude

Insolation over the Globe

Most natural phenomena on the Earth’s surface—from the downhill flow of a river to the movement of a sand dune to the growth of a forest—are powered by the Sun, either directly or indirectly. It is the power source for wind, waves, weather, rivers, and ocean currents, as we will see here and in later chapters. Although the flow of solar […]

Wavelength of electromagnetic radiation

Electromagnetic Radiation

All surfaces—from the fiery Sun in the sky to the skin covering our bodies—constantly emit radiation. Very hot objects, such as the Sun or a light bulb filament, give off radiation that is nearly all in the form of light. Most of this energy is visible light, which we perceive with the colors of the rainbow, but the Sun also […]

The Ozone Layer— Shield to Life

High above the Earth’s surface lies an atmospheric layer rich in ozone—a form of oxygen in which three oxygen atoms are bonded together (O3). Ozone is a highly reactive gas that can be toxic to life and damaging to materials, but high in the atmosphere it serves an essential purpose—sheltering life on the Earth’s surface from powerful ultraviolet radiation emitted by […]

Orbit of the Earth around the Sun

The Earth’s Revolution around the Sun

So far, we have discussed the importance of the Earth’s rotation on its axis. But what about the Earth’s movement as it orbits the Sun? We refer to this motion as the Earth’s revolution around the Sun. The Earth takes 365.242 days to travel around the Sun—almost a quarter of a day longer than the calendar year of 365 days. […]

The relation of longitude to time

Global Time

There’s an old Canadian joke that goes, “Repent! The world will end at midnight! or 12:30 A.M. in Newfoundland.” It’s humorous because independent-minded Newfoundlers use a time zone that is a half-hour ahead of the other Canadian maritime provinces. It highlights the fact that one single instant across the world—no matter how cataclysmic—is simultaneously labeled by different times in different local places. […]

A polar projection

Map Projections

The problem of how to best display the Earth’s surface has puzzled cartographers, or mapmakers, throughout history. The oldest maps were limited by a lack of knowledge of the world, rather than by difficulties caused by the Earth’s curvature. They tended to represent political or religious views rather than geographic reality. Ancient Greek maps from the sixth century B.C. show the world […]

Latitude and longitude of a point

The Geographic Grid

It is impossible to lay a flat sheet of paper over a sphere without creasing, folding, or cutting it—as you know if you have tried to gift-wrap a ball. This simple fact has caused mapmakers problems for centuries. Because the Earth’s surface is curved, we cannot divide it into a rectangular grid anymore than we could smoothly wrap a globe in […]

Direction of Earth rotation

Earth Rotation

The Earth spins slowly on its axis —an imaginary straight line through its center and poles—a motion we refer to as rotation. We define a solar day by one complete rotation, and for centuries we have chosen to divide the solar day into exactly 24 hours. The North and South Poles are defined as the two points on the Earth’s […]

The Shape of the Earth

The Shape of the Earth

As we all learn early in school, the Earth’s shape is very close to a sphere. Pictures taken from space by astronauts and by orbiting satellites also show us that the Earth is a ball rotating in space. Today it seems almost nonsensical that many of our ancestors thought the world was flat. But to ancient sailors voyaging across the […]

Earth Visualization Tools

Within the last few years, remote sensing, geographic information systems, and GPS technology have been integrated into new and exciting Internet tools for visualizing the Earth. Google Earth and World Wind are outstanding examples of these Earth visualization tools. GOOGLE EARTH Google Earth is a program for personal computers that allows users to roam the Earth’s surface at will and zoom […]

Reflectance spectra of vegetation, soil, and water

Remote Sensing for Physical Geography

Another important geographic technique for acquiring spatial information is remote sensing. This term refers to gathering information from great distances and over broad areas, usually through instruments mounted on aircraft or orbiting spacecraft. These instruments, or remote sensors, measure electromagnetic radiation coming from the Earth’s surface and atmosphere as received at the aircraft or spacecraft platform. The data acquired by remote sensors are […]

Data layers in a GIS

Geographic Information Systems

Maps, like books, are very useful devices for storing information, but they have limitations. Recent advances in computing capability have enabled geographers to develop a powerful new tool to work with spatial data—the geographic information system (GIS). A GIS is a computer-based system for acquiring, processing, storing, querying, creating, analyzing, and displaying spatial data. Geographic information systems have allowed geographers, geologists, geophysicists, ecologists, planners, […]

GPS satellite

The Global Positioning System

The latitude and longitude coordinates of a point on the Earth’s surface describe its position exactly. But how are those coordinates determined? For the last few hundred years, we have known how to use the position of the stars in the sky coupled with an accurate clock to determine the latitude and longitude of any point. Linked with advances in mapping […]

Maps and Cartography

Cartography is the field of geography concerned with making maps. A map is a paper representation of space showing point, line, or area data—that is, locations, connections, and regions. It typically displays a set of characteristics or features of the Earth’s surface that are positioned on the map in much the same way that they occur on the surface. The map’s […]

Tools in Physical Geography

Geographers use a number of specialized tools to examine, explore, and interact with spatial data. One of the oldest tools is the map—a paper representation of space showing where things are. While maps will never go out of style, computers have enhanced our ability to store, retrieve, and analyze spatial data through the development of geographic information systems (GIS). Acquiring geographic information […]

Physical Geography, Environment, and Global Change

Physical geography is concerned with the natural world around us—in short, with the human environment. Because natural processes are constantly active, the Earth’s environments are constantly changing. Sometimes the changes are slow and subtle, as when crustal plates move over geologic time to create continents and ocean basins. At other times, the changes are rapid, as when hurricane winds flatten vast areas […]

The Earth realms

Spheres, Systems, and Cycles

As a part of your introduction to physical geography, it will be useful to take a look at the big picture and examine some ideas that arch over all of physical geography—that is, spheres, systems, and cycles. The first of these ideas is that of the four great physical realms, or spheres of Earth—atmosphere, lithosphere, hydrosphere, and biosphere. These realms […]

Perspectives of geography

Introducing Geography

What is geography? Put simply, geography is the study of the evolving character and organization of the Earth’s surface. It is about how, why, and where human and natural activities occur and how these activities are interconnected. What makes geography different from other disciplines? Geography adopts a unique set of perspectives to analyze the world and its human and natural phenomena. These […]

Competitiveness

Introduction Although rarely confronted directly, competitiveness is a central concept in economic geography. In location and regional development theories, and in their work on industrial restructuring, uneven development, industrial district formation, learning regions, and neoliberalization, economic geographers have asked what gives particular advantages to enterprises located in particular places. Far from unified in their approaches to this question, different authors have […]

Community

Community is one of those concepts about which social and cultural geographers worry. It is a difficult term to tie down, and it is used in a myriad of ways by all spectrums of society. In his influential Keywords, Raymond Williams points out that unlike other terms for social relations, such as state and nation, and even society, the term ‘community’ […]

Communist and Post-Communist Geographies

Efforts in geography to address the issues of socialism/communism failed to be seminal to the emergence of any powerful theory that could have been the result of putting the perspective of scientific communism on geography. It was the political economic approach of Marxism that imbued the geographies of state socialist countries the profoundly. Human geography was replaced with economic geography. […]

Communicable Diseases, Globalization of

Introduction Communicable diseases are the greatest disease threat facing humankind. Diseases previously considered eradicated are re emerging and new viruses are emerging. Due to increased human population and accelerated global travel, local outbreaks become instant global threats. Despite technological advances in medicine, devastating communicable diseases such as Ebola, severe acute respiratory syndrome (SARS) or avian influenza continue to surface and ravage humankind. […]

Sectors and actors in the commodity chain system.

Commodity Chains

Commodity Chains: An Introduction The production of any commodity, whether it be a manufactured product or a service, involves an intricate articulation of individual activities and transactions across space and time. Such production networks – the nexus of interconnected functions and operations through which goods and services are produced and distributed – have become not only organizationally more complex but also increasingly […]

Differences in color hue (red, green, and blue peaks), color lightness (light and dark green peaks), and color saturation (pure blue and grayish blue peaks)

Color, Mapping

Introduction The word color is often associated with sensations that are named, such as red, blue, purple, and brown. However, the phenomenon of color is actually multidimensional. Color can be differentiated along three different dimensions: hue, lightness, and saturation. Color hue is related to the wavelengths of light that are perceived by the map reader, and is typically described […]

Colonialism, Internal

Definition Internal colonialism refers to a complex set of sociospatial relationships of exploitation and domination that characterize certain culturally distinct populations residing in sovereign, mainly ThirdWorld, societies. The two defining relationships of internal colonialism are that subjected populations are (1) exploited principally by mechanisms which may not be ‘capitalist proper’ and (2) institutionally dominated, both politically and culturally. In the first […]

Colonialism II

New Imperialisms, New Colonialisms, and New Political Geographies The later decades of the nineteenth century and the first years of the twentieth century witnessed European colonialism accelerate in pace and expand in scale. By 1914, much of the world was shaped by this process and its attendant, entwined webs of trade, migrants, political power, and knowledge. Historians usually trace this […]

Colonialism I

Introduction In recent years, there has been an enormous body of work which tries to understand modern European colonialism in all of its economic, social, and cultural dimensions, and to grapple with its legacies. The focus of this article is especially on British and, to a lesser extent, on French colonialism up to about 1870. The terms ‘colonialism’ and ‘imperialism’ […]

Cold War

The Cold War was named in 1947 by Bernard Baruch in his advisory role to President Truman as the United States, Great Britain, France, and its other Western allies faced off against the Soviet Union, with mutually aggressive maneuvers and countermoves, especially in Europe. This label was publicized more broadly by Walter Lippmann in a 1947 book with same name, […]

Figure 1 Photo of Saul Bernard Cohen.

Cohen, S.

Cohen, Saul (1925–) Born in Malden, Massachusetts, and was educated in Boston, Saul Cohen graduated in geography of Harvard (MA 1948, PhD 1954) and served in Europe in World War II. A liberal Democrat, he is married to Miriam, has two daughters and seven grandchildren. In 50 prolific years of writing, teaching, and studying in geography, Saul Bernard Cohen has […]

Cognitive Geography

What Is Cognitive Geography? Cognitive geography is the study of cognition, primarily human cognition, about space, place, and environment. Cognition is knowledge and knowing by sentient entities, including humans, nonhuman animals, and artificially intelligent machines. Cognitive structures and processes include those of sensation, perception, thinking, learning, memory, attention, imagination, conceptualization, language, and reasoning and problem solving. Some of these structures and processes […]

Paul Cloke

Cloke, P.

Cloke, Paul (1956 –) Professor of Human Geography at the University of Exeter, England, having previously worked in geography departments at Lampeter, Wales, and Bristol, England; by the early 1990s Martin Bodman identified Paul Cloke as an emerging ‘master weaver’ in human geography, a phrase used to characterize people having a significant influence within the discipline. Bodman argued that Cloke was one […]

Climate Change

Introduction Communities which cope with climatic hazards by im plicitly assuming a continuance of the status quo learn harsh lessons. Despite this, quite limited adaptation to known risks is often apparent in contemporary society. In the past, the catastrophe of harvest failure led to sometimes quite sophisticated coping responses and the shunning of areas of known high risk based on […]

Claval, Paul

Claval, P.

Claval, Paul (1932–) Paul Claval, born in Paris in 1932, is one of the most important geographers of his generation, both in terms of the extensive nature of his work and his originality, eclecticism, and international influence. His passion for geography developed during his teenage years in south-western France. While accompanying his father on summer work trips, Claval very quickly […]

Meeting of a women’s neighborhood committee, Guatemala City

Civil Society

Introduction Civil society is a contested term that broadly describes the arena of collective social interaction situated between the state, market, and household. Despite being used in a normative manner to encompass a host of values linked with participation and cooperation, it is more commonly used to describe a range of formal and informal nonstate organizations, groups, and associations that form […]

Example of a top-down approach to city-region definition in England, 2001

City-Region

Origin of the City-Region Since the 1990s, there has been a remarkable resurgence of the concept of the city-region in both academic and policy communities. In broad terms, the concept articulates the relationships between the city and its environs. For almost 30 years the focus on the city-region had been overshadowed by a shift of emphasis toward urban and particularly […]

City Marketing

Introduction Classic city slogans like ‘‘I ? New York’’ and ‘‘Glasgow’s Miles Better’’ are so embedded in the popular consciousness as to have long outlasted their official use by their respective municipalities, chambers of commerce, and convention and visitors bureaus. Cities and towns are increasingly associated with symbols, slogans, or taglines (‘‘What Happens Here Stays Here. Las Vegas’’ or ‘‘Johannesburg. A […]

Citizenship and Governmentality, Rural

Introduction In its most straightforward sense, citizenship is understood as bestowing upon individuals a legal status as members of a national polity, enacted by state apparatus and defended by legal and administrative rule and regulations. As members of that polity, individuals are entitled to certain political, civic, economic, and social rights, including individual freedom of speech, rights to property, the right […]

Citizenship

Introduction Citizenship refers to particular ways of being situated within and responding to relations of power through which a community is governed or ruled. It involves claiming, exercising, and contesting rights, entitlements, and obligations (e.g., rights to vote and strike, the obligation to pay taxes) and diverse ways of engaging with the institutions (such as the state) and relations through which […]

The determinants of chronic disease

Chronic Disease

Introduction Chronic diseases are ongoing/recurring, not caused by infection, or passed on by contact. They generally cannot be prevented by vaccines, do not resolve spontaneously, and are rarely cured by medication or other medical procedures. Chronic diseases are often caused by a combination of health damaging behaviors (smoking, drinking, high fat diet, and physical inactivity) and exposure to socioenvironmental conditions (stressful […]

Christian Geography

Introduction Many a different adjective and prepositional phrase added to the word ‘geography’ has become common currency to identify and parcel out geography’s distinctive fields, topics, regions, paradigms, approaches, research groups, national traditions, and historical periods. Christian is almost never one of them. There is Berkeley geography, Classical geography, the geography of aging, Japanese geography, idealist geography, the geography of the […]

Christaller, W.

Christaller, W.

Walter Christaller (Figure 1), a German geographer and one of the founding fathers of the ‘central place theory’, was born on 21 April 1893 in Berneck in the Black Forest, and died on 9 March 1969 in Ko?nigstein in Taunus (Hesse), at the age of 75. His mother belonged to a cultured middle class family of Darmstadt and in her mature […]

Nested structure of housing choice alternatives.

Choice Modeling

Introduction A conventional premise of microeconomic theory is that demand and supply are traded off through continuous adjustments in quantities. Individual demand is determined by calculus methods that maximize consumer utility (i.e., satisfaction), subject to constraints. By the 1970s, it had become clear from the pioneering work undertaken in transportation, marketing, and economics that many consumer decisions do not conform to […]

The changing distribution of articles published in different subfields of human geography

Chinese-Language Geography

A Long History of Chinese Human Geography Recognition of Human–Land Relation during the Formative Stage Human geography started to flourish in China more than 2500 years ago. The concept of ‘geography’ was first coined in the classic text of Yi Jing (or I Ching, Book of Changes), referring to the observation and understanding of the Earth’s surface for the pursuance of […]

The Persistence of the State in Chinese Urbanism

It is clear that Chinese urbanism has evolved differently under different historical contexts. It has always contributed to state formation while reflecting the national concerns of the period in question. What sets Chinese urbanism apart from the urbanisms elsewhere is the persistently strong role of the state in shaping its character that began with China’s first cities in the […]

Multiplex Urbanism in the Reform Era

China’s dramatic urban transformation since the 1978 reforms is a consequence of the interplay between exogenous and endogenous forces at global, national, and local scales. As elsewhere, globalization and neoliberalism have strongly impacted the Chinese economy, but major endogenous policy shifts have been more important in effecting changes in the Chinese city, including the initiation of the policies of […]

Socialist Urbanism (1949–1978)

Socialist urbanism in China was created very quickly during the first three decades of Communist rule. From 1949 to 1978, cities served two major functions. First, they continued to serve as centers of national and local administration, a function that directly affected their growth. Second, cities played a passive supporting role in China’s centrally planned socialist industrialization, serving essentially as spatial containers […]

The Arrival of the West and Modernist Urbanism (1840–1949)

Urbanism in China experienced a dramatic change in the mid nineteenth-century when increasing numbers of Western traders arrived in China demanding expanded trade along the China coast, which precipitated the Opium War (1839–1842) between the British and Chinese empires. China’s loss of the Opium War and other subsequent wars with foreign powers resulted in a series of unequal treaties that forced […]

Administrative and Commercial Urbanism (770 BC–AD 1840)

Childe’s key criteria defining early cities in the Old World show clearly the importance of economic production and trade in the rise of its early cities, and economic factors have remained dominant in subsequent Western urban history. In China, during the Zhou period (c. 1122–256 BC), a politically fragmentary era with many independent states contending for territory and superiority, […]

Neolithic Settlements and Incipient Urbanism (c. 5000–770 BC)

As in other parts of the world, early Chinese towns evolved from villages. During the Middle Neolithic era (c. 6500–5000 BC), large sedentary villages with a few hundred people based mainly on agriculture and animal domestication had emerged. Widely distributed in China, many of the villages were surrounded by circular ditches and walls constructed with the hangtu (tamped earth) technique, whereby layers […]

Chinese Urbanism

Cities are complex spatial entities consisting of economic, social, political, and cultural dimensions that differ significantly in different cultures, where they tend to undergo varying patterns of transformation over time. Cities and states are dynamically related and mutually constituted, with the former often embodying the essence of the latter. This is especially true in the case of China. Relative to other […]

Critiques and Challenges

Outside of academia, the children’s rights movement has, as yet, had only limited success. The global position of children remains poor, with significant numbers of children lacking a basic education, clean water, or food. The UN Convention has been criticized for trying to impose a global vision of childhood which fails to adequately recognize cultural differences or varying needs. Moreover […]

Children’s Experiences of Place

The following section will explore one of the key contributions geographers are making to the study of childhood, by focusing on the empirical work geographers are doing in the everyday spaces of childhood which shape (and are shaped by) their lives. The Home The home is an important site for the negotiation of child–adult power relations. The home […]

The Spatial Construction of Childhood

One of the most important ways in which human geography can enhance our understanding of childhood is to highlight the importance of space and place to children’s lives. Geographers question essentialist notions of a universal child by illustrating through diverse empirical studies the ways in which children’s experiences vary in different places and in different contexts. The notion of what constitutes […]

Children’s Geographies

The following sections will explore children’s geographies by drawing on a range of empirically rich material from both the ‘minority and majority world’, to highlight the relationships between children and the spaces they inhabit. The first part will explore the socioeconomic structures, institutions, discourses, etc. – including globalization, ‘development’, and poverty that ‘place’ children in particular ways. The second part […]

Theoretical Concepts

The Social Constructedness of Childhood The concept of a socially constructed child is relatively new in geography. It developed in part as a response to the crisis of representation in the social sciences which began in the mid 1970s. Focusing on academic texts, concern was expressed over the ability of academics to misrepresent others through their writing. Children were viewed as […]

Origins of Work on Children by Human Geographers

Children remained absent from most geographical work until William Bunge’s detailed empirical studies of Detroit and Toronto in the early 1970s, in which he focused on the spatial oppression of children in the built environment. At a time when geography was heavily dominated by the quantitative revolution, Bunge used a variety of methods including observation of children at play to highlight […]

Definitions

Defining childhood is problematic due to the spatial and temporal fluidity of prevalent ideas and laws pertaining to children. On one level, the definition used by many human geographers and other social scientists reflects the 1989 UN Convention on the Rights of the Child, which defines childhood as the period up to 18 years of age. However, while this implies that […]

Children/Childhood

Definitions Origins of Work on Children by Human Geographers Theoretical Concepts Children’s Geographies The Spatial Construction of Childhood Children’s Experiences of Place Critiques and Challenges