Drakensberg Mountains

THE DRAKENSBERG Mountains form one of the most scenic natural areas in SOUTH AFRICA. The mountain range straddles the eastern border of LESOTHO, a LANDLOCKED nation lying within the boundaries of South Africa, located about 150 mi (250 km) northwest of Durban. The name Drakensberg means “Dragon Mountains” in Afrikaans. The range is also known to the Zulu nation as “uKhahlamba” (the “Barrier of Spears”).

The Drakensberg Mountains are the southern extension of the interior highlands of Africa, rising to

10,826 ft (3,300 m) before dropping to the coastal lowlands near Durban. The Drakensbergs serve as the headwaters of South Africa’s largest river, the Orange River, which flows west from the highlands of Lesotho to the South Africa-NAMIBIA border before emptying into the ATLANTIC OCEAN. The steep gradients and land use cause many of South Africa’s rivers to have a high rate of runoff and soil EROSION.

Seasonality is reflected in dry, sunny winters (April to October) and summer rains (November to March). Rainfall varies from 15.7 in (40 cm) to 35.4 in (90 cm) of precipitation per year, with some areas occasionally receiving up to 78.7 in (200 cm) per year. A “rainfall line” denotes grazing and irrigated crops to the west and land more suitable for farming to the east. Record snowfalls (19.7 in or 50 cm) occurred in July 1994. 

Bushmen (called “San”) have inhabited the basalt ESCARPMENT from thousands of years ago up until the late 1800s, leaving tens of thousands of rock paintings at over 500 sites. This is a major reason part of the mountain range was designated the uKhahlamba-Drakensberg World Heritage Site in 2000 by the United Nations.

The Drakensberg Mountains also hold numerous national parks, the most scenic of which is Royal Natal National Park, located at the northern end of the range. Here lies the Amphitheatre, a natural ring of thousand-meter high cliffs that includes multilevel Thukela Falls, the second-highest waterfall in the world.

In addition to cultural and scenic amenities, the Drakensberg Mountains also harbor high levels of biodiversity, much of this resulting from the steep elevation gradients. Ninety-eight of 2,153 plant species are endemic or near-endemic to the area; the almost 300 bird species include the globally endangered cape parrot and white-winged fluff-tail.

Despite efforts by Zulu kings to limit the range of trophy hunters, several wildlife species nearly became extinct from hunting here by the late 1800s. The eland, endemic gray rhebock, and clawless and spotted-neck otters are species populations exhibiting healthy recovery from this historic setback. Other traditional African wildlife that inhabit the Drakensberg Mountains include leopard, baboon, jackal, wildebeest, and zebra.

Historic battlefields dot the region, marking sites of the British-Zulu wars and British-Boer wars of the 1800s. Nearby towns and cities include Ladysmith, through which Mahatma Gandhi and Winston

Churchill passed early in their careers. Ladysmith is the home of Ladysmith Black Mambazo, a musical group popularized globally by Paul Simon.

Don River

THE DON RIVER IS one of RUSSIA’s major commercial rivers, which, connected to the VOLGA through the 65-mi (105-km) Volga-Don Canal, allows river traffic to sail from Russia’s interior ports as far inland as MOSCOW to ports on the BLACK SEA and beyond to the MEDITERRANEAN. The Don River basin also includes its most important tributary, the Donets, which flows through the northeastern corner of the UKRAINE, the most industrially active region of that country, known for its coal and production of steel and heavy manufacturing machinery.

The Don rises near the city of Tula, about 125 mi (200 km) southeast of Moscow. It then flows for 1,220 mi (1,950 km), first southeast to a bend a few kilometers west of Volgograd (coming within 31 mi or 50 km of the Volga River), then southwest to its mouth on the Sea of Azov. It is at this bend where the rivers Don and Volga are joined by the Volga-Don Canal, built in 1952. The canal joins the Don in the Tsimlyanskoye Reservoir, one of Russia’s numerous vast hydroelectric projects built in the Soviet era, with a large dam between the towns of Tsimlyansk and Volgodonsk.

The Don basin’s largest cities are clustered below this point (Rostov, Bataysk, Novocherkassk) or along the industrial Donets basin in Ukraine (Kharkov, Lisichansk, Lugansk). Altogether, the Don basin drains 178,894 square mi (458,703 square km), most of it Russia’s breadbasket (83 percent is cropland). Known as the Tanaïs to ancient geographers, it was the center of Scythian culture in the centuries before and after the Christian era. It is the busiest trade river of south Russia, navigable for 800 mi (1,290 km), bringing Siberian raw materials and manufactured goods from the north to the warm-water ports of the south. Frozen during three months of the year, it is also occasionally hampered by severe spring flooding, but also large volumes of silt that make navigation in its lower reaches treacherous because of shifting sandbanks and shallows. Its entryway into the Sea of Azov, the Gulf of Taganrog, is one of the shallowest bodies of water in the world, with depths averaging a mere 3.3 ft (1 m).

Domino Theory

THE DOMINO THEORY states that if one vital country in a region falls to an expansionist negative philosophy, then other countries in the region similarly situated and similarly structured would fall victim to the same philosophy, either through force or through influence of example. In its pure form, the negative philosophy is communism but in variants it can be socialism or theocratic Islam, The theory was used as a rationale for American interventions, including most disastrously the intervention in the Vietnam War. After World War II, the geopolitical situation of an already shaky alliance between the Western capitalist democracies and the communist Union of Soviet Socialist Republics fell apart as the Soviets sought to establish a buffer zone of satellite states and the UNITED STATES asserted the rights of all nations to independence in a postcolonial world. Each side accused the other of starting the Cold War, and the world quickly polarized as each camp took an “either against us or with us” attitude and enforced it through alliances, such as the Soviet bloc Warsaw Pact and the U.S.-led NORTH ATLANTIC TREATY ORGANIZATION (NATO). Battling monoliths faced each other across the Iron Curtain in a Cold War where none was allowed to be neutral.

The West definitely feared communism, as it had since the Russian Revolution had generated Red Berlin and America’s red scare back in the aftermath of World War I. The communists had been active in the intervening years, notably in SPAIN, and there were examples where briefly democratic countries became communist as the map of Europe turned “red” after World War II. The U.S. consensus was that all communist movements were part of the communist international, puppets of the Kremlin. Communism was a monolith, not a an idea, like democracy, that might arise in a nation independently of either the United States or the Soviet Union.

Dominica

THE LAST OF THE islands of the West Indies to be colonized, chiefly because of the fierce resistance of the native Carib population, the island of Dominica now retains the only pre-Columbian population in the eastern CARIBBEAN SEA. Dominica also maintains more of its original tropical vegetation, due to the roughness of its terrain—it is 66 percent forested, compared to 36 percent on SAINT VINCENT, and only 9 percent on GRENADA. The inability to establish large plantations thus served to preserve Dominica’s natural riches, a fact that is now a blessing to the country’s economy as a chief draw for tourism, supplemented by reserves of timber for export.

As with the other islands in the Windward group of the Antilles, Dominica is volcanic in origin. Morne Diablatins is the island’s highest volcanic peak, but there is also considerable thermal activity and a large crater lake located only 7 mi (11 km) from the capital city of Roseau. The Caribs (approximately 3,000 in number) live mostly in a reservation set up for them in the northeastern part of the island. Many still farm small plots and are involved in weaving traditional baskets used all over the island and sold to tourists. Having richer and more luxuriant soil than its neighbors, Dominica grows most tropical products with ease but specializes in limes.

The island, named by Christopher Columbus on Sunday (Domingo), November 3, 1493, lies between the French departments of GUADELOUPE and MARTINIQUE and was itself a French colony until 1763. Among those many North American and Caribbean territories reassigned to the British by the Treaty of Paris, Dominica remained a British colony until independence in 1978.

Because of Carib resistance and the steepness of its volcanic slopes, Dominica was not developed as a major sugar producer like its neighbors. Small farmers continued to live much as they had done before the British takeover, and the island retains much of its French flavor, especially in its patois. Possibly as a result of this duality of loyalties, Dominica has chosen to become a republic while remaining a member of the British Commonwealth—in other words, unlike ANTIGUA or SAINT KITTS, the chief executive of Dominica is an elected president, not the hereditary British monarch. With one of the lowest per capita incomes in the Lesser Antilles, the population is increasingly young and urban, with nearly a third living in the capital of Roseau.

Djibouti

BORDERED BY ETHIOPIA, ERITREA, and SOMALIA in Africa, the country of Djibouti (the former French Somaliland and then AFARS and Issas) is the epitome of a geopolitical state. It is a state that has been created and defined by its geographic location. Similar to GIBRALTAR and Aden, Djibouti controls access and egress from a major waterway: the Suez Canal and RED SEA. From 1862, Djibouti was controlled by the French, especially the French Foreign Legion, until 1977. In 2002, the UNITED STATES established a military base here. Were it not for its geopolitical value, there would be no economy beyond herding of goats and no political unit.

Small in area, with some features such as Lake Assal below sea level (550 ft or 168 m), Djibouti is arid and occupied primarily by pastoralists and refugees from the war between Ethiopia and Eritrea. Its deep harbor and the fact that all traffic to and from the Suez Canal (and thus Mediterranean Europe) must pass its location has made the area important far beyond any local resources—of which there virtually are none to speak of.

The only natural resource, other than its location, is the salt deposit at Lake Assal. However, salt is more easily and cheaply obtained in many other areas. The closest local parallel to the geopolitical value of Djibouti would be Aden, which also controls access to the BAB AL MANDEB, Red Sea and Suez Canal, but Aden was controlled by the British.

Djibouti also is located on a major fault (fracture) zone known as AFAR (for Africa/Arabia), where major geologic plates are separating and rotating, making it an extremely active earthquake and volcanic area as well.

Distance

EMPLOYING THE GEOGRAPHIC sense of the term, distance can be defined as the amount of separation between two points or objects on the surface of the Earth. Geographic distance is usually expressed as a linear measurement between locations using one of several commonly accepted metrics (a metric is a standard of measurement using associated units).

Historical distance metrics were often based on the lengths of human body parts. Among these was the cubit, defined as the distance from the tip of the elbow to the end of the middle finger, and the foot (whose corporal association is obvious). These measuring instruments were extraordinarily useful in that they were always available and could not be misplaced. Unfortunately such metrics differed based on the size of person making the measurements, sometimes by several inches or more.

Although attempts at standardizing distance metrics have appeared throughout history, only a few have persisted in wide use to the present day. One of these originated with King Edward I of England when he commissioned the Iron Ulna, or master yardstick, in the early 14th century. One-third of the yard was decreed to be a foot, and one-36th was termed the inch.

This system of linear measurement has persisted as two related systems: the British Imperial System and the U.S. Customary System. In the U.S. Customary System the yard is the base unit while a rod equals 5.5 yards, a furlong equals 220 yards, and a mile equals 1,760 yards. The distances related to the depth of bodies of water are often given in fathoms, each fathom being equivalent to 2 yards. The UNITED STATES is the only major country widely employing this system for linear measurement, and efforts have been made to replace it with the more widely accepted metric system.

The metric system became standardized in the late 18th century in France when several proposals were made for defining the standard length of a meter. The successful proposal used the size of the Earth as the ultimate standard of measurement. More specifically, a meter was defined as one ten-millionth of the distance between the North Pole and the equator along a meridian traveling through Paris. Although error associated with making this measurement (due to miscalculations of the shape of the Earth) resulted in the standard meter being slightly shorter than it ought to be given its definition, this distance became the standard nevertheless.

A prototype bar of platinum-iridium was constructed as the standard meter and was kept at standard atmospheric pressure to avoid changes in its length. A subsequent definition of the meter was made based on the length of the path traveled by light in a vacuum over a very small fraction of a second. With the meter established as the basis for the metric system of linear measurement other units were computed as decimal ratios of the meter. The metric system is now the most widely used system of measurement and is more accurately termed the International System of Units (SI).

Given that there are several well-accepted units for linear measure, one can use these metrics to determine geographic distances. In many cases, a geographic distance to be measured is small enough that the curvature of the earth does not alter the measurement within the precision capabilities of the measuring instruments being used.

Diffusion

DIFFUSION IS the spread of a phenomenon, such as an idea, a technological innovation, or a disease, over space and time. The origins of interest in diffusion in geography can be traced back to the work of the German geographer Frederick Ratzel (1844–1904). In the second volume of his highly influential Anthropogeographie, Ratzel described the diffusion of cultural traits. This work laid the foundation for the studies by geographers on cultural history, which came to be most influential in the work of Carl SAUER (1889–1975) and the geography department at the University of California, Berkeley, from the 1930s through the 1950s, which is referred to as the Berkeley School.

Sauer (1952) argued that issues of cultural diffusion should be one of the main concerns of geography. Sauer believed that the diffusion of ideas, such as agriculture, from “cultural hearths” (cultural centers) has been one of the main driving forces in human history. The research undertaken by the Berkeley School also influenced the study of the origin and spread of culture in the 1960s and, more recently, the study of environmentalism and the processes of cultural globalization.

Another key geographer in ideas of diffusion was the Swede Torsten Hägarstrand (1916–2004). His 1952 doctoral dissertation on innovation diffusion as a spatial process had limited impact until its publication in English in 1967. Hägarstrand observed that the diffusion process can be likened to a wave pattern that loses its strength as it moves away from its source of origin.

Hägarstrand provided a mathematical basis for simulating innovation diffusion on the basis of probability although it is rare for diffusion to be completely random. Each location is regarded as having a different set of probabilities for diffusion based on a mean information field that structures the way in which diffusion flows through a region. Four different types of diffusion are usually recognized.

In expansion diffusion (also referred to as contagious diffusion), a phenomenon, such as knowledge of an innovation or a disease, is spread by direct contact or word of mouth. This type of diffusion exhibits the frictional effects of distance by which those furthest away are less likely to receive this information than those closer to the initial source (distance decay).

A more developed model of the simple epidemic model of contagious diffusion in which all members of a population are regarded as susceptible to a disease is the General Epidemic Model. In this approach a threefold division of the population is made into susceptibles, infectives and removals (infectives who after a period of time either cease to pass a disease on to others or communicate information regarding an innovation).

The General Epidemic Model has been utilized to study a number of different types of diffusion with respect to disease and the dispersal of plants and animals and has also been refined to introduce greater complexity into studying transmission. The third type of diffusion is termed hierarchical. In this case diffusion can leap over intervening people and places. Hierarchical diffusion helps explain diffusion within large bureaucratic systems such as multinational firms. It is also a useful way to explain diffusion in the fashion industry, where innovations may originate in fashion centers such as PARIS, NEW YORK, or Melbourne, then diffuse to chain stores in larger cities and from there to retail stores in smaller towns.

The fourth type of diffusion is relocation. In relocation diffusion, information (or plants and animals) moves along with the people who know it. Once relocated, migrants will often then spread innovations via an expansion diffusion process. Indeed, the different types of diffusion are usually occurring almost simultaneously. Absolute or absorbing barriers are a feature or condition that completely prevent diffusion, for example, mountain ranges that prevent population dispersal.

However, over time barriers may become permeable because of technological advances or changes in perception, such as the Appalachians with respect to European settlement in the United States. Finally, there are reflective barriers that deflect an innovation wave back on itself, such as in the case of human settlement on a coastline.

Substantial research continues to be done on diffusion in geography with respect to innovation particularly with respect to technology and products. In this there is a strong relationship to research on time geography as well as trying to understand the social processes behind individual adoption and resistance to adoption.

Dhaka

DHAKA BECAME the capital of the newly formed sovereign state of BANGLADESH in 1971. The city has a tropical monsoon climate with heavy summer rainfall (June through September), about 80 in (203 cm) annually. Summer is hot and humid and winter is dry and mild.

It is located on a tributary of the Meghna-GANGES river system and was founded by the Hindu Sena kings in the 7th century C.E. After a Delhi-based Muslim Sultan’s conquest of Bengal, Dhaka remained a regional capital between 1203 to 1764. After the British conquest of Bengal in 1757, Dhaka became a secondary capital as Kolkata (Calcutta) became the capital of both Bengal and British India. As a result of the partition of South Asia in 1947, the present-day Bangladesh became a province of PAKISTAN (from 1947 to 1971) and Dhaka again was relegated to a provincial capital.

National capital status in 1971 turned Dhaka into a fast-growing dynamic metropolis. From a population base of 104,000 in 1901, and 239,000 in 1941, Dhaka has grown to 12.5 million in 2000, making it the primate city of the country, and 9th most populous metropolis of the world. The very congested and badly maintained old city, heart of the commercial center, has given rise to a typical traditional bazaar city center. Dhaka is one of the most homogeneous cities, as 95 percent of its population speak Bengali and 90 percent are Muslims.

Because of their number, Dhaka is designated as the City of Mosques. Its long history bears architectural imprints from Hindu, Muslim, British, and postindependence periods. A third of modern Dhaka’s population live in dire poverty and in slums, though the rich have built buildings of brick and mortar. 

Dhaka’s problems are many: A preponderance of mosquitoes, high level of noise pollution, flooding after heavy rains, jammed streets with three-wheelers, buses, motorbikes, cycle-rickshaws, and pedestrians. Dhaka prepared a metropolitan plan in 1995 based on a modern approach. This plan addressed “residential provisions of middle and upper income groups, industrial and commercial development and intra-city transportation.” The proposed flood abatement efforts include construction of huge retention ponds on the eastern and western fringes of the city. The problem of enacting the plan is a lack of funding.