Geography of Peru

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Peru is a complex amalgam of ancient and modern cultures, populations, conflicts, questions, and dilemmas. The land itself offers great challenges. With 1,285,216 square kilometers, Peru is the eighteenth largest nation in area in the world and the fourth largest Latin American nation. It ranked fifth in population in the region, with 22,767,543 inhabitants in July 1992. Centered in the heart of the 8,900-kilometer-long Andean range, Peru's geography and climates, although similar to those of its Andean neighbors, form their own peculiar conditions, making the region one of the world's most heterogeneous and dynamic. Peru's principal natural features are its desert coast; the forty great snow-covered peaks over 6,000 meters in altitude, and the mountain ranges they anchor; Lake Titicaca, which is shared with Bolivia, and at 3,809 meters above sea level the world's highest navigable lake; and the vast web of tropical rivers like the Ucayali, Marañón, and Huallaga, which join to form the Amazon above Peru's "Atlantic" port of Iquitos.

The Costa, Sierra, and Selva (selva--jungle), each comprising a different and sharply contrasting environment, form the major terrestrial regions of the country. Each area, however, contains special ecological niches and microclimates generated by ocean currents, the wide range of Andean altitudes, solar angles and slopes, and the configurations of the vast Amazonian area. As a consequence of these complexities, thirty-four ecological subregions have been identified.

Although there is great diversity in native fauna, relatively few animals lent themselves to the process of domestication in prehistoric times. Consequently, at the time of European arrival the only large domesticated animals were the llamas and alpacas. Unfortunately, llamas and alpacas are not powerful beasts, serving only as light pack animals and for meat and wool. The absence of great draft animals played a key role in the evolution of human societies in Peru because without animals such as horses, oxen, camels, and donkeys, which powered the wheels of development in the Old World, human energy in Peru and elsewhere in the Americas could not be augmented significantly. As far as is known, the enormous potential in hydrologic resources in preconquest times was tapped only for agricultural irrigation and basic domestic usage. Through the elaborate use of massive irrigation works and terracing, which appeared in both highland and coastal valleys in pre-Chavín periods (1000 B.C.), the environment of the Andes was opened for intensive human settlement, population growth, and the emergence of regional states.

The development of Andean agriculture started about 9,000 years ago, when inhabitants began experimenting with the rich vegetation they utilized as food gatherers. Each ecological niche, or "floor," begins about 500 to 1,000 meters vertically above the last, forming a minutely graduated and specialized environment for life. The central Andean area is, thus, one of the world's most complex biospheres, which human efforts made into one of the important prehistoric centers of plant domestication. Native domesticated plants number in the hundreds and include many varieties of such important crops as potatoes, maize (corn), lima beans, peppers, yucca or manioc, cotton, squashes and gourds, pineapples, avocado, and coca, which were unknown in the Old World. Dozens of varieties of fruits and other products, despite their attractive qualities, are little known outside the Andean region.

Conquest of the Aztec alliance in Mexico and the Inca Empire (Tawantinsuyu) in the Andes gave impetus to one of the most important features of the colonial process, the transfer of wealth, products, and disease between the hemispheres. Andean plant resources, of course, contributed significantly to life in Europe, Africa, and Asia. Although attention has usually focused on the hoards of Inca gold and silver shipped to Spain and thus funneled to the rest of Europe, the value of Andean potatoes to the European economy and diet probably far exceeded that of precious metals. By the same token, the Spanish conquerors introduced into the New World wheat, barley, rice, and other grains; vegetables like carrots; sugarcane; tea and coffee; and many fruits, such as grapes, oranges, and olives. The addition of Old World cattle, hogs, sheep, goats, chickens, and draft animals--horses, donkeys, and oxen--vastly increased Andean resources and altered work methods, diets, and health. The trade-off in terms of disease was one-sided; measles, malaria, yellow fever, cholera, whooping cough, influenza, smallpox, and bubonic plague, carried by rats, arrived with each ship from Europe. The impact of these diseases was more devastating than any other aspect of the conquest, and they remain major scourges for the majority of Peruvians.

The Coastal Region

Peru's coast is a bleak, often rocky, and mountainous desert that runs from Chile to Ecuador, punctuated by fifty-two small rivers that descend through steep, arid mountains and empty into the Pacific. The Costa is a strange land of great dunes and rolling expanses of barren sand, at once a desert but with periods of humidity as high as 90 percent in the winter from June to September, when temperatures in Lima average about 16 degrees Celsius. Temperatures along the coast rise near the equator in the north, where the summer can be blazingly hot, and fall to cooler levels in the south. If climatic conditions are right, there can be a sudden burst of delicate plant life at certain places on the lunar-like landscape, made possible by the heavy mist. Normally, however, the mist is only sufficient to dampen the air, and the sand remains bleakly sterile. These conditions greatly favor the preservation of delicate archaeological remains. The environment also facilitates human habitation and housing because the climate is benign and the lack of rain eases the need for water-tight roofing.

Humans have lived for over 10,000 years in the larger coastal valleys, fishing, hunting, and gathering along the rich shoreline, as well as domesticating crops and inventing irrigation systems. The largest of these littoral oases became the sites of towns, cities, religious centers, and the seats of ancient nations. Although migration from the highlands and other provincial regions has long occurred, the movement of people to the Costa was greatly stimulated by the growth of the fishing industry, which transformed villages and towns into frontier-like cities, such as Chimbote. In the early 1990s, over 53 percent of the nation's people lived in these sharply delimited coastal valleys. As the population becomes ever more concentrated in the coastal urban centers, people increasingly overrun the rich and ancient irrigated agricultural lands, such as those in the Rímac Valley where greater Lima is situated, and the Chicama Valley at the site of the city of Trujillo. Although the region contains 160,500 square kilometers of land area, only 4 percent, or 6,900 square kilometers of it, is arable. By 1990 population growth had increased the density of habitation to 1,715 persons for each square kilometer of arable land. Throughout all the coastal valleys, human settlements remain totally dependent on the waters that flow from the Andes along canals and aqueducts first designed and built 3,000 years ago. Here, uncontrolled and unplanned urban growth competes directly with scarce and vitally needed agricultural land, steadily removing it from productive use.

The Andean Highlands

The Sierra is the commanding feature of Peru's territory, reaching heights up to 6,768 meters. Hundreds of permanently glaciated and snowcapped peaks tower over the valleys. The steep, desiccated Pacific flank of the Andes supports only a sparse population in villages located at infrequent springs and seepages. In contrast, tropical forests blanket the eastern side of the Andes as high as 2,100 meters. Between these extremes, in the shadows of the great snowpeaks, lie the most populous highland ecological zones: the intermontane valleys (kichwa) and the higher uplands and grassy puna or Altiplano plateaus. Approximately 36 percent of the population lives in thousands of small villages and hamlets that constitute the rural hinterland for the regional capitals and trading centers. Over 15 percent of Peruvians live at altitudes between 2,000 and 3,000 meters, 20 percent live between 3,000 and 4,000 meters, and 1 percent regularly reside at altitudes over 4,000 meters.

Although rich in mineral resources, such as copper, lead, silver, iron, and zinc, which are mined at altitudes as high as 5,152 meters, the Andes are endowed with limited usable land. The highlands encompass 34 percent of the national territory, or 437,000 square kilometers, but only 4.5 percent of the highlands, or 19,665 square kilometers, is arable and cultivated. Nevertheless, this area constitutes more than half the nation's productive land. About 93,120 square kilometers of the Sierra is natural pasture over 4,000 meters in altitude, too high for agriculture. The 4.5 percent of arable land, therefore, has fairly dense populations, particularly in Puno, Cajamarca, and in valleys such as the Mantaro in Junín Department and Callejón de Huaylas in Ancash Department. The highland provinces have a population density of 460 persons per square kilometer of habitable, arable land.

The best areas for cultivation are the valleys, which range from 2,000 to 3,500 meters in altitude. Although many valleys have limited water supplies, others, due to glacial runoffs, enjoy abundant water for irrigation. In the protected valleys, the dry climate is temperate, with no frost or great heat. In the high plateau or puna regions above 3,939 meters, the climate is cold and severe, often going below freezing at night and seldom rising above 16° C by day. A myriad of native tubers thrives at altitudes from 2,800 meters to almost 4,000 meters, including over 4,000 known varieties of the potato, oca, and olluco, as well as grains such as quinoa. The hardy native llamas and alpacas thrive on the tough ichu grass of the punas; European sheep and cattle, when adapted, do well at lesser altitudes.

For the Peruvians, there are two basic Andean seasons, the rainy winter from October through April and the dry summer in the remaining months. Crops are harvested according to type throughout the year, with potatoes and other native tubers brought in during the middle to late winter and grains during the dry season. The torrential rains of the winter months frequently cause severe landslides and avalanches, called huaycos, throughout the Andean region, damaging irrigation canals, roads, and even destroying villages and cities. In the valley of Callejón de Huaylas, the city of Huaraz (Huarás) was partially destroyed in 1941 by just such a catastrophe, an event repeated a few kilometers away in 1962, when the town of Ranrahirca was annihilated by a huayco that killed about 3,000 people.

The formidable terrain of the Andes, where the land may fall away from 4,848 meters to 545 meters and then rise to 6,666 meters in a space of 48 kilometers as the condor flies, poses a ubiquitous challenge to any modern means of transport. Thus, the Andean region was not penetrated by wheeled vehicles until railroads were built in the latter half of the nineteenth century. Moreover, most of the nation did not see wheels until the dirt road system was under construction in the 1920s. To do this, President Augusto B. Leguía y Salcedo (1908-12, 1919-30) revived a national system of draft labor harkening back to the Inca's conscripted labor force, or mita, used for road and bridge building in ancient times.

High-Altitude Adaptations

As with the Himalayan mountains, the Andes impose severe conditions and many limitations on life. Consequently, Andean people are physically adapted to the heights in special ways. In contrast to persons born and raised at sea level, those living at Andean altitudes 2,500 meters or more above sea level have as much as 25 percent more blood that is more viscous and richer in red cells, a heart that is proportionately larger, and specially adapted, larger lungs, with an enhanced capacity to take in oxygen from the rare atmosphere. Biological adaptations have permitted the native highlanders to work efficiently and survive successfully in the Andean altitudes for 20,000 years.

The first important scientific research on high-altitude biology was undertaken by the Peruvian physician-scientist Carlos Monge Medrano in the 1920s. He showed that coca-leaf chewing played a role in aiding the metabolism in high-altitude populations. More recent studies have shown that coca chewing significantly aids in metabolizing high carbohydrate foods like potatoes, yucca, and corn, which are traditional staples in the Andean region, thus providing the chewer with more rapid energy input from his meals. Supposed narcotic effects of coca-leaf chewing are nil because enzymes in the mouth convert coca into atropine-like substances, unlike those involved in cocaine. Anthropologists Catherine Allen and Enrique Mayer have also demonstrated the central role traditional coca use plays in Andean communities as a medicine, ritual substance, and an element in economic and social affairs.

The Amazonian Tropics

The Selva, which includes the humid tropics of the Amazon jungle and rivers, covers about 63 percent of Peru but contains only about 11 percent of the country's population. The region begins high in the eastern Andean cloud forests, called the ceja de montaña (eyebrow of the jungle), or Montãna or Selva Alta, and descends with the rush of silt-laden Andean rivers--such as the Marañon, Huallaga, Apurímac, and Urubamba--to the relatively flat, densely forested, Amazonian plain. These torrential rivers unite as they flow, forming the Amazon before reaching the burgeoning city of Iquitos. Regarded as an exotic land of mystery and promise throughout much of the twentieth century, the Selva has been seen in Peru as the great hope for future development, wealth, and the fulfillment of national destiny. As such, it became President Fernando Belaúnde Terry's "Holy Grail" as he devoted the energies of his two administrations (1963-68, 1980-85) to promoting colonization, development schemes, and highway construction across the Montaña and into the tropical domain.

Human settlements in the Amazonian region are invariably riverine, clustering at the edges of the hundreds of rivers and oxbow lakes that in natural conditions are virtual fish farms in terms of their productivity. The streams and rivers constitute a serpentine network of pathways plied by boats and canoes that provide the basic transport through the forest. Here, the Shipibo, Asháninka (Campa), Aguaruna, and other tribes lived in relative independence from the Peruvian state until the midtwentieth century. Although the native people have cleverly exploited the extraordinary riverine environment for at least 5,000 years, both they and the natural system have been under relentless pressures of population, extractive industries, and the conversion of forest into farm and pasture. Amazonian forest resources are enormous but not inexhaustible. Amazonian timber is prized worldwide, but when the great cedar, rosewood, and mahogany reserves are cut, they are rarely replaced.

Peru's tropics are also a fabled source for traditional medicinal plants, such as the four types of domesticated coca, which are prized through the entire Andean and upper Amazonian sphere, having been widely traded and bartered for 4,500 years. Unfortunately, coca's traditional uses as a beneficial drug for dietary, medical, and ritual purposes, and, during the twentieth century, as a primary flavoring for cola drinks have given way to illegal plantings on a large scale for cocaine production. All of the new, illegal plantations are located in Peru's upper Amazon drainage and have seriously deteriorated the forests, soils, and general environment where they exist. The use of chemical sprays and the widespread clearing of vegetation to eliminate illegal planting has also created unfortunate and extensive environmental side-effects.

In the early 1990s, the Selva was still considered an important potential source for new discoveries in the medicinal, fuel, and mineral fields. Petroleum and gas reserves have been known to exist in several areas, but remained difficult to exploit. And, in Peru's southern Amazonian department of Madre de Dios, a gold rush has been in progress since the 1970s, producing a frontier boom effect with various negative repercussions. The new population attracted to the region has placed numerous pressures on the native tribal communities and their lands.

All of these intrusions into the fragile Amazon tropics were fraught with environmental questions and human dilemmas of major scale. In this poorly understood environment, hopes and development programs have often gone awry at enormous cost. In their wake, serious problems of deforestation, population displacement, challenge to the tribal rights of the native "keepers of the forest," endless infrastructural costs, and the explosive expansion of cocaine capitalism have emerged. In the 1963-90 period, Peru looked to the tropics as the solution for socioeconomic problems that it did not want to confront in the highlands. In the early 1990s, it was faced with paradox and quandary in both areas.

The Maritime Region

A maritime region constitutes a fourth significant environment within the Peruvian domain. The waters off the Peruvian coast are swept by the Humboldt (or Peruvian) Current that rises in the frigid Antarctic and runs strongly northward, cooling the arid South American coastline before curving into the central Pacific near the Peru-Ecuador border. Vast shoals of anchovy, tuna, and several varieties of other valued fish are carried in this stream, making it one of the world's richest commercial fisheries. The importance of guano has diminished since the rise of the anchovy fishing industry. The billions of anchovy trapped by modern flotillas of purse seiners guided by spotter planes and electronic sounding devices are turned into fish meal for fertilizer and numerous other industrial uses. Exports of fish meal and fish products are of critical importance for Peru's economy. For this reason, changes in the environmental patterns on the coast or in the adjacent ocean have devastating consequences for employment and, therefore, national stability. The periodic advent of a warm current flowing south, known as El Niño (The Christ-child), and intensive fishing that has temporarily depleted the seemingly boundless stocks of anchovy have caused major difficulties for Peru.

SOURCE: Library of Congress Country Studies/Area Handbook

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