MEXICO AREA, TOPOGRAPHY, AND CLIMATE Area and Topography.-Mexico is 760,290 square miles in area, or one-fourth the size of the United States. It has a coast line of 5,648 miles, as compared with a length of 4,833 miles for the United States. The central and northern portion of the Republic is a great plateau, bounded on the east and on the west by mountain ranges the Eastern Sierra Madre (Sierra Madre Oriental), which follows the coast of the Gulf of Mexico, and the Western Sierra Madre (Sierra Madre Occidental), which borders the Pacific coastal area. Between each range and the coast are narrow, hot, coastal strips. The great plateau or tableland slopes generally toward the north, from an elevation of about 8,000 feet near Mexico City, 6,100 feet at San Luis Potosi, and 5,200 at Saltillo, to 3,900 feet at Agua Prieta (opposite Douglas, Ariz.) and 3,800 at Ciudad Juarez (across the Rio Grande from El Paso, Tex.). Two fairly well-defined plateaus lie to the south and to the southeast of Mexico City. They are the broken Mesa del Sur, in the States of Oaxaca and Guerrero, and the Chiapas Highlands, which continue at a higher elevation into Guatemala. The highest peak in Mexico, and the second highest in the Western Hemisphere, is the Pico de Orizaba (18,000 feet). Following, according to elevation, are Popocatepetl (17,880 feet); Ixtaccihuatl (17,670); Nevado de Toluca (15,003); La Malintzi (14,635); Nevado de Colima (14,103); Ajusco (12,958); and Tancitaro (12,663). These peaks lie on an east-west mountain axis which passes roughly through Mexico City. All are volcanoes, and several are active. Rivers. There are no navigable rivers of importance in Mexico except in the tropical southeastern States, where such streams as the Grijalva and Usumacinta were the only means of transportation until the advent of aviation. Lakes. The largest lake in Mexico is Chapala (on the boundary between the States of Jalisco and Michoacan), about 70 miles long and 20 miles wide. Lake Tamiahua, in the State of Veracruz, is about 60 miles long and 10 miles wide. Connecting canals lead south from Tampico and north from Tuxpan. This lake is navigable for craft drawing 5 or 6 feet. Other lakes are Chairel and Carpintero, in Tamaulipas; Encantada, in Tabasco: Bacalar, in Yucatan; Alcuzague, in Colima ; Cuitzeo and Patzcuaro, in Michoacan; Yuriria, in Guanajuato and Mezitlan, in Hidalgo. Their value to navigation is negligible. Climate and Seasons. Although Mexico is on the margin of the Tropics, only the lowlands (about one-fourth the total area) are tropical. The great plateau comprises the remainder of the area. Although the plateau reaches high elevations at several points, it has a varied but temperate climate. The lowlands are called the "tierra caliente" (hot land). The region above them, comprising the slopes upward to the plateau and the plateau itself, are the "tierra templada" (temperate land). The upper mountain slopes above the plateau are in the "tierra fria” (cold land). Climatically, the year is broadly divided into the "dry season,” extending from November to April, inclusive, and the "rainy season." which comprises the rest of the year. Several territorial zones have varying temperatures. In Mexico City, where the plateau elevation is 7,343 feet, the temperature averages range from 56° F. in January to 66° in June and precipitation averages 24 inches annually. Farther north on the plateau the temperature is warmer and drier than in Mexico City. At Monterrey (1.739 feet) the temperature varies from an average of 58° and 59° F. in December and January to an average of 8° F. from June through August. More than two-thirds of the average annual rainfall of 19.5 inches occurs from June to October. Plateau rainy season mornings are pleasant, noons are hot, and heavy showers fall regularly in the afternoon or early evening. Dry-season shade is cool, and nightfall brings cvidi The Gulf coastal plain, which varies in width from a few miles to more than 1000 miles, is warm throughout the year. The lowest mean monthly temperature is 71° F. for January and the highest S2 in August. Summer heat is intense, but sea breeZES temper the nights. At Veracruz in January, the driest mouth, only 04 inch of rain falls. In July, however, records show rainfall of 148 inches, and the total for the year is 68 inches. The average temperature ranges from TO F. in January to 80° in June, July, and August. Windstorms. “Nortes" dering Septembec to April. list from 24 hours to 5 days and are often severe. but they moderate the temperature considerably. In contrast, the relatively sat, low-bring peninsula of Yucatan is a dry land. A: Progreso celeration 40 feet) the year's ratfall is slightly less than to inches: Fedreary and March are the driest months. The average temperature ranges from 72 F. in January to 302 F. for May through September. On the west coast the mournins slope directly to the sed- AT Mamilan, the wean January temperature of er F is the lowest of the years the my mean i F. Matlan has a total yearly rainfall of $1 inches, two-thirds of which occurs in JuX, AZIM, and September. From February through April total rainfall is barely more than half an inch. Thus, the long dry season and the high temperatures make irrigation necessary for most crops. The southern highlands lie south of the great plateau, between the Rio Balsas and the Isthmus of Tehuantepec. Here rainfall is uncertain and cattle raising dominates agriculture. At Salina Cruz (elevation 184 feet) the average temperature ranges from 77° F. in January to 82° in June and July. The Chiapas Highlands are in the extreme southern part of Mexico. Temperatures are favorable for pasture grass, and precipitation is fairly well distributed. The higher mountain sections of Mexico, or the "tierra fria,” have an annual temperature of less than 59° F. POPULATION AND PURCHASING POWER POPULATION The population of Mexico was officially estimated as 19,478,791 in June 1938. This total represents a gain of 2,925,791 since the 1930 census, and of 5,144,011 since the 1921 census. The largest population center is the capital, Mexico City, which in June 1938 was estimated to have 1,150,930 inhabitants. Distribution of population by States and other territorial divisions as of June 1938 is shown in the following table. Table 2.-Population of Mexico, by Governmental Divisions, 1938 |