Physical Geography

There are about 7,100 islands, many of them unnamed and uninhabited small islands and islets. Luzon, in the north, and Mindanao, in the south, are by far the largest. Together, they form about two-thirds of the Philippines' total area. Other major islands include Mindoro, Palawan, and those forming the heart of the Visayan Islands—Masbate, Samar, Panay, Negros, Cebu, Bohol, and Leyte. The distance from the northern end of Luzon to the southern tip of Mindanao is about 1,000 miles (1,600 km).

The islands consist mainly of mountains thrust up from the floor of the Pacific. They were formed by folding, faulting, and much volcanic activity. In the east the ranges trend in either a north-south or a northwest-southeast direction. In some of the more westerly islands, including Cebu, Negros, Palawan, and the Sulu Archipelago, the trend is predominantly northeast-southwest.

Most of the ranges rise 2,000 to 6,000 feet; (600 to 1,800 m) above sea level. They culminate in 9,606-foot (2,928-m) Mount Pulog, on Luzon, and 9,692-foot (2,954-m) Mount Apo, on Mindanao. Apo is an active volcano and the country's highest peak. Mayon Volcano, on Luzon, is one of the world's most perfectly shaped volcanic cones; it reaches a height of 7,943 feet (2,421 m). Earthquakes of varying intensity frequently strike the islands.

Luzon has sizable interior plains, chief of which are the Cagayan River valley and the central plain. The heavily populated central plain runs from Manila Bay northward to Lingayen Gulf. There are also large interior plains on Mindanao and small ones on Panay, Leyte, and Negros. Elsewhere, level land consists mainly of narrow coastal lowlands.

Most rivers in the Philippines are relatively short and swift. Among the major rivers on Luzon are the Pasig, which flows through Manila, and the Cagayan, Agno, and Pampanga rivers. Chief rivers on Mindanao are the Agusan and Mindanao-Pulangi rivers. Except for Laguna de Bay, Taal, and Lanao, there are no large lakes.

The Philippines lie roughly between the Tropic of Cancer and the Equator and have a tropical to subtropical climate. Except in the mountains, where the weather is cool, average temperatures range from about 75° to 85° F. (24° to 29° C.) throughout the year, the warmest areas being in the south.

Rainfall totals 40 to 140 inches (1,020 to 3,560 mm) a year, with the different regions of the country varying in the seasonal incidence of rainfall. Southern Mindanao and adjacent parts of the country are rainy throughout the year. Farther north, exposed western sides of islands receive heavy rains from June through October from the southwest monsoon. The rest of the year is relatively dry. The eastern islands receive their heaviest rains from November through March.

The Philippines lie in a path taken by many typhoons, which often bring widespread destruction with their violent winds, high waves, and torrential rains.

Because of abundant rainfall and warm temperatures, tropical vegetation predominates in most parts of the islands. Forests cover about 35 per cent of the land area. Tropical hardwoods are the chief trees, except in some mountain areas, where there are large stands of pine. Mangrove swamps and palm trees are found along the coasts. Flowering plants and ferns are abundant.

Large animals include wild buffalo, deer, wild hogs, and monkeys. A number of rodent and reptile species and a great variety of birds are native to the Philippines.