The Republic of the Philippines is located on an archipelago of some 7 100 islands between latitudes 4° 23´ and 21° 25´ N and longitudes 116° 55´ and 126° 34´ E, covering a land area of about 300 000 km2. The republic is bounded on the east by the Philippine Sea, on the south by the Celebes Sea, and on the west by the South China Sea. The country is divided into four geographic regions (Luzon, Visayas, Mindanao and Palwan) that are further subdivided into 13 administrative regions and 71 provinces.
The Philippines islands arose from the sea as a result of a very complex pattern of continental drift and volcanic activity. Nearly all the islands have rugged interior uplands, usually rising to between 1 250 and 2 500 m. The highest mountain, Mt. Apo in Mindanao, reaches 2 954 m while Mt. Pulong in Luzon is about 2 929 m high.
Lowlands are scarce and even in the largest islands the coastal plain is rarely as much as 15 km wide. The most important lowland area is the central plain of Luzon, but there are other important agricultural areas in the Cagayan valley in north-eastern Luzon, the Bicol plain in south-eastern Luzon, the Agusan and Cotabato plains in Mindanao and the plains in western Negros and eastern Panay.
There are a large number of extinct and dormant volcanoes in the Philippines. Today, about a dozen are still active. The most famous of the active volcanoes is Hibok-Hibok on Camiguin Island just north of Mindanao that erupted extremely violently in 1948. Mt. Mayon erupted in 1968. Most volcanoes eject acidic lava which does not make as good soil as basic lava. The islands exhibit great diversity in topographic features. Bohol is karstic; Cebu is coralline while the rest of the islands are either volcanic or alluvial.
The country enjoys an equatorial climate. The mean annual temperature varies from 22 to 31° C, the difference mainly due to elevation. It is affected by the south-west monsoon in the summer months and the north-east monsoon and trade winds in the winter months. Manila has an average temperature of 24° C in January and 28° C in May.
In addition, typhoons originate in the intertropical front that, in the region of the Philippines, lies over the island of Mindanao for much of the time. Typhoons account for between a quarter and a third of the annual rainfall and sweep north and west across the central and northern parts of the archipelago. They occur mainly during the months of July to November.
The annual amount of precipitation ranges from about 1 500 mm to about 4 500 mm. However, in the area of General Santos and Zamboanga, located in the south and south-west respectively of Mindanao; in the south-east Negros, in Palawan; in Laguna, situated in the south-east of Manila, and in northern Luzon small rain shadow pockets exist where the annual rainfall is considerably less than 1 500 mm.
Rainfall distribution depends a great deal upon topographic features and resultant rain shadows. The east coast receives annual amounts in excess of 3 000 mm, largely concentrated in the winter months when the north-east monsoon is at its peak.
The absence of rainfall from typhoons in eastern Mindanao is counterbalanced by the occurrence of more rain associated with the intertropical front, except for those areas in rain shadows. The central and eastern Visayas are largely sheltered from the influence of both the Northeast monsoon and the typhoons, and their rainfall is mainly a result of the Southwest monsoon and occurs during the summer months.
The Bureau of Forest Development (BFD) has divided the country into four climatic types for forest management purposes as follows:
- Climates with two pronounced seasons and a dry season between November and April;
- Climates without a dry seaso
The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.