The Cagayan River is the longest and largest river in the Philippines. It is located in the Cagayan Valley region in northeastern part of Luzon island and traverses the provinces of Nueva Vizcaya, Quirino, Isabela and Cagayan. 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... December 22 is the 356th day of the year (357th in leap years) in the Gregorian Calendar. ... Cagayan Valley (Lambak ng Cagayan in Filipino) is a region of the Philippines, also designated as Region II or Region 02. ... Map of the Philippines showing the island groups of Luzon, Visayas, and Mindanao. ... Map of the Philippines showing the regions and provinces (click for larger version). ... Nueva Vizcaya is a province of the Philippines located in the Cagayan Valley region in Luzon. ... REPUBLIC OF THE PHILIPPINES Province of Quirino Region: Cagayan Valley (Region II) Capital: Cabarroguis, Quirino Founded: June 18, 1966 Population: 2000 census—148,575 (8th smallest) Density—49 per km² (2nd lowest) Area: 3,057. ... This is about the province of Isabela in the Philippines. ... Philippines Luzon Cagayan Province Cagayan Valley an administrative region Cagayan Valley (valley) Cagayan River Mindanao Cagayan de Oro (city) cloth? Cagayan de cillo Palawan Cagayan Island Category: ...

Topography

The river's headwaters are at the Caraballo Mountains of the Central Luzon at an elevation of approximately 1,524 meters. The river flows north for some 446 kilometers to its mouth at the Babuyan Channel near the town of Aparri, Cagayan. The river drops rapidly to 91 meters above sea level some 227 kilometers from the river mouth. Its principal tributaries are the Chico, Siffu, Malling, Magat and Ilagan Rivers. Caraballo Mountains is a mountain range in the central part of Luzon, Philippines. ... Central Luzon region contains the largest plain of the Philippines and produces most of the countrys rice supply. ... Aparri is a municipality of the province of Philippines. ... Philippines Luzon Cagayan Province Cagayan Valley an administrative region Cagayan Valley (valley) Cagayan River Mindanao Cagayan de Oro (city) cloth? Cagayan de cillo Palawan Cagayan Island Category: ...

Magat River is the largest tributary with an estimated annual discharge of 9,808 million cubic meters. It lies in the southwestern portion of the basin, stretching approximately 150 kilometers from Nueva Vizcaya down to its confluence with Cagayan River about 55 kilometers from the river mouth.

Both Magat and Chico Rivers have extensive drainage areas which comprise about 1/3 of the whole basin.

The Ilagan River originates from the western slopes of the Sierra Madre and drains the eastern central portion of the Cagayan River basin with an estimated annual discharge of 9,455 million cubic meters. It flows westward and joins the Cagayan River at Ilagan, Isabela, 200 kilometers from the mouth. Ilagan is a 1st class municipality in the province of Isabela, Philippines. ...

The Siffu-Malling system lies on the slope of the Central Cordillera ranges flowing almost parallel to the Magat River. Marshes and swamps are found in some parts of its lower reaches. Montes Cordillera is a mountain range on the Moon. ...

Cagayan River and its tributaries have deposited sediments of Tertiary and Quaternary origin, mostly limestone sands and clays, throughout the relatively flat Cagayan Valley which is surrounded by the Cordillera Mountains in the east, Sierra Madre in the west and the Caraballo Mountains in the south. Montes Cordillera is a mountain range on the Moon. ... The Sierra Madre is a mountain range in the Philippines. ... Caraballo Mountains is a mountain range in the central part of Luzon, Philippines. ...

The river has a drainage area of about 27,300 km². in the provinces of Apayao, Aurora, Cagayan, Ifugao, Isabela, Kalinga, Mountain Province, Nueva Vizcaya, and Quirino. Apayao is a landlocked province of the Philippines in the Cordillera Administrative Region in Luzon. ... Aurora is a province of the Philippines located in the Central Luzon region. ... Ifugao is a landlocked province of the Philippines in the Cordillera Administrative Region in Luzon. ... Kalinga is a landlocked province of the Philippines in the Cordillera Administrative Region in Luzon. ... Mountain Province is a landlocked province of the Philippines in the Cordillera Administrative Region in Luzon. ...

The estimated annual discharge is 53,943 million cubic meters with a groundwater reserve of 47,895 million cubic meters.

Flooding

The Cagayan River and its tributaries are subject to extensive flooding during the monsoon season in Southeast Asia from May to October. Monsoon in the Vindhya mountain range, central India A monsoon is a wind pattern that changes direction depending on the season. ... Location of Southeast Asia Southeast Asia is a subregion of Asia. ...

The average annual rainfall in 1,000 mm in the northern part and 3,000 mm in the southern mountains where the river's headwaters lie. Water from the mountains flow down very slowly because of surface retention over the extensive flood plain, the gorges in the gently-sloping mountains and the meandering course of the river.

The inundation of the Cagayan River and its tributaries have caused great loss of life and property and substantial losses to the local and national economies. The Philippine government has established several flood warning stations along the river. Experts are specifically monitoring the lower reaches from Tuguegarao to Aparri and the alluvial plain from Ilagan to Tumauini, Isabela. Tuguegarao City is a city in the province of Cagayan, Philippines. ... Tumauini is a 2nd class municipality in the province of Isabela, Philippines. ...

Flora and fauna

The Cagayan River passes through one of the few remaining primary forests in the Philippines.

It supports the lives of numerous endemic and endangered species, like the Luzon bleeding-heart pigeon (Gallicolumba luzonica luzonica), Philippine eagle (Pithecophaga jefferyi) and a rare riverine fish, locally called ludong (Cestreaus plicatilis).

The ludong spawns in Cagayan River's upper reaches in Jones, Isabela. In late October until mid-November, the fish travel down the river to release their eggs at the river mouth near Appari. Jones is a 2nd class municipality in the province of Isabela, Philippines. ...

In February, ludong fry by the millions are again caught in fine nets as these travel upstream.

Due to the dwindling number of ludong caught yearly, local governments have imposed a ban on catching the fish and its fry, but the ban has failed.

People

The river traverses four provinces: Nueva Vizcaya, Quirino, Isabela and Cagayan. These provinces have an approximate population of two million people, mostly farmers and indigenous tribesmen. Nueva Vizcaya is a province of the Philippines located in the Cagayan Valley region in Luzon. ... REPUBLIC OF THE PHILIPPINES Province of Quirino Region: Cagayan Valley (Region II) Capital: Cabarroguis, Quirino Founded: June 18, 1966 Population: 2000 census—148,575 (8th smallest) Density—49 per km² (2nd lowest) Area: 3,057. ... Isabela is a province of the Philippines located in the Cagayan Valley region in Luzon. ... Philippines Luzon Cagayan Province Cagayan Valley an administrative region Cagayan Valley (valley) Cagayan River Mindanao Cagayan de Oro (city) cloth? Cagayan de cillo Palawan Cagayan Island Category: ...

The Ibanag people derive their tribe's name from Cagayan River's ancient name, Bannag. The Gaddang tribe lived in the upper riches of the Cagayan River and its tributaries.

Economic importance

The river drains a fertile valley that produces a variety of crops, including rice, corn, bananas, coconut, citrus and tobacco.

There are dams in two of the river's tributaries, the Magat and Chico Rivers, and there are also several mining concessions in the mineral-rich Cordillera Mountains near the headwaters of the two tributary rivers.

The the provincial governments along the river have also developed tourism programs that offer activities on the river, particularly whitewater rafting.

Further reading

• Wernstedt, F. L., and J. E. Spencer (1967). The Philippine Island World. Berkeley and Los Angeles: University of California Press. 

External links

• Philippine Atmospheric, Geophysical and Astronomical Services Administration
• International River Network