The Abulog River or Abulug River is the 9th largest

river system In geomorphology, drainage systems, also known as river systems, are the patterns formed by the streams, rivers, and lakes in a particular drainage basin. They are governed by the topography of land, whether a particular region is dominated by har ...

in the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

in terms of watershed size."Principal River Basins of the Philippines" Published by the National Water Resources Board, October 1976 (p 12) It has an estimated drainage area of and a length of from its source in the mountains of

Apayao Apayao, officially the Province of Apayao ( ilo, Probinsia ti Apayao; fil, Lalawigan ng Apayao), is a landlocked province in the Philippines in the Cordillera Administrative Region in Luzon. Kabugao serves as its capital. The provincial capit ...

in the Cordillera Administrative Region. More than 90% of the drainage area of the river is located in

province while the remaining, including the mouth of the river, is in

Cagayan Cagayan ( ), officially the Province of Cagayan ( ilo, Probinsia ti Cagayan; ibg, Provinsiya na Cagayan; itv, Provinsiya ya Cagayan; fil, Lalawigan ng Cagayan), is a province in the Philippines located in the Cagayan Valley region, covering ...

province. The upper reaches of the Abulug River, especially upstream from

Kabugao Kabugao, officially the Municipality of Kabugao, ( ilo, Ili ti Kabugao; tl, Bayan ng Kabugao), is a 1st class municipality and ''de jure'' capital of the province of Apayao, Philippines. According to the 2020 census, it has a population of 16,2 ...

, is commonly known as the

Apayao River The Apayao River is a river on the island of Luzon in the Apayao province of the Philippines. It flows from an extensive watershed in the western slopes of the province, flows past the town of Kabugao and runs into the Pacific Ocean at the coasta ...

References

Rivers of the Philippines Landforms of Cagayan Landforms of Apayao {{Philippines-river-stub