Ratanakiri Province - Geography and Climate

Geography and Climate

The geography of Ratanakiri Province is diverse, encompassing rolling hills, mountains, plateaus, lowland watersheds, and crater lakes. Two major rivers, Tonle San and Tonle Srepok, flow from east to west across the province. The province is known for its lush forests; as of 1997, 70–80% of the province was forested, either with old-growth forest or with secondary forest regrown after shifting cultivation. In the far north of the province are mountains of the Annamite Range; the area is characterized by dense broadleaf evergreen forests, relatively poor soil, and abundant wildlife. In the highlands between Tonle San and Tonle Srepok, the home of the vast majority of Ratanakiri's population, a hilly basalt plateau provides fertile red soils. Secondary forests dominate this region. South of the Srepok River is a flat area of tropical deciduous forests.

Like other areas of Cambodia, Ratanakiri has a monsoonal climate with a rainy season from June to October, a cool season from November to January, and a hot season from March to May. Ratanakiri tends to be cooler than elsewhere in Cambodia. The average daily high temperature in the province is 34.0 °C (93.2 °F), and the average daily low temperature is 22.1 °C (71.8 °F). Annual precipitation is approximately 2,200 millimetres (87 in). Flooding often occurs during the rainy season and has been exacerbated by the recently built Yali Falls Dam.

Ratanakiri has some of the most biologically diverse lowland tropical rainforest and montane forest ecosystems in mainland Southeast Asia. One 1996 survey of two sites in Ratanakiri and one site in neighboring Mondulkiri recorded 44 mammal species, 76 bird species, and 9 reptile species. A 2007 survey of Ratanakiri's Virachey National Park recorded 30 ant species, 19 katydid species, 37 fish species, 35 reptile species, 26 amphibian species, and 15 mammal species, including several species never before observed. Wildlife in Ratanakiri includes Asian elephants, gaur, and monkeys. Ratanakiri is an important site for the conservation of endangered birds, including the giant ibis and the greater adjutant. The province's forests contain a wide variety of flora; one half-hectare forest inventory identified 189 species of trees and 320 species of ground flora and saplings.

Nearly half of Ratanakiri has been set aside in protected areas, which include Lomphat Wildlife Sanctuary and Virachey National Park. Even these protected areas, however, are subject to illegal logging, poaching, and mineral extraction. Though the province has been known for its relatively pristine environment, recent development has spawned environmental problems. The unspoiled image of the province often conflicts with the reality on the ground: visitors "expecting to find pristine forests teeming with wildlife are increasingly disappointed to find lifeless patches of freshly cut tree stumps". Land use patterns are changing as population growth has accelerated and agriculture and logging have intensified. Soil erosion is increasing, and microclimates are being altered. Habitat loss and unsustainable hunting have contributed to the province's decreasing biodiversity.