The 4Ps Area is formed by the drainage basins of four preks (small rivers) that discharge into the Mekong: Prek Preah, Prek Krieng, Prek Kampi and Prek Te. The area covers parts of Kratie and Mondulkiri provinces. The area is 12,470 km2 and the population is estimated at 163,000. The area belongs to the least developed parts of Cambodia. The poverty rate is among the highest in the country, as well as the occurrence of malnutrition and water-borne diseases. Along the Mekong mainstream (and including the town of Kratie), the population density is high, and the economy is better developed and more diversified as compared with the inland parts of the area.