EVALUATION OF POTENTIAL WATER EROSION OF HYDROGRAPHIC DEMARCATION OF MANABI, ECUADOR

Water erosion is the most essential reason of destruction of soils in the whole world. So, in Asia, from the 747 million hectares of earth suffering from erosion, 60% correspond to water erosion; in Africa from 497 million, 46%; in South America, from 243 millions, 51%; in Europe, from 219 million, 53%; 106 millions in a North and Central America, Bifani (1984). The same author specifies that, the phenomenon of erosion is closely related to the phenomenon of settling. The process of water erosion is usually measured on volume alluviums. The Rivers Ganges, Brahmaputra and Huang He, transport 1451, 726 and 1887 million tons annually, respectively, as compared to the rivers Mississippi, Amazon and Nile, that carry only 97, 63 and 31 tons on the square kilometer of basin (Holeman, 1968) [9].Erosion of soil in Ecuador is a serious ecological problem that affects greater part of country in one or another degree. The use of methods of prognostication of washing off of superficial fertile layer of soils from fallouts did not get wide use, as numerous researches were directed to on a quantitative estimation speed of erosion for the different types of land-tenure in the off-shore zones of river basins, and only not many were concentrated on prognostication of erosive processes on all territory. In 1986 the Ecuadorian Center of Geographical Researches (CEDIG), for the first time conducted the row of the researches related to the capture of common data about the problems of erosion in a country [4].In this paper, based on actual data on rainfall in 51 years and the composition of the soils, was carry out the estimation of potential water erosion for Hydrographic Demarcation of Manabi (Ecuador)