Amount of sediment drained into the Pacific coast in northwestern Baja California, Mexico

Abstract

The amount of sediment drained into the Pacific coast due to the orographic system of northern Baja California was estimated by indirect methods. Langbein and Schumm’s (1958) equation was used to relate the erosive action of the rain and the protective action of the vegetation. Statistics on pluvial precipitation for 1950 to 1983 of 21 stations of the Secretaría de Agricultura y Recursos Hidráulicos were used. Furthermore, topographical data of 44 charts of the Instituto Nacional de Estadística, Geografía e Informática (INEGI), corresponding to the northern area of Baja California, were digitized on a PRIME 750 computer and processed with a program (TOPOGRAFIC) developed at the Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE). Two drainage basins were identified as maximum potential sources of sediment: the Tijuana River basin (S = 809649.88 tons/year) and the Guadalupe River basin (S = 834889.13 tons/year). According to the model, these are not maximum values. Higher values can be expected with greater rainfall and we therefore consider this area to be one of high geological risk.