Laura Alicia Ibáñez-Castillo

LAND USE CHANGE AND RUNOFF IN THE HUEHUETAN WATERSHED

In this work, an analysis of land use change was done under two scenarios, 1990 and 2005, to evaluate its effects in Huehuetan watershed runoff by using the same historical storm of the hurricane Stan and the HEC-HMS software; this watershed is located in Chiapas, Mexico. The land use change was made with satellite images interpretation and overlay cartographic operation in the GIS software, ArcView GIS 3.2; the satellite image for 1990 year was LANDSAT TM while 2005 year was SPOT 5. With GeoHMS, an extension for Arc View, was delimitated 25 subbasins and calculated hydrologic parameters to build HMS models, which were constructed in the HEC-HMS 2.2.2 software under synthetic SCS unit hydrograph and with a historical storm during hurricane STAN in October 2005 year. The results show that there were not significant differences in runoff between the two scenarios. In 1990 the flow was 2,566.4 m3·s-1 and 2005 year the flow was 2,544.0 m3·s-1. The runoff decreased 0.87 % in the period of analysis. The results obtained are an expression of good condition of natural resources conservation in the watershed. Additional key words: land use change, runoff, HEC-HMS. doi: 10.5154/r.inagbi.2009.07.015