Análisis y evaluación preliminar de cuencas como base para el estudio y cálculo de derrames en la ruta nacional n°150, tramo Jáchal - Cuesta del viento, San Juan, Argentina

ESPER ANGILLIERI, M.Y; FERNÁNDEZ, M.

Tucumán

Congreso; 20° Congreso Geológico Argentino; 2017

Asociaión Geologica Argentina

This work analyzes variousmorphometric characteristics of basins in order to evaluate flash floodhazards. The chosen area includes astretch of National Road No. 150 up to the International Border Pass Agua Negra between Argentina and Chile on asector of the Precordillera Occidental and Central (Ortiz yZambrano, 1981). Italso includes the road access to the future international tunnel. One of the most importanttools in hydric analysis is the morphometric survey of a basin, which allowsestablishing evaluation parameters on the behavior of the hydrological systemof the basin areas. This study, when properly combined with geomorphology andgeology, helps elaborate a primary hydrological diagnosis to predict the approximatebehavior of the basin at the time of heavy rainstorms.The study areahas a general arid climate. The total annual average precipitation is scarce:about 121 mm. Winter temperatures are generally mild, ranging between -9°C and8°C; whereas summers are very dry and hot, with maximum temperatures of 44°C.In the period between December and March, heavy rainfalls of short duration buttorrential character are responsible for the generation of large flash floods.The area?s steep gradient rapidly drains these precipitated volumes of water,funneling them towards the Río Jáchal.In the present research, thedrainage networks were derived from digital elevation models (ASTER GDEM V2) (NASA, 2011), satellite imageries from Google Earth? (SPOT 5 image) and field works. Severalmorphometric characteristics of the basins are analyzed and some basicparameters (area, perimeter, length, altitude and slope of the main channel,etc.) are calculated. These measurements permit to predict approximately thebehavior of the basin in the presence of a series of theoretical rainstormsthat may generate unusual runoff volumes that make up such flash floods. Theresults suggest that the hydrological response of the basin are determined bysteep slopes and steep channels in the mountain area makes it a potentiallydangerous area with high levels of destruction.