Quantitative geomorphology applied to fluvial dynamic in Aviles and Moneta basins, Tierra Del Fuego, Southern Argentina

摘要

The morphometric characteristics of the Moneta river basin are compared to those of the Aviles river basin. Both are located in the north of the province of Tierra del Fuego in Argentina, and they also have their catchment area in the same range: the Sierras del Bosque; runoff on the NE-oriented slopes forms the Aviles river basin, while runoff on the SE slopes forms the Moneta river basin. The analysis was made in two different scales: the first as a general scale of the basin, and the second as the catchment sector (upper, middle and lower). The quantitative analysis was applied in order to know the behavior of these two fluvial systems. For the analysis, a cartographic basis scale to 1: 20,000 was used, which was made on a mosaic of images from Google Earth (R); the altimetric information was obtained throughout a digital elevation model of 45-m spatial resolution SRTM45 (Shuttle Radar Topographic Mission). The indices used were R-r, R-b, I-sh and D-d to characterize the geological and geomorphological context, and R-l, R-e, I-f, C-t and C-a to infer the behavior of the runoff in the catchment. It was established that the Moneta river basin reaches 6 in order of hierarchy; its main channel is 65.52 km long. The Re determines an elongated basin. The Ct obtained in the basin is 0.96, whereas the sub-basin level was identified to a maximum value of the O3-SM-10 (1.46). The D-d is low (1.94 km/km(2)), which is directly proportional to the intensity of rainfall and the slopes of the area considered. The comparison, made at the same scale, between basins determines specific fluvial characteristics of each sector (upper, middle and lower).