Morphometric analysis of river basins using GIS and remote sensing of an Andean section of Route 150, Argentina. A comparison between manual and automated delineation of basins

Abstract

A morphometric analysis using Geographic Information System and Remote Sensing tools was performed to study the Agua Negra River basin, in the Central Andes of western Argentina. Well-delineated drainage basin boundaries are a critical factor in numerous natural resources studies such as flood assessment, water-usage, basin protection, preservation, planning, and resources management. In spite of their advantages, morphometry and automatic delineation of basins have rarely been applied in western Argentina. Through such an approach, the current study has successfully used computer-assisted methods and digital elevation models to delineate 17 basins through which a section of International 150 road passes. The resulting automated delineations were later compared with digital-manual delineations made with digital satellite imagery and topographic maps. The computer-assisted delineation compared very well to the digital-manual delineations, generally following drainage divides. The work load (including reprocessing and editing) was sharply decreased with the DEM computer-assisted delineating method, because digitally derived polygonal sub-basins areas were delineated in shorter times than those of the conventional manual method. Statistically, the absolute difference between computer-assisted and manually-derived basin area delineations was 5.29 percent, in average, on a range of 0.50 – 13.83 percent. In addition, a peak discharge analysis has been done as well. The slight differences in some results were irrelevant, when realizing the amount of resources and time saved with the automated techniques.