Dissertação
Avaliação ambiental por geoprocessamento na sub-bacia do Rio Angasmarca, Região la Libertad, Peru
Fecha
2012-04-11Registro en:
RIMARACHIN, Jorge Luis Diaz. ENVIRONMENTAL ASSESSMENT BY GEOPROCESSING OF THE
SUB-BASIN ANGASMARCA RIVER, IN LA LIBERTAD REGION,
PERU.. 2012. 166 f. Dissertação (Mestrado em Geociências) - Universidade Federal de Santa Maria, Santa Maria, 2012.
Autor
Rimarachin, Jorge Luis Diaz
Institución
Resumen
The agricultural activities, without considering the potential and limitations on the land use, are a
potential source of environmental degradation. This study proposed the environmental diagnose of the
sub-basin Angasmarca river, in La Libertad region in Peru, using geoprocessing techniques. For the
execution of the work were incorporated into a Geographic Information System (ArcGIS 9.2) data
obtained by remote sensing (CBERS multispectral image and ASTER DEM G-2 digital elevation
model), topographic maps, rainfall data, soil analyzes and thematic maps existing (geology, soils,
ecology). From the morphometric characterization of the study area, we obtained the potential use of
land (from the roughness coefficient) characterizing areas liable to degradation by environmental
conflicts and identify areas susceptible to laminar erosion supported in Equation Universal Soil Loss
(USLE). From the analysis of hydrologic conditions and soils of watersheds evaluated by the circularity
index (CI), compactness coefficient (Kc) and form factor (Kf), the region is favorable to processes of
runoff, but nevertheless not subject to floods. In the evaluation of potential soil use, it was found that
33.18% of the sub-basin is appropriate for agricultural practice, 52.12% for pasture, 9.45% for
pasture/forestry and 5.25% for forestry. 50.88% (17963.53 ha) of the total area of the sub-basin is in
use conflicts therefore requires adaptations that reduce environmental degradation. In the analysis of
rainfall erosivity was found that the annual average value (EI30) is 4.762 MJ.mm.ha-1.h-1.year-1 (R
factor), with a monthly average of the 396.8MJ.mm.ha-1.h-1. In the rainy season (October to April) was
4678.5MJ.mm.ha-1.h-1 (considered erosive) and the dry season (May to September) of
83.5MJ.mm.ha1.h-1 (considered non-erosive). Therefore the estimates soil losses upper than
97.82t.ha-1.year-1 area located in the watersheds with the greater slopes (88.88km²), however, the
watersheds with the lowest soil loss area (mean 77.47t.ha-1.year-1 76.92 km2) area located on flatter
land. The mathematical modeling performed in the Geographic Information System enabled the
integration data of the estimates of erosion potential laminar and environmental assessment Physical-
Conservationist, permitting spatialize areas the potential risk both conflicts of land use, erosion and
environmental deterioration, the which allows to propose mitigation actions for areas that present the
biggest problems.