Análisis multitemporal en el cambio de la dinámica fluvial en relación con el cambio de coberturas de la tierra en el afluente principal de la subcuenca del Río San Juan Cundinamarca
Fecha
2021-06-15Registro en:
Vargas Pérez, J. A., & Suarez Casas, J. D. (2021). Análisis multitemporal en el cambio de la dinámica fluvial en relación con el cambio de coberturas de la tierra en el afluente principal de la subcuenca del Río San Juan-Cundinamarca [Trabajo de grado, Especialización en Ordenamiento y Gestión Integral de Cuencas Hidrográficas]. Universidad Santo Tomas.
reponame:Repositorio Institucional Universidad Santo Tomás
instname:Universidad Santo Tomás
Autor
Vargas Pérez, John Alejandro
Suarez Casas, José David
Institución
Resumen
Fluvial dynamics of a tributary is a variable to take into account during the integral management of a hydrographic basin because, despite being a phenomenon of natural origin, the anthropic pressure in the basins can influence its variation. Therefore, this document was carried out from the need to determine patterns in the changes in fluvial dynamics in the main tributary of the San Juan river sub-basin, specifically in its fluvial morphology and to determine how the variation of certain coverage of the land associated with the buffer established for the main channel, can alter the natural process of variation of this morphology, and additionally identify the main generating causes in the transformation of land cover. The evaluation was carried out through a multitemporal analysis, in which the relationship between the transformation of land cover and the change in fluvial dynamics was established, a relationship that was determined from obtaining satellite images for the periods 2002, 2010 and 2018, which were established according to the availability of image information for the sub-basin and parameters such as: spatial resolution, number of bands and% of cloudiness, and their correlation with the indices of total sinuosity, hydraulic sinuosity and topographic sinuosity, which were established because they allowed to establish the change in the fluvial dynamics at a morphological level for the tributary presented, which has alluvial plain-type conditions. Based on this correlation, it was determined that there is a relationship between the transformation of land cover and the change in fluvial dynamics, where the cover with the greatest variation regarding increase between the periods 2002-2018, corresponds to the cover of pastures. clean with a variation of 14.79%, regarding the coverage with the greatest variation in decrease for this same period corresponds to the coverage of dense bushland with a variation of 30.87%, regarding the sinuosity indices, it was determined that the total sinuosity has a direct relationship with anthropic coverage, because the increase in the percentage of anthropic coverage in the sub-basin represents an increase in the total sinuosity of the tributary, in terms of hydraulic sinuosity there is an inversely proportional relationship between the increase in natural covers and the increase in this index, compared to topographic sinuosity, it was determined that there is a direct relationship between the amount of natural covers and the increase in the index and an inverse relationship between the increase in the hydraulic sinuosity index and the increase in the topographic sinuosity index. Regarding the level of correlation established between the variation of coverage and the variation of the indices, it was determined that the variation of coverage with the greatest influence on the total sinuosity, hydraulic sinuosity and topographic sinuosity corresponds to the variation of transitory, permanent and mosaic crops of crops with a correlation index of 0.970, 0.937 and -0.982 respectively, which translates into a very strong positive correlation, a strong positive correlation and a very strong negative correlation respectively. Likewise, from this analysis it was possible to establish that the expansion of the livestock frontier and the expansion of the agricultural frontier are the main generating causes in the transformation of land cover for the sub-basin, in this way this document represents a An important tool for risk management in this area, because it is possible to establish how the variation of certain coverage influences the morphology of the tributary, in this way these relationships can be taken into account when preparing any document or plan of action that involves the ordering and comprehensive management of this sub-basin to promote the conservation of some strategic coverage that may generate possible risk scenarios.