Ī significant reallocation from heterogeneous farm uses to pasturelands has occurred since 2005, which represent 23.4% (1280 km 2) of the basin’s total area. The setup of forest recovery policies allowed the introduction of non-native species and forests plantation (Pinus spp, Acacia melanoxylum, A. These cloud forests have the ability to catch this humidity, playing in this way a key role into the hydrological cycle regulation, levels of runoff, and wide water supply. The main characteristic of these areas is the high level of air humidity because of the hot air condensation in lower areas generating cloudiness. The high-Andean cloud forest is mainly constituted by trees (up to 25 m) and shrubs (from genus Weinmania, Miconia, Ilex sp., Hesperomeles sp Clusia, Brunnellia sp, Befaria sp Drymis, and Oreopanax). This historical process of fragmentation has led to its altitudinal and latitudinal isolation.
Andean forest is considered among the most threatened ecosystems in Colombia. Land Change Modeler Application to Bogotá River BasinĬurrently only 31% of the initial area covered by natural Colombian Andean forests remain, as farming and industrial extractive activities have degraded this natural ecosystem or simply taken its place. CORINE category 4.1 includes inland wetlands and water surfaces, while inland water bodies (natural or artificial) and major watercourses are included in category 5.1 ( Figure 2). The Andean forests in the upper river basin are formed by lush vegetation, including cloud forests (CORINE category 3.1) and high mountain lands with grasslands called Andean Páramos (included in category 3.2). “Permanent” or “semi-permanent crops” correspond in the Bogotá river basin to rice, sugar cane, coffee, potatoes, flowers (in greenhouses), and bananas production. “Agricultural areas” (gathering CORINE categories 2.1, 2.2, 2.3, and 2.4) mainly include pasturelands and areas with heterogeneous agricultural uses. Artificial lands, which were modified by characteristic geometric distribution, correspond either to high- or low-density urban areas, rural settlements, and mixed infrastructures/amenities.
The category “artificial areas” (gathering CORINE categories 1.1, 1.2, 1.3, and 1.4) included all the areas occupied by human settlements and/or designated for human use. Study Area: The Bogotá River Basinįinal maps considered 13 categories in the Bogotá basin. Based on results obtained from the simulations, specific findings are highlighted since they can be useful for policy-making mid-long-term. The historical analysis of LUCL as well as results of forecasting scenarios are presented in Section 3, focusing on the expansion of urban areas and the influence on other land uses. This paper presents in Section 2 an overview of the datasets and methodologies applied to the Bogotá river basin. Building on these results, the development of LULC forecasting scenarios is then performed at horizons 20. LCM is based on neuronal networks that define potential transitions of land categories and it considers potential explanatory variables that support the understanding of LULC changes. Land Change Modeler (LCM) is selected since it has already shown its good ability to model LULC changes in urban areas and megacities. This work includes first the analysis of historical LULC dynamics in the Bogotá river basin performed from 1985 to 2014. A replacement of crop and pasture lands near the city is expected, even though Bogotá lands are among the best agricultural lands in the Andean region of Colombia. This dynamic is expected to continue, with a 50% increase of urban areas between 2012 to 2050, thus the megacity and neighbor cities potentially become an “urban continuum”. These changes implied a loss of 58% of forest surface, a strategic ecosystem, from 1985 to 2014. Results show an expansion of the Bogotá megacity toward the Northeast and an increase of urban areas within the basin. Reliable forecasting scenarios were developed using the Land Change Modeler to support sustainable management and planning. The main objective of this work was to analyze the historical LULC dynamics from 1985 to 2014. In this study, the Bogotá river basin and the Bogotá megacity were analyzed as a case study. This is a major challenge for the sustainable management of these territories, justifying the need for a better knowledge of land use/land cover (LULC) distribution and characteristics to observe spatial anthropogenic dynamics. Usually, megacities expand without proper planning in a context of demographic growth and are increasingly dependent on the natural resources related to the occupied area.
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