Abstract
With over 200,000 km2of natural savannas, the Orinoquia region of Colombia is a key and strategic conservation area. Because of Colombia’s fast economic growth, there are significant plans for agro-industrial expansion in the Orinoquia. This expansion may seriously affect water availability. To evaluate the cumulative impacts on freshwater ecosystems derived by different expansion scenarios, the use of a comprehensive framework for mathematical modeling, able to represent the hydrological processes at a macro-basin scale, is crucial for analysis and as a tool to bridge the gap between science and practice. In this work, we developed a general methodological framework for hydrological analysis at macro-basin scale consisting of four main stages: 1) collection and processing of hydro-climatological data, 2) characterization of hydro dependent water use sectors, 3) mathematical modeling and 4) scenario simulation. As a result of applying the proposed framework, we obtained a coupled hydrological model, which allows us to represent the rain-runoff process, the river-floodplain interaction and anthropic processes such as surface water extraction and groundwater extraction, enabling us to represent the complexity of the Orinoquia region. The model was successfully implemented in Matlab showing a Nash-Sutcliffe efficiency coefficient between 0.62 and 0.92 in calibration and between 0.49 and 0.92 in validation. With this model we analyzed five different agro-industrial expansion scenarios, finding that the Colombian Orinoquia may have future high pressure on water resource areas with critical changes in the water availability regime. The scenarios show reductions of up to 85% in low water flows in more than 50% of the area of the Colombian Orinoco basin. In the most extreme scenarios, the Meta, Vichada and Guaviare rivers show reductions of 95, 98 and 50% in low water flows. The results show an urgent need to consider hydrology in planning processes to ensure the sustainability of this important area in Colombia.
Highlights
Extensive cattle ranching has played an important role in the economy of the Colombian Orinoco (Andrade and Castro, 2012; Buriticá, 2016)
The Orinoquia region has been identified as the major area of agro-industrial expansion in Colombia, so it is urgent to develop tools for prospective analysis. Considering this need, this study presents a hydrological modeling exercise with monthly time step for the Colombian Orinoquia region, addressed by two parsimonious conceptual models: the ABCD model proposed by Thomas (1981) and the river-floodplain interaction model proposed by Angarita et al (2018)
The coupling of the Thomas (1981) model and the Angarita et al (2018) floodplain river interaction model demonstrated satisfactory results according to the performance metrics obtained in the calibration (NSE from 0.62 to 0.92) and validation (NSE from 0.49 to 0.92) exercises
Summary
Extensive cattle ranching has played an important role in the economy of the Colombian Orinoco (Andrade and Castro, 2012; Buriticá, 2016). In the last 2 decades, agriculture has expanded, reaching a significant increase from 1,000 km to 8,000 km of planted area (around 2.3% of the Colombian Orinoco basin) This expansion of the agricultural Frontier (Vargas et al, 2015; Cárdenas-Santamaría et al, 2018) may have a strong impact in savanna ecosystems, Hydrological Modeling for Multifunctional Landscapes derived from the alteration of the land for crops such as rice, sugar cane and oil palm (Andrade and Castro, 2012). The Colombian Orinoquia covers 8.5% of the flooded savannas in South America and it is a strategic ecosystem of great economic, biological and ecological importance for the country (Mora et al, 2015). It is one of the most important biodiversity reserves in the neotropics (Gassón, 2002)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
