Analysis of meteorological and hydrological drought events in the “La Lejía” stream in the municipality of Durania, Norte de Santander.

Abstract

Introduction: Droughts are one of the most concerning environmental issues in recent years, as water resources are essential for human quality of life and the maintenance of ecosystems. The lack of water can generate severe impacts in various areas. In the last decade, the municipality of Durania has faced several drought events caused by high temperatures and low precipitation affecting the entire department of Norte de Santander, as a result of the climate variability phenomenon "El Niño" and global warming. The occurrence of droughts can lead to water rationing for the community, as well as economic losses in sectors such as agriculture and livestock, directly impacting the municipality's economy. Additionally, it can generate negative effects on the flora and fauna of the area. Analyzing how drought phenomena affect agriculture can help farmers better plan their crops to avoid significant losses. Objective: To analyze meteorological and hydrological drought events in the "La Lejía" stream of the municipality of Durania, Norte de Santander. Methodology: First, the physical, shape, relief, and drainage parameters of the watershed were obtained using the digital terrain model from Global Mapper Trial version and QGis free version. Then, climatic indices and anomalies were calculated based on temperature and precipitation variables

using the Google Earth Engine platform, with a 45-year historical series. Additionally, evapotranspiration was obtained using the Thorntwaite equation. Subsequently, meteorological drought indices such as SPI, SPEI, and hydrological indices were obtained using the DrinC program. Results: Historical drought events were identified, occurring in two periods of the year, one from June to September and another from December to February. A comparative analysis was also conducted between the occurrence of these events and the influence of climate variability phenomena such as "El Niño." Conclusions: A bimodal precipitation pattern was analyzed, with periods of lower rainfall identified between June and September and from December to February. Furthermore, the study highlights the years 1980, 1983, 1984, 1996, 2001, 2002, 2014, 2015, and 2016 as the years with the greatest water scarcity. Identifying these years helped to understand the drought events in the watershed and relate them to the "El Niño" phenomenon.