The objective of this study was to assess droughts in the department of La Guajira, Columbia, on the basis of their operational characteristics. Droughts were assessed using the Standardized Precipitation Index (SPI) at three- and six-month aggregation periods (SPI-3 and SPI-6), and their operational characteristics were analyzed by the run theory and via analysis of temporal trends using the modified Mann-Kendall (MMK) test. The results indicated that droughts were most frequent in La Guajira between 1995 and 2004. The occurrence of droughts was most accurately identified by SPI-6. It was observed that the central, southern, and western areas of the department had droughts of greater duration, severity, and intensity. The MMK test shows negative (decreasing) temporal trends at significance levels α between 0.1 and 0.01 in 6.12% of the meteorological stations located in the central and southern areas of La Guajira. These results support the conclusion that droughts are recurrent events in the department of La Guajira as a result of the arid and semi-arid climate prevalent in significant portions of the department’s land area. This elucidates the vulnerability of agriculture and livestock in such areas that are prone to droughts of greater duration, severity, and intensity.

Objetivo: Esta investigación tuvo como objetivo evaluar la salud ambiental del ecosistema lótico río Ranchería en el área de influencia del complejo carbonífero El Cerrejón, a través de bioindicación con macroinvertebrados acuáticos. Metodología: Se establecieron tres estaciones de monitoreo (E1, E2 y E3), en las cuales se realizaron mediciones de variables fisicoquímicas como: temperatura (ºC), oxígeno disuelto (mg/l), pH, salinidad (%o), conductividad (µS/cm), turbidez (UNT), sólidos suspendidos totales (mg/l), cloruros (mg/l), amonios (µg/l), nitritos -(µg/l), nitratos (µg/l), fosfatos (µg/l) y demanda bioquímica de oxígeno (mg/l) Los macroinvertebrados acuáticos se colectaron a través de muestreo multihábitat por arrastre con red surber, red D-net y recolección de organismos bentónicos, usando nucleadores PVC. La calidad de las aguas en cada estación de monitoreo se clasificó mediante el índice BMWP/col. Resultados: Como resultados relevantes, se encontró que las familias de macroinvertebrados acuáticos con más abundancia en E1 fueron Baetidae, Coenagrionidae, Philopomamidae, Leptohyphidae y Leptophlebiidae; en E2, Culicidae, Hydrophilidae, Coenagrionidae, Psephenidae e Hydrobiidae, y en E3, Coenagrionidae, Hydrobiidae, Belastomatidae y Palaemonidae. Conclusiones: Se concluye que E1 posee aguas de buena calidad (BMWP/col = 130; ASPT = 6,50), con alta diversidad y riqueza (H’E1 = 3,75 bits/ind; IE1 = 4,76); E2 y E3 poseen aguas de calidad aceptable (BMWP/col = 65; ASPT = 5,00) y calidad dudosa (BMWP/col = 50; ASPT = 5,25), respectivamente, con mediana diversidad de familias (H’E2 = 2,97 bits/ind y H’E3 = 2,32 bits/ind) y mediana riqueza (IE2 = 2,82 y IE3 = 1,88).