Fisico-química de las aguas superficiales de la Cuenca del río Rincón, Península de Osa, Costa Rica

The Rincon River Basin is characterized by steep and rugged topography with outcrops of recent sediments as well as igneous and sedimentary rocks. The area is mostly covered by forest (Tropical Wet Forest) and agricultural land, with some scattered towns. The basin collects water from a total area of 209,8km2. Water samples were taken along the dry, transition and rainy seasons of 2004 and 2005, through six sampling campaigns and 11 selected sites in the study area. The waters are characterized by an average temperature of 26,8°C, and an average dissolved oxygen concentration of 7,7mg O2/L. The average electrical conductivity (EC) was 161,8μS/cm. They are moderately soft with a range of pH values between 6,62 and 8,17 and a maximum change of 0,5pH units. The bicarbonate concentration ranged from 54,3mg HCO3/L up to 160,8mg HCO3/L. They meet the criteria for calcium bicarbonate waters.