Climate Change

Biography

Biography: Carla Idely Palencia-Aguilar

Abstract

Remote sensing has been widely used for determining climate changes characteristics, also in wetland studies. Aster images from 2002 and 2008 demonstrated that the water surface in a wetland located at Guasca Municipality in Colombia increased from 3934 m² to 126403 m² respectively at 15 m resolution. Modis images 13A3 allowed calculation of Normalized Difference Vegetation Index (NDVI) on a monthly basis from June to November 2008 with a resolution of 1 km. The results showed how variables such as Net Radiation, Temperature and Rain explained 83 percent of the NDVI monthly changes (data obtained from the meteorological stations HOBO and Campbell placed close to the wetland). In addition, Potential Evapotranspiration was calculated with formulas and compared with the ILWIS software with similar results with averages of 7.7 mm/day. Groundwater level fluctuations on a daily basis were studied as well as data from a piezometer placed next to the wetland during the same time period. Data was fitted with Rain changes with multiple regression analysis and time series, with R² of 0.98. Groundwater temperature and conductivity changes were also analysed, no significant changes over the studied time were noticed. However, conductivity changes were influenced by NDVI, Rain and Evapotranspiration with polynomial fittings greater than 90%. November was characterized by increasing NDVI, meaning that more agriculture took place. Agricultural runoff could increase conductivity due to additional phosphate and nitrate ions. Surface water quality analysis was performed to determine the possible contaminants. The results show that coliforms were the most significant contaminant.