Abstract

FERRER-SANCHEZ, Yarelys; RAMIREZ CASTILLO, Andy Jafet; PLASENCIA-VAZQUEZ, Alexis Herminio  and  ABASOLO-PACHECO, Fernando. Impact of land use and landscape fragmentation on water quality of the Teaone river in Ecuador. Rev. Int. Contam. Ambient [online]. 2024, vol.40, 54900.  Epub May 09, 2024. ISSN 0188-4999.  https://doi.org/10.20937/rica.54900.

Water quality in watersheds depends on several factors and in Ecuador many rivers are polluted by anthropogenic impact. This study evaluated the influence of different land uses and landscape fragmentation on the physical and chemical characteristics of the Teaone river, Ecuador. Eight sampling points were located by land use (livestock, agroforestry systems, forests, and urban areas) where temperature, turbidity, total dissolved solids (TDS), pH, electrical conductivity, dissolved oxygen (DO), salinity, vegetation type, flow width, substrate, and water depth were measured. Digital circular plots were created to calculate indicators of landscape structure and fragmentation (edge index, dominance, and fragmentation index), and spectral indicators through vegetation indices such as the normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), and near infrared (NIR), red, and blue bands. Several physical and chemical parameters were within allowable limits (turbidity = -38.7 UNT, pH = 8.1, electrical conductivity = 365 μS/cm, temperature = 26.0 ºC, salinity = 0.15 UPS). However, OD and SDT were outside the limits in all land uses (OD = 4.04, SDT = 186.1 mg/L). Grassland had the highest number of fragments (12.1), followed by settlements (9.4). For NIR, EVI and NDVI high values were observed in native forest, agroforestry, and livestock and lowest values in the urban area. The parameters show that agroforestry systems and native forests maintain good water quality, while in livestock and urban areas water quality decreases.

Keywords : anthropogenic activities; environmental problems; spatial analysis; water contamination; watersheds.