title: Application of cluster analysis to the geochemistry zonation of the estuary waters in the Tinto and Odiel rivers (Huelva, Spain).
abstract: The combination of acid water from mines, industrial effluents and sea water plays a determining role in the evolutionary process of the chemical makeup of the water in the estuary of the Tinto and Odiel rivers. This estuary is in the southwest of the Iberian Peninsula and is one of the estuarine systems on the northwest coast of the Gulf of Cádiz. From the statistical treatment of data obtained by analyzing samples of water from this system, which is affected by industrial and mining pollution processes, we can see how the sampling points studied form two large groups depending on whether they receive tidal or fluvial influences. Fluvial input contributes acid water with high concentrations of heavy metal, whereas industrial effluents are responsible for the presence of phosphates, silica and other nutrients. The estuarine system of the Tinto and Odiel Rivers can be divided into three areas--the Tinto estuary, the Odiel estuary and the area of confluence--based on the physical--chemical characteristics of the water.
authors.affiliation: Grupo de Recursos y Calidad del Agua, Departamento de Ingeniería Minera, Mecánica y Energética, Universidad de Huelva, E-21819 Palos de la Frontera, Huelva, Spain. grangil@uhu.es
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Grande
authors.forename: José
authors.initials: J
authors.lastname: Borrego
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: de la Torre
authors.forename: A
authors.initials: A
authors.lastname: Sáinz
mesh_terms: D016000:Cluster Analysis; D017753:Ecosystem; D055593:Geological Phenomena; D005844:Geology; D007220:Industrial Waste; D019216:Metals, Heavy / Q000032:analysis; D008906:Mining; D010710:Phosphates / Q000032:analysis; D012822:Silicon Dioxide / Q000032:analysis; D013030:Spain; D014867:Water / Q000737:chemistry*; D014881:Water Supply
chemical_list: D007220:Industrial Waste; D019216:Metals, Heavy; D010710:Phosphates; D014867:Water; D012822:Silicon Dioxide