Geochemical characterisation of soil of Beira city, Mozambique: Geogenic origin and relation with land cover
Autor: | Elsa Cristina Ramalho, Dino Milisse, Judite Fernandes, Vicente Manhiça, Grácio Cune, José Tomás Oliveira, Elias Xavier Daudi, Maria João Batista, Ussene Vasco Ussene, Lídia Maria Quental, Ruben P. Dias |
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Rok vydání: | 2018 |
Předmět: |
Hydrology
education.field_of_study 010504 meteorology & atmospheric sciences Population Geochemistry Sediment Land cover 010501 environmental sciences 01 natural sciences Deposition (geology) Geochemistry and Petrology Tropical climate Erosion Economic Geology Sedimentary rock Mafic education Geology 0105 earth and related environmental sciences |
Zdroj: | Journal of Geochemical Exploration. 187:184-200 |
ISSN: | 0375-6742 |
Popis: | Beira city and Dondo district in Mozambique were studied with the purpose of evaluating the environmental quality of soil and to relate its quality with land cover and geology. This study revealed, by means of statistical tools, such as principal component analysis and multidimensional scaling, geochemical signatures of geogenic and anthropogenic origin in top- and sub-soil samples. Elements present in detrital minerals, deposited in recent geological formations of sedimentary origin (Ba, Cr, Hf, Ti, Th, U and REE), are related to the erosion products of mafic and orthogneissic formations derived from the upstream reaches of Pungwe River. Shallow coastal areas, where tropical climate (mean annual temperature of 24.5 °C) facilitate oxidation and deposition of iron oxides on the surface of particles in soil/sediment, have a characteristic element association, comprising Al, Br, Co, Fe, K, Mg, Mn, Na, Ni, Rb and Sc. Anthropogenic influence in overpopulated areas, identified with discontinuous urban fabric, is characterised by Cu, Pb, P and Zn, and is considered as potential hazardous because of unpaved roads, an unprotected urban waste dump, and inexistent sewage network, thus, increasing the risk of exposure to the population. A comparison of the potentially hazardous elements in the soil of Beira with other cities from around the world shows that Beira has lower concentrations in these elements. This is because the historical industry that has given rise and development to many world cities is absent in Beira. |
Databáze: | OpenAIRE |
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