title: Vertical and lateral distribution of fallout137Cs and soil properties along representative toposequences of central Rif, Morocco.
abstract: The purpose of this study is to understand and quantify the relationships between current137Cs inventories and the soil properties and the physiographic characteristics. A total of 36 cores were taken in seven transects with different slopes, lithology and land use. The analysis focused on the137Cs mass activity as well as inventories and its relationship with soil properties as grain size and organic matter. The mass activity of137Cs and the inventories varied between 3.6 and 63.7 Bq kg-1and between 521.7 and 3304.4 Bq m-2, respectively. At uncultivated soils, high concentrations of137Cs are located in the top 10 cm and decreased exponentially in depth. Cultivated soils record disturbed and heterogeneous137Cs profiles with values of mass activity and inventories up to 38.7 Bq kg-1and 2510.8 Bq m-2, respectively. The137Cs inventories were significantly higher in uncultivated soils (mean: 2086.9 Bq m-2) compared to cultivated soils (mean: 1397.1 Bq m-2). The137Cs mass activity showed a significant positive correlation with organic matter, silt and clay, but it was negatively correlated with sand and pH respectively. High levels of137Cs were found at altitudes between 500 m and 640 m a.s.l, and at slopes from 8° to 11°, as well as in dense scrub land and Fersialitic soils. A principal component analysis showed that more than 86.7% of the variance in137Cs mass activity was explained by the organic matter content and the land use. The results of this study provide insights into the effects of soil properties and physiographic factors on the behaviour of137Cs in soils of Mediterranean environments of North Africa and strengthen the reliability of this radioisotope as an erosion tracer.
authors.affiliation: Université Sidi Mohammed BenAbdellah, Faculté des Sciences Dhar Mahraz-Fès, Département des sciences de la terre, B.P.1796, Fès - Atlas, Morocco. Electronic address: haytam.mesrar@usmba.ac.ma.
authors.forename: Haytam
authors.initials: H
authors.lastname: Mesrar
authors.affiliation: Université Sidi Mohammed BenAbdellah, Faculté des Sciences Dhar Mahraz-Fès, Département des sciences de la terre, B.P.1796, Fès - Atlas, Morocco.
authors.forename: Abdelhamid
authors.initials: A
authors.lastname: Sadiki
authors.affiliation: Laboratoire des Études Géographiques, Aménagement et Cartographiques, Faculté de Lettres saïs Fès, Morocco.
authors.forename: Ali
authors.initials: A
authors.lastname: Faleh
authors.affiliation: Estación Experimental de Aula Dei, EEAD-CSIC Avda, Montañana 1005,50059 Zaragoza, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Quijano
authors.affiliation: Estación Experimental de Aula Dei, EEAD-CSIC Avda, Montañana 1005,50059 Zaragoza, Spain.
authors.forename: Leticia
authors.initials: L
authors.lastname: Gaspar
authors.affiliation: Estación Experimental de Aula Dei, EEAD-CSIC Avda, Montañana 1005,50059 Zaragoza, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Navas
mesh_terms: D002588:Cesium Radioisotopes / Q000032:analysis*; D009018:Morocco; D011834:Radiation Monitoring; D011847:Radioactive Fallout / Q000032:analysis*; D012987:Soil / Q000737:chemistry; D012990:Soil Pollutants, Radioactive / Q000032:analysis*
chemical_list: D002588:Cesium Radioisotopes; D011847:Radioactive Fallout; D012987:Soil; D012990:Soil Pollutants, Radioactive
keywords: (137)Cs; Biogeographical features; Central Rif; Land uses; Morocco; Physico-chemical properties; Soils