Plynlimon research catchments: soil parent materials

Distribution of soil parent materials in the Severn and Wye catchments. These were mapped during the Soil Hydrology Study conducted by JP Bell in 1968-1969: Bell, J.P. (1969). The Soil Hydrology of the Plynlimon Catchments. Institute of Hydrology Report No. 8, Institute of Hydrology, Wallingford, UK.塞文与怀伊流域集水区（Severn and Wye catchments）的成土母质（soil parent materials）分布。该数据集由J.P.贝尔于1968-1969年开展的土壤水文学研究（Soil Hydrology Study）期间完成测绘：贝尔，J.P.（1969）。《普林利蒙集水区（Plynlimon Catchments）土壤水文学》，英国沃林福德水文研究所（Institute of Hydrology）第8号研究报告，英国沃林福德水文研究所。