Fingerprinting sediment sources of mountainous catchments disturbed by built-up land expansion in southern China
The data were used to investigate and quantify sediment sources of mountainous catchments disturbed by built-up land expansion. We selected a target watershed in the field. Representative source materials (including five potential sources, a total of 60 samples) and 14 sediment samples were collected. All source materials and sediment samples were air dried, ground with a mortar and pestle and passed through specific-sized nylon screens. Based on local geological conditions, particle size, soil organic carbon (SOC), total nitrogen (TN), magnetic susceptibility, and the geochemical element concentration as potential tracers (fingerprint properties) were selected for testing. The particle size was determined by using a Mastersizer 2000 analyser (Malvern Instruments, Malvern, UK) after all samples were sieved through 2-mm screens. The grain size classification followed the United States Department of Agriculture (USDA) scale standard (USDA, 1951). The high-frequency (χhf) and low-frequency (χlf) magnetic susceptibilities were measured by using the MS2 dual-frequency magnetic susceptibility instrument (Bartington Instruments Ltd., Witney, UK). When all samples were sieved to < 75 μm, the SOC and TN contents were determined by using the external heat potassium dichromate method and an automatic Kjeltec apparatus (Foss A/S, Hillerod, Denmark), respectively. The above indices were determined in the State Key Laboratory of Soil Erosion and Dryland Agriculture on the Loess Plateau. A total of 4 oxides and 48 geochemical elements were measured by using inductively coupled plasma‒mass spectrometry (ICP‒MS) at the Shaanxi Provence Land Engineering Construction Group Laboratory. The measured geochemical elements and oxides included Ca, Zn, Mo, Cu, Fe, Mn, Mg, Pb, Th, Ba, P, Al, Li, Be, Na, Si, S, K, Ti, V, Cr, Co, Ni, Cu, Ga, As, Se, Rb, Sr, Y, Zr, Nb, Mo, Ag, Cd, In, Sn, Sb, Te, La, Ce, Hf, Ta, W, Re, Tl, Bi, U, SiO2, Fe2O3, TiO2 and MnO. Ultimately, this study obtained a total of 56 potential tracers.
Water Conservancy Science and Technology Innovation Project in Guangdong Province of China