title: Using 137Cs to quantify the sediment delivery ratio in a small watershed.
abstract: Understanding the sediment delivery ratio (SDR) is important in controlling sediments for the sustainable development of natural resources and in the design of the construction such as dams and reservoirs. The purpose of this investigation is to determine the SDR by the (137)Cs tracing method in a small watershed in the Sichuan Hilly Basin of China. In the study watershed, different land plots are divided according to the land use type, and 97 sampling sites were selected from these plots. The results show that the average net soil loss rates from the forest land and sloping cultivated land are 1759 and 4468t/km(2)a, respectively. No (137)Cs was detectable on the bare rock surfaces and previous work showed that the erosion rate from the bare rock area was 14,260t/km(2)a. In the depositional zone, the sedimentation rates in the Caoto (a kind of cultivated land located at the foot of hills) and paddy field are 3113 and 3562t/km(2)a, respectively. Combining the area of each land use in the small watershed, the SDR of 0.40 is obtained in the past four decades. The (137)Cs technique was shown to provide an effective and rapid means of estimating the SDR within the small watershed.
authors.affiliation: Yellow River Institute of Hydraulic Research, Key Laboratory of Sediment Research of Yellow River of Ministry of Water Resources, Zhengzhou, Henan 450003, China. hnli-mian@163.com
authors.forename: Mian
authors.initials: M
authors.lastname: Li
authors.forename: Wenyi
authors.initials: W
authors.lastname: Yao
authors.forename: Zhanbin
authors.initials: Z
authors.lastname: Li
authors.forename: Puling
authors.initials: P
authors.lastname: Liu
authors.forename: Er
authors.initials: E
authors.lastname: Yang
authors.forename: Zhenzhou
authors.initials: Z
authors.lastname: Shen
mesh_terms: D002588:Cesium Radioisotopes / Q000032:analysis*; D019015:Geologic Sediments / Q000032:analysis* / Q000737:chemistry*; D007553:Isotope Labeling / Q000379:methods*; D012212:Rheology / Q000295:instrumentation*; D045483:Rivers / Q000737:chemistry*; D014867:Water / Q000032:analysis / Q000737:chemistry*
chemical_list: D002588:Cesium Radioisotopes; D014867:Water