SOIL EROSION, SEDIMENT YIELD, CONSERVATION STRUCTURES, AND DSS FOR SUSTAINABLE LAND MANAGEMENT ON SEMIARID RANGELAND WATERSHED
Location: Southwest Watershed Research
Title: Sediment tracers in water erosion studies: Current approaches and challenges
| Guzmán, G. - |
| Quinton, J. - |
| Mabit, L. - |
| Gómez, J.A. - |
Submitted to: Journal of Soils and Sediments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 28, 2013
Publication Date: N/A
Interpretive Summary: This paper is a review of the use of various types of tracers used to study soil erosion and sediment movement in the field. These tracers include the use of radionuclides, rare earth elements, fingerprinting by use of soil physical and chemical characteristics, magnetism and others. These tracers help us understand where sediment comes from is important to know because sediment caused by soil erosion is a major contributor to non-point source pollution of America's rivers, streams, and reservoirs. The use of radioactive Cesium is common; because it was deposited in soils across the entire world as a result of atmospheric atomic bomb testing that was conducted by various nations in the period largely around the early 1960s. After that time bomb testing was largely restricted to underground tests, specifically to reduce the release of such radioactive material into the atmosphere. Loss or gain of this material in the environment allows identification of erosion or deposition since the early 1960s. Another technique discussed is the use of rare earth oxide materials. These materials bind strongly to soil and sediment particles and can be measured in sediment and soil samples, thus they are ideal for tracking soil movement in the field. This report has significant implications for improving our ability to measure attributes that help us manage the soil and water resources of this nation by improving our knowledge of erosion rates in rangelands of southern Arizona and providing spatial data needed to test and improve the tools we use for conservation planning.
The interest in the use of sediment tracers as a complementary tool to traditional water soil erosion or deposition measurements or assessment has increased due to the additional information they may provide such as sediment source identification and tracking of sediment movement over the landscape at various time scales. The potentials of sediment tracer techniques utilizing a wide range of materials, substances and soil properties have been evaluated through numerous investigations, but it is difficult to find background studies comparing in a general way,. This manuscript is a detailed comparison of the origins, applicability and uses of the various tracing approaches recently developed. Five different groups of sediment tracers are distinguished (i.e. Radionuclides, Rare earths, Fingerprinting, Magnetism and Others). Although these groups present notable differences in both technique and potential types of information provided, there are also a number of issues common to all these tracing techniques. Strengths and weaknesses of current tracer methodologies used, their potential to assess soil erosion and soil redistribution, research gaps, and future trends are discussed.