Assessing sedimentological connectivity using WATEM/SEDEM model in a hilly and gully watershed of the Loess Plateau, China

Abstract

a b s t r a c tSedimentological connectivity is an important issue in soil erosion and sediment transport. Landscape patterns, in combination with the rainfall regime, are known to shape such sedimentological connectivity. The quantification of sedimentological connectivity provides a link between sediment delivery and landscape pattern. There are two categories of connectivity: structural connectivity, which describes the physical coupling of landscape units, and functional connectivity, which delineates the linkage among landscape elements maintained by material transport. To quantify sedimentological connectivity, both the physical coupling of, and material transfer between, the various landscape components need to be assessed. This study quantifies the sedimentological connectivity of a headwater catchment in the Loess Plateau of China using the soil erosion and sediment delivery model (WATEM/SEDEM). Based on the model, two indicators of connectivity were developed: the area of sedimentologically effective catchment area (SEA) that contributes sediment to the sinks, and the minimum sediment output of locations on the flow path that link sources and sinks. This approach effectively represents the annual status of catchment-scale sedimentological connectivity and, furthermore, the simple structure and readily available input data make it highly practicable. However, for larger river systems in which sediment transport between sources and sinks occur over longer time scales and larger spatial scales, we suggest different techniques for quantifying the sediment flux and parameters delineating the physical coupling of landscape units.

The synergistic effects of afforestation and the construction of check‐dams on sediment trapping: Four decades of evolution on the Loess Plateau, China

“…The use of WATEM/SEDEM enables the exploration of sedimentation and soil erosion at the grid cell level as long‐term annual average values (Van Rompaey, Bazzoffi, Jones, & Montanarella, ; Van Rompaey, Verstraeten, Van Oost, Govers, & Poesen, ). Note that WATEM/SEDEM has been calibrated in catchments on the Loess Plateau using 137 Cs plot‐based field measurements of sediment yield in the authors' previous studies (Feng et al, ; Y. Liu & Fu, ; Z. C. Zhou et al, ).…”

“…According to Y. Liu and Fu (), WATEM/SEDEM performs well on the Loess Plateau with the calibrated values of K tc ‐ high and K tc ‐ low ; the model efficiency coefficient, an indicator of model performance, reaches its highest value of 0.8 (Figure ) for these values. The reasonableness of the simulation using the calibrated parameters has been examined, with particular emphasis on the spatial–temporal patterns of sediment yield and soil erosion (Y. Liu & Fu, ).…”

“…The effects of land use/cover changes decreased 40.6% of the sediment yield under the baseline condition in the Loess Plateau (H. Wang et al, ; Zuo et al, ). The effectiveness of these measures has been thoroughly evaluated (Díaz‐Gutiérrez et al, ; Y. Liu & Fu, ; Mount, Smith, & Stott, ; Ramos‐Diez, Navarro‐Hevia, San Martín, & Mongil‐Manso, ; Ran, Lu, Xin, & Yang, ; van Oost, van Rompaey, Poesen, Govers, & Verstraeten, ). However, to formulate effective river management on the basin scale, it is necessary to carefully evaluate the synergistic effects of diverse erosion control measures.…”

“…The effects of land use/cover changes decreased 40.6% of the sediment yield under the baseline condition in the Loess Plateau (H. Wang et al, 2006;Zuo et al, 2016). The effectiveness of these measures has been thoroughly evaluated (Díaz-Gutiérrez et al, 2018;Y. Liu & Fu, 2016;Mount, Smith, & Stott, 2005;Ramos-Diez, Navarro-Hevia, San Martín, & Mongil-Manso, 2017;Ran, Lu, Xin, & Yang, 2013;van Oost, van Rompaey, Poesen, Govers, & Verstraeten, 2002).…”

“…The reduction of the newly increased sediment storage capacity reflects the variance of the con- Rompaey, Verstraeten, Van Oost, Govers, & Poesen, 2001). Note that WATEM/SEDEM has been calibrated in catchments on the Loess Plateau using 137 Cs plot-based field measurements of sediment yield in the authors' previous studies (Feng et al, 2010;Y. Liu & Fu, 2016; Z. C. Zhou et al, 2006).…”