Sand source and formation mechanism of riverine sand dunes: a case study in Xiangshui River, China

Abstract

Riverine sand dunes develop as a result of fluvial-aeolian interactions. The primarily barchan dune chains along the Xiangshui River (a branch of the Xar Moron River in the western part of the Horqin Sandy Land of China) form a typical riverine dune field. We collected a series of samples from the riverine sand dunes parallel to the direction of the prevailing wind and investigated the sand sources and formation mechanisms of these dunes by determining the grain size, heavy mineral content and optically stimulated luminescence (OSL) of the samples. The sand of the near-river dunes was coarser than the sand of the dunes distant from the river, indicating that coarse sand of the valley mainly deposited on near-river dunes. The heavy mineral analysis suggested that wind-sand activity levels were intense on the upwind dunes, but relatively weak on the downwind dunes. This indicated that the sand sources for the near-river dunes were more abundant than those of the distant dunes. Our OSL analysis of samples suggested that the deposition rates on dunes near the river were greater than the deposition rates on dunes distant from the river. The development of dunes along the river indicated that the river played an important role in dune formation and development. In addition, airflow fluctuation and the formation of the waveform dunes had a type of feedback relationship. Grain size, heavy mineral and OSL analyses are widely used methods in wind-sand research. Sand dune grain size characteristics reflect the effects of airflow on the transport and separation of sand materials, as well as the physical characteristics of the sand sources. Heavy mineral characteristics are often used to investigate the relationships between sediments and sand sources. OSL indicates dune age, revealing formation of dunes. Therefore, it is useful to explore dune sand sources, as well as the mechanisms underlying dune formation, by determining grain size, heavy mineral content and OSL. This study investigated the sand sources of riverine dunes and provided new information about riverine dune formation and development.

Blowing the rivers: Regional-scale control of the drainage network by wind in northern Kalahari (Africa)

“…Riverine parabolic dunes similar to those presented above have been described along the Xiangshui and Laoha rivers in NE China (Wang et al, 2019) (SupFig. 3).…”

“…Journal Pre-proof the wind along the edges of the dunes, propagating the dune-tip downwind. This model implies that the sand forming the riverine dunes is brought into the system partly by the regional aeolian load but mainly from the river load mobilized by the airflow directly from sand bars in the riverbed or from the banks (Muhs et al, 1996;O'Connor and Thomas, 1999;Draut, 2012;Thomas and Bailey, 2017;Sankey et al, 2018;Wang et al, 2019). This model can be applied to our study area (Fig.…”

“…In arid and semi-arid environments redistribution of clastic sedimentary material results from the interactions between fluvial and aeolian erosion and transport processes (Maroulis et al, 2007;Williams, 2015). A number of studies have addressed the influence of fluvial valleys and rivers on the propagation of a dune field Wang et al, 2019) or on modifying the shape of dunes . Others addressed the effects of dune propagation on river systems, such as damming or enhanced avulsion frequency (Krapf et al, 2003;Liu and Coulthard, 2017).…”

Morphological characteristics and dynamic changes of seif dunes in the eastern margin of the Kumtagh Desert, China

“…The seasonal behaviour of these rivers leads to significant fluctuations in the surfaces of the riverbeds. Desiccation can uncover riverbed sediments, which can be intermittently exposed to aeolian erosion and generate atmospheric dust (Montes et al, 2017;Wang et al, 2019). The sand particles transported by wind could be deposited in some cases, such as when the wind speed drops, vegetation is present, or the topography changes, as well as by other mechanisms.…”

Alternative Bedding Materials for Poultry: Availability, Efficacy, and Major Constraints

“…Sand is increasingly used by several industries, including the building industry (houses and roads), electronics (computer chips and microprocessors), cosmetics, and detergents, among others. River sand is clean and has high water absorbing capacity but desert sand is too fine and smooth, high in clay, iron oxides, and lime but lacks silicon dioxide (4,49,50), making the former a better litter material than the latter. The poor absorbency of desert sand and the increasing demand of river sand for bedding and the construction industry may, however, exacerbate the already existing environmental consequences of sand mining (48,51).…”