The effect of prevailing wind on shoreline landform evolution - Illustrated by the case of Buha River Delta and Hargai River Delta in the Qinghai Lake, western

China

Chao Liua,b, Zaixing Jianga,b

a School of Energy Resources, China University of Geosciences (Beijing), Beijing, 100083, Chinab Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Enrichment Mechanism, Ministry of

Education, China University of Geosciences (Beijing), Beijing, 100083, China

Quaternary stratigraphy of Qinghai Lake

Structure map of Qinghai Lake

Its geographic location and remote sensing images

A

B

C

wind frequency

leeward side

windward side

wind

IWWB = Fm/Dm

Fm — lake length parallel to the dominant wind directionDm — mean depth of the lake (Nutz et al. 2018)

IWWB=106km/21m=5>3

wind driven lake !

Landform features of windward side

Landform features of leeward side

leeward;River > Wave;Bird-foot shaped;Mouth bars developed

River dominated delta

Mouth bars

1985 2013

2019

lake rising;stable shape;migration of Mouth bars;river dominated

Field photo of the estuary at Buha River Delta

Migration of the mouth bars between 2009-5-31 and 2013-8-2

No waves

Lake

Channel lag deposits Current climbing ripples Planar cross-lamination

Unidirectional flow structures

flow direction

Barrier bar

Windward;Wave > River;Destructional shape;Barrier bar developed

Wave dominated delta

1985 2013

2019

the formation of barrier bar;wave dominated

Field photo of the estuary at Hargai River Delta

landlake

lakeland

lake land

lake land land lake

Field photo of the estuary at Hargai River Delta

Field photo of the barrier bar at Hargai River Delta on a windy day

barrier bar

Lake

beach ridge

planar cross-beds

swash cross-beds

washover deposits