| The fluvial-aeolian interactions on semiarid areas are becoming a new hot issue of aeolian geomorphology research.In order to investigate the interaction between the river water and the river dunes in the western Horqin Sandy Land of eastern Inner Mongolia,In the spring and summer,4 typical contains 21 river sections were measured to analyzes their shape and speed in Inner Mongolia Wengniute Xiangshuihe River,simultaneously 181 samples were collected,and then tested to calculate the cross section flow and sediment content in the interior,carried out a preliminary analysis of catchment effect changes between the river and sand dunes of various interactions,and the strength of sand dunes;and the use of simple device of 6 typical sand dunes along the side in 2016 August seepage flow velocity were measured,and the use of catchment area to calculate the parameters associated with the catchment effect value,then analyzes the causes of river catchment effect of sand dunes.The main findings and conclusions are as follows:1)In spring and summer,the instantaneous flow rate of Xiangshui River from south to north showed an increasing trend,on the one hand,because in the process of the southern section from the river upstream to the downstream of the north,along the river on both sides of sand dune recharge the river in form of groundwater obviouly,relative to the fixed sand dunes,water-sand dune river the moisturizing effect is more significant;on the other hand,there are also exist other supplies: torso mountain dam near the river upstream;many of the small tributaries of river valley and the old affluent of the reach of A have certain effect on Xiangshui River in supply.2)Similarly,in spring and summer,the sediment content from south to north each typical reach downstream end show an increasing trend,the reason is that in the case of increasing traffic,the fluvial erosion effect on river dunes is obvious,and the interaction between them is very active,the formation of the wind river sand dunes bury river;the river bank erode the steep slope;river also erode the flood plain;river dunes are eroded by stream laterally;the dunes in the river vally bury the river under the sand;comprehensive effect of 5 ways makes the sediment content of stream segment increasing.3)There is a typical bend forming two under the fluvial-aeolian interaction,the interaction contains two aspects as dynamic formation and sand material sources mainly,so the dynamics of the wind and the water formation process is: the wind sand river forced backward extrusion concave steering,thus changing the river plane shape;downwind concave arc the prevailing atmosphere flow compression,make the slope near ground wind accelerated sharply,to provide the necessary power for the wind.The material source of sand formation is river beach riverbank dune sand source directly downwind,caused by river concave lateral erosion collapse,provide rich material for wind sand promote the formation and development of riparian dunes as well as meandering swing and create favorable conditions.4)The river sand dunes on both sides,there is a slow runoff and infiltration of water seeping point,the storage of infiltration accounted the dune water storage years for 52%,the annual runoff for 89%,which indicates that the effective rainfall in the region through the infiltration of different layers in the riparian dune contents constitute important recharge source of river dunes groundwater.By the side of the dunes dunes groundwater seepage,become the main recharge way Xiangshuihe River catchment,become a very important aspect of the river-sand dune interaction. |
