黄河内蒙古段输沙用水量分析

Analysis on Water Consumption for Sediment Transport at Inner Mongolia Reach of the Yellow River

根据1953—2004年黄河宁蒙河段下河沿、石嘴山、巴彦高勒、三湖河口、头道拐5个典型水文站的水沙资料,分别用输沙量法、含沙量法及冲淤比修正法对内蒙古段的输沙用水量进行了计算,并对黄河内蒙古段各典型水文站汛期单位输沙用水量与汛期水沙条件的关系进行了分析。结果表明：1953—2004年内蒙古段各站全年、汛期输沙用水量均随时间呈明显的减小趋势,1987年后各站汛期输沙用水量已不足刘家峡水库运用前的50%,而非汛期输沙用水量随时间的变化较小;各站汛期单位输沙用水量与汛期平均流量、含沙量存在相关性较好的降幂级数关系;在汛期,若巴彦高勒—头道拐区间各站平均含沙量大于9 kg/m^3、单位输沙用水量小于200 m^3/t,则该河段均发生淤积;若含沙量小于4 kg/m^3、单位输沙用水量大于400 m^3/t,则该河段均发生冲刷;若含沙量为4-9 kg/m^3、单位输沙用水量为100-400 m^3/t,则该河段淤积比随汛期单位输沙用水量的增加而增大。

The paper calculates the water consumption for sediment transport of Inner Mongolia reach by using method of sediment discharge,method of sediment concentration and revision method of scour and fill ratio respectively based on silt-discharge data of 5 hydrometric stations of Xiaheyan,Shizuishan,Bayangaole,Sanhehukou and Toudaoguai situated on Ningxia-Inner Mongolia reach of the Yellow River in 1953-2004 period and analyzes the relationship between unit water consumption for sediment transport in flood season and silt-discharge conditions in flood season of each typical hydrometric station of Inner Mongolia reach.The outcomes show that a) the water consumption for sediment transport of a whole year and flood season of each station at Inner Mongolia reach in 1953-2004 period has obvious trend of reduction along with the time.The water consumption for sediment transport of each station during flood season after 1987 is less than that of 50% before the operation of Liujiaxia Reservoir and the water consumption for sediment transport during non-flood season is smaller along with the variation of time;b) the unit water consumption for sediment transport of each station in flood season exists good relation of decreasing power series with the mean discharge and sediment concentration;c) during flood season,Bayangaole-Toudaoguai section is deposited when the average sediment concentration of each station is greater than 9 kg/m3 and the unit water consumption for sediment transport smaller than 200 m3/t;d) the section is scoured if sediment concentration is smaller than 4 kg/m3 and the unit water consumption for sediment transport greater than 400 m3/t and;e) the rate of silting of the section increases along with the increase of unit water consumption for sediment transport in flood season if sediment concentration is 4-9 kg/m3 and the unit water consumption for sediment transport is 100-400 m3/t.