Medium And Long-term Research On Ice Regime Of Ningxia And Inner Mongolia Reach Of The Yellow River

Freezing is a general phenomenon in the cold area. Ice flood is a rise of water when ice is hindered in river course. Ice will not only influence shipping, transportation and sewage, but also lead to ice flood when ice condition is severe which cause huge losses. Because of the location and river characteristics, in winter, the ice flood is very serious and often cause ice flood disaster in NingXia and Inner Mongolia (for short: NingMeng) reach of the Yellow River, so it is one of the most important reaches of preventing ice flood. In recent years, ice flood is more severe because of temperature changes, mankind activities, scouring and silting.The special geographical position, hydro meteorological condition, river course characteristics are main reason for ice flood. Firstly, NingMeng Reach lies in the top north of the Yellow River. It flows from south to north. The temperature of upper reach is higher than that of lower reach, therefore, the river freezes up from lower reach to upper reach and breaks up from upper reach to lower reach. Secondly, there are many river bends and shoals in the NingMeng Reach. Ice flood will occur in these places at the break-up time.The thesis reviews the concerned study status of domestic and overseas first, then make factor analysis for ice flood, Partial Least-square model, Artificial Neural Network based on Genetic Algorithm model, Support Vector Machine model for ice drift, ice freeze and ice break are established. The results are reasonable and precise.