Title: Runoff Space-time Distribution Rule and Evolution Tendency of Yellow River Upstream and Main Tributaries
Abstract: Based on the observed runoff data of the related hydrometry stations,we analyzed the supply source,space-time distribution rule and evolution tendency of the runoff in the area above the Lanzhou station of the Yellow River upstream and main tributaries.The results show that the runoff is mainly from precipitation.The supplied runoff in the flood season(from May to October) amounts to 52.4%~68.0% of the total in a year,the supplied runoff from groundwater in the non-flood season accounts for 35.1%~43.1% of the total,and the runoff from snow and ice melt accounts for 2.5%~5.0% of the total.In the space distribution,because of different underlying surface conditions,difference of the runoff yield modulus is very big in spatial distribution,with the modulus being 7.874~8.500 L/s·km2 in the great-sized contributing area,being 5.047~6.536 L/s·km2 in medium-sized contributing area,and being 3.416~3.812 L/s·km2 in small-sized contributing area.In the time distribution,from start observation to 2008,the year of 1986 is a set apart.The runoff multi-annual variation process firstly displays long continuous fluctuation rise,then displays decline tendency process.The variation tendency of monthly runoff shows that runoff has a great decrease in flood season and has a smaller decrease in non-flood season.In view of the fact that the runoff reduces continually in the various reaches of the source area,there is decline tendency process of the runoff at the Lanzhou station since 1986,and this kind of change tendency is continuing.
Publication Year: 2011
Publication Date: 2011-01-01
Language: en
Type: article
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Cited By Count: 4
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