扎陵湖、鄂陵湖对黄河源头年径流的影响

黄河源头扎陵湖、鄂陵湖为吞吐湖泊，是黄河源头二大主要湖泊。对黄河源头年径流具有滞蓄、调节作用。利用黄河源头控制站黄河沿站和下游吉迈、唐乃亥、循化3个测站水文资料，依据年径流在地区上的变化特点，分析了扎、鄂二湖对黄河源头径流影响。①扎、鄂二湖滞蓄，改变了源头径流年内分配，使其均匀化；②在枯水年份，入湖水量小，加上湖面强烈蒸发，使得湖泊以下黄河沿站年径流量更小，致使枯水程度加剧，加大了年径流年际变化；③黄河沿站与下游吉迈站年径流丰、平、枯程度对比分析，二站丰、平、枯水年同步出现机率为78．8％，扎、鄂二湖没有改变源头黄河沿站年径流丰、枯规律，是年调节湖泊，不是多年调节湖泊。

Influence of Zaling and Eling Lake on the Annual Discharge of the Huanghe River Source Area

ZalingLake and Eling Lake, the two major lakes in the Huanghe River source area, effectively serve as reservoirs that lag the flood peak and regulate the annual discharge budget. Based on hydrologic data from the four control stations-Huangheyan, Jimai, Tangnaihai, and Xunhua, analysis are made according to the characteristics of the annual discharge spatial distribution to give the influence of these two lakes on the annual discharge in the Huanghe River source. First, Zaling and Eling Lake average the annual discharge budget due to their large capacity to hold water. second, in the low water years, the less discharge into the two Lakes combined with stronger surface evaporation lead to less annual discharge measured at Huangheyan station, which contributes to increase the annual discharge variation and aggravates the dryness. Third, based on comparing and analyzing the degree of water sufficiency at Huangheyan and downstream Jimai station, we find that Zaling and Eling Lake don't significautly change the annual discharge measured at Huangheyan station, neither in abundant water years nor in insufficient one. These two Lakes are actually annual regulating lakes rather than multiannual ones.