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1 黄河水资源的特点1.1 水沙异源。黄河水主要来自上游,而泥沙主要来自中游,兰州以上径流量占总水量的58%,而沙量仅占9%,是黄河的主要清水来源,90%的泥沙来自中游,需上游的清水输送入海。因此,上游的水资源利用要兼顾中下游的输沙和供水需要。1.2 径流年内年际变化大,枯水期长。特别是进入90年代后连年断流,形成了长时间的枯水期,而且断流时间逐年提前,时
1 The characteristics of the Yellow River water resources 1.1 Heterologous. The Yellow River water is mainly from the upper reaches, while the sediment mainly comes from the middle reaches. The runoff above Lanzhou accounts for 58% of the total, while the sediment accounts for only 9% of the total. Yellow River water is the main source of water and 90% of the sediment comes from the middle reaches. Water delivery into the sea. Therefore, the utilization of water resources in the upstream should take into account the needs of sediment transport and water supply in the middle and lower reaches. 1.2 Annual runoff years, large changes, long dry season. Especially after entering the 1990s, the current has been cut off year after year, resulting in a long period of dry season, and the flow-off time is advanced year by year.