The difficulty of hydrologic scaling mainly comes from the organized complexity of hydrologic systems, the heterogeneity and variability in space and time, and the insufficiency of data.

水文系统的有组织复杂性、时空变异性和数据不足是当前水文研究的难点所在。

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"The complexity lies in the fact that the theft and the sabotage is part of an organized crime ... that siphons away a billion dollars a month, " from Nigeria, Castelain said.

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