上游之力 · UPSTREAM POWER
The Rain Above Egypt — Ethiopia · Highlands and Blue Nile
青尼罗河发源于埃塞俄比亚，雨季可贡献尼罗河水量约 80%。高原把夏季风降雨转化为下游肥力，也转化为上游议价能力。
从高处看，青尼罗河先是一条山河，后来才成为外交事实。它在玄武岩高原中切出峡谷，到喀土穆与白尼罗河相会，把雨季送向北方。
The Blue Nile rises in Ethiopia and can supply around 80% of Nile water in the rainy season. The highlands turn summer monsoon rain into downstream fertility and upstream leverage.
From above, the Blue Nile is a mountain river before it becomes a diplomatic fact. It cuts gorges through basalt country, then joins the White Nile at Khartoum and sends the wet season north.