It is possible that the rivers in West Gansu, such as the Shule me river and the other rivers to its east are all Oceanic rivers except Dang he river, which was an inland river even in ancient times.
甘肃河西诸河流、除党河从古以来是内流河外，疏勒河及其以东各河，早期可能全是外流河。
2
So when he adds up all the air, oceanic/lake/river and underground water he gets, roughly 1.2 "Global Oceans;"