 According to the estimates by Boris Tkachenko, a Russian historian, the treaty resulted in net territorial gain for China, which received about 720 km², including some seven hundred islands.Because islands on the Argun, Amur, and Ussuri rivers often split the rivers into multiple streams, the location of the main stream (and thus the border) was often not immediately apparent.Obviously, each country would receive a greater number of islands if the recognized main channel was closer to the opposite bank.