Because the mountainous location is totally on the japanese A part of the peninsula, the primary rivers tend to move westwards. Two exceptions tend to be the southward-flowing Nakdong River and Seomjin River.
Even so the Sui army was lured right into a lure by the famed Koguryŏ commander Ŭlchi Mundŏk, and experienced a calamitous defeat on the Salsu (Ch'ŏngch'ŏn) River. It is said that only two,700 with the 300,000 Sui troopers who experienced crossed the Yalu survived to locate their way again, as well as the Sui emperor now lifted the siege of Liao-tung Fortress and withdrew his forces to China proper. Yang Ti ongoing to send his armies from Koguryŏ but once again without accomplishment, and prior to extensive his war-weakened empire crumbled." 파라곤 ^