first_id	second_id	description
5J	5J4	Tatong He
5K	5K4	Jinsha Jiang
5K	5K5	Yalongjiang River
5L	5L3	Sequ,Angqu River
5L	5L4	Zaqu,Ziqu River
5L	5L2	right banks of middle reaches in LancangJiang
5N	5N2	Thanlwin River
5O	5O1	Ganga River
5O	5O2	Yarlung Zangbo
5Q	5Q1	Sengge Zangb(Shiquan River),etc
5Q	5Q2	Langqen Zangbo(Xiangquan River),etc
5X	5X0	Baerkashi Lake
5Y	5Y1	Hobudo He
5Y	5Y4	Hexi
5Y	5Y5	Qaidam Interior Drainage basin
5Y	5Y6	Tarim
5Y	5Y7	Interior drainage area of Jungger
5Y	5Y8	Interior drainage area of Turpan-Hami
5A	5A2	Ertix He
5Z	5Z1	Ayakkum and Hoh Xil Lake
5Z	5Z2	Siling Lake
5Z	5Z3	Zharinam Lake
5Z	5Z4	Bangong Lake
5Z	5Z5	Dogaicoring Lake
5Z	5Z6	Yibuchaka Lake
5J	5J3	Upper reaches of Yellow River
5K	5K6	Minjiang River
5K	5K7	Jialingjiang River
5X	5X1	Kala Lake
5N	5N1	Yigewadijiang River