Figure 2: (IMAGE) Science China Press Caption Drainage network is labeled with stream numbers in four catchments (HY1, HY2, HY3 and HY4). The division of these catchments is mainly based on the channel flow direction, fault distribution and topographic features. Note the sharp flow direction change in the R59-R65. Credit ©Science China Press Usage Restrictions Use with credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.