On the evening of August 29, Li Guoying, Deputy Commander-in-Chief of the State Flood Control and Drought Relief Headquarters and Minister of Water Resources, chaired a special consultation meeting. The meeting conducted rolling analyses of the evolving situation of the barrier lake on the Purepu Tsangpo River, made an in-depth assessment of the chain risk posed by the impact crater on the upstream Chhochen Khola River, and systematically arranged for the investigation and elimination of potential risks and hidden dangers, as well as water related support for rescue and relief operations in the Gyirong debris flow disaster.
Li Guoying stressed that we must resolutely implement the important instructions of President Xi Jinping, always put people’s lives and safety first, foster a bottom‑line mindset and worst‑case‑scenario thinking, prepare for the most adverse‑case scenarios and make fullest‑possible preparations, and go all out to deliver water related support for emergency rescue and disaster‑relief operations.
First, close and continuous monitoring and assessment of the outburst risk of the dammed lake caused by Purepu Tsangpo River landslide must be carried out. The MWR will dynamically track changes in inflow, outflow, water surface area, water depth, and storage volume of the lake, and promptly determine the stability of the barrier body with respect to seepage and overflow. The MWR will conduct in-depth research and disaster-chain simulations concerning the breaching of the Chhochen Khola River impact crater and moraine-dammed lakes in Nepal, as well as surrounding landslides, and issue risk warnings in a timely manner. Besides, the MWR should urgently study and put forward recommendations for emergency response plans for the dammed lake due to Purepu Tsangpo landslide.
Second, high priority must be given to managing the breach and discharge risks posed by the Chhochen Khola River impact crater. This impact crater represents the greatest risk factor for the dammed lake. A digital twin of the impact crater should be developed through integrated monitoring using UAVs, satellite remote sensing, and other technologies. This digital twin should be used to dynamically simulate the time required for the crater to fill to capacity and begin overflowing, assess its structural composition and the likelihood of breaching, evaluate the potential impact of such a breach on the downstream dammed lake, and enable the timely issuance of risk warnings.
Third, continuous risk monitoring of moraine-dammed lakes in the Gyirong Tsangpo basin must be carried out. All moraine-dammed lakes within the Gyirong Tsangpo basin should be comprehensively identified. Each lake should be individually and precisely monitored, its structure analyzed, and the potential evolution of a glacial lake outburst flood from each lake and its impact on the Gyirong Port should be individually assessed.
Fourth, close attention must be given to the risk of new landslide‑dammed lakes forming as a result of slope failures. Recent rainfall events are still occurring in the Gyirong Tsangpo basin, and there remains a possibility that landslides could create new barrier lakes. The MWR will conduct rolling identification and expanded surveys of potential new landslide‑dammed lake risks along rivers such as the Gyirong Tsangpo, Donglin Tsangpo, Purepu Tsangpo, and Guobalong Tsangpo, and we must issue risk warnings in a timely manner.
Fifth, a comprehensive three‑dimensional monitoring and early‑warning system must be rapidly established that integrates space‑, air‑, and ground‑based observations. By employing satellite remote sensing, UAV monitoring, hydrological emergency monitoring, and seismograph monitoring, we should build a multi‑dimensional, multi‑factor monitoring and early‑warning framework covering space, air, and ground. This system should integrate multi‑source information, enable comprehensive and efficient hazard identification, and provide advance risk warnings.
Source: INTCE