西藏地质灾害易发性及对水能开发适宜度影响

Distribution of hydropower development suitability in Tibet in the face of geological hazard susceptibility

西藏自治区是中国水能资源的战略储备库与未来重点开发区域,然而该区域地质灾害频发,给水能开发带来极大挑战,亟需系统研究。本文综合考虑西藏地区地质地貌、水文气象和植被覆盖等致灾因子,基于最大熵(MaxEnt)模型分析泥石流、崩塌、滑坡等典型地质灾害的易发性,结合水能资源分布禀赋,实现西藏地区水能开发适宜度评价。结果表明,雅鲁藏布江大拐弯羌纳—帮辛段水能开发适宜度最高,可优先开发;雅鲁藏布江上游夏如—拉孜段、怒江中游马利—林卡段、中林卡—察瓦龙段、支流伟曲河田妥—碧土段、澜沧江中游察雅—措瓦段、如美—盐井段、金沙江上段木协—戈波段、喜马拉雅山脉朋曲河流域为高水能开发高风险地区,需谨慎开发;雅鲁藏布江中游仁布—曲水段、易贡藏布忠玉—易贡段、察隅河下察隅以南段、朗钦藏布下游段为中水能开发低风险区,可根据需求局部开发或暂缓开发;其余区域水能开发适宜度较低,不建议开发。本文针对西藏地区提出一种快速有效的水能开发适宜度评价体系,可为该区域水能开发规划提供科学依据。

Tibet is recognized as the key repository and focal area for future hydropower development in China because of its high capacity for hydropower storage;however, frequent occurrence of geological hazards in this region have posed great challenges to us. Priority should be given to the effects of geological hazards on the suitability of areas in Tibet for hydropower development. Based on the maximum entropy model, the susceptibility of potential development areas to three typical geological hazards(debris flow, avalanche, and landslide) was calculated using data of landforms, hydrometeorology, and vegetation coverage of Tibet. Furthermore, hydropower development suitability was evaluated by considering distribution of potential hydropower storage alongside geological hazard susceptibility. The results show that the Qiangna-Bangxin section of the Great Bend of the Yarlung Tsangpo River has the highest suitability and would be a prime development target. The Mali-Linka and Zhonglinka-Chawalong sections in the middle reaches of the Nujiang River, the Tiantuo-Bitu section of the Weiqu River, the Chaya-Cuowa, Rumei-Yanjing, and Muxie-Gobo sections in the upper reaches of the Jinsha River, the Motuo-Lijia and Xiaru-Penji sections in the lower and upper reaches, respectively, of the Yarlung Tsangpo River, and the Pengqu River Basin in the Himalayas are all highly suitable for hydropower development. However, these areas also show high susceptibility to geological hazards, so they should be developed with caution. The RenbuQushui section in the middle reaches of the Yarlung Tsangpo River, the Zhongyu-Yigong section of the Yigong Tsangpo River, the southern section of the Chayu River, and the lower reaches of the Langqin Tsangpo River show moderate suitability and low hazard susceptibility,and thus present future development opportunities. Therefore, other areas are not suitable for hydropower development. This study presents an effective suitability evaluation method for hydropower development in Tibet, and its results provide a scientific basis for hydropower planning and site selection in this region.