【摘要】 风沙活动威胁着龙羊峡水库的安全运营,查清沙害来源和入库量对于防治水患和沙害具有重要意义。基于1987、1995、2003、2013、2019年的Landsat卫星影像,利用COSI-Corr技术监测了龙羊峡库区不同时空的沙丘移动特征,并重新评估库区近32 a的潜在风沙入库量。结果显示:（1）1987—2019年龙羊峡库区沙丘平均移动速率为5.81 m·a^-1,呈先加速（1987—2003年）后减速（2003—2013年）再加速（2013—2019年）趋势;沙丘移动方向在132.81°—165.82°范围内,与该区主风向一致。（2）近32 a向龙羊峡水库输送的潜在风沙量可达7.82×10⁷m³（1.20×10⁸t）。上风向塔拉滩潜在输送量为7.38×10⁷m³（1.14×10⁸t）,下风向木格滩仅贡献了0.44×10⁷m³（0.68×10⁷t）。（3）库区内风沙输移受风况、气候、植被等多种因素的影响,在未来全球变暖条件下,青藏高原的风沙活动将会持续发展,风沙入库量的长期累计效应将对水库安全构成严重威胁,必须引起足够重视。更多还原

【Abstract】 Aeolian sand invasion has negative effect on the Yellow River and Longyangxia reservoirs. It is of great significance to sort out the provenance and the potential amount of sand transported into the reservoir to reduce the aeolian sandy hazards. In this study,the dune migrating trends were monitored and the potential amount of sand transported into the Longyangxia reservoir was evaluated using the Co-registration of Optically Sensed Images and Correlation(COSI-Corr)technique based on the Landsat images in 1987,1995,2003,2013 and2019. The results revealed that:(1)The mean annual dune migration rates upwind the study area was 5.81 m ·a-1,with a trend of increasing from 1987 to 2003,then decreasing from 2003-2013 and increasing finally from2013 to 2019. The dune migration directions were ranged from 132.81° to 165.82° during the 32 years,consisting well with the local prevailing wind.(2)The total potential amount of sand transported into the Longyangxia Reservoir from 1987 to 2019 was 7.82×10~7 m~3(1.20×10~8 t). The upwind Talatan sandy land contributed 7.38×10~7 m~3（1.14×10~8 t）sand into the reservoir,while the downwind Mugetan sandy land only contributed 0.44×10~7 m~3（0.68×10~7 t）.(3)The factors that affect the sand into the reservoir include the wind,climate and vegetation cover. With the future global warming on the Tibet Plateau,the intensity of aeolian activity will increase,therefore the long-term sand cumulative damage will seriously threaten the security of the reservoir area according to our evaluation,which must be paid enough attention and take some necessary actions to control it.更多还原