Sand hazards are serious at the Danghe Reservoir of Dunhuang,and efforts to control sand are ineffective because disaster-causing mechanisms are currently unclear.The source of sandy materials,dynamic environment of b...Sand hazards are serious at the Danghe Reservoir of Dunhuang,and efforts to control sand are ineffective because disaster-causing mechanisms are currently unclear.The source of sandy materials,dynamic environment of blown sand,and controlling measures of the reservoir area are investigated using different methods,such as granularity analyses,wind regime and sand transport field observation and analyses,sand drift potential calculation.Accordingly,the sandy materials are found to derive chiefly from the Mingsha Mountain on the north side of the reservoir area.In addition,sand grain in the range of 0.50-0.25 mm and 0.25-0.10 mm are dominant.The prevailing sand-moving wind originates from the N direction,accounting for 15.38% of the yearly total,which coincides in the same direction with sand source,thereby increasing the severity of sand hazards in the reservoir area.The yearly sand DP is 1386.59 VU,the yearly RDP is 567.31 VU,the yearly RDP/DP is 0.41,and the yearly RDD is 183.15°.In the windy season(mainly in summer),sand materials are blown by wind from north to south,and then blocked by the Danghe River.The sand materials then move with an approximate east-west trend into the river channel and produce sediment,thereby causing adisaster.We propose that the sand-controlling pattern of the Danghe Reservoir is dominated by sand blocking in the outer fringe and sand fixing in the inner fringe.Applying windbreak and sand fixation to control sandy material movement into the river channel plays an important role in retarding sedimentation and extending the useful life of the Danghe Reservoir.展开更多
基金funded by the National Natural Science Foundation of China (Grant No.41401611)one of Special Fund for Forest Scientific Research in the Public Welfare (201504401)+1 种基金the China Postdoctoral Science Foundation (Grant Nos.2014M560817 and 2015T81069)the science and technology program of Gansu Province (Grant No.145RJZA118)
文摘Sand hazards are serious at the Danghe Reservoir of Dunhuang,and efforts to control sand are ineffective because disaster-causing mechanisms are currently unclear.The source of sandy materials,dynamic environment of blown sand,and controlling measures of the reservoir area are investigated using different methods,such as granularity analyses,wind regime and sand transport field observation and analyses,sand drift potential calculation.Accordingly,the sandy materials are found to derive chiefly from the Mingsha Mountain on the north side of the reservoir area.In addition,sand grain in the range of 0.50-0.25 mm and 0.25-0.10 mm are dominant.The prevailing sand-moving wind originates from the N direction,accounting for 15.38% of the yearly total,which coincides in the same direction with sand source,thereby increasing the severity of sand hazards in the reservoir area.The yearly sand DP is 1386.59 VU,the yearly RDP is 567.31 VU,the yearly RDP/DP is 0.41,and the yearly RDD is 183.15°.In the windy season(mainly in summer),sand materials are blown by wind from north to south,and then blocked by the Danghe River.The sand materials then move with an approximate east-west trend into the river channel and produce sediment,thereby causing adisaster.We propose that the sand-controlling pattern of the Danghe Reservoir is dominated by sand blocking in the outer fringe and sand fixing in the inner fringe.Applying windbreak and sand fixation to control sandy material movement into the river channel plays an important role in retarding sedimentation and extending the useful life of the Danghe Reservoir.
