【作者】 赵广明；

【导师】 李广雪； 叶思源；

【作者基本信息】 中国海洋大学 ， 海洋地质， 2009， 硕士

【摘要】 黄河三角洲湿地是世界上最年轻、最具特色的湿地,湿地类型比较丰富。本文收集了8个时期的黄河三角洲遥感数据,旨在揭示黄河三角洲1976年以来海岸线冲淤变化规律和河口保护区生境演替规律。目前黄河三角洲湿地受气候变化、自然灾害、黄河断流、人类活动、海平面上升、海岸侵蚀、地下海水入侵等影响,生态环境比较脆弱。为此国家自2002年实施的黄河调水调沙工程就是借助自然的力量,依靠大型水库的人工调节,制造可冲刷下游河床的“人造洪水”,改变主河槽的淤塞状态,给河口湿地带来新的生机,是一项伟大的湿地修复工程。本文在对黄河三角洲野外调查的基础上,结合黄河变迁等历史资料,将现代黄河三角洲表层沉积物沉积环境分为7个区,针对1区清水沟流路,将下伏地层沉积物沉积环境进一步划分为5个亚区,并通过3个剖面揭示了河口保护区湿地沉积体系由不同时代和不同沉积相形成的沉积物相互交错迭置,沉积相态演替较复杂的垂向沉积特征。TM 3(R)-4(G)-2(B)的波段组合方式有助于提取黄河三角洲海岸线,TM 4(R)-5(G)-3(B)波段组合方式有助于提取黄河三角洲湿地保护区湿地类型信息。1976年-2006年,黄河三角洲北部刁口流路低潮线以上面积减少423km~2,三角洲南部海岸面积减少65km~2,清水沟流路面积增加296km~2。距黄河水的远近,土壤盐分含量是控制河口湿地保护区植被宏观分布的重要因素,黄河断流和黄河调水调沙工程对河口保护区湿地类型的变化影响很大。2007年第六次调水调沙期间,河槽受到冲刷,过流能力增大,河槽形态得到调整,河势向有利的方向发展。通过实测资料对比估算黄河下游河道冲刷的临界流量为2600m~3/s。2007年6月30日-2007年7月5日,大约有5.6×107m~3泥沙,1.12×10~9 Kg沙子流入湿地,大大改善了湿地的生态环境。但到2007年10月底,Q4和C2断面河道淤积情况较调水调沙前略有改善,Q7断面已全面回淤,恢复到原来的水平。更多还原

【Abstract】 Wetland of the Yellow River delta is the youngest and the most characterful wetland in the world. The type of wetland is quite rich, and the area change is unstable.We have collected 8 time of Yellow River delta remote sensing data, in order to identify alluvion and erosion of Yellow River delta from 1976 as well as entironment succession in estuary reserve. At present the Yellow River delta wetland is affected by the climatic change, the natural disaster, drying up of Yellow River, the human’s activity, sea level rising, coastal erosion, underground sea water invasion, the ecological environment is quite frail. So governmental entities have carried out Yellow River water and sediment regulation from 2002 which depends on the power of nature in order to erode the riverbed ,and it brings the new vitality for the estuary mouth wetland which is an item of great wetland repair project..Based on fieldwork in Yellow River delta and historical data of Yellow River variance, the modern Yellow River delta surface layer deposit environment is divided into 7 deposition areas. In view of 1 deposition area, the further division is 5 sub-areas.We realize that Yellow River mouth wetland deposition system through 3 section planes is composed of deposition of the different time ,and the deposition succession is complex.The TM 3(R)-4(G)-2(B) band combination mode is helpful to obtain the Yellow River delta coastline, the TM 4(R)-5(G)-3(B) band combination mode is helpful to obtain the typy of the Yellow River delta wetland.From 1976 to 2006, the area of Diaokou promontory in north of the Yellow River delta reduced 423km~2 above the low-tidal level, the area of south seacoast reduces 65km~2, and Qingshuigou promontory increased 296km~2.The distance to the Yellow River water and the soil salinity content dominated macroscopic distribution of the estuary wetland protectorate vegetation.Drying up of Yellow River and Yellow River water and sediment regulation play an important role in the typy of the Yellow River delta change.Because of the sixth Yellow River water and sediment regulation in 2007, the riverbed was scoured, the flood carrying capactity was enlarged, the shape of riverbed was adjusted, and the river developed well.In contrast to the actual data ,we estimate that 2600m~3/s is the critical discharge when the Yellow River downstream river course is scoured.from June 30 to July 5 in 2007,about 5.6×107m~3 of bedload and 1.12×10~9 Kg of sand inflooded wetland,which improved the wetland ecological environment greatly.But to at the end of October, 2007, river course siltation situation of Q4 and the C2 cross section improved less slightly than that of water and sediment regulation before, and the Q7 cross section which have already comprehensive backsilted, returned to the original level.更多还原