Based upon the analysis of Cs and grain-size parameters, the total amounts of 137Cs deposition by wind and water in the Dalian Lake of Gonghe Basin, Qinghai Province are defined. The vertical profile of 137Cs in the l...Based upon the analysis of Cs and grain-size parameters, the total amounts of 137Cs deposition by wind and water in the Dalian Lake of Gonghe Basin, Qinghai Province are defined. The vertical profile of 137Cs in the lacustrine sediments exhibits three 137Cs activity maxima and one minimum. The major maximum corresponds to the global I37Cs fallout in 1963; the two secondary maxima correspond to the leakage of the Chernobyl reactor in 1986 and complete desiccation of the lake in 1994, respectively. The minimum corresponds to aeolian deposition caused by extensive reclamation in the late 1980s and early 1990s. The 137Cs data set was used to evaluate average sedimentation rate of the Dalian Lake since 1963. The deposition was stable in 1963-1986 and 1994-1998, and it was rapid during 1986?994. This preliminary study reveals that l37Cs has the same potential to trace environmental changes introduce by human interference in arid/semiarid regions as in humid regions.展开更多
本文选取共和盆地达连海湖泊沉积物为研究对象,在达连海湖心取得深度为4 m的浅井剖面,剖面底部年龄为3 800 a B.P.,以沉积物粒度和孢粉为环境代用指标,粗颗粒指示强水动力,细颗粒指示弱水动力,用AMS14C建立时间标尺,探讨了达连海晚全新...本文选取共和盆地达连海湖泊沉积物为研究对象,在达连海湖心取得深度为4 m的浅井剖面,剖面底部年龄为3 800 a B.P.,以沉积物粒度和孢粉为环境代用指标,粗颗粒指示强水动力,细颗粒指示弱水动力,用AMS14C建立时间标尺,探讨了达连海晚全新世以来的环境演变,结果表明：①3 800~2 900 a B.P.气候半干旱;②2 900~1 500 a B.P.气候干旱;③1 500~400a B.P.气候半干旱;④ 400~0 a B.P.气候干旱。展开更多
Choosing Dalian Lake as study area to implement ecological restoration project,the existing environmental problems in Dalian Lake were analyzed firstly,and then the project area in Dalian Lake was divided into wetland...Choosing Dalian Lake as study area to implement ecological restoration project,the existing environmental problems in Dalian Lake were analyzed firstly,and then the project area in Dalian Lake was divided into wetland restoration and reconstruction area,forest wetland cultivation area and shallow wetland restoration and diversity conservation area,finally corresponding restoration measures were put forward according to various function areas,so as to improve the economic output of wetland and operability and sustainability of ecological restoration project,discuss harmonious development of lake ecological restoration and regional economy,and further provide references for wetland restoration project in Dianshan Lake and water environment control in Taihu Lake basin.展开更多
基金This work was supported by the National Key Basic Research Program of China (Grant No. 0048702) the National Natural Science Founda- tion of China (Grant No. 40001001).
文摘Based upon the analysis of Cs and grain-size parameters, the total amounts of 137Cs deposition by wind and water in the Dalian Lake of Gonghe Basin, Qinghai Province are defined. The vertical profile of 137Cs in the lacustrine sediments exhibits three 137Cs activity maxima and one minimum. The major maximum corresponds to the global I37Cs fallout in 1963; the two secondary maxima correspond to the leakage of the Chernobyl reactor in 1986 and complete desiccation of the lake in 1994, respectively. The minimum corresponds to aeolian deposition caused by extensive reclamation in the late 1980s and early 1990s. The 137Cs data set was used to evaluate average sedimentation rate of the Dalian Lake since 1963. The deposition was stable in 1963-1986 and 1994-1998, and it was rapid during 1986?994. This preliminary study reveals that l37Cs has the same potential to trace environmental changes introduce by human interference in arid/semiarid regions as in humid regions.
文摘本文选取共和盆地达连海湖泊沉积物为研究对象,在达连海湖心取得深度为4 m的浅井剖面,剖面底部年龄为3 800 a B.P.,以沉积物粒度和孢粉为环境代用指标,粗颗粒指示强水动力,细颗粒指示弱水动力,用AMS14C建立时间标尺,探讨了达连海晚全新世以来的环境演变,结果表明：①3 800~2 900 a B.P.气候半干旱;②2 900~1 500 a B.P.气候干旱;③1 500~400a B.P.气候半干旱;④ 400~0 a B.P.气候干旱。
基金Supported by National Key Science and Technology Project of Water Pollution Control and Management (2008ZX-07421-001)
文摘Choosing Dalian Lake as study area to implement ecological restoration project,the existing environmental problems in Dalian Lake were analyzed firstly,and then the project area in Dalian Lake was divided into wetland restoration and reconstruction area,forest wetland cultivation area and shallow wetland restoration and diversity conservation area,finally corresponding restoration measures were put forward according to various function areas,so as to improve the economic output of wetland and operability and sustainability of ecological restoration project,discuss harmonious development of lake ecological restoration and regional economy,and further provide references for wetland restoration project in Dianshan Lake and water environment control in Taihu Lake basin.
