Dynamic characteristics and spatial-temporal distribution patterns of wetland landscapes in northeast China from 1986 to 2000 were quantitatively analyzed and studied by applying theories and methods of landscape ecol...Dynamic characteristics and spatial-temporal distribution patterns of wetland landscapes in northeast China from 1986 to 2000 were quantitatively analyzed and studied by applying theories and methods of landscape ecology,Land Change Science,remote sensing and GIS techniques.Through analyzing the dynamic spatial-temporal change degree,direction and pattern of wetland within the study area,as well as the characteristics of landscape pattern change and landscape transformation,this study got the following results:area and patch amount of wetland in northeast China showed a decreasing trend as a whole in the past 15 years.In terms of dynamic landscape changes,although the annual decrease rate of the last 5 years was 28 times more than that of the first 10 years,the first 10 years was a period with relatively more drastic patch changes of wetland landscapes in northeast China.By reviewing the overall changes of wetland landscapes in northeast China,the following characteristics were summarized:expanding in certain periods but decreasing in the overall trend,shrinking in parts but expanding from boundaries,showing high fragmentation and so on.Study on its driving forces showed that a unique spatial pattern of wetland landscapes was formed with the dual intervention of natural and artificial factors.展开更多
扎布耶湖9级大型沙砾堤记录了约30.0 ka B P以来水位退缩历史,与北部拉果错、南部塔若错的垭口沉积记录了3 个湖泊最后分离的时间。本文应用数字地面高程模型(DEM),计算了扎布耶各级沙堤对应湖面期的湖水面积、体积与含盐 量;分析了扎...扎布耶湖9级大型沙砾堤记录了约30.0 ka B P以来水位退缩历史,与北部拉果错、南部塔若错的垭口沉积记录了3 个湖泊最后分离的时间。本文应用数字地面高程模型(DEM),计算了扎布耶各级沙堤对应湖面期的湖水面积、体积与含盐 量;分析了扎布耶与拉果错、塔若错的分-合历程,计算了各时期汇流盆地总面积;参考湖泊、冰川、孢粉、天文学等多学科关于 古温度、辐射平衡的结论,得出了较为可信的计算参数。在此基础上,应用根据西藏实际情况得出的辐射平衡和水面蒸发、陆 面蒸发计算模型,代入封闭盆地水量平衡方程,得出了较Kutzbach水-能方程更可靠的降雨量-水域面积／流域面积比的非线 性方程,计算出泛湖期(9级沙堤,40.0～28.0 ka B P)该区降雨量567 mm／a,盛冰阶时降至350 mm／a以下,冰期后增至402 mm／a,随后逐步下降直至约I-1级阶地时(海拔4 421 m,3.53 ka B P)为280 mm／a(约为现代的两倍)。通过定量恢复该区 30.0 ka B P以来降水量变化,为认识西藏高原湖泊演化和古环境、古季风演化提供了定量依据。展开更多
Lakes in China have undergone considerable environmental changes during the past 50 years, e.g. lake level, water area changes, as did in the past several thousands years. The enhanced human activities, such as land r...Lakes in China have undergone considerable environmental changes during the past 50 years, e.g. lake level, water area changes, as did in the past several thousands years. The enhanced human activities, such as land reclamation, application of chemical fertilizer, land use and cover, irrigation and industrialization in the catchment etc., have played an important role on the recent decades＇ changes of these lakes, although constrained to a great extent by the natural impact. Comparative study on variations of lake volume （water level, depth and area） in the eastern and western lake regions of China during 1950-2000 indicated that, lake volume in the eastern region had approximately undergone a two-stage change, i.e. a dramatic decrease from the 1950s to 1970s, and a continuous increase between the 1980s and 1990s; while, in the western region, lake volume had been decreasing nearly all the time. Further studies on some typical lakes concluded that, climatic change was a primary factor for the variations of lake volume during the past 50 years, although human activities showed important effect.展开更多
基金Supported by Talents Education Program of Beijing Municipal Universities (PHR201008346)D Program of Talents Training of Beijing City (20081D0502200244)~~
文摘Dynamic characteristics and spatial-temporal distribution patterns of wetland landscapes in northeast China from 1986 to 2000 were quantitatively analyzed and studied by applying theories and methods of landscape ecology,Land Change Science,remote sensing and GIS techniques.Through analyzing the dynamic spatial-temporal change degree,direction and pattern of wetland within the study area,as well as the characteristics of landscape pattern change and landscape transformation,this study got the following results:area and patch amount of wetland in northeast China showed a decreasing trend as a whole in the past 15 years.In terms of dynamic landscape changes,although the annual decrease rate of the last 5 years was 28 times more than that of the first 10 years,the first 10 years was a period with relatively more drastic patch changes of wetland landscapes in northeast China.By reviewing the overall changes of wetland landscapes in northeast China,the following characteristics were summarized:expanding in certain periods but decreasing in the overall trend,shrinking in parts but expanding from boundaries,showing high fragmentation and so on.Study on its driving forces showed that a unique spatial pattern of wetland landscapes was formed with the dual intervention of natural and artificial factors.
文摘扎布耶湖9级大型沙砾堤记录了约30.0 ka B P以来水位退缩历史,与北部拉果错、南部塔若错的垭口沉积记录了3 个湖泊最后分离的时间。本文应用数字地面高程模型(DEM),计算了扎布耶各级沙堤对应湖面期的湖水面积、体积与含盐 量;分析了扎布耶与拉果错、塔若错的分-合历程,计算了各时期汇流盆地总面积;参考湖泊、冰川、孢粉、天文学等多学科关于 古温度、辐射平衡的结论,得出了较为可信的计算参数。在此基础上,应用根据西藏实际情况得出的辐射平衡和水面蒸发、陆 面蒸发计算模型,代入封闭盆地水量平衡方程,得出了较Kutzbach水-能方程更可靠的降雨量-水域面积／流域面积比的非线 性方程,计算出泛湖期(9级沙堤,40.0～28.0 ka B P)该区降雨量567 mm／a,盛冰阶时降至350 mm／a以下,冰期后增至402 mm／a,随后逐步下降直至约I-1级阶地时(海拔4 421 m,3.53 ka B P)为280 mm／a(约为现代的两倍)。通过定量恢复该区 30.0 ka B P以来降水量变化,为认识西藏高原湖泊演化和古环境、古季风演化提供了定量依据。
基金National Natural Science Foundation of China, No.40771197 No.40472085 The Natural Science Foundation of Jiangsu Province, No.BK2007534 We are indebted to Prof. Yu Ge and Prof. Wang Sumin for their continuous supports and encouragements to this study.
文摘Lakes in China have undergone considerable environmental changes during the past 50 years, e.g. lake level, water area changes, as did in the past several thousands years. The enhanced human activities, such as land reclamation, application of chemical fertilizer, land use and cover, irrigation and industrialization in the catchment etc., have played an important role on the recent decades＇ changes of these lakes, although constrained to a great extent by the natural impact. Comparative study on variations of lake volume （water level, depth and area） in the eastern and western lake regions of China during 1950-2000 indicated that, lake volume in the eastern region had approximately undergone a two-stage change, i.e. a dramatic decrease from the 1950s to 1970s, and a continuous increase between the 1980s and 1990s; while, in the western region, lake volume had been decreasing nearly all the time. Further studies on some typical lakes concluded that, climatic change was a primary factor for the variations of lake volume during the past 50 years, although human activities showed important effect.
