Reconstruction of the Hydrological Cycle in the Nam Co Area Utilizing Sediment Records and Cllimate Models

本文对西藏纳木错地区的水文循环进行了时空评价，以定量重建过去亚洲季风变化及其对湖泊泥沙动力学的影响。已经进行的海底剖面和试点取心提供了对湖泊沉积历史的第一次了解。此外，地震和沉积地层学（沉积岩石学、无机/有机化学）可以识别沉积制度的变化。此外，还进行了实验和模拟工作，以重建湖泊的同位素含量。因此，采用自底向上的多代理方法，包括特定陆地和水生生物标志物的同位素比值，可以直接重建湖泊水和降水的同位素含量，而不受环境条件的影响。一种互补的自上而下的方法侧重于区域古气候模拟来重建湖水的同位素含量。所有这些方法的紧密结合可以定量地理解和重建纳木错流域降水和蒸发通量的变化及其与沉积体系的相互作用。综合这一联合研究计划的合作伙伴提供的辅助代理数据以及碳定年将有助于解释有关晚第四纪气候变化的地方和全球方面的结果。

The hydrological cycle in the Nam Co area, Central Tibet is spatio-temporally assessed in order to quantitatively reconstruct the past Asian Monsoon variability and its influence on lake sediment dynamics. The already conducted sub bottom profiling and pilot coring provide a first insight into the sedimentary history of the lake. Furthermore, seismic and sediment stratigraphy (sedimentary petrology, inorganic/organic chemistry) allows identifying changes in the sedimentary regime. Additionally experimental and modelling work is carried out to reconstruct the isotopic content of the lake. Therefore, in a bottom-up multi proxy approach including isotope ratios of specific terrestrial and aquatic biomarkers the isotopic content of the lake water and precipitation is reconstructed directly and independently from environmental conditions. A complementing top-down approach focussing on regional palaeoclimate simulations to reconstruct the isotopic content of the lake water is initialised. Tight integration of all these methods allows a quantitative understanding and reconstruction of precipitation and evaporation flux changes as well as their interaction with the sedimentary system of the Nam Co catchment. A synthesis with supporting proxy data from the partners of this joint research initiative as well as C dating will serve to interpret the results with regard to local and global aspects of Late Quaternary climate change.