Modern Sedimentary Characteristics and Environmental Indication Significance of the Cibi Lake

Based on the particle size test results of 36 surface sediment samples from the Cibi Lake, the spatial distribution characteristics and rules of components were discussed by the combination of natural geographical factors with statistical analysis methods in the basin, which provides scientific evidence and basic data for the study of paleoclimate environment in this region. The results show that:\mathrm{①} The samples mainly include clay, silty and sand, among which silty is the main type in the study area and has the widest distribution due to the disturbance caused by groundwater recharge without obvious spatial variation law;\mathrm{②} The clay distribution is somewhat smaller, and its locality affected by the slope alluvial fan is in the northwest and near the center of the lake, where the sedimentary environment is stable and is the best selected location for the borehole core so that the reconstruction of the paleoclimate environment can be carried out;\mathrm{③} Sand is mainly distributed in the southwest corner and near the north shore of the lake, which is influenced by the rivers entering the lake and human activities, and these two locations have a great influence on the source of surface sediment. Therefore, the management of the north and southwest regions should be strengthened to prevent a large number of pollutants from entering the lake;\mathrm{④} The grain size frequency curve shows that the sediments include suspended and saltant components. Besides the formation by their own biochemistry, other materials come from the aeolian sediments in the basin, and the coarse particles transported over a long distance have a great impact on the grain size components. Section CB-1 indicates that transport process and distribution are significantly affected by the southwest monsoon and more attention should be paid to the prevention and control of pollution at the river inlet and upwind area.