关键词: 洱海, 湖泊沉积, 环境指标, 人类活动

Abstract: Based on the results of lacustrine environmental proxies from Erhai Lake, Yunnan Province,the lake responses of human activities recorded by lacustrine sediment in the catchment have been discussed. The Erhai Core of 310 cm long was sampled in the center of Erhai Lake with the water depth of 4 6 m. The modern sedimentation rate by 137 Cs test is ≤0 25 mm/a, which is consistent with the average sedimentation rate of the upper 100 cm with radio carbon years of 4 473±40 a BP at the bottom. Because the surface soil are rich in magnetic materials. The environmental proxy of magnetic susceptibility was obviously influenced by the way of land use especially the occurrence of farming agriculture. So the sharp increase of magnetic susceptibility at 100 cm with ca 4 500 a BP means the intensification of human activities especially the occurrence of farming agriculture. The time of the ancient farming occurrence recorded by the lake sediment is older than the archaeological relics with the radio carbon years of ca 3 800 a BP in Baiyang Village near the catchment of Erhai Lake. The surface soil is rich with elements of Fe and Al in the catchment of Erhai Lake. So the changes of chemical elements contents （Fe, Al） had close relationship with surface water soil erosion which controlled by the human activities in the catchment. The huaman relics of Malong in the catchment of Erhai Lake with the age of 34003100aBP which corresponding with the sharp increase of element Fe and Al. The lower content of Fe, Al in the upper 15 cm may be affected by the aquatic vegetation which can absorb some chemical elements including Fe and Al. The variations of pigments indicated the process of lake eutrophication induced by human activities. The first and second peaks of pigments correspond with the time of Malong Relics and the first population summit of Yunnan Province. The obvious increase of pigments was occurred in 1100 AD with the large population migrated to Yunnan. The proxies of lacustrine magnetic susceptibility, chemical elements and pigments are the efficient parameters to demonstrate the human activities in the catchment, which has important significance in the research on archaeology.

Key words: Erhai Lake, Lacustrine sediments, Evironmental proxies, Human activities