摘要
通过对乌伦古湖2个沉积柱样的210Pb和137Cs剖面的观测,运用210Pb过剩法和137Cs时标法估算了近几十年来的平均沉积速率。研究结果表明:210Pb过剩法的CRS模式测定的沉积速率的变化范围为0.018~0.071 g/(cm2.a),137Cs时标法测定沉积速率的变化范围为0.034~0.060 g/(cm2.a),两者具有较高的一致性。20世纪60年代以前,人类活动对本区影响相对较小,湖泊的沉积速率主要受自然因素的影响;20世纪60年代以后,随着乌伦古河中、下游农业的发展和调水工程的实现,人类活动逐渐成为主导湖泊演化的因素,从而影响乌伦古湖沉积速率。
Using 210Pb and 137Cs dating methods,based on observation on profiles of two sediment core samples,the average deposition rate of the Wulungu lake in recent decades is determinated. Sedimentation rates of 210Pb（CRS model） determination range from 0.018 to 0.071 g/（cm2·a） and sedimentation rates of 137Cs determination range from 0.034 to 0.060 g/（cm2·a）.The results showed a relatively good agreement with each other.It is indicated that natural factors have much more influence than human activities on the sedimentation rate of Wulungu lake before 1960s.With the development of agriculture and implementation of water transfer project at the middle and lower reaches of Wulungu River,human activities gradually become the dominant factor in the evolution of lakes,thus affecting the sedimentation rate of Wulungu lake after 1960s.
出处
《现代地质》
CAS
CSCD
北大核心
2010年第2期377-382,共6页
Geoscience
基金
国家自然科学基金项目(40802084
40671193)
江苏省高校自然科学基金项目(08KJD170006)
