| 摘要: |
| 为了更精确地探讨河控级别和水位变化对湖泊河控三角洲砂体展布距离的影响,以鄱阳湖赣江三角洲和沾化凹陷孤北洼陷为主要研究对象,通过对典型河控三角洲高精度卫星照片的统计分析以及地下研究区三角洲的精细解剖,提出两个表示河控级别的参数,明确三角洲延伸距离与海拔的关系以及沉积水深与三角洲前缘朵叶体长度、坡角的关系,阐明河控级别和水位变化对三角洲展布距离的影响。结果表明:三角洲分叉级别与分流河道累积数量关系式中的斜率和三角洲的展开角度是描述河控级别的两个主要参数,斜率和展开角度越小,河控级别越高,河流作用越强,三角洲展布距离越大;随着河控三角洲向前延伸,其海拔高度呈现对数性减小,直到前三角洲的高度,三角洲前缘坡角呈现先增大后减小的趋势;随着沉积水深的增大,每一期三角洲朵叶体前积层的水平长度呈线性增大,斜坡角呈对数性增大直至休止角;水位的变化ΔH与三角洲展布距离的变化ΔL主要受控于湖盆的坡角α以及三角洲前缘斜坡角β,并满足ΔL=1〖〗tan α-1〖〗tan βΔH。 |
| 关键词: 河控三角洲 展布距离 河控级别 水位变化 |
| DOI：10.3969/j.issn.1673-5005.2019.04.002 |
| 分类号::TE 121 |
| 文献标识码:A |
| 基金项目:国家科技重大专项(2011ZX05009-002)；中央高校基本科研业务费专项(15CX06010A);中国博士后科学基金项目(2019M650998) |
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| Effects of river dominated level and water level fluctuations on distribution distance of a lake, river dominated delta |
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ZHANG Yang1, LU Fengming1, QIU Longwei2, JIANG Jiguo3, GUO Zhiqiao1, DAI Li3
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(1.Dagang Oilfield Company, PetroChina, Tianjin 300280, China;2.School of Geosciences in China University of Petroleum(East China), Qingdao 266580, China;3.Zhuangxi Oil Production Plant, Shengli Oilfield Company, SINOPEC, Dongying 257000, China)
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| Abstract: |
| Taking the Poyang Lake Ganjiang Delta and Gubei Depression as main study objects, this study focuses on the distribution distance of a lake river dominated delta affected by river and water level fluctuations.Using statistical analysis of typical river dominated deltas satellite photos and fine anatomic of underground work area delta, this paper first used two parameters to express river dominated level, then illustrated the relationship between delta distribution distance and altitude, sediment depth and length, and slope angel of delta front lobe.Lastly, the effects of river dominated level and water level fluctuations on the distribution distance of delta are clarified. The results show that there are two parameters to express river dominated level:the slope in relationship type of delta split level and cumulative quantity of distributary channel, and the delta 's opening angel. The smaller the slope and opening angel, the larger the river dominated level and the delta 's distribution distance. With the extension of the delta, its altitude decreases logarithmically decrease up to the prodelta 's height. The slope angle of delta front first increases and then decreases subsequently. With the increase of sediment depth, the length of every delta lobe linearly increases, and the slope angle increases logarithmically until the suspension angle. Water level fluctuation ΔH and delta distribution change ΔL are mainly controlled by basins slope α and delta front slope β and ΔL=1〖〗tan α-1〖〗tan βΔH. |
| Key words: river dominated delta distribution distance river dominated level water level fluctuation |
