浅海贝藻养殖水域沉积物再悬浮的发生机制及生态效应

沉积物再悬浮作为一个比较普遍的物理现象，对浅海生态系统污染物的生物地球化学循环具有强烈的干扰作用。本研究以我国北方重要养殖海湾——桑沟湾为研究对象，从物理、化学、生物三个角度出发，研究了沉积物再悬浮的发生过程以及再悬浮介质-沉积物的源汇转换角色及其与养殖藻类的关系，构建了波流耦合模型和再悬浮颗粒物浓度预测数学模型。主要研究结果如下： 1）桑沟湾的海湾动力比约为1.54，沉积物具有发生再悬浮的潜在动力条件；推导出波流耦合切应力的计算公式。 2）悬浮颗粒物浓度（SSC）与浊度（NTU）之间符合线性方程SSC=15.908×ln（NTU）+7.0888（n＝33，R2＝0.7209）；碎屑有机碳库是桑沟湾养殖生态系统中最大的有机碳库，占总POC库储量的81.87%。 3）沉积物再悬浮的临界切应力在0.059 N/m2左右，耦合切应力与悬浮颗粒物浓度符合方程= 238.06 SSC + 25.215（n=25，R2 = 0.7298）；最大剪切深度可达8.81 cm；桑沟湾沉积物再悬浮通量的数量级在10-5~10-6 kg·m-2·s-1之间，再悬浮临界风速约为5.51 m/s，全年约有171天沉积物处于再悬浮状态；构建了沉积物再悬浮颗粒物浓度预测数学模型。 4）桑沟湾表层沉积物总氮的含量范围313.09~1094.44µg/g，有机氮是总氮的主要形态，平均占总氮的60.86%；交换态氮是无机氮的主要形式，平均占无机氮的71.40%，交换态氮中NO3--N的含量最大；桑沟湾表层沉积物的TOC/TN比值为9.38，表明沉积物中有机质具有混合来源的特征；无机磷是桑沟湾表层沉积物中磷的主要形态，平均占总磷的73.33%，钙结合磷是无机磷的主要赋存形态；表层沉积物中潜在生物有效性磷的含量占总磷的86.54%，具有很强的释磷潜力。桑沟湾重金属的潜在生态危害指数RI约为36.17，表明重金属的潜在生态危害轻微。 5）再悬浮过程中沉积物春季表现为氮磷源，释放溶解无机氮和磷酸盐；夏、秋季表现为氮汇磷源，释放磷酸盐而吸附溶解无机氮；冬季表现为氮磷汇，吸附磷酸盐和溶解无机氮。

松辽盆地河流-三角洲体系高分辩率层序地层学、储层构形及非均质模型研究

This dissertation tries to combine the new theories of high-resolution sequence stratigraphy and reservoir architecture with fine sedimentology to form a integral theory system -"high-resolution sequence sedimentology", which can be applied widely ranging from the early petroleum exploration to the tertiary recovery stage in marine and terrestrial basin. So the west slope area in south of Songliao basin, in which, early-fine exploration have been developed, and Xingnan area of Daqing placantictine in high water-bearing and tertiary recovery stage, are selected as target areas to research and analyze. By applying high-resolution sequence stratigraphy theory as well as analysis of source area-facies, the west slope area has been divided into two source areas and three drainage systems and the following conclusions have been drawn: three high values sandstone areas, two sandstone pinchout zones and one stratigraphic pinchout overlap; the facies between Baicheng-Tongyu drainage system is frist ascertained as large-scale argillaceous filled plain facies; fine-grained braided channel-delta depositional system has been found; plane sedimentary facies and microfacies maps of different-scale sequence have been completed, and then twenty-eight lithologic traps have been detected in the east of Taobao-Zhenlai reverse fault zone; In no exploration area of the west, large-scale stratigraiphic overlap heavy oil reservoirs has first been found, which has become an important prograss. In Xingnan area, in the view of high-resolution sequence stratigraphy, the surface of unconformity (the bottom of SSC13) in P I group has been identified, and the following method and technique have been advanced: the division and correlation methods of short-scale base-level cycle sequence (SSC); the comprehensive research methods of SSC plane microfacies; the division technique of hierarchy and type of flow unit, the origin of large-scale composite sandbody and flow unit; And ,on the basis of these, 103 monosandstone bodies and 87 flow units of the third levels have been identified, and four levels of flow units model of five sandstone-bodies types have been established. Because it is a very difficult task all over the world to research architecture in subsurface monosandstone body, brings forward a series of techniques as follows: technique of researching architecture of thin interbed in subsurface monosandstone body; classification, type and liquid-resisting mechanism of thin interbed; multiple-remember vertical subsequence model of remaining oil in monosadstone body. Models of heterogeneity and architecture of thin interbed in five types of monosandstone body have been established. Applying these techniques, type and distribution of remaining oil in different types of monosandstone bodies have been predicated.