After transformation of the data model and processing of the thematic mapping elements , the paper constructs a mapping system of the seabed sediment thematic digital map 经过对数据模型的转换以及专题制图要素的处理，建立了海洋底质专题数字图成图系统。
The experiment results show the validity of system scheme and accuracy of real time algorithms . it is also proved that this device is suitable for different depth and bottom material 实验结果充分验证了方案的正确性以及实时算法的准确性，体现了该实验装置对不同水深、不同的底质等复杂环境的适应性。
The design principle of the seabed sediment thematic digital map is researched and the production of seabed sediment thematic digital map based on seabed sediment table data is studied in this paper firstly 摘要本文研究海洋底质专题数字图的设计原则以及如何利用海洋底质调查表格数据生成海洋底质专题数字图。
The study shows that the substrate and other physical variables ( stream mean width , depth and velocity ) in changjiang river system from 1st to 6th order streams present a continuous gradient of physical conditions 研充表明阊江河一至六级支流平均宽度、深度、流速及底质组成和颗粒大小等物理参数具有明显的梯度变化。
The shrimps ' consumption of oxygen was the most important factor at the final culture period in industrial culture , however , the oxygen consumption of sediment was the most significant factor at the final culture in soiled pond culture 在对虾的工厂化养殖中，对虾耗氧是最大的耗氧因子；而土池养殖后期，底质耗氧是主要耗氧因子。
Potential ecological risk index was applied to assessing the sediments of yaer lake , hubei province before and after dredging , which can provide scientific basis for the decision making and management of environment agencies 摘要通过对鸭儿湖底质在工程清淤前后的潜在生态风险评价，为环境保护管理部门的决策和管理提供科学的依据。
Improved substrate : activated sludge to improve the bottom of the anaerobic environment , greatly reduce the hydrogen sulfide produced , the lower organic oxygen consumption and improve dissolved oxygen , water conditioning stability ph value 改良底质：活化污泥，改善池底的厌氧环境，大大减少硫化氢产生，降低有机物耗氧量，提高溶氧，调节稳定水体ph值。
The authors analyzed the water quality and bottom sediment quality near the zhuyuan and bailonggang sewage outfalls and compared them with those from the large waters of the changjiang estuary 摘要本文分析了上海竹园和白龙港两处污水排放口附近水域的水质和底质现状，并与长江口大水域进行比较，研究了城市污水排放对长江口局部水域造成的污染和对水域富营养化的影响。
By means of monitoring sediments of the grand canal ( hangzhou section ) , the correlativity between organic matter and eight heavy metals in sediment was discussed . then the easy sinking sequence of the eight metals was arranged 通过对京杭大运河(杭州段)底质的监测，探讨了底质有机质与8种重金属元素的相关性，并对其成因作出了解释，得出了8种重金属在运河(杭州段)底质中易积累的顺序。
The current situation of sediment pollution in li canal was introduced in this article . with individual and nemerow index evaluation methods , the sediment pollution by heavy metals was analyzed systematically , and pollution control measures were put forward 介绍了淮安市里运河底质污染的现状,运用单项和内梅罗指数评价方法系统地对里运河底质中重金属污染状况进行了分析研究,并提出了污染防治措施。
