Changes in the Sediment Regime and Channel Morphology of the Lower Mississippi River

在上个世纪，许多河道都有了很大的改装。为了控制洪水和改善通航，修建了堤坝、堤坝、护岸、曲折断流和水库。这些改造严重改变了河道的形态，改变了侵蚀和沉积的模式。然而，这些变化的确切特征并没有很好的记录。密西西比河下游是改造最严重的河流之一。该项目将使用历史水文测量地图来测量上个世纪以来密西西比河下游河道形态和泥沙状况的变化。该项目收集的数据还将用于分析人类和自然力量改变水流和沉积模式的程度，这些数据将为更详细地研究大河流的蜿蜒过程提供基础。这一项目将在多个层面产生有益的成果。它将提供一个特定于密西西比河下游的数据集。这些数据将对研究这条河流的学者和必须直接与洪水控制和导航系统打交道的从业人员提供宝贵的帮助。该项目得出的结论也将具有更广泛的意义，为河流水流和泥沙输送对人类改变和自然条件变化做出反应的过程提供了新的见解。

Many stream channels have been modified significantly in the last century. Dams, levees, revetments, meander cut-offs, and reservoirs have been constructed to control floods and to improve navigation. These modifications have severely altered the morphology of the channels and have changed the patterns of erosion and sedimentation. The exact character of these changes is not well documented, however. Among the most drastically modified streams is the lower Mississippi River. This project will use historic hydrographic survey maps to measure changes in channel morphology and sediment regimes on the lower Mississippi over the last century. The data gathered in this project will also be used to analyze the degree to which human versus natural forces have altered flows and depositional patterns, and they will provide a basis for more detailed examination of the processes of meandering in large streams. This project will yield useful results at a number of levels. It will provide a data set specific to the lower Mississippi River. These data will be valuable aids to scholars studying this stream and to practitioners who must deal directly with flood control and navigation systems. The conclusions drawn in this project will also have broader significance, offering new insights into the processes by which stream flow and sediment transport respond to modification by humans and to changes in natural conditions.