Abstract The morphological changes of spits and inlets of the Chilika lagoon, the largest brackish water tropical coastal lagoon in Asia, are investigated using real-time kinematic GPS observation and numerical models during 2009–2013. The seasonal/interannual variations of the spit and inlet cross-sectional areas with varying widths and depths are recorded in association with different physical processes. The results show significant changes in spit morphology: particularly, the south spit accreted continuously, while the middle and north spits eroded. The cross-sectional depth of inlets becomes narrower and deeper during summer and winter seasons, while they are wider and shallower during the monsoon. The model results show that sediment transport rate is larger during monsoon and summer, while it is relatively less during the winter. Alongshore, sediment transport is predominantly northward throughout the study period. The result shows that gain/loss of the spits and closure/opening of inlets are significantly controlled by the high wave power, longshore drifts, and river discharge. The study demonstrates that the combined use of observational and numerical models is very effective to understand the changes of spit and inlet morphology and their impact on ecological conditions of the lagoon environment.

中文翻译：

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热带沿海泻湖的喷口和入口形态动力学

摘要 利用实时运动学 GPS 观测和数值模型研究了 2009-2013 年亚洲最大的咸水热带沿海泻湖 Chilika 泻湖的喷口和入口的形态变化。具有不同宽度和深度的吐痰和入口横截面面积的季节性/年际变化与不同的物理过程有关。结果表明，沙嘴形态发生了显着变化，尤其是南沙嘴不断增生，中、北沙嘴被侵蚀。入海口横断面深度在夏季和冬季变窄和变深，而在季风期间变宽和变浅。模型结果表明，季风和夏季输沙速率较大，冬季输沙速率相对较小。近岸，在整个研究期间，沉积物主要向北迁移。结果表明，高波功率、沿岸漂流和河流流量显着控制了喷口的得/失和入口的关闭/打开。研究表明，观测模型和数值模型的结合使用对于了解吐口和入口形态的变化及其对泻湖环境生态条件的影响非常有效。