RAPID:Geomorphic Changes to the Amite River Channel and Floodbasin Induced by the August 2016 Flood in Louisiana

2016年8月路易斯安那州的长时间降雨事件是意料之外的，洪水的程度是一个不受欢迎的意外。这个RAPID项目将记录人类对阿米特河周围景观的干预可能如何影响洪水的范围和模式。具体地说，从河流和洪泛平原开采砾石导致了大面积的流动沙和河道缩短，以及随后沉积物重新迁移到柏树沼泽和三角洲地区。从该项目收集的数据将绘制出高水位和沉积物沉积的范围，以便开发有助于预测对未来强降雨事件反应的模型。该RAPID项目将支持实地工作(1)记录阿米特河对2016年8月降雨的地貌响应，(2)分析河道平台变化并与遥感图像交叉核对，(3)开发预测未来事件形态响应的数值模型。此外，本研究还将研究Amite河下游流域的洪水层沉积，以量化和绘制洪水沉积物分布。河床淤积物对盆地下游河道的堵塞可能加剧了某些地区的回水泛滥。然而，沉积物也可能滋养下游盆地的柏树沼泽，这些沼泽由于与密西西比河隔绝而缺乏沉积物，并被不断上升的海平面淹没。

The long-duration Louisiana rainfall event of August 2016 was not anticipated and the extent of flooding came as an unwelcome surprise. This RAPID project will document how human interventions on the landscape surrounding the Amite River may have influenced the extent and patterns of flooding. Specifically, mining of gravel from the river and floodplains has led to large areas of mobile sand and channel shortening as well as the subsequent remobilization of sediment into cypress swamps and delta regions. Data gathered from this project will map the extent of high water and sediment deposition in order to develop models that will help predict the response to future heavy-rainfall episodes.This RAPID project will support a field effort (1) to document the geomorphic response of the Amite River to the August 2016 rainfall, (2) to analyze channel planform changes and cross-check with remote-sensing images and (3) to develop numerical models for predicting morphological response to future events. In addition, the research will examine flood layer deposition in the lower Amite River basin to quantify and map the sediment distribution from the flood. Choking of the lower basin channel by bed-load material may have exacerbated backwater flooding in some areas. However, the sediment may also nourish the cypress-tupelo swamps in the lower basin that have been sediment-starved due to isolation from the Mississippi River and are drowning under rising sea levels.