Lidar quantification of bank erosion in Blue Earth County, Minnesota.
Lidar quantification of bank erosion in Blue Earth County, Minnesota.
复制标题
明尼苏达州蓝土县河岸侵蚀的激光雷达量化。
DOI：
10.2134/jeq2011.0181
复制
发表时间：
2012
影响因子：
2.4
通讯作者：
David P. Thoma
中科院分区：
文献类型：
--
作者：
Andrew C. Kessler;Satish C Gupta;H. Dolliver;David P. Thoma
近年来，沉积物和磷(P)从明尼苏达河流域运输到密西西比河上游的佩平湖引起了人们的广泛关注。然而，缺乏沉积物和河岸对-à-vis高地和沟壑的磷贡献程度的数据。利用2005年和2009年采集的两个光探测和测距（激光雷达）数据集，对明尼苏达州蓝土县河岸的沉积物和相关磷损失进行了量化研究。在过去的4年里，由于河岸侵蚀，河谷的体积变化达到了171万米。体积变化紧跟这一趋势：蓝土河、明尼苏达河、勒苏尔河、Maple河、Watonwan河、大科布河、珀奇溪、小科布河。利用代表三种母质的37个河岸样本的细沉积物含量（粉砂+粘土）和体积密度，我们估计了蓝地球和勒苏尔河河口测量的悬浮固体总量的48%至79%的河岸侵蚀贡献。相应的可溶性磷和全磷贡献率分别为0.13% ~ 0.20%和40% ~ 49%。虽然高河岸（约3米高）占总长度的33%和总面积的63%，但它们占河谷体积变化的75%。我们的结论是，多时段激光雷达数据集对于估计大尺度上的河岸侵蚀和相关的P贡献是有用的，对于传统测量设备不容易接近的河岸也是有用的。
Sediment and phosphorus (P) transport from the Minnesota River Basin to Lake Pepin on the upper Mississippi River has garnered much attention in recent years. However, there is lack of data on the extent of sediment and P contributions from riverbanks vis-à-vis uplands and ravines. Using two light detection and ranging (lidar) data sets taken in 2005 and 2009, a study was undertaken to quantify sediment and associated P losses from riverbanks in Blue Earth County, Minnesota. Volume change in river valleys as a result of bank erosion amounted to 1.71 million m over 4 yr. Volume change closely followed the trend: the Blue Earth River > the Minnesota River at the county's northern edge > the Le Sueur River > the Maple River > the Watonwan River > the Big Cobb River > Perch Creek > Little Cobb River. Using fine sediment content (silt + clay) and bulk density of 37 bank samples representing three parent materials, we estimate bank erosion contributions of 48 to 79% of the measured total suspended solids at the mouth of the Blue Earth and the Le Sueur rivers. Corresponding soluble P and total P contributions ranged from 0.13 to 0.20% and 40 to 49%, respectively. Although tall banks (>3 m high) accounted for 33% of the total length and 63% of the total area, they accounted for 75% of the volume change in river valleys. We conclude that multitemporal lidar data sets are useful in estimating bank erosion and associated P contributions over large scales, and for riverbanks that are not readily accessible for conventional surveying equipment.