Techniques for GIS modeling of coastal dunes
Techniques for GIS modeling of coastal dunes
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DOI：
10.1016/s0169-555x(02)00186-1
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发表时间：
2002-11-01
期刊：
影响因子：
3.9
通讯作者：
Colby, JD
中科院分区：
文献类型：
--
作者：
Andrews, BD;Gares, PA;Colby, JD
由于大多数沿海沙丘系统的动态性质，沿海沙丘对沿海科学家提出了一个独特的问题。由于风暴产生的风和浪，沿海沙丘可以迅速而频繁地改变形状。盛行风可以在整个沙丘系统中输送大量的沙子。通过1997年5月至1998年5月为期一年的一系列每月实地调查，对北卡罗来纳州外河岸150 × 40英寸场地的地形和体积变化进行了评估。本文讨论了用于数据采集和分析的地理信息系统（GIS）方法，并提出了一种方法来测量三维沙丘形态动力学使用2-D和3-D GIS。它可以作为其他沿海研究人员谁可能有有限的测量或地理信息系统的经验指南。讨论了采样程序、数据密度和网格单元尺寸等问题。该方法遵循的结果是生成内插高程值网格，可以以多种方式表示，包括地形图、数字高程模型（DEM）或沙丘系统的二维横截面。从1997年5月的格网中减去1998年5月测量的格网，以获得高程变化信息，进而可以用图形表示。分析结果表明，在1年期间的体积变化主要是由侵蚀沿着向海面的沙丘。每月的调查表明，这种侵蚀是1998年1月和2月两次东北风暴造成的。体积的损失部分地被堆积到前脊后部所补偿，主要是在井喷有利于沉积物从海滩风成搬运的地方。这意味着沙丘系统由于风暴活动正在迅速侵蚀。它还表明，存在一种机制，可以抵消通过风成作用进入沙丘系统而造成的部分体积损失。(C)2002 Elsevier Science B. V.保留所有权利。
Coastal dunes present a unique problem to coastal scientists because of the dynamic nature of most coastal dune systems. Coastal dunes can change shape quickly and frequently due to storm-generated winds and waves. Prevailing winds can transport significant amounts of sand throughout the dune system. Topographic and volumetric changes in a 150 X 40 in site on the Outer Banks of North Carolina were assessed through a series of monthly field surveys conducted over a I-year period from May 1997 to May 1998. This paper discusses the Geographic Information System (GIS) methodology used for data acquisition and analysis and presents one methodology developed to measure 3-D dune morphodynamics using a 2-D and 3-D GIS. It serves as a guide for other coastal researchers who may have limited surveying or GIS experience. Issues concerning sampling routine, data density and grid cell size are discussed. The methodology followed results in the production of a grid of interpolated elevation values that can be represented in a variety of ways, including as topographic maps, digital elevation models (DEM) or two-dimensional cross-sections of the dune system. The grid from the May 1998 survey is subtracted from the May 1997 grid to obtain elevation change information that in turn can be represented graphically. The results of the analysis show that volumetric change over the 1-year period was dominated by erosion along the seaward face of the dune. The monthly surveys show that this erosion was the result of two northeasters in January and February 1998. The loss of volume is partially compensated for by accumulation to the rear of the foredume ridge, primarily in locations where blowouts facilitate aeolian transport of sediment from the beach. The implication is that the dune system is eroding rapidly due to storm activity. it also suggests that there is a mechanism for offsetting some of the volumetric loss through aeolian transport into the dune system. (C) 2002 Elsevier Science B.V. All rights reserved.