Morphometric analysis of sinkholes in a karst coastal area of southern Apulia (Italy)
Morphometric analysis of sinkholes in a karst coastal area of southern Apulia (Italy)
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DOI：
10.1007/s12665-013-2297-z
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发表时间：
2013-11-01
影响因子：
2.8
通讯作者：
Pepe, M.
中科院分区：
文献类型：
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作者：
Basso, A.;Bruno, E.;Pepe, M.
萨伦托是阿普利亚地区（意大利东南部）的南部，是一个狭窄而细长的碳酸盐岩半岛，海岸线普遍较低，局部被高大的岩石悬崖打断。狭长的低海岸以典型的喀斯特地貌为特征，由塌陷的陷坑组成。正如在世界上许多其他喀斯特海岸环境中所观察到的那样，在沿海地区，天坑的发展可能特别严重，在那里，自然和人为过程都有助于加速碳酸盐岩的溶解和沉降过程，甚至影响海岸线的演变。在之前的研究中，对Torre Castiglione （Taranto省）的陷坑的主要特征进行了调查和描述，并制作了初步的敏感性图，根据本文中更新的数据和阐述，我们对已确定的陷坑样本进行了详细的形态计量学分析。本研究考虑了通常用于天坑表征的主要形态测量参数：天坑的形状、最大和最小轴的方位角和长度、深度、延伸率以及与海岸线的距离。每一个都被描述为单独的参数，并与其他参数相结合，试图确定控制该地区天坑发展的主要因素，以及它们的演变。对于后一个方面，除了对Torre Castiglione陷坑样品进行简单的形态测量外，我们还重点研究了陷坑的分布和形状与构造不连续之间可能存在的关系。为了研究这一问题，本研究进行了三个阶段的分析：对陷落孔边界裂缝进行现场测量，对拉长陷落孔的长轴方位角进行现场测量，并将先前描述的集与主要区域地质构造的走向进行比较。研究结果表明，除了主要的区域不连续体系与长形陷落孔的长轴重合外，陷落孔的发育和演化对海岸进水口和海湾的形成有明显的控制作用。最后，本文提出的方法可以应用于其他喀斯特海岸天坑易发地区，以获得关于海岸天坑成因和演化的新知识，并正确评价其对人为环境的危害。
Salento, the southern portion of Apulia region (SE Italy), is a narrow and elongated peninsula in carbonate rocks, with prevailing low coastlines, locally interrupted by high rock cliffs. The long stretches of low coasts are marked by typical karst landforms consisting of collapse sinkholes. As observed in many other karst coastal settings worldwide, development of sinkholes may be particularly severe along the coasts, where both natural and anthropogenic processes contribute to accelerate the dissolution of carbonate rocks and subsidence processes, even influencing the coastline evolution. Following a previous study, where the main features of sinkholes at Torre Castiglione (Taranto province) were investigated and described, and a preliminary susceptibility map produced, at the light of updated data and elaborations in the present paper we perform a detailed morphometric analysis on the sample of identified sinkholes. The main morphometric parameters generally used for sinkhole characterization have been considered in this study: shape of the sinkhole, azimuth and length of maximum and minimum axes, depth, elongation ratio, and distance from the shorelines. Each of them is described, both as individual parameter and in conjunction with the others, in the attempt to identify the main factors controlling development of sinkholes in the area, and their evolution as well. With regard to this latter aspect, beside simple morphometry of the sample of sinkholes at Torre Castiglione, we also focused our attention on the likely relationships existing between distribution and shape of the sinkholes and the tectonic discontinuities. To investigate the matter, a three-stage analysis has been carried out in this study by means of: field measurements of the fractures bounding the sinkholes, field measurement of the long axes azimuth of the elongated sinkholes, comparison of the previously described sets with the strikes of the main regional geological structures. The obtained results show, in addition to the coincidence of the main regional discontinuity systems with the major axis of elongated sinkholes, a clear control exerted by development and evolution of the sinkholes on the formation of coastal inlets and bays. Eventually, the approach here presented may be applied in other karst coastal sinkhole-prone areas, to gain new knowledge on the genesis and evolution of coastal sinkholes, and to properly evaluate the hazard they pose to the anthropogenic environment.