對威尼斯古城中心所做的高分辨率衛(wèi)星監(jiān)測,,為自然沉降和人類活動對該城市過去20年的土地運動的相對貢獻做出了估計。這些發(fā)現(xiàn)發(fā)表在本期Scientific Reports上,。
Luigi Tosi,、Pietro Teatini和Tazio Strozzi設計了一項研究,來區(qū)分威尼斯的自然土地沉降與人類活動誘導的土地運動,。抽地下水所產生的影響(這種影響歷史上對土地沉降有貢獻)幾十年前停止了,。然而,由于最近發(fā)生的海平面變化(這種變化增加了該城市的脆弱性),,關于影響威尼斯市中心的土地沉降的可靠,、詳盡的知識仍然非常重要。作者利用兩種不同類型的高分辨率衛(wèi)星監(jiān)測(這種監(jiān)測能顯示各個建筑物的微小運動)研究了該市市中心的長期和短期位移,。
該研究表明,,自然沉降正在以每年大約0.8-1毫米的速度在威尼斯發(fā)生,而人類活動目前對土地運動的貢獻大約為每年2-10毫米,,但只是在非常局部化的(空間)尺度上和短時間尺度上產生這種貢獻,。作者說,人類造成的變化主要是由以保護歷史建筑為目的的保護和重建工作,、以及市政工程(包括為穩(wěn)定運河壁所做的工作)引起的,。(生物谷Bioon.com)
生物谷推薦的英文摘要
Scientific Reports doi:10.1038/srep02710
Natural versus anthropogenic subsidence of Venice
Luigi Tosi,,Pietro Teatini& Tazio Strozzi
We detected land displacements of Venice by Persistent Scatterer Interferometry using ERS and ENVISAT C-band and TerraSAR-X and COSMO-SkyMed X-band acquisitions over the periods 1992–2010 and 2008–2011, respectively. By reason of the larger observation period,, the C-band sensors was used to quantify the long-term movements,, i.e. the subsidence component primarily ascribed to natural processes. The high resolution X-band satellites reveal a high effectiveness to monitor short-time movements as those induced by human activities. Interpolation of the two datasets and removal of the C-band from the X-band map allows discriminating between the natural and anthropogenic components of the subsidence. A certain variability characterizes the natural subsidence (0.9 ± 0.7mm/yr), mainly because of the heterogeneous nature and age of the lagoon subsoil. The 2008 displacements show that man interventions are responsible for movements ranging from 10 to 2mm/yr. These displacements are generally local and distributed along the margins of the city islands.