Maghrebi Mohsen, Noori Roohollah, Sadegh Mojtaba, Sarvarzadeh Fereshteh, Akbarzadeh Aliasghar Erfanian, Karandish Fatemeh, Barati Reza, Taherpour Hamid
Graduate Faculty of Environment, University of Tehran, Tehran, 1417853111, Iran.
Hydropars Khorasan consulting engineering company, Mashahd, Iran.
Ground Water. 2023 Jan;61(1):139-146. doi: 10.1111/gwat.13248. Epub 2022 Sep 5.
Qanat is an ancient underground structure to abstract groundwater without the need for external energy. A recognized world heritage, Qanat has enabled civilization in arid and semi-arid regions that lack perennial surface water resources. These important structures, however, have faced significant challenges in recent decades due to increasing anthropogenic pressures. This study uses remote sensing to investigate land-use changes and the loss of 15,983 Qanat shafts in the Mashhad plain, northeast of Iran, during the past six decades. This entails obtaining a rare aerial imagery from 1961, as well as recent satellite imagery, over a region with the highest density of Qanats in Iran, the birthplace of Qanat. Results showed that only 5.59% of the Qanat shafts in 1961 remained intact in 2021. The most prominent Qanat-impacting land-use changes were agriculture and urban areas, that accounted for 42.93 and 31.81% Qanat shaft destruction in the study area, respectively. This study also showed that groundwater table decline, demographic changes, and reduction in the appeal of working in the Qanat maintenance and construction industry among the new generation are existential threats to Qanats, and may result in the demise of these ancient structures in the future. Findings of this study can be used for urban planning in arid and semi-arid areas with the aim of protecting these historic water structures.
坎儿井是一种无需外部能源就能抽取地下水的古老地下建筑。作为一项公认的世界遗产，坎儿井使干旱和半干旱地区在缺乏常年地表水资源的情况下得以发展文明。然而，由于日益增加的人为压力，这些重要建筑在最近几十年面临着重大挑战。本研究利用遥感技术调查了伊朗东北部马什哈德平原在过去六十年间的土地利用变化以及15983个坎儿井竖井的消失情况。这需要获取1961年的珍贵航空影像以及近期的卫星影像，研究区域位于伊朗坎儿井密度最高的地区，也是坎儿井的发源地。结果显示，1961年的坎儿井竖井在2021年仅剩下5.59%完好无损。对坎儿井影响最显著的土地利用变化是农业和城市区域，分别占研究区域内坎儿井竖井破坏的42.93%和31.81%。本研究还表明，地下水位下降、人口结构变化以及新一代对从事坎儿井维护和建设行业兴趣的降低，都是坎儿井面临的生存威胁，可能导致这些古老建筑在未来消失。本研究结果可用于干旱和半干旱地区的城市规划，以保护这些历史悠久的水利建筑。
