TY - JOUR

T1 - Ground surface response to continuous compaction of aquifer system in Tehran, Iran

T2 - Results from a long-term multi-sensor InSAR analysis

AU - Haghshenas Haghighi, Mahmud

AU - Motagh, Mahdi

N1 - Funding information: This work was supported by the Initiative and Networking Fund of the Helmholtz Association in the framework of the Helmholtz Alliance ‘Remote Sensing and Earth System Dynamics'. The TerraSAR-X data were provided by DLR under proposal number GEO1916, and the Envisat data were provided by the European Space Agency (ESA) under CAT-1 project ID 31014. The original ALOS data are copyright Japanese Aerospace Exploration Agency and were provided under proposal 1162. The Copernicus Sentinel data were provided by ESA. Some of the figures were generated using Generic Mapping Tools ( Wessel et al., 2013 ). We would like to thank Siavash Arabi from the National Cartographic Center of Iran (NCC) for providing leveling data, Leila Karimi from University of Tehran for sharing groundwater level measurements from Tehran Regional Water Authority, and Hans-Ulrich Wetzel from GFZ for preparing geological map of Tehran. We are grateful to Bahman Akbari from Forest, Range and Watershed Management (FRWM) organization of Iran for supporting us during the field work. We acknowledge contructive reviews by Pascal Castellazzi and three anonymous reviewers, whose comments greatly improved the quality of the original manuscript.

PY - 2019/2

Y1 - 2019/2

N2 - Most of the developed groundwater basins in Iran are subject to land subsidence hazards resulting from the over-extraction of groundwater. Several areas in Tehran, the capital city and a provincial center in north-central Iran, have been reported to be subsiding at different rates. In this study, we present the results of an Interferometric Synthetic Aperture Radar (InSAR) time series analysis of Tehran using different SAR data between 2003 and 2017. By constructing more than 400 interferograms derived from 39 Envisat ASAR (C-band), 10 ALOS PALSAR (L-band), 48 TerraSAR-X (X-band), and 64 Sentinel-1 (C-band) SAR datasets, we compile displacement time series from interferometric observations using the Small Baseline (SB) technique. Our analysis identifies 3 distinct subsidence features in Tehran with rates exceeding 25 cm/yr in the western Tehran Plain, approximately 5 cm/yr in the immediate vicinity of Tehran international airport, and 22 cm/yr in the Varamin Plain to the southeast of Tehran city. The temporal pattern of land subsidence, which is dominated by a decreasing trend, generally follows the regional decline in groundwater level, which suggests that anthropogenic processes caused by excessive groundwater extraction are the primary cause of land subsidence. Integrating a decadal time series of subsidence constructed from multi-sensor InSAR with in-situ observations suggests that inelastic and permanent compaction dominates the main deformation regime of the Tehran aquifer, and the ratio between elastic and inelastic deformation is approximately 0.4. A geological analysis indicates that the shape of the subsidence bowl in the western Tehran Plain does not follow the trend of major mapped faults in the region. In contrast, the subsidence bowl in Varamin is controlled by the Pishva Fault, which suggests that either this fault acts as a hydrologic barrier to the groundwater flow in this region or that the differences in sediment thickness causes the discontinuity in land subsidence.

AB - Most of the developed groundwater basins in Iran are subject to land subsidence hazards resulting from the over-extraction of groundwater. Several areas in Tehran, the capital city and a provincial center in north-central Iran, have been reported to be subsiding at different rates. In this study, we present the results of an Interferometric Synthetic Aperture Radar (InSAR) time series analysis of Tehran using different SAR data between 2003 and 2017. By constructing more than 400 interferograms derived from 39 Envisat ASAR (C-band), 10 ALOS PALSAR (L-band), 48 TerraSAR-X (X-band), and 64 Sentinel-1 (C-band) SAR datasets, we compile displacement time series from interferometric observations using the Small Baseline (SB) technique. Our analysis identifies 3 distinct subsidence features in Tehran with rates exceeding 25 cm/yr in the western Tehran Plain, approximately 5 cm/yr in the immediate vicinity of Tehran international airport, and 22 cm/yr in the Varamin Plain to the southeast of Tehran city. The temporal pattern of land subsidence, which is dominated by a decreasing trend, generally follows the regional decline in groundwater level, which suggests that anthropogenic processes caused by excessive groundwater extraction are the primary cause of land subsidence. Integrating a decadal time series of subsidence constructed from multi-sensor InSAR with in-situ observations suggests that inelastic and permanent compaction dominates the main deformation regime of the Tehran aquifer, and the ratio between elastic and inelastic deformation is approximately 0.4. A geological analysis indicates that the shape of the subsidence bowl in the western Tehran Plain does not follow the trend of major mapped faults in the region. In contrast, the subsidence bowl in Varamin is controlled by the Pishva Fault, which suggests that either this fault acts as a hydrologic barrier to the groundwater flow in this region or that the differences in sediment thickness causes the discontinuity in land subsidence.

KW - Groundwater depletion

KW - InSAR time series analysis

KW - Land subsidence

KW - Non-recoverable deformation

UR - http://www.scopus.com/inward/record.url?scp=85057737550&partnerID=8YFLogxK

U2 - 10.1016/j.rse.2018.11.003

DO - 10.1016/j.rse.2018.11.003

M3 - Article

AN - SCOPUS:85057737550

VL - 221

SP - 534

EP - 550

JO - Remote Sensing of Environment

JF - Remote Sensing of Environment

SN - 0034-4257

ER -