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Highlights • The subsidence center was always located in the southeast of Chaoyang District 2011-2015, in Beijing, China. • The exploitation the second and the third confined aquifers had great impacts on the settlement development in Beijing. • The lag time between land subsidence and the groundwater level changes in the main exploration aquifer layers was 0.57–1.76 months. Abstract Land subsidence is rapidly developing across the Beijing Plain, China. Long-term intense overexploitation of groundwater is the main reason for land subsidence in Beijing. In this study, an optimized Small Baseline Subset (SBAS) interferometry method was developed to process 46 RADATSAT-2 images from 2011 to 2015 to investigate the spatial and temporal dynamics of land subsidence in the Beijing Plain. The lag time between land subsidence and groundwater exploitation was first analyzed by the Continuous Wavelet Transform (CWT) and Cross Wavelet Transform (XWT) methods Our study found that the maximum subsidence rate reached 141 mm per year. The analysis of the areas and volumes of the annual subsidence rates indicated that the overall deformation trend slowed down from 2011 to 2015. Our results indicate that the subsidence center is always located in the southeast of Chaoyang District from 2011 to 2015. The lag time between the observed subsidence and the groundwater level drops in the main exploration aquifer layers was 0.57–1.76 months. This information is helpful to reveal the mechanism of land subsidence and build hydrogeological model. [ABSTRACT FROM AUTHOR]

Interferometric synthetic aperture radar (InSAR) time-series analysis provides high spatial resolution and continuous temporal coverage for investigations of long-term ground displacement. Beijing, the capital city of China, has suffered from land subsidence since the 1950s, and extreme groundwater extraction has led to subsidence rates of > 100 mm/year. In this study, InSAR time-series analysis is performed on different data subsets to investigate the ground displacement at Capital International Airport, Beijing, between June 2003 and November 2013. The results show that the ground surface in the airport has deformed at different rates ranging from − 66.2 mm/year (sinking) to 8.2 mm/year (uplift) relative to the reference point. The projected vertical displacement rates agreed with measurements estimated from ground-leveling surveys, and the correlation coefficient of the fitting result is 0.96, with a standard deviation of 0.9 mm/year and a mean different of 2.0 mm/year. The runways and terminals have been affected by land subsidence to various degrees. Previous studies has indicated that long-term intense groundwater extraction is the main reason leading to land subsidence in this area. Other triggering factors, such as active faults, the quaternary compressible layers and urbanization, also have different degrees of contribution or impact on land subsidence in Beijing Plain. Furthermore, some interesting behaviors from groundwater (such as inter- and semi-annual variations) and subsidence, the relationship between them are also found in this study. [ABSTRACT FROM AUTHOR]

Long-term over-exploitation of underground water, static and dynamic load is increasing year by year, which influenced the occurrence and development of regional land subsidence in Beijing, China. We used Envisat advanced synthetic aperture radar data acquired from 2003 to 2009 and PSI (persistent scatterers for SAR interferometry) and small baseline technology to estimate regional land subsidence information in Beijing, China. In different situation of space utilization, we chose five typical settlement areas according to classified information of land-use, multi-spectral remote sensing images and geological data. We analyzed the time-series evolution characteristics of uneven subsidence by GIS spatial analysis. The comparative analysis results suggest that for five typical settlement areas, the complex situations of space utilization affect the trend of uneven subsidence, the simpler space utilization situation (relatively fewer transport lines, construction), the smaller settlement differences and the smaller trend of the uneven subsidence. [ABSTRACT FROM AUTHOR]

Irrigation is an important factor affecting the change of terrestrial water storage (TWS), especially in grain-producing areas. The Northeast China Plain (NECP), the Huang-Huai-Hai Plain (HHH) and the middle and lower reaches of the Yangtze River Basin Plain (YRB) are major grain-producing regions of China, with particular climate conditions, crops and irrigation schemes. However, there are few papers focusing on the different variation pattern of water storage between NECP, HHH and YRB. In this paper, the characteristics of terrestrial water storage anomaly (TWSA) and groundwater storage in the three regions mentioned above from 2003 to 2014 were analyzed, and the main reasons for water storage variations in the three regions were also discussed. The result shows that although effective irrigated areas increased in all three regions, TWSA only decreased in HHH and TWSA in the other two regions have shown an increasing trend. Spatially, the water storage deficit was more serious in middle and south NECP and HHH. In the three regions, water storage variations were impacted by meteorological condition and anthropogenic stress (e.g., irrigation). However, irrigation water consumption has a greater impact on water storage deficit in HHH than the other two regions, and water storage variation in YRB was mainly impacted by meteorological conditions. In this case, we suggest that the structure of agricultural planting in HHH should be adjusted to reduce the water consumption for irrigation. [ABSTRACT FROM AUTHOR]

With Graph: Figure 3 (a) Mean vertical displacement velocities throughout the NCP derived from the Sentinel-1A (S1A) data by using persistent scatterer interferometric synthetic aperture radar (PS-InSAR), (b) statistics of the subsidence rates at persistent scatterer (PS) points, (c) changes in the area with subsidence over 50 mm from 2016 to 2018, and (d) changes in the maximum subsidence rates from 2016 to 2018: PP, CP, and LP represent the piedmont alluvial-proluvial plain, central alluvial-lacustrine plain, and littoral plain, respectively. Replace Graph: Figure 3 (a) Mean vertical displacement velocities throughout the NCP derived from the Sentinel-1A (S1A) data by using persistent scatterer interferometric synthetic aperture radar (PS-InSAR), (b) statistics of the subsidence rates at persistent scatterer (PS) points, (c) changes in the area with subsidence over 50 mm from 2016 to 2018, and (d) changes in the maximum subsidence rates from 2016 to 2018: PP, CP, and LP represent the piedmont alluvial-proluvial plain, central alluvial-lacustrine plain, and littoral plain, respectively. Recent Ground Subsidence in the North China Plain, China, Revealed by Sentinel-1A Datasets. [Extracted from the article]

Groundwater resources have been exploited and utilized on a large scale in the North China Plain (NCP) since the 1970s. As a result of extensive groundwater depletion, the NCP has experienced significant land subsidence, which threatens geological stability and infrastructure health and exacerbates the risks of other geohazards. In this study, we employed multi-track Synthetic Aperture Radar (SAR) datasets acquired by the Sentinel-1A (S1A) satellite to detect spatial and temporal distributions of surface deformation in the NCP from 2016 to 2018 based on multi-temporal interferometric synthetic aperture radar (MT-InSAR). The results show that the overall ground displacement ranged from −165.4 mm/yr (subsidence) to 9.9 mm/yr (uplift) with a standard variance of 28.8 mm/yr. During the InSAR monitoring period, the temporal pattern of land subsidence was dominated by a decreasing tendency and the spatial pattern of land subsidence in the coastal plain exhibited an expansion trend. Validation results show that the S1A datasets agree well with levelling data, indicating the reliability of the InSAR results. With groundwater level data, we found that the distribution of subsidence in the NCP is spatially consistent with that of deep groundwater depression cones. A comparison with land use data shows that the agricultural usage of groundwater is the dominant mechanism responsible for land subsidence in the whole study area. Through an integrated analysis of land subsidence distribution characteristics, geological data, and previous research results, we found that other triggering factors, such as active faults, precipitation recharge, urbanization, and oil/gas extraction, have also impacted land subsidence in the NCP to different degrees. [ABSTRACT FROM AUTHOR]

Land subsidence is a global environmental geological hazard caused by natural or human activities. The high spatial resolution and continuous time coverage of interferometric synthetic aperture radar (InSAR) time series analysis techniques provide data and a basis for the development of methods for the investigation and evolution mechanism study of regional land subsidence. Beijing, the capital city of China, has suffered from land subsidence for decades since it was first recorded in the 1950s. It was reported that uneven ground subsidence and fractures have seriously affected the normal operation of the Beijing Capital International Airport (BCIA) in recent years before the overhaul of the middle runway in April 2017. In this study, InSAR time series analysis was successfully used to detect the uneven local subsidence and ground fissure activity that has been gradually increasing in BCIA since 2010. A multi-temporal InSAR (MT-InSAR) technique was performed on 63 TerraSAR-X/TanDem-X (TSX/TDX) images acquired between 2010 and 2017, then deformation rate maps and time series for the airport area were generated. Comparisons of deformation rate and displacement time series from InSAR and ground-leveling were carried out in order to evaluate the accuracy of the InSAR-derived measurements. After an integrated analysis of the distribution characteristics of land subsidence, previous research results, and geological data was carried out, we found and located an active ground fissure. Then main cause of the ground fissures was preliminarily discussed. Finally, it can be conducted that InSAR technology can be used to identify and monitor geological processes, such as land subsidence and ground fissure activities, and can provide a scientific approach to better explore and study the cause and formation mechanism of regional subsidence and ground fissures. [ABSTRACT FROM AUTHOR]

Land subsidence is the ground surface response to underground space development, utilization and evolution. Presently, land subsidence has developed into a global, comprehensive and interdisciplinary complex systems problem. More than half a century has passed since the discovery of subsidence in the Beijing Plain in the 1960s. In this study, we investigate the land subsidence in the Beijing Plain over the period of 2003–2015 using ENVISAT ASAR and RADARSAT-2 interferometric datasets and the small baseline subset interferometric synthetic aperture radar (SBAS-InSAR) technique. Furthermore, we introduced the data field model and index-based built-up index (IBI) to obtain the dynamic and static load information of the Beijing Plain. Then, based on a machine learning method, we selected the gradient lifting decision tree (GBDT) model to quantitatively analyze the contributions of groundwater level change, compressible deposit thickness and dynamic and static loads to land subsidence. The results showed that the maximum land subsidence rate was 122 and 141 mm/year in 2003–2010 and 2010–2015, respectively. Comparisons between the SBAS-InSAR results and leveling measurements showed that the minimum absolute error achieved was only 0.2 mm/year. We suggest that the groundwater exploitation in the third confined aquifer has greater impacts on land subsidence in the Beijing Plain than the other factors. The land subsidence likely occurred in compressible deposit thicknesses exceeding 90 m. Moreover, we found that the compressible thickness and groundwater level contributions to land subsidence exceeded 60%. Our results provide a scientific basis for the regulation and control of regional land subsidence. Unlabelled Image • The causes of land subsidence in Beijing Plain are complex. • The maximum land subsidence rate is 122 and 141 mm/year in 2003–2010 and 2010–2015. • The dynamic load by using a spatial data mining method of data field model. • The third confined aquifer groundwater has greater impacts on land subsidence. • Compressible thickness and groundwater contribution to land subsidence exceed 60%. [ABSTRACT FROM AUTHOR]

Background: The shortage of water resources and the increase of greenhouse gas emissions from soil seriously restrict the sustainable development of agriculture. Under the premise of ensuring a stable yield of winter wheat through a reasonable irrigation scenario, identifying a suitable straw returning method will have a positive effect on agricultural carbon sequestration and emission reduction in North China Plain., Results: Straw burying (SR) and straw mulching (SM) were adopted based on traditional tillage under in the winter wheat growing season of 2020-2021 and 2021-2022. Three irrigation scenarios were used for each straw returning method: no irrigation (I0), irrigation 60 mm at jointing stage (I1), and irrigation of 60 mm each at the jointing and heading stages (I2). Soil moisture, soil respiration rate, cumulative soil CO 2 emissions, yield, water use efficiency (WUE) and soil CO 2 emission efficiency (CEE) were mainly studied. The results showed that, compared to SM, SR improved the utilization of soil water and enhanced soil carbon sequestration. SR reduced soil respiration rate and cumulative soil CO 2 emissions in two winter wheat growing seasons, and increased yield by increasing spike numbers. In addition, with an increase in the amount of irrigation, soil CO 2 emissions and yield increased. Under SR-I1 treatment, WUE and CEE were the highest. SR-I1 increases crop yields at the same time as reducing soil CO 2 emissions., Conclusion: The combination of SR and irrigation 60 mm at jointing stage is a suitable straw returning irrigation scenario, which can improve water use and reduce soil CO 2 emission in NCP. © 2023 Society of Chemical Industry., (© 2023 Society of Chemical Industry.)