scholarly journals Different scale land subsidence and ground fissure monitoring with multiple InSAR techniques over Fenwei basin, China

2015 ◽  
Vol 372 ◽  
pp. 305-309 ◽  
Author(s):  
C. Zhao ◽  
Q. Zhang ◽  
C. Yang ◽  
J. Zhang ◽  
W. Zhu ◽  
...  
Keyword(s):  
Land Subsidence ◽  
Large Scale ◽  
Deformation Gradient ◽  
Small Scale ◽  
Ground Fissure ◽  
Envisat Asar ◽  
Persistent Scatterers ◽  
Sar Data ◽  
Large Scale Land ◽  
Sbas Insar

Abstract. Fenwei basin, China, composed by several sub-basins, has been suffering severe geo-hazards in last 60 years, including large scale land subsidence and small scale ground fissure, which caused serious infrastructure damages and property losses. In this paper, we apply different InSAR techniques with different SAR data to monitor these hazards. Firstly, combined small baseline subset (SBAS) InSAR method and persistent scatterers (PS) InSAR method is used to multi-track Envisat ASAR data to retrieve the large scale land subsidence covering entire Fenwei basin, from which different land subsidence magnitudes are analyzed of different sub-basins. Secondly, PS-InSAR method is used to monitor the small scale ground fissure deformation in Yuncheng basin, where different spatial deformation gradient can be clearly discovered. Lastly, different track SAR data are contributed to retrieve two-dimensional deformation in both land subsidence and ground fissure region, Xi'an, China, which can be benefitial to explain the occurrence of ground fissure and the correlation between land subsidence and ground fissure.

Transformation from Subsistence to Commercial Agriculture in Nigeria

2015 ◽  
pp. 409-431 ◽  
Author(s):  
Abiodun E. Obayelu
Keyword(s):  
Large Scale ◽  
Land Acquisition ◽  
Small Scale ◽  
Collective Actions ◽  
Commercial Agriculture ◽  
Land Owners ◽  
Research Designs ◽  
Large Scale Land ◽  
Small Scale Farmers ◽  
Policies And Programs

Agriculture is in critical state in Nigeria with domestic food production being less than the growing population. The chapter analyzes the ongoing transformation of subsistence agriculture to commercial in Nigeria and the attendant effects of large-scale land acquisition on small-scale farmers. It uses both theoretical and empirical research designs with direct interviews of relevant stakeholders and case studies. It reviews past and present policies and programs aimed at transforming agriculture from subsistence to commercial in Nigeria. The results reveal that large-scale land acquisition and farming is not new in Nigeria. Acquisitions of land by foreigners has always been with the help and consent of government, unlike the case when it involves indigenous investors. Acquisitions have in most cases been characterized by conflicts between the landowners or tillers and investors. To transition successfully from subsistence to commercial agriculture, there is a need for strong collective actions between the depraved land owners, government, and investors.

scholarly journals The Problematic of Small-Scale Land Acquisition (Less than 5 Hectares) for Public Interest Development

2016 ◽  
Vol 1 (1) ◽  
pp. 61
Author(s):  
Donna Okhtalia Setiabudhi
Keyword(s):  
Public Interest ◽  
Large Scale ◽  
Preventive Measures ◽  
Public Consultation ◽  
Land Acquisition ◽  
Small Scale ◽  
Interest Development ◽  
Large Scale Land ◽  
Legal Substances ◽  
The Impact

Land acquisition for public interest development is stipulated in Act No. 2 of 2012 concerning Land Acquisition for Development of Public Interest. One arrangement of land acquisition in legal substances that have been formed are small-scale land acquisition (less than 5 hectares), but it is still governed by very vague and thus susceptible to the multi-interpretation and raises doubts in its implementation. This paper discusses the problematic that arise due to unclear regulations concerning small-scale land acquisition and to provide solutions to these problems. Based on the discussion the authors concluded first, the problematic of small-scale land acquisition is the arrangement of land acquisition that is so vague that there is no clarity regarding the procedures for determining of location, the phase of land acquisition, which excludes public consultation, there is no regulation regarding preventive measures against the impact for the community around location of land acquisition. Second, the solution could be found to this problem is a regulation of small-scale land acquisition should ideally be regulated more comprehensively considering that small-scale land acquisition allows the emergence of adverse effects for the community around location of land acquisition so that the stages of planning and preparation that is set for the large-scale land acquisition is similarly applied for small-scale.

scholarly journals Adjacent-Track InSAR Processing for Large-Scale Land Subsidence Monitoring in the Hebei Plain

2021 ◽  
Vol 13 (4) ◽  
pp. 795
Author(s):  
Xi Li ◽  
Li Yan ◽  
Lijun Lu ◽  
Guoman Huang ◽  
Zheng Zhao ◽  
...  
Keyword(s):  
Time Series ◽  
Synthetic Aperture Radar ◽  
Land Subsidence ◽  
Large Scale ◽  
Synthetic Aperture ◽  
Hebei Plain ◽  
Deformation Velocity ◽  
Large Scale Land ◽  
Subsidence Monitoring ◽  
Aperture Radar

Large-scale land subsidence has threatened the safety of the Hebei Plain in China. For tens of thousands of square kilometers of the Hebei Plain, large-scale subsidence monitoring is still one of the most difficult problems to be solved. In this paper, we employed the small baseline subset (SBAS) and NSBAS technique to monitor the land subsidence in the Hebei Plain (45,000 km2). The 166 Sentinel-1A data of adjacent-track 40 and 142 collected from May 2017 to May 2019 were used to generate the average deformation velocity and deformation time-series. A novel data fusion flow for the generation of land subsidence velocity of adjacent-track is presented and tested, named as the fusion of time-series interferometric synthetic aperture radar (TS-InSAR) results of adjacent-track using synthetic aperture radar amplitude images (FTASA). A cross-comparison analysis between the two tracks results and two TS-InSAR results was carried out. In addition, the deformation results were validated by leveling measurements and benchmarks on bedrock results, reaching a precision 9 mm/year. Twenty-six typical subsidence bowls were identified in Handan, Xingtai, Shijiazhuang, Hengshui, Cangzhou, and Baoding. An average annual subsidence velocity over −79 mm/year was observed in Gaoyang County of Baoding City. Through the cause analysis of the typical subsidence bowls, the results showed that the shallow and deep groundwater funnels, three different land use types over the building construction, industrial area, and dense residential area, and faults had high spatial correlation related to land subsidence bowls.

scholarly journals LAND SUBSIDENCE MONITORING IN DEZHOU CITY BASED ON SBAS-INSAR TECHNOLOGY

2020 ◽  
Vol XLIII-B3-2020 ◽  
pp. 299-304
Author(s):  
G. Huang ◽  
H. Fan ◽  
L. Lu ◽  
W. Yu
Keyword(s):  
Urban Area ◽  
Land Subsidence ◽  
Large Scale ◽  
Vertical Direction ◽  
Ground Subsidence ◽  
Large Area ◽  
Coverage Area ◽  
Radar Images ◽  
Seasonal Characteristics ◽  
Sbas Insar

Abstract. To monitor the large area land subsidence in Dezhou city, Shandong province, China. This paper uses 23 scenes of Sentinel-1A radar images from August 2017 to February 2019, and based on small baseline subset (SBAS) technology to obtain the subsidence information in Dezhou urban area. The monitoring results show that: Dezhou city has a serious subsidence phenomenon in large coverage area. A subsidence funnel with Chenzhuang as the center was formed. The average annual subsidence rate (along the vertical direction) of the subsidence center exceeded 45 mm/yr. There was also a serious subsidence phenomenon in the eastern and northeastern parts of the urban area, and there was a tendency of forming a whole area. After detailed data analysis, it is found that the ground subsidence presents seasonal characteristics closely related to the groundwater level and is affected by large-scale engineering construction on the surface.

scholarly journals IoT technology and big data processing for monitoring and analysing land subsidence in Central Taiwan

2020 ◽  
Vol 382 ◽  
pp. 103-109
Author(s):  
Wei-Chia Hung ◽  
Yi-An Chen ◽  
Cheinway Hwang
Keyword(s):  
Land Subsidence ◽  
High Speed ◽  
Large Scale ◽  
Alluvial Fan ◽  
Monitoring Wells ◽  
Multi Temporal ◽  
Multiple Sensor Monitoring ◽  
Large Scale Land ◽  
Central Taiwan ◽  
Subsidence Monitoring

Abstract. Over 1992–2018, groundwater overexploitation had caused large-scale land subsidence in the Choshui River Alluvial Fan (CRAF) in Taiwan. The Taiwan High Speed Railway (THSR) passes through an area of severe subsidence in CRAF, and the subsidence poses a serious threat to its operation. How to effectively monitor land subsidence here has become a major issue in Taiwan. In this paper, we introduce a multiple-sensor monitoring system for land subsidence, including 50 continuous operation reference stations (CORS), multi temporal InSAR (MT-InSAR), a 1000 km levelling network, 34 multi-layer compaction monitoring wells and 116 groundwater monitoring wells. This system can monitor the extent of land subsidence and provide data for studying the mechanism of land subsidence. We use the Internet of Things (IoT) technology to control and manage the sensors and develop a bigdata processing procedure to analyse the monitoring data for the system of sensors. The procedure makes the land subsidence monitoring more efficient and intelligent.

scholarly journals Spatial–temporal characterization of land subsidence induced by large area distribution of recent dredger fill

2020 ◽  
Vol 382 ◽  
pp. 131-135
Author(s):  
Jinxin Lin ◽  
Hanmei Wang ◽  
Tianliang Yang ◽  
Xinlei Huang
Keyword(s):  
Comparative Analysis ◽  
Land Subsidence ◽  
Large Scale ◽  
Soft Soil ◽  
Soil Layer ◽  
Geological Survey ◽  
Dredger Fill ◽  
Large Scale Land ◽  
And Control ◽  
Level Monitoring

Abstract. Large-scale land subsidence often occurs after large-scale land formation caused by dredger fill, which affects the sustainable development of the region. In order to prevent and control land subsidence in the area with dredger fill, the characteristics of land subsidence and its main influencing factors need to be studied. A typical region was examined using geological survey data, land-level monitoring and comparative analysis, to provide insight regarding the variability of dredger-fill characteristics and impacts on land subsidence. The geological survey results provided the information about burial distribution characteristics of dredger fill and its underlying soil layers. The land-level monitoring results were analyzed to characterize the spatial–temporal distribution of land subsidence. The comparative analysis of land subsidence with the formation time, soil properties, thicknesses of dredger fill and the lower soft soil layer provided information about the different impacts. The monitoring results show that the land subsidence of dredger fill areas was substantially larger than that of adjacent areas. The later the filling was formed, the thicker the filling is, and the more clay-rich the soil property and the thicker the soft soil layer is, the larger the land subsidence is. Finally, the future trend of land subsidence in the study area are given and some suggestions on the prevention and control of land subsidence are also given.

scholarly journals Analysis of the Spatiotemporal Variation in Land Subsidence on the Beijing Plain, China

2019 ◽  
Vol 11 (10) ◽  
pp. 1170 ◽  
Author(s):  
Lin Guo ◽  
Huili Gong ◽  
Feng Zhu ◽  
Lin Zhu ◽  
Zhenxin Zhang ◽  
...  
Keyword(s):  
Land Subsidence ◽  
Research Unit ◽  
Alluvial Fan ◽  
Envisat Asar ◽  
Beijing Plain ◽  
Persistent Scatterers ◽  
North Water ◽  
Variation Characteristics ◽  
The Impact ◽  
Mutation Information

Since the 1970s, land subsidence has been rapidly developing on the Beijing Plain, and the systematic study of the evolutionary mechanism of this subsidence is of great significance in the sustainable development of the regional economy. On the basis of Interferometric Synthetic Aperture Radar (InSAR) results, this study employed the Mann–Kendall method for the first time to determine the mutation information of land subsidence on the Beijing Plain from 2004 to 2015. By combining the hydrogeological conditions, “southern water” project, and other data, we attempted to analyse the reasons for land subsidence mutations. First, on the basis of ENVISAT ASAR and RADARSAT-2 data, the land subsidence of the Beijing Plain was determined while using small baseline interferometry (SBAS-InSAR) and Persistent Scatterers Interferometry (PSI). Second, on the basis of the Geographic Information System (GIS) platform, vector data of displacement under different scales were obtained. Through a series of tests, a scale of 960 metres was selected as the research unit and the displacement rate from 2004 to 2015 was obtained. Finally, a trend analysis of land subsidence was carried out on the basis of the Mann–Kendall mutation test. The results showed that single-year mutations were mainly distributed in the middle and lower parts of the Yongding River alluvial fan and the Chaobai River alluvial fan. Among these mutations, the greatest numbers occurred in 2015 and 2005, being 1344 and 915, respectively. The upper and middle alluvial fan of the Chaobai River, the vicinity of the emergency water sources, and the edge of the groundwater funnel have undergone several mutations. Combining hydrogeological data of the study area and the impact of the south-to-north water transfer project, we analysed the causes of these mutations. The experimental results can quantitatively verify the mutation information of land subsidence in conjunction with time series to further elucidate the spatial-temporal variation characteristics of land subsidence in the study area.

scholarly journals Surface Deformation from Sentinel-1A InSAR: Relation to Seasonal Groundwater Extraction and Rainfall in Central Taiwan

2019 ◽  
Vol 11 (23) ◽  
pp. 2817 ◽  
Author(s):  
Yi-Jie Yang ◽  
Cheinway Hwang ◽  
Wei-Chia Hung ◽  
Thomas Fuhrmann ◽  
Yi-An Chen ◽  
...  
Keyword(s):  
Land Subsidence ◽  
High Speed ◽  
Large Scale ◽  
Surface Deformation ◽  
Dry Season ◽  
Severe Drought ◽  
Groundwater Extraction ◽  
Large Scale Land ◽  
Small Baseline ◽  
Central Taiwan

Extracting groundwater for agricultural, aquacultural, and industrial use in central Taiwan has caused large-scale land subsidence that poses a threat to the operation of the Taiwan High Speed Railway near Yunlin County. We detected Yunlin subsidence using the Sentinel-1A Synthetic Aperture Radar (SAR) by the Small BAseline Subset (SBAS) method from April 2016 to April 2017. We calibrated the initial InSAR-derived displacement rates using GPS measurements and reduced the velocity difference between the two sensors from 15.0 to 8.5 mm/a. In Yunlin’s severe subsidence regions, cumulative displacements from InSAR and GPS showed that the dry-season subsidence contributed 60%–74% of the annual subsidence. The InSAR-derived vertical velocities matched the velocities from leveling to better than 10 mm/a. In regions with few leveling measurements, InSAR increased the spatial resolution of the vertical velocity field and identified two previously unknown subsidence spots over an industrial zone and steel factory. Annual significant subsidence areas (subsidence rate > 30 mm/a) from leveling from 2011 to 2017 increased with the declining dry-season rainfalls, suggesting that the dry-season rainfall was the deciding factor for land subsidence. A severe drought in 2015 (an El Niño year) dramatically increased the significant subsidence area to 659 km2. Both InSAR and leveling detected similarly significant subsidence areas in 2017, showing that InSAR was an effective technique for assessing whether a subsidence mitigation measure worked. The newly opened Hushan Reservoir can supply surface water during dry seasons and droughts to counter rain shortage and can thereby potentially reduce land subsidence caused by groundwater extraction.

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