Monitoring of land surface subsidence in Zonguldak coal mining field in the northern Turkey using multi temporal sar interferometry

This thesis examines the availability of finding out the ground surface deformation which occur in long time period with slow displacements by using multi temporal satellite SAR images. A case study is applied on Zonguldak underground coal mine areas using two techniques as Persistent Scatterers Interferometry (PSI) and Small Baseline (SB). The results of these techniques are compared and discussed.In Turkey Zonguldak and Bartın provinces are the only mining area that underground hardcoal mine is produced. This mine has a national economy vauable especially for at iron-steel industry and energy production. Mining activities have been started in the mid-19th. Century and is still active at five regions under Turkish Coal Enterprises (Türkiye Taşkömürü Kurumu - TTK) auditing. These mining are namely Kozlu, Karadon, Üzülmez and Armutçuk which are located in Zonguldak province, and Amasra mine region which is located in Bartın province.In this region mining has been continued more than 150 years and during this period approximately 400 million ton hardcoal is produced. Constant and dense production of coal mine caused subsidence at the surface of mine region. However, settlements and environment are suffered due to mining where urbanization is located on. This situation effected negatively human life as life losses. It also effected people economically as many buildings became useless and people lost their properties.Furthermore, in this region many landslide hazard is happening and also sinkholes occur resulting from having karstic properties at the geological structure. Additionally these mining activities trigger the natural hazards and increase the vulnerability. In last years the amount of coal mine production has been decreased and due to this fact government aimed to increase the production. New reserve survey was complited up to -1200 m from the surface by TTK. An amount of 1.3 billion tone reserve of coal was disclosured by the end of 2011.In this study coal mines in Zonguldak city as Kozlu, Karadon and Üzülmez regions are chosen as study area to investigate the deformation which occured in long time period. Kozlu mining is the first mining area and also is the only mine where production is continued under sea. Coal production is processed at different levels under the surface in these three mines. Production is continued under surface level as -630 m, -540 m and -250 m deep in Kozlu, Karadon and Üzülmez respectively.The investigation is concerned on the behalf of to address these facts:a) Residential areas are under a significant danger because of constant surface subsidenceb) Long term subsidence phenomena has not been monitored before. Previous techniques are used for short terms and have not been used for all mining areas. It is aimed to find out the deformation which occur both in urban and rural areas.c) InSAR technique gives a golden opportunity to monitor deformation which happend in long time period and also provide analysis of evolution of displacement in time.For these purposes 33 C-band satellite SAR images of ERS-1 and ERS-2 are acquired between 1993 and 2001 years. Also C-band 29 descending ENVISAT images are acquired between 2003 and 2010, and 17 ascending ENVISAT images are gathered between 2004 and 2010. Moreover, 23 L-band ALOS/PALSAR SAR images are acquired for the long term InSAR analyses between 2007 and 2010. PSI and SB approaches are applied for all these four dataset.PSI and SB approaches are applied for all these four dataset. For the PSI approach in each data set one image is chosen as master and interferograms are computed with this master image. For the SB processes all images are matched each other to compute interferograms. In SB applications InSAR pairs are computed with a threshold of temporal and geometrical baselines. Deformations are determined as mm/year. As an result it is find out that subsidence pattern at Kozlu is monitored with all ERS, ENVISAT and PALSAR processes. Results have consistency with previous DInSAR results. In the results of ERS and ENVISAT deformation is more clear at urbanized part of Kozlu city over the mine. Also at Karadon and Üzülmez deformation is identified with less dense pattern. PALSAR results gave dense deformation pattern both at urbanized Kozlu and at rural Karadon and Üzülmez. PSI results identified more points than SB results in all applications. Higher deformation is monitored in SB results at rural areas.In this study surface subsidence caused by underground hardcoal mining at Zonguldak region is investigated. For this intention multi-temporal and multi-track satellite SAR images are acquired. The evolution of subsidence phenomena for 17 years is revealed with InSAR method. Beside subsidece and potential subsidence areas which were identified by TTK new areas where deformation is monitored are found out. It is obvious that this region requires continuous monitoring. In conclusion, a footer information was prepared which can be useful for further risk analyses researches.Key words: InSAR, surface subsidence, multi temporal SAR, time series, coal mining