Standing on the shoulder of a giant landslide:A six-year long InSAR look at a slow-moving hillslope in the western Karakoram

In this work, we investigate a slow-moving, large landslide (∼20 km2) in the Chitral district in Northern Pakistan, near several villages. The slow-moving landslide was reported more than four decades ago but has never been examined afterward. Interferometric Synthetic Aperture Radar (InSAR) analyses, using Sentinel-1 data that span a period of six years, allowed us to retrieve the spatio-temporal pattern of hillslope deformation. We combined both ascending and descending orbits to identify vertical and horizontal deformations. Our results showed that the crown is moving relatively fast in comparison to the nearby regions; 30 mm/year and 40 mm/year in downward and eastward directions, respectively. Also, step-like deformations observed over the crown reflect a deep-seated landslide. At the footslope, on the other hand, we captured relatively high deformations but in an upward direction; specifically 30 mm/year and 30 mm/year in upward and eastward directions, respectively. We have discussed the possible roles of meteorologic and anthropogenic factors causing hillslope deformation occurred during the six-year period under consideration. We observed a seasonal deformation patterns that might be mainly interpreted to be governed by the influence of snowmelt due to increasing temperatures during the start of spring. Overall, the same mechanism might be present in many other hillslopes across the whole Hindukush-Himalayan-Karakoram range, where seasonal snowmelt is an active agent. In this context, this research provides a case study shedding a light on the hillslope deformation mechanism at the western edge of the Himalayan range.</p

Terkedilmiş bir maden ocağı için jeomekansal bilgi teknolojileri ile arazi bozulmasının değerlendirilmesi.

This study proposes an approach for land degradation assessment for an abandoned coal mine by using geospatial information technologies. The land degradation assessment focuses on two major changes: topographical and Land Use and Land Cover (LULC). For this purpose, stereo aerial photos, Worldview-1, Landsat and ASTER images, Terrestrial Laser Scanning (TLS) data, Global Positioning System (GPS) data, and ancillary maps were used for abandoned Ovacık surface coal mine. Volume of excavations and fillings, drainage network deviations, and slope instabilities were the investigated topographical disturbances by comparison of the Digital Elevation Models (DEM) for pre- and post-mining stages. Using aerial photos and Worldview-1 satellite image, LULC maps were prepared based on the same time period. Then areal extent and spatial pattern of the LULC change was calculated and mapped by post classification comparison method. The results of land degradation assessment show that there was a significant topographical disturbance and LULC change in the research area. Particularly, three dump areas with a total volume of 2,334,878 m3 were identified by DEM subtraction. It was found that stream network around the primary dump site shifted towards south with a maximum displacement of 60m. Slope analysis reveals that slopes higher that 60 degrees were mainly observed in excavation area with 81 percent. LULC change study showed that the forest area decreased an amount of 106,485 m2 from 1951 to 2008. However; by means of the forestation efforts in dump sites, an amount of 106,012 m2 forest land was recovered.M.S. - Master of Scienc

Landuse change detection in a surface coal mine area using multi-temporal high-resolution satellite images

Surface mining activities, exploitation of ore, and stripping and dumping of the overburden cause changes in the land cover and land use of a mine area. The area of land disturbance can be very large in the case of surface coal mining, due to the nature of the coal extraction process. Sustainable mining requires continuous monitoring of changes in land cover and land use induced by the mining activities. This is essentially important for identifying the long-term impacts of mining on the environment and on land cover in order to provide necessary mine closure and reclamation measures. In this sense, digital image classification provides a powerful tool for obtaining rigorous data, and reduces the cost of field measurements in time and money, particularly when dealing with large areas. Various remote sense data records and image classification techniques serve different features for numerous purposes. The selection of a suitable data and image classification method is significant for ensuring the effective use of information extracted from the satellite images, e.g. land-use classes. This paper proposes a methodology for identifying land-use change in surface coal mines using multi-temporal high-resolution satellite images. The methodology has been implemented for identifying, quantifying and analysing the spatial response of landscape to surface mining activities in the Goynuk, Bolu surface mine in Turkey, from 2004 to 2008. The methodology essentially entails (i) acquiring data, (ii) preprocessing the data, (iii) image classification using the maximum likelihood classification algorithm (iv) accuracy assessment and (v) change detection analysis depending on class-based approaches. The results show that the methodology can be utilised effectively in monitoring land-use change in surface coal mining areas. It also provides essential input for planning mine reclamation and closure activities

Landuse Change Detection in a Surface Coal Mine Area Using Multi Temporal High Resolution Satellite Images

Surface mining activities, exploitation of ore and stripping and dumping overburden, cause changes on the land cover and landuse of the mine area. The areal extend of the land disturbance could substantially be large for surface coal mining due to the nature of the coal extraction process. Sustainable mining requires continuous monitoring of the land cover and landuse change induced by the mining activities. This is essentially important for identifying the long-term impacts of mining on environment and land cover to provide required mine closure and reclamation measures. In this sense, digital image classification provides a powerful tool to obtain a rigorous data and hence diminishes the essence of time-consuming and costly field measurements particularly for large areas. Various satellite-based remotely sensed data serve different features for different purposes. The selection of suitable data and image classification method is significant for effective use of extracted information from the satellite imagery like landuse classes. This paper proposes a methodology for identifying landuse change in surface coal mines using multi temporal high resolution satellite images. The methodology was implemented for identifying, quantifying, and analyzing the spatial response of landscape due to surface mining activities in the surface mine, Goynuk, Bolu, Turkey, from 2004 to 2008. The methodology essentially entails (i) acquiring data, (ii) preprocessing the data, (iii) image classification using maximum likelihood classification algorithm (iv) accuracy assessment, (v) change detection analysis depending on class-based approaches. The results showed that the methodology can effectively be utilized in monitoring landuse change in surface coal mining areas. It also provides essential input for planning mine reclamation and closure activities

Evaluation of pollution levels at an abandoned coal mine site in Turkey with the aid of GIS

Determination of the level of pollution at contaminated sites can be costly due to the number of samples required to identify the areas with higher contaminant concentrations. Yet, if pollution transport pathways can be found, then contamination level can be detected with fewer samples. In this case study, pollution levels at an abandoned coal mine site at Ovacik-Yaprakli (Cankiri, Turkey) are evaluated with respect to topography and surface runoff pathways derived using Geographical Information System (GIS) tools. First, surface runoff pathways are identified using ArcGIS 9.3. Then, the concentrations of trace elements (Mn, Cr, V. Cu, Ni, Zn, Ba, and Sr), pH, Fe and S contents in soil samples taken at random locations around the mine area are determined in a laboratory. In addition, pH and electrical conductivity (EC) are measured in flowing waters in-situ at different locations using pH and EC probes. The spatial distribution of pollutant concentrations is evaluated with respect to the surface runoff pathways and locations of potential contamination sources (i.e. open pit, coal storage and dump sites). Finally, the contamination level in the study area is assessed based on the limit values stated in the Soil Pollution Control Regulation of Turkey (SPCR). Results indicate that the site is contaminated with Cr, Ni, and Cu. In general, pollutant concentrations are higher close to the contamination sources and along the surface runoff pathways determined by the ArcGIS. Results indicate that GIS can aid in locating the areas that are more likely to have high pollutant concentrations. This would in return prevent overlooking highly contaminated spots which may be located far away from contamination sources. Moreover, these areas can be determined using a smaller number of samples which would decrease the sampling costs

Countrywide Monitoring of Ground Deformation Using InSAR Time Series: A Case Study from Qatar

Over the past few decades the country of Qatar has been one of the fastest growing economies in the Middle East; it has witnessed a rapid increase in its population, growth of its urban centers, and development of its natural resources. These anthropogenic activities compounded with natural forcings (e.g., climate change) will most likely introduce environmental effects that should be assessed. In this manuscript, we identify and assess one of these effects, namely, ground deformation over the entire country of Qatar. We use the Small Baseline Subset (SBAS) InSAR time series approach in conjunction with ALOS Palsar-1 (January 2007 to March 2011) and Sentinel-1 (March 2017 to December 2019) synthetic aperture radar (SAR) datasets to assess ground deformation and conduct spatial and temporal correlations between the observed deformation with relevant datasets to identify the controlling factors. The findings indicate: (1) the deformation products revealed areas of subsidence and uplift with high vertical velocities of up to 35 mm/yr; (2) the deformation rates were consistent with those extracted from the continuously operating reference GPS stations of Qatar; (3) many inland and coastal sabkhas (salt flats) showed evidence for uplift (up to 35 mm/yr) due to the continuous evaporation of the saline waters within the sabkhas and the deposition of the evaporites in the surficial and near-surficial sabkha sediments; (4) the increased precipitation during Sentinel-1 period compared to the ALOS Palsar-1 period led to a rise in groundwater levels and an increase in the areas occupied by surface water within the sabkhas, which in turn increased the rate of deposition of the evaporitic sediments; (5) high subsidence rates (up to 14 mm/yr) were detected over landfills and dumpsites, caused by mechanical compaction and biochemical processes; and (6) the deformation rates over areas surrounding known sinkhole locations were low (+/−2 mm/yr). We suggest that this study can pave the way to similar countrywide studies over the remaining Arabian Peninsula countries and to the development of a ground motion monitoring system for the entire Arabian Peninsula

Remote Sensing Application for Landslide Detection, Monitoring along Eastern Lake Michigan (Miami Park, MI)

We assessed the nature and spatial and temporal patterns of deformation over the Miami Park bluffs on the eastern margin of Lake Michigan and investigated the factors controlling its observed deformation. Our approach involved the following steps: (1) extracting bluff deformation rates (velocities along the line of sight of the satellite) using a stack of Sentinel-1A radar imagery in ascending acquisition geometry acquired between 2017 and 2021 and applying the Intermittent Small Baseline Subset (ISBAS) InSAR time series analysis method; (2) generating high-resolution (5 cm) elevation models and orthophotos from temporal unmanned aerial vehicle (UAV) surveys acquired in 2017, 2019, and 2021; and (3) comparing the temporal variations in mass wasting events to other relevant datasets including the ISBAS-based bluff deformation time series, lake level (LL) variations, and local glacial stratigraphy. We identified areas witnessing high line-of-sight (LOS) deformation rates (up to &minus;21 mm/year) along the bluff from the ISBAS analysis and seasonal deformation patterns associated with freeze-thaw cycles, suggesting a causal effect. The acceleration of slope failures detected from field and UAV acquisitions correlated with high LLs and intensified onshore wave energy in 2020. The adopted methodology successfully predicts landslides caused by freezes and thaws of the slope face by identifying prolonged slow deformation preceding slope failures, but it does not predict the catastrophic landslides preceded by short-lived LOS deformation related to LL rise

Land Subsidence Induced by Rapid Urbanization in Arid Environments: A Remote Sensing-Based Investigation

The rapid increase in the population of many of the older major cities within the countries of the Saharan-Arabian Desert is steering vast and disorganized urban expansion and in many cases introducing adverse environmental impacts such as soil erosion, rise in groundwater levels, and contamination of shallow aquifers, as well as development of deformational features including land subsidence. Using the rapidly growing city of Riyadh (1992: 467 km2; 2018: 980 km2), the capital of the Kingdom of Saudi Arabia as a test site, we utilized Small Baseline Subset (SBAS) interferometric analyses of 2016 to 2018 Sentinel-1 images together with multi-temporal high-resolution images viewable on Google Earth, GPS, field, land use land cover (LULC), and geological data to assess the distribution and rates of land subsidence and their causal effects. Three main causes of subsidence were identified and assessed: (1) discharge of wastewater effluents from septic systems in newly urbanized areas that lead to an increase in soil moisture, rise in groundwater levels, waterlogging, and wetting and hydrocompaction of dry alluvium loose sediments causing land subsidence (up to −20 mm/y) in wadis and lowlands; (2) the subsurface dissolution of karst formation by wastewater effluents and the collapse of voids and cavities at depth under stresses introduced by heavy construction machinery, causing sagging and land subsidence (up to −5 mm/y); and (3) leveling, compaction, and degradation of municipal and building waste materials in organized landfills and disorganized dump sites that resulted in significant land subsidence (up to −21 mm/y) and differential settling that could jeopardize the stability of structures erected over these sites. Our findings highlight the potential use of the advocated integrated approach to assess the nature and extent of land deformation associated with rapid urban growth in arid lands, and to identify areas most impacted for the purpose of directing and prioritizing remediation efforts

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field