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1.
A final paper on water-level monitoring from space outlines principles for the use of space imagery in interpretation of short-term changes in the position of shorelines and coastal water levels resulting from storm surges and strong offshore winds. Over 100 images of various types, seasons, and storm-surge conditions, carefully referenced with field data on slope, vegetation cover, water level, and wind direction, were used to determine “maximal” and “minimal” positions of the Caspian shoreline for the period 1973-1983. This information is useful in understanding the seasonal regime of water-level fluctuations and anticipating flooding associated with winds of a given velocity. Translated from: Izvestlya vysshikh uchebnykh zavedenly, geodeziya i aerofotos'yemka, 1986, No. 4, pp. 93-97.  相似文献   

2.
The first of three papers devoted to Soviet monitoring of the hydrosphere from space outlines general principles for interpreting changes in the levels of reservoirs and agents responsible for those changes. These are illustrated using case studies and sample imagery derived from several of the better known water resource problems within that country (Caspian and Aral' Sea problems), as well as others not widely recognized outside the USSR (such as the creation of artificial reservoirs from drainage of excess irrigation waters or escape of groundwater from poorly constructed wells). Satellite remote sensing is an integral, officially recognized component of comprehensive government efforts to manage such problems. Translated from: Antropogennyye vozdeystviya no prirodnuyu sredu po nablyudeniyam iz kosmosa. Leningrad, Nauka, 1985, pp. 11-23.  相似文献   

3.
This study describes a method to map shoreline indicators on a sandy beach. The hypothesis is that, on this beach, spectral albedo is predominantly determined by moisture content and water lines can, therefore, be detected as albedo contrasts. A laboratory experiment is performed to relate moisture content to image albedo, and supervised edge detection is subsequently used to map the shoreline indicators with remote sensing imagery. The algorithm is tested with data from visible, near-infrared and shortwave-infrared wavelength regions. These results are compared to shoreline indicators obtained by a field survey and a shoreline indicator derived from a digital elevation model. Both the water line present when the imagery was acquired, as well as the maximum extent of the last flood, can be detected as a single edge. Older high water lines are confused with the last high water line and appear dispersed, as there are multiple debris lines present on the beach. The low water line, usually in saturated sand, also appears dispersed due to the presence of channels and troughs. Shorelines are constant moving boundaries, which is why shoreline indicators are used as a proxy. Unlike a mathematical indicator that is based on an elevation model, our method is more sensitive to the dynamic nature of shorelines. Supervised edge-detection is a technique for generating reproducible measurements of shoreline indicator positions over time, and aids in the monitoring of coastline migration.  相似文献   

4.
The shoreline is one of the rapidly changing landforms in coastal areas.They are the key element in coastal GIS and provide the most information on coastal land form dynamics.Therefore,accurate detection and frequent monitoring of shorelines is very essential to understand the coastal processes and dynamics of various coastal features.The present study is to investigate the shoreline changes along the coast between Kanyakumari and Tuticorin of south India(where hydrodynamic and morphologic changes occur continuously after the December 2004 tsunami)by using Digital Shoreline Analysis System(DSAS),an extension of ArcGIS.Multidate IRS and Landsat Satellite data(1999,2001,2003,2005,2007,and 2009)are used to extract the shorelines.The data is processed by using the ERDAS IMAGINE 9.1 software and analyzed by ArcGIS 9.2 workstation.The rates of shoreline changes are estimated by three statistical methods,namely,End Point Rate(EPR),Linear Regression Rate(LRR),and Least Me-dian of Squares(LMS)by using DSAS.The study reveals that most of the study area has undergoing erosion.Both natural and an-thropogenic processes along the coast modify the shoreline configuration and control the erosion and accretion of the coastal zones.The coastal zones along the estuary have experienced accretion due to the littoral processes.The zones with headlands have more eroded than other zones along the study area.The study also shows that the coastal zones where sand is mined have relatively more rate of erosion than that of the other zones.Improper and unsustainable sand mining may also lead to severe erosion problem along this area.The shoreline change rates are altered by various geological processes along the coast.Thus,the present study implies that proper beach filling and nourishment projects should be made in the study area to save from hazards.It also indicates the advantage and suitability of DSAS to assess the shoreline changes compared with the traditional manual shoreline change analysis and prom-ising its applications for coastal zone management in other regions.  相似文献   

5.
The author surveys the use of remote sensing imagery in the study of mass exchange in glaciers, i.e., glacier dynamics resulting from phase changes in the water which they contain. A program of research now underway at the Institute of Geography (USSR Academy of Sciences) in conjunction with the “Priroda” Remote Sensing Center (Moscow) focuses on improving methods of data collection and mapping of glacier dynamics from space imagery, and particularly on identifying natural glacioclimatic zones believed to represent specific mass exchange conditions or regimes. The boundary of glacier nourishment separating areas of accumulation and ablation represents a key glacioclimatic indicator of mass exchange on satellite imagery and aerial photography. Translated from: Geodeziya i kartografiya, 1986, No. 5, pp. 26–31.  相似文献   

6.
The authors describe how remote sensing imagery can be employed in the identification of different types of chernozem soils in a predominantly agricultural zone (forest steppe), where natural vegetation (normally one of the best vegetation indicators) has been largely displaced by farm fields. A multi-stage methodology is outlined whereby small-scale imagery is used to delineate large regions of similar bioclimatic-geologic characteristics, from which areas of similar soil formation conditions are distinguished. Multispectral and multitemporal space imagery then is employed to detect less salient ecological-soil differences that can affect phototone and image texture. Translated by Edward Torrey, Alexandria, VA 22308 from: G. V. Dobrovol'skiy and V. L. Andronikov, eds., Aerokosmicheskiye metody v pochvovedenii i ikh ispol'zovaniye v sel'skom khozyaystve: sbornik nauchnykh trudov [Remote Sensing Methods in Soil Science and Their Utilization in Agriculture: A Collection of Scientific Works]. Moscow: Nauka, 1990, pp 103–109.  相似文献   

7.
This paper deals with the processes operating on the beaches of Goa, interpreted from imagery, followed by ground-truth collection and field checks. Studies on Landsat imagery bring out two distinct coastal geomorphological features, one north and the other south of Vasco-da-Gama. The beaches to the south indicate the prograding shoreline with deposition being the dominant phenomenon. The beaches to the north of Vasco-da-Gama reveal a retrograding shoreline where erosion is dominant. The presence of chimneys and stacks to the north of Vasco-da-Gama are characteristic of intensive erosional action while to the south a wide regular beach backed by a palaeo-strand line points to deposition. The pattern of the sediment load (in Band 4) is used as an index of longshore current movement. The action of erosion as against that of deposition in the two regions can be surmised from the diffused pattern vis-a-vis the uniformly wide even tone. Sand samples from the northern portion give a sorting coefficient of 1.100 while the southern portion shows a value of 0.712. It is hypothesised that the promontory on which Vasco-da-Gama lies is responsible for the formation of two different geomorphic zones.  相似文献   

8.
Funafuti Atoll, Tuvalu is located in the southwestern Pacific Ocean, which has experienced some of the highest rates of global sea-level rise over the past 60 years. Atoll islands are low-lying accumulations of reef-derived sediment that provide the only habitable land in Tuvalu, and are considered vulnerable to the myriad possible impacts of climate change, especially sea-level rise. This study examines the shoreline change of twenty-eight islands in Funafuti Atoll between 2005 and 2015 using 0.65 m QuickBird, 0.46 m WorldView-2, and 0.31 m WorldView-3 imagery using an image segmentation and decision tree classification. Shoreline change estimates are compared to previous study that used a visual interpretation approach. The feasibility of estimating island area with Landsat-8 Operational Land Imager (OLI) data is explored using CLASlite software. Results indicate a 0.13% (0.35 ha) decrease in net island area over the study time period, with 13 islands decreasing in area and 15 islands increasing in area. Substantial decreases in island area occurred on the islands of Fuagea, Tefala and Vasafua, which coincides with the timing of Cyclone Pam in March, 2015. Comparison between the WorldView-2 shoreline maps and those created from Landstat-8 indicate that the estimates tend to be in higher agreement for islands that have an area > 0.5 ha, a compact shape, and no built structures. Ten islands had > 90% agreement, with percent disagreements ranging from 2.78 to 100%. The methods and results of this study speak to the potential of automated EoV shoreline monitoring through segmentation and classification tree approach, which would reduce down data processing and analysis time. With the growing constellation of high and medium spatial resolution satellite-based sensors and the development of semi or fully automated image processing technology, it is now possible to remotely assess the short and medium-term shoreline dynamics on dynamic atolls. Landsat estimates were reasonably matched to those derived from fine resolution imagery, with some caveats about island size and shape.  相似文献   

9.
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10.
The author argues for a new, qualitative concept of “geographical” resolution, i.e., for certain changes in thinking about the extent to which spatial resolution per se can be accepted as an indicator of the suitability of various types of imagery for geographic analysis. She argues that more attention must be paid to other factors affecting the photographic reproducibility and perceptibility of geographical features on imagery: figure-ground contrast; configuration, size, and boundaries; etc. Examples of differences in the perceptibility of the same features (fields, erosional forms, populated places) at the same spatial resolution are presented for different parts of the country. Translated by Edward Torrey, Alexandria, VA 22308 from: G. V. Dobrovol'skiy and V. L. Andronikov, eds., Aerokosmicheskiye metody v pochvovedenii i ikh ispol'zovaniye v sel'skom khozyaystve: sbornik nauchnykh trudov [Remote Sensing Methods in Soil Science and Their Utilization in Agriculture: A Collection of Scientific Works]. Moscow: Nauka, 1990, pp. 34-46.  相似文献   

11.
Coastal zone is very dynamic, being the meeting place of land and sea water. The development in coastal area and subsequent population growth have given rise to problems such as erosion, sedimentation, saltwater intrusion, degradation of natural resources, etc. Satellite data has proved to be more appropriate for change detections quantifying and monitoring coastal zones compared to conventional sources. An attempt is being made to elucidate the effect of shoreline changes with reference to the spatial and field data observed along the Tharangampadi area. The base map was prepared on 1:50,000 scale for delineation and identification of shoreline changes. The spatial variability of shoreline changes are studied using IRS 1B LISS-II 1991, IRS 1C LISS-III 2004 and IRS P6 LISS-IV and IRS 1D PAN merge data 2006. The corresponding Survey of India toposheets of 1852, 1972 and survey and land record village map of 1918 also supplemented for this study. The kind and extent of shoreline changes were investigated by using GPS during ground truth verification. The results are analyzed and presented in this paper. The study results revealed that 180 m receding of the shoreline occurred in the past 155 years.  相似文献   

12.
This paper outlines some principles believed necessary for the establishment of integrated collections of remote sensing imagery, including, at the national level, a unified state image repository for the USSR. A multi-criterion classification of imagery is introduced, which provides a framework for structuring such a repository, and a number of measures for evaluating the utility of imagery within it are described. One of the latter is “geographic” resolution (levels of image detail), which provides a relatively straightforward indication of the type of geographic information embedded within particular types of remote sensing imagery. Translated by Jay K. Mitchell, PlanEcon, Inc., Washington, DC 20005 from: Vestnik Moskovskogo Universiteta, geografiya, 1988, No. 6, pp. 53-62.  相似文献   

13.
A Siberian geographer explores real and potential applications of remote sensing imagery in research on geosystem dynamics. Four different methodological approaches to the analysis of geosystem dynamics are identified and described: comparison of heterochronous and seasonal imagery, geosystem forecasting and reconstruction based on image analysis, determination of current state and extant geosystem trends, analysis of linkages and interactions among geosystem components. Translated by Edward Torrey, Alexandria, VA 22308 from: Geografiya i prirodnyye resursy, 1992, No. 4, pp. 140-146.  相似文献   

14.
The findings of a program monitoring the growth of an enormous man-made lake, created by the flooding of a low-lying area by irrigation water drainage, are described. Black-and-white space images for the period 1973-1985 are used to determine rates of shoreline displacement, map the growth in the lake's water area, and to determine probable areas of future flooding as a basis for prediction of future lake levels and shoreline positions. Translated from: Geodeziya i kartografiya, 1988, No. 7, pp. 44-46.  相似文献   

15.
海岛岸线遥感立体测图精细测量方法   总被引：2，自引：0，他引：2  
提出了一种海岛岸线遥感测图精细测量新方法,该方法直接基于理论定义的海岸线,利用航空影像瞬时水涯线数据在立体测图环境中提取瞬时水位高程;利用海岛周边精密海潮模型和瞬时水位高程推算海岛岸线高程;最后依据海岛岸线高程,采用立体测图方法测制海岛岸线的平面位置。该方法确保了海岛岸线成果的唯一性和连续性,适合大比例尺的大陆海岸线和海岛岸线测量。测试结果显示,在较高精度海潮模型和海面地形支持下,海岛岸线高程精度优于0.2 m,可满足1：2000测图要求。  相似文献   

16.
This study uses space imagery, particularly false-color composites, to identify and map major natural complexes of the Yerevan basin and the changes they are undergoing as a result of a variety of in situ and “imported” pollution impacts. Interpretation aides in the identification of areas affected by different types of pollution in the basin are identified. Translated by Edward Torrey, Alexandria, VA 22308 from: Izvestiya [Rossiyskoy] Akademii Nauk, seriya geograficheskaya, 1992, No. 1, pp. 112–121.  相似文献   

17.
The paper presents a series of guidelines, developed by the “Aerogeologiya” prospecting trust, for the use of remote sensing imagery in the study of oil-gas potential in remote areas of the USSR. These guidelines take into consideration both conventional oil-gas exploration strategies and the sequence typical of remote sensing research [from small-scale, general analysis, to large-scale detailed studies]. At present predominantly small-scale imagery is used for general reconnaissance, although instances where larger-scale images provide the basis for more specific investigations are also mentioned. A diagram demonstrates how remote sensing might be incorporated into the traditional framework of oil-gas exploration. Translated from: Kompleksnyye aerokosmicheskiye issledovaniya Sibiri, A. L. Yanshin and L. K. Zyat'kova, eds. Novosibirsk: Nauka, 1984, pp. 33-40.  相似文献   

18.
The author, a remote sensing specialist in Leningrad University's Department of Atmospheric Physics, describes the use of space imagery in a program for monitoring the city's impacts on the surrounding environment. The paper examines applications of LANDSAT and “Meteor” satellite imagery and “Soyuz-22” space photography in the study of industrial smoke plumes, jet contrails, atmospheric haze, albedo, the urban heat island, urban sprawl (including nighttime imagery), fallout of suspended particulates, and wastewater discharges into the Gulf of Finland. Translated from: Grigor'yev, A. A. Antropogennyye vozdeystviya na prirodnuyu sredy po nablyudeniyam iz kosmosa [Human Impacts on the Environment From Observations From Space]. Leningrad: Nauka, 1985, pp. 129-141 [Chapter 7].  相似文献   

19.
TOPSAR wave spectra model and coastal erosion detection   总被引：2，自引：0，他引：2  
This paper presents work done utilizing TOPSAR data to detect shoreline change along the Terengganu coast (Malaysia). TOPSAR data were used to extract information on wave spectra. This wave spectra information was then used to model shoreline changes by investigating the wave refraction patterns. From these patterns, the volume transport at several locations was estimated. The shoreline change model developed was designed to cover a 20 km stretch of shoreline of Kuala Terengganu. The model utilized data from aerial photographs, TOPSAR data and ground truth data. The location of sedimentation and erosion along the shoreline of Kuala Terengganu was estimated. The wave spectra extracted from TOPSAR data showed wavelengths ranging from 20 m to 175 m. The main direction of the waves given by the spectra was from the northeast. The wave refraction patterns varied, showing both convergence and divergence, indicating erosion and sedimentation locations, respectively. A comparison between the TOPSAR shoreline change model and aerial photographs and ground truth data showed a significant relationship. Finally, the regression model showed that erosion occurred particularly at Sultan Mahmed Airport, at a rate of −1.5 m/year. The maximum rate of sedimentation along the 20 km stretch was 1 m/year.  相似文献   

20.
A method of correlating spectral signatures of vegetation with soil chemistry and, in turn, of inferring the presence of subsurface mineral deposits (oil in particular) is outlined. Variations in the content of nitrogen, sulfur, and trace elements in the soil, known to correspond, for example, with underground deposits of oil, induce changes in chlorophyll content of vegetation that are detectable on imagery in different zones of the spectrum, which upon statistical analysis can be used to predict the presence of oil in underlying strata. Translated from: Izvestiya vysshikh uchebnykh zavedeniy, Geodeziya i aerofotos'yemka, 1986, No. 4, pp. 88-93.  相似文献   

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