Аналіз методів і систем контролю та прогнозування рівня паводкових вод

Проаналізовано сучасний стан методів і систем контролю та прогнозування рівня паводкових вод, що використовуються, а також перебувають на стадіях розробки і впровадження. Наведено один із можливих напрямків розробки методу прогнозування повеней, паводків і підтоплень.Проанализировано современное состояние методов и систем контроля и прогнозирования уровня паводковых вод, которые используются, а также находятся на стадиях разработки и внедрения. Приводится одно из возможных направлений разработки метода прогнозирования наводнений, паводков и подтоплений.Modern state of the methods and systems of control and projection (prognostication) of the floodwaters level, which are currently used and also are on the stage of development and implementation, has been analyzed. One of the posible ways of development of flooding prognostication has been pointed

A Neural Network Approach to Flood Mapping Using Satellite Imagery

This paper presents a new approach to flood mapping using satellite synthetic-aperture radar (SAR) images that is based on intelligent techniques. In particular, we apply artificial neural networks, self-organizing Kohonen's maps (SOMs), for SAR image segmentation and classification. Our approach was used to process data from different satellite SAR instruments (ERS-2/SAR, ENVISAT/ASAR, RADARSAT-1) for different flood events: the Tisza river, Ukraine and Hungary, 2001; the Huaihe river, China, 2007; the Mekong river, Thailand and Laos, 2008; and the Koshi river, India and Nepal, 2008

Potential of nonlocally filtered pursuit monostatic TanDEM-X data for coastline detection

This article investigates the potential of nonlocally filtered pursuit monostatic TanDEM-X data for coastline detection in comparison to conventional TanDEM-X data, i.e. image pairs acquired in repeat-pass or bistatic mode. For this task, an unsupervised coastline detection procedure based on scale-space representations and K-medians clustering as well as morphological image post-processing is proposed. Since this procedure exploits a clear discriminability of "dark" and "bright" appearances of water and land surfaces, respectively, in both SAR amplitude and coherence imagery, TanDEM-X InSAR data acquired in pursuit monostatic mode is expected to provide a promising benefit. In addition, we investigate the benefit introduced by a utilization of a non-local InSAR filter for amplitude denoising and coherence estimation instead of a conventional box-car filter. Experiments carried out on real TanDEM-X pursuit monostatic data confirm our expectations and illustrate the advantage of the employed data configuration over conventional TanDEM-X products for automatic coastline detection

Методика прогнозування та планування водних ресурсів та перерозподіл стокових витрат при пропуску паводків

Economic losses from floods have become catastrophic due to the increase in the number and scale of their propagation. Existing procedures for passing floods and pre-preparing reservoirs for flood water acceptance are ineffective and need to be improved. Therefore, the task to devise a methodology that would eliminate these shortcomings was urgent. This paper has proposed a procedure for calculating the passage of floods based on the forecasts of water inflow, taking into consideration the characteristics of the flood wave and the mode of reservoir filling, which makes it possible to bring down (reduce) the maximum flow rate through a waterworks by accumulating floodwaters in the reservoir. The software package Mike 11 (Danish Institute, Denmark) was employed to build a hydrodynamic model of floodwater movement along the examined river section from a hydrological station to a waterworks, which makes it possible to determine the levels of water and the flow rate in a reservoir at any time in the form of free surface curves when passing floods of various range. Based on the devised methodology, recommendations have been compiled for the forced discharges of water through hydroelectric turbines (in m3/s) when passing floods of various probabilities (which is especially important for floods whose probability is 0.01 %). The constructed hydrodynamic model of floodwater movement through a reservoir has allowed the verification of the devised procedure. The procedure was devised in order to effectively pass floodwaters and bring down the maximum flow rate through a waterworks. The introduction of the methodology for calculating the passage of floods could make it possible to avoid idle water discharge through the water drains of waterworks to the lower pool and provide for the most efficient utilization of floodwater resourcesЭкономический ущерб от наводнений и паводков получили катастрофических значений из-за роста количества и масштабов их распространения. Существующие методики пропуска паводков и заблаговременной подготовки водохранилищ до принятия паводковых вод неэффективны и требуют совершенствования. Поэтому актуальной была задача разработки методики. Предложена методика расчетов пропуска паводков на основе прогнозов приточности воды с учетом характеристик паводковой волны и режима наполнения водохранилища, которая дает возможность срезания (уменьшение) максимальных расходов через гидроузел путем аккумулирования паводковых вод в водохранилище. В программном комплексе MIKE 11 (Датский институт, Дания) создана гидродинамическая модель движения паводковых вод, которая позволяет определить уровни воды і расходы в водохранилище в любой момент времени в виде кривых свободной поверхности при пропуске паводков различной обеспеченности. На основе разработанной методики подготовлены рекомендации по форсированным сбросам воды через турбины ГЭС (в м3/с) при пропуске паводков различной обеспеченности (что особенно важно для паводков 0,01 % обеспеченности). Созданная гидродинамическая модель движения паводковых вод через водохранилище позволила осуществить верификацию разработанной методики. Методика разработана с целью эффективного пропуска паводковых вод и срезки максимальных расходов через гидроузел. Введение методики при осуществлении расчетов пропуска паводков позволит избежать холостых сбросов воды через водосливы гидросооружений в нижний бьеф и максимально эффективно использовать гидроресурсы паводковых водЕкономічні збитки від повеней та паводків набули катастрофічних значень через зростання кількості та масштабів їх розповсюдження. Існуючі методики пропуску паводків та завчасної підготовки водосховищ до прийняття паводкових вод є неефективними та потребують удосконалення. Тому актуальною була задача розробки методики, яка б усунула зазначені недоліки. Запропоновано методику розрахунків пропуску паводків на основі прогнозів приточності води з урахуванням характеристик паводкової хвилі та режиму наповнення водосховища, яка дає можливість зрізання (зменшення) максимальних витрат через гідровузол шляхом акумулювання паводкових вод у водосховищі. У програмному комплексі MIKE 11 (Датський інститут, Данія) створено гідродинамічну модель руху паводкових вод на досліджуваній ділянці річки від гідрологічного поста до гідровузла, яка дає змогу визначити рівні води та витрати у водосховищі у будь-який момент часу у вигляді кривих вільної поверхні при пропуску паводків різної забезпеченості. На основі розробленої методики підготовлені рекомендації щодо форсованих скидів води через турбіни ГЕС (у м3/с) при пропуску паводків різної забезпеченості (що особливо важливо для паводків 0,01 % забезпеченості). Створена гідродинамічна модель руху паводкових вод через водосховище дозволила здійснити верифікацію розробленої методики. Методика розроблена з метою ефективного пропуску паводкових вод та зрізання максимальних витрат через гідровузол. Запровадження методики при здійсненні розрахунків пропуску паводків дозволить уникнути холостих скидів води через водозливи гідроспоруд у нижній б’єф та максимально ефективно використовувати гідроресурси паводкових во

Методика прогнозування та планування водних ресурсів та перерозподіл стокових витрат при пропуску паводків

Economic losses from floods have become catastrophic due to the increase in the number and scale of their propagation. Existing procedures for passing floods and pre-preparing reservoirs for flood water acceptance are ineffective and need to be improved. Therefore, the task to devise a methodology that would eliminate these shortcomings was urgent. This paper has proposed a procedure for calculating the passage of floods based on the forecasts of water inflow, taking into consideration the characteristics of the flood wave and the mode of reservoir filling, which makes it possible to bring down (reduce) the maximum flow rate through a waterworks by accumulating floodwaters in the reservoir. The software package Mike 11 (Danish Institute, Denmark) was employed to build a hydrodynamic model of floodwater movement along the examined river section from a hydrological station to a waterworks, which makes it possible to determine the levels of water and the flow rate in a reservoir at any time in the form of free surface curves when passing floods of various range. Based on the devised methodology, recommendations have been compiled for the forced discharges of water through hydroelectric turbines (in m3/s) when passing floods of various probabilities (which is especially important for floods whose probability is 0.01 %). The constructed hydrodynamic model of floodwater movement through a reservoir has allowed the verification of the devised procedure. The procedure was devised in order to effectively pass floodwaters and bring down the maximum flow rate through a waterworks. The introduction of the methodology for calculating the passage of floods could make it possible to avoid idle water discharge through the water drains of waterworks to the lower pool and provide for the most efficient utilization of floodwater resourcesЭкономический ущерб от наводнений и паводков получили катастрофических значений из-за роста количества и масштабов их распространения. Существующие методики пропуска паводков и заблаговременной подготовки водохранилищ до принятия паводковых вод неэффективны и требуют совершенствования. Поэтому актуальной была задача разработки методики. Предложена методика расчетов пропуска паводков на основе прогнозов приточности воды с учетом характеристик паводковой волны и режима наполнения водохранилища, которая дает возможность срезания (уменьшение) максимальных расходов через гидроузел путем аккумулирования паводковых вод в водохранилище. В программном комплексе MIKE 11 (Датский институт, Дания) создана гидродинамическая модель движения паводковых вод, которая позволяет определить уровни воды і расходы в водохранилище в любой момент времени в виде кривых свободной поверхности при пропуске паводков различной обеспеченности. На основе разработанной методики подготовлены рекомендации по форсированным сбросам воды через турбины ГЭС (в м3/с) при пропуске паводков различной обеспеченности (что особенно важно для паводков 0,01 % обеспеченности). Созданная гидродинамическая модель движения паводковых вод через водохранилище позволила осуществить верификацию разработанной методики. Методика разработана с целью эффективного пропуска паводковых вод и срезки максимальных расходов через гидроузел. Введение методики при осуществлении расчетов пропуска паводков позволит избежать холостых сбросов воды через водосливы гидросооружений в нижний бьеф и максимально эффективно использовать гидроресурсы паводковых водЕкономічні збитки від повеней та паводків набули катастрофічних значень через зростання кількості та масштабів їх розповсюдження. Існуючі методики пропуску паводків та завчасної підготовки водосховищ до прийняття паводкових вод є неефективними та потребують удосконалення. Тому актуальною була задача розробки методики, яка б усунула зазначені недоліки. Запропоновано методику розрахунків пропуску паводків на основі прогнозів приточності води з урахуванням характеристик паводкової хвилі та режиму наповнення водосховища, яка дає можливість зрізання (зменшення) максимальних витрат через гідровузол шляхом акумулювання паводкових вод у водосховищі. У програмному комплексі MIKE 11 (Датський інститут, Данія) створено гідродинамічну модель руху паводкових вод на досліджуваній ділянці річки від гідрологічного поста до гідровузла, яка дає змогу визначити рівні води та витрати у водосховищі у будь-який момент часу у вигляді кривих вільної поверхні при пропуску паводків різної забезпеченості. На основі розробленої методики підготовлені рекомендації щодо форсованих скидів води через турбіни ГЕС (у м3/с) при пропуску паводків різної забезпеченості (що особливо важливо для паводків 0,01 % забезпеченості). Створена гідродинамічна модель руху паводкових вод через водосховище дозволила здійснити верифікацію розробленої методики. Методика розроблена з метою ефективного пропуску паводкових вод та зрізання максимальних витрат через гідровузол. Запровадження методики при здійсненні розрахунків пропуску паводків дозволить уникнути холостих скидів води через водозливи гідроспоруд у нижній б’єф та максимально ефективно використовувати гідроресурси паводкових во

Hybrid approach on multi- spatiotemporal data framework towards analysis of long-lead upstream flood: a case of Niger State, Nigeria

Floods have become a global concern because of the vast economic and ecological havoc that ensue. Thus, a flood risk mitigation strategy is used to reduce flood-related consequences by a long-lead identification of its occurrence. A wide range of causative factors, including the adoption of hybrid multi-spatiotemporal data framework is considered in implementing the strategy. Besides the structural or homogenous non-structural factors, the adoption of various Information Systems-based tools are also required to accurately analyse the multiple natural causative factors. Essentially, this was needed to address the inaccurate flood vulnerability classifications and short time of flood prediction. Thus, this study proposes a framework named: Hybrid Multi-spatiotemporal data Framework for Long-lead Upstream Flood Analysis (HyM-SLUFA) to provide a new dimension on flood vulnerability studies by uncovering the influence of multiple factors derived from topography, hydrology, vegetal and precipitation features towards regional flood vulnerability classification and long-lead analysis. In developing the proposed framework, the spatial images were geometrically and radiometrically corrected with the aid of Quantum Geographic Information System (QGIS). The temporal data were cleaned by means of winsorization methods using STATA statistical tool. The hybrid segment of the framework classifies flood vulnerability and performs long-lead analysis. The classification and analysis were conducted using the corrected spatial images to acquire better understanding on the interaction between the extracted features and rainfall in inducing flood as well as producing various regional flood vulnerabilities within the study area. Additionally, with the aid of regression technique, precipitation and water level data were used to perform long-lead flood analysis to provide a foresight of any potential flooding event in order to take proactive measures. As to confirm the reliability and validity of the proposed framework, an accuracy assessment was conducted on the outputs of the data. This study found the influence of various Flood Causative Factors (FCFs) used in the developed HyM-SLUFA framework, by revealing the spatial disparity indicating that the slope of a region shows a more accurate level of flood vulnerability compared to other FCFs, which generally causes severe upstream floods when there is low volume of precipitation within regions of low slope degree. Theoretically, the HyM-SLUFA will serve as a guide that can be adopted or adapted for similar studies. Especially, by considering the trend of precipitation and the pattern of flood vulnerability classifications depicted by various FCFs. These classifications will determine the kind(s) of policies that will be implemented in town planning, and the Flood Inducible Precipitation Volumes can provide a foresight of any potential flooding event in order to take practical proactive measures by the local authority

An Assessment Of Sea Turtle Nesting Behavior In Relation To Hurricane- And Restoration-induced Beach Morphodynamics

Coastal habitats are highly dynamic and vulnerable to landscape-level disturbances such as storms and restoration projects. Along the east coast of Florida these areas are particularly valuable as they provide significant nesting habitat for two sea turtle species, the threatened loggerhead (Caretta caretta) and the endangered green turtle (Chelonia mydas). This coast was heavily impacted by three major hurricanes in 2004 and in some areas by large restoration projects in 2005. Recent remote sensing methods allow for broad evaluation of the shoreline and thus the ability to assess sea turtle nesting habitat at a landscape scale. I collected nesting data for southern Brevard County, Florida from 1989 – 2005 and for Canaveral National Seashore, Florida from 1995 – 2005. I used LiDAR (Light Detection and Ranging) and IfSAR (Interferometric Synthetic Aperture Radar) remote sensing to map sea turtle nesting habitat in both areas following the 2004 hurricanes and any subsequent restoration. Canaveral National Seashore underwent no restoration while southern Brevard County received extensive restoration. Topographic variables (e.g., total sand volume, width, and slope) derived from the remote sensing data were compared across three time periods (pre-hurricane, posthurricane, and recovery period) and I compared nesting success data from 2004 to 2005. I built regression models for 2004 and 2005 to determine which topographic features influenced loggerhead and green turtle nesting the most. Green turtle nesting success declined from 2004 to 2005 only in highly restored areas while loggerhead nesting sucess declined throughout. Hurricanes caused a reduction in most of the topographic variables and restoration predominantly impacted aspects of the beach profile (e.g. slope and width). Loggerheads responded to profile characteristics (e.g. upper and lower iii beach slopes) though green turtles showed no consistent response to topography. The results indicate that both loggerheads and green turtles are sensitive to beach restoration, although loggerhead nesting is more influenced by beach morphology and green turtle nesting may be influenced more by other dune features such as vegetation cover

Automatic Shoreline Position and Intertidal Foreshore Slope Detection from X-Band Radar Images using Modified Temporal Waterline Method with Corrected Wave Run-up

Automatic and accurate shoreline position and intertidal foreshore slope detection are challenging and significantly important for coastal dynamics. In the present study, a time series shoreline position and intertidal foreshore slope have been automatically detected using modified Temporal Waterline Method (mTWM) from time-averaged X-band radar images captured throughout the course of two-week tidal cycle variation over an area spanning 5.6 km on the Hasaki coast between 12 April 2005 and 31 December 2008. The methodology is based on the correlation map between the pixel intensity variation of the time-averaged X-band radar images and the binary signal of the tide level ranging from −0.8 m to 0.8 m. In order to ensure the binary signal represented each of the water levels in the intertidal shore profile, determining the water level direction-wise bottom elevation is considered as the modification. Random gaps were detected in the captured images owing to the unclear or oversaturation of the waterline signal. A horizontal shift in the detected shoreline positions was observed compared to the survey data previously collected at Hasaki Oceanographical Research Station (HORS). This horizontal shift can be attributed to wave breaking and high wave conditions. Wave set-up and run-up are the effects of wave breaking and high wave conditions, respectively. The correction of the wave set-up and run-up is considered to allow the upward shift of the water level position, as well as shoreline position, to the landward direction. The findings indicate that the shoreline positions derived by mTWM with the corrected wave run-up reasonably agree with the survey data. The mean absolute bias (MAB) between the survey data and the shoreline positions detected using mTWM with the corrected wave run-up is approximately 5.9 m, which is theoretically smaller than the spatial resolution of the radar measurements. The random gaps in the mTWM-derived shoreline positions are filled by Garcia’s data filling algorithm which is a Penalized Least Squares regression method by means of the Discrete Cosine Transform (PLS-DCT). The MAB between survey data and the gap filled shoreline positions detected using TWM with corrected wave run-up is approximately 5.9 m. The obtained results indicate the accuracy of the mTWM with corrected wave run-up integrated with Garcia’s method compared to the survey observations. The executed approach in this study is considered as an efficient and robust tool to automatically detect shoreline positions and intertidal foreshore slopes extracted from X-band radar images with the consideration of wave run-up correction

Investigation of coastal dynamics of the Antarctic Ice Sheet using sequential Radarsat SAR images

Increasing human activities have brought about a global warming trend, and cause global sea level rise. Investigations of variations in coastal margins of Antarctica and in the glacial dynamics of the Antarctic Ice Sheet provide useful diagnostic information for understanding and predicting sea level changes. This research investigates the coastal dynamics of the Antarctic Ice Sheet in terms of changes in the coastal margin and ice flow velocities. The primary methods used in this research include image segmentation based coastline extraction and image matching based velocity derivation. The image segmentation based coastline extraction method uses a modified adaptive thresholding algorithm to derive a high-resolution, complete coastline of Antarctica from 2000 orthorectified SAR images at the continental scale. This new coastline is compared with the 1997 coastline also derived from orthorectified Radarsat SAR images, and the 1963 coastline derived from Argon Declassified Intelligence Satellite Photographs for change detection analysis of the ice margins. The analysis results indicate, in the past four decades, the Antarctic ice sheet experienced net retreat and its areal extent has been reduced significantly. Especially, the ice shelves and glaciers on the Antarctic Peninsula reveal a sustained retreating trend. In addition, the advance, retreat, and net change rates have been measured and inventoried for 200 ice shelves and glaciers. A multi-scale image matching algorithm is developed to track ice motion and to measure ice velocity for a number of sectors of the Antarctic coast based on 1997 and 2000 SAR image pairs. The results demonstrate that a multi-scale image matching algorithm is much more efficient and accurate compared with the conventional algorithm. The velocity measurements from the image matching method have been compared with those derived from InSAR techniques and those observed from conventional ground surveys during 1970-1971. The comparison reveals that the ice velocity in the front part of the Amery Ice Shelf has increased by about 50-200 m/a. The rates of ice calving and temporal variation of ice flow pattern have been also analyzed by integrating the ice margin change measurement with the ice flow velocity at the terminus of the outlet glacier

Metodología para determinar la línea costera con imágenes radar en el departamento del Magdalena

Se presenta una metodología de procesamiento digital con imágenes de Radar de Apertura Sintética (SAR) que sirve para delimitar semiautomáticamente la línea costera, ya que las imágenes SAR aseguran la obtención de imágenes todo momento, en zonas con cobertura nubosa donde la utilización de sensores ópticos imposibilita la extracción del borde costero, con imágenes ópticas los procesos automatizados no corresponderían a la línea costera que se desearía. La delimitación entre la tierra y el agua es una fortaleza de las imágenes SAR, debido a que su definición en el rango del microondas es bastante notoria y posibilita de manera óptima la extracción de la línea costera. La metodología desarrollada consistió en tipificar la forma de costa en irregular y recta, recortar la imagen de acuerdo al tipo regular e irregular; reducir el speckle con el filtro Lee-sigma, Gamma MAP, Geométrico; clasificar la imagen utilizando el algoritmo ISODATA, convertir la clasificación a línea, delimitando la línea costera. Se comprobó en dos imágenes Radarsat-2, tres ERS-2 y una CosmoSkyMed.Abstract. A digital processing methodology is presented with imagesMaestrí