Про використання вільно поширюваних глобальних цифрових моделей рельєфу високої просторової роздільної здатності для розрахунків водної ерозії грунту
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Дата
2020
Науковий керівник
Укладач
Редактор
Назва журналу
ISSN
E-ISSN
Назва тому
Видавець
Одеський національний університет імені І. І. Мечникова
Анотація
Виконано оцінку точності відображення рельєфу вільно поширюваними глобальними цифровими моделями рельєфу високої просторової роздільної здатності SRTM, ASTER GDEM і AW3D30 і можливості їх використання для просторово-розподілених розрахунків водної ерозії грунтів. Оцінка точності цифрових моделей рельєфу виконана для тестової ділянки площею близько 340 км2,
розташованої на півночі Одеської області на південних відрогах Подільської
височини. Як еталон використана цифрова модель рельєфу, побудована на основі оцифровки великомасштабної топографічної карти і подальшої просторової
інтерполяції результатів методом звичайного точкового кригінга.
Выполнена оценка точности отображения рельефа свободно распространяемыми глобальными цифровыми моделями рельефа высокой пространственной разрешающей способности SRTM, ASTER GDEM и AW3D30 и возможности их использования для пространственно-распределенных расчетов водной эрозии почв. Оценка точности цифровых моделей рельефа выполнена для тестового участка площадью около 340 км2, расположенного на севере Одесской области на южных отрогах Подольской возвышенности. В качестве эталона использована цифровая модель рельефа, построенная на основе оцифровки крупномасштабной топографической карты и последующей пространственной интерполяции результатов методом обычного точечного Кригинга.
Problem Statement and Purpose. In the last two decades, when digital elevation models (DEMs) of global coverage and high spatial resolution have appeared in free access, the problem of assessing not only the planned or vertical accuracy of these DEMs but also the assessment of their applicability for mathematical modeling of hydrological or geomorphological processes has become relevant. The aim of this article is to evaluate the possibility of using freely distributed global digital elevation models of high spatial resolution for calculations of soil erosion losses, including their spatial distribution within a slope or a small catchment area. Data & Methods. The article evaluated the global DEMs SRTM with spatial resolution of 3 angular seconds and 1 angular second, ASTER GDEM (ASTER30) and AW3D30 with spatial resolution of 1 angular second. Estimation of the DEMs was performed for a test site with an area of about 340 km2, located in the north of Odessa region on the southern spurs of the Podolsk Upland. A digital elevation model based on the digitization of a large-scale topographic map and subsequent spatial interpolation of the results by the method of ordinary point Kriging was used as a reference. Calculations of soil erosion losses were performed using a spatially distributed GIS-implemented physical-statistical model of erosion-accumulation, developed at the Department of Physical Geography and Nature Management of ONU named after I. I. Mechnikov. Results. All evaluated digital elevation models in general well reflect the basic features of a relief of a test site. The average absolute heights of the estimated digital elevation models differ from the average height of the local reference DEM by no more than 0.5 %. However, the minimum and maximum heights, average surface slopes, length of current lines, slope exposure and, especially, their spatial distributions obtained using evaluated global DEMs, to some extent differ from those obtained using a cartographic digital elevation model. In addition to the technical features of the survey, this is influenced by the presence within the test site of trees, buildings, structures (ASTER30 and AW3D30), as well as the representation of heights in integers (SRTM90, SRTM30 and ASTER30). For ASTER30, it is also important the existance of post-processing errors ("artifacts") that have not been eliminated.The inadequacy of a quantitative assessment of the main factors of the erosion process, which are the slopes and exposure of slopes, as well as the lengths of water flow lines, inevitably affect the accuracy of calculating both the average values of soil erosional losses and, especially, their spatial distribution. This inadequacy manifested itself to the greatest extent in the digital elevation model ASTER GDEM. Based on the study for calculations and mapping of soil erosion losses using spatially distributed mathematical models, we recommend digital elevation models AW3D30 and SRTM90, which provided good compliance of the results of calculations of both average values of soil erosion losses and spatial distribution of them to the corresponding characteristics obtained using cartographical digital elevation model.
Выполнена оценка точности отображения рельефа свободно распространяемыми глобальными цифровыми моделями рельефа высокой пространственной разрешающей способности SRTM, ASTER GDEM и AW3D30 и возможности их использования для пространственно-распределенных расчетов водной эрозии почв. Оценка точности цифровых моделей рельефа выполнена для тестового участка площадью около 340 км2, расположенного на севере Одесской области на южных отрогах Подольской возвышенности. В качестве эталона использована цифровая модель рельефа, построенная на основе оцифровки крупномасштабной топографической карты и последующей пространственной интерполяции результатов методом обычного точечного Кригинга.
Problem Statement and Purpose. In the last two decades, when digital elevation models (DEMs) of global coverage and high spatial resolution have appeared in free access, the problem of assessing not only the planned or vertical accuracy of these DEMs but also the assessment of their applicability for mathematical modeling of hydrological or geomorphological processes has become relevant. The aim of this article is to evaluate the possibility of using freely distributed global digital elevation models of high spatial resolution for calculations of soil erosion losses, including their spatial distribution within a slope or a small catchment area. Data & Methods. The article evaluated the global DEMs SRTM with spatial resolution of 3 angular seconds and 1 angular second, ASTER GDEM (ASTER30) and AW3D30 with spatial resolution of 1 angular second. Estimation of the DEMs was performed for a test site with an area of about 340 km2, located in the north of Odessa region on the southern spurs of the Podolsk Upland. A digital elevation model based on the digitization of a large-scale topographic map and subsequent spatial interpolation of the results by the method of ordinary point Kriging was used as a reference. Calculations of soil erosion losses were performed using a spatially distributed GIS-implemented physical-statistical model of erosion-accumulation, developed at the Department of Physical Geography and Nature Management of ONU named after I. I. Mechnikov. Results. All evaluated digital elevation models in general well reflect the basic features of a relief of a test site. The average absolute heights of the estimated digital elevation models differ from the average height of the local reference DEM by no more than 0.5 %. However, the minimum and maximum heights, average surface slopes, length of current lines, slope exposure and, especially, their spatial distributions obtained using evaluated global DEMs, to some extent differ from those obtained using a cartographic digital elevation model. In addition to the technical features of the survey, this is influenced by the presence within the test site of trees, buildings, structures (ASTER30 and AW3D30), as well as the representation of heights in integers (SRTM90, SRTM30 and ASTER30). For ASTER30, it is also important the existance of post-processing errors ("artifacts") that have not been eliminated.The inadequacy of a quantitative assessment of the main factors of the erosion process, which are the slopes and exposure of slopes, as well as the lengths of water flow lines, inevitably affect the accuracy of calculating both the average values of soil erosional losses and, especially, their spatial distribution. This inadequacy manifested itself to the greatest extent in the digital elevation model ASTER GDEM. Based on the study for calculations and mapping of soil erosion losses using spatially distributed mathematical models, we recommend digital elevation models AW3D30 and SRTM90, which provided good compliance of the results of calculations of both average values of soil erosion losses and spatial distribution of them to the corresponding characteristics obtained using cartographical digital elevation model.
Опис
Ключові слова
SRTM90, SRTM30, ASTER GDEM, AW3D30, ерозія грунту, розрахунки, оцінка точності, водная эрозия почвы, расчеты, оценка точности, water soil erosion, calculations, accuracy assessment
Бібліографічний опис
Вісник Одеського національного університету = Odesa National University Herald