Algorithm of Assessment of the MODIS NDVI Long-Term Variations

Разработан алгоритм оценки долговременных вариаций характеристик растительного покрова, использующий значения вегетационного индекса NDVI спектрорадиометра MODIS спутников Terra и Aqua. Алгоритм содержит процедуры предварительной обработки данных – восстановление отсутствующих значений, сглаживание фильтром Савицкого-Голея. Для анализа территорий со снежным покровом определяется минимальная длина вегетационного периода для всей длины временного ряда. Полученные после удаления сезонной компоненты значения NDVI используются для построения линейной регрессии и определения тренда. В результате применения алгоритма создана карта пространственного распределения линейных трендов NDVI с 2000 по 2016 гг. для территории Западного Забайкалья. Представлены примеры визуальной верификации изменения растительного покрова с использованием спутниковых изображений сверхвысокого пространственного разрешенияAn algorithm was developed for assessment of long-term variations of vegetation characteristics. The algorithm use NDVI data from spectroradiometer MODIS of Terra and Aqua satellites. The algorithm includes pre-processing procedures – the restoration of missing values, smoothing using Savitsky-Golay filter. To analyze the areas with snow cover the minimum length of the growing season is determined for the full length of the time series. Obtained after removing the seasonal component NDVI values are used to construct a linear regression and determine the trend. As a result of applying the algorithm the map of the spatial distribution of NDVI linear trends was created from 2000 to 2016 for the West Transbaikalia. Examples of visual verification of vegetation cover changes using satellite images of ultra-high spatial resolution are presente

Environmental Conditions Of Zakamensk Town (Dzhida River Basin Hotspot)

Ecological problems of Zakamensk town are associated with sand deposits that were formed as a result of mining activities of former Dzhidinsky tungstenmolybdenum plant. Sands are accumulated in large quantities and they contain dangerous concentrations of heavy metals. Desertification in an urbanized area is manifested locally, but it differs from agricultural desertification by a profound and comprehensive destructive change in the components of the environment. Maps of soils, vegetation, types of lands, as well as ecological zoning maps of Zakamensk were created. The basis for the creation of electronic maps using GIS were stock, archive and own materials, topographic maps and remote sensing data. Urbanized desertification in Zakamensk is caused by chemical contamination of sandy eluvium, the spreading of pollutants by water flows and wind currents. Erosion occurs both in the form of flat flushing and linear erosion. The most intensive is gully erosion. Quantitative parameters of temporal variability of the erosive rainfall potential for the Zakamensk town are received. The quantitative characteristics of loads of pollutants on the territory of the town are determined on the basis of the erosion-deflation models. The calculations showed that 204 tons/ha of contaminated sand annually falls into the settlement area with water-erosion flows (Pb – 3.7 tons, W – 4.3 tons). Moreover, active wind activity led to the deposition of more metals (Pb – 5.6 tons, W – 6.5 tons) in the town

Algorithm of Assessment of the MODIS NDVI Long-Term Variations

Разработан алгоритм оценки долговременных вариаций характеристик растительного покрова, использующий значения вегетационного индекса NDVI спектрорадиометра MODIS спутников Terra и Aqua. Алгоритм содержит процедуры предварительной обработки данных – восстановление отсутствующих значений, сглаживание фильтром Савицкого-Голея. Для анализа территорий со снежным покровом определяется минимальная длина вегетационного периода для всей длины временного ряда. Полученные после удаления сезонной компоненты значения NDVI используются для построения линейной регрессии и определения тренда. В результате применения алгоритма создана карта пространственного распределения линейных трендов NDVI с 2000 по 2016 гг. для территории Западного Забайкалья. Представлены примеры визуальной верификации изменения растительного покрова с использованием спутниковых изображений сверхвысокого пространственного разрешенияAn algorithm was developed for assessment of long-term variations of vegetation characteristics. The algorithm use NDVI data from spectroradiometer MODIS of Terra and Aqua satellites. The algorithm includes pre-processing procedures – the restoration of missing values, smoothing using Savitsky-Golay filter. To analyze the areas with snow cover the minimum length of the growing season is determined for the full length of the time series. Obtained after removing the seasonal component NDVI values are used to construct a linear regression and determine the trend. As a result of applying the algorithm the map of the spatial distribution of NDVI linear trends was created from 2000 to 2016 for the West Transbaikalia. Examples of visual verification of vegetation cover changes using satellite images of ultra-high spatial resolution are presente

Estimation of Anthropogenic Forest Disturbancy Using Modis Ndvi Data (on the Example of Zaigraevskoe Forestry, Republic of Buryatia)

В работе представлены результаты оценки изменения лесного покрова после природно- антропогенного воздействия (пожары, рубки) на примере модельного участка, а также сравнительный анализ результатов, полученных по статистическим архивным данным и данным дистанционного зондирования. Выявлено, что по снимкам MODIS детектируются только крупные лесные пожары и сплошные рубки леса большой протяженности. Также обнаружено, что не детектируются разнесенные в пространстве небольшие рубки в пределах пикселяThe paper presents the results of assessment the forest cover changes as a result of natural and anthropogenic impact (fires, forest felling) by the example of a model area. A comparative analysis of the results obtained from statistical archival data and remote sensing data was conducted. It has been revealed that according to MODIS images only large forest fires and continuous long-length felling of forests are detected. It has also been discovered that small felling within a pixel is not detecte

Trend Analysis of Precipitation, Runoff and Major Ions for the Russian Part of the Selenga River Basin

At present, the problem of climate change is becoming increasingly acute. This is especially pressing for Lake Baikal, a World Natural Heritage site. The Russian part of the Selenga watershed is a suitable site for climate change research. The study of changes in precipitation, runoff, and chemical runoff is important for sustainable water resources management. This study presents a trend analysis of precipitation and runoff at hydrological stations and weather stations in the Russian part of the Selenga River basin. A comparative analysis of the concentrations of major ions in the surface water of the Selenga River depending on water levels was also carried out. Analysis of the data series on precipitation revealed a slight negative trend at the Novoselenginsk, Ulan-Ude, and Kabansk stations, and a weak positive trend—at the Kyakhta station. Runoff analysis revealed negative trends at the two used stations (Novoselenginsk and Mostovoi). The hydrochemical regime of the Selenga River is characterized by an increase in major ions and salinity during winter low-water periods, and a decrease during high-water periods. Mineralization and major ion content are lower in the high-water period (2019–2021) than in the low-water period (2015–2017)