The influence of land-use activities and regional drought on historical fire regimes of Buryatia, Siberia

Every year, millions of hectares burn across Siberia, driven by a combination of warming temperatures, regional drought and human-caused ignitions. Dendrochronology provides a long-term context to evaluate recent trends in fire activity and interpret the relative influence of humans and climate drivers on fire regimes. We developed a 400 year record of fire-scarred trees from 17 sites in pine-dominated forests located southeast of Lake Baikal. Site-level mean fire return intervals (MFIs) ranged from 4 to 27 years for all fires and 8 to 35 years for widespread fires within sites. Sites with the lowest MFI values were located within 1 km of agricultural fields in grassland valleys, suggesting that agricultural burning influenced MFIs at nearby sites. Fire frequency varied over the record, with significantly high values around 1790, from 1865 to 1880, 1948 to 1955 and 1995 to 2005. The increased fire activity corresponded with migration waves to the region and major socio-economic change connected with the establishment and breakdown of the Soviet Union. At broader scales, superposed epoch analysis showed that synchronous fire years were associated with regional drought and precipitation deficits. Wet conditions for 2&ndash;3 years prior to the event year were also significant, suggesting that increased moisture promoted growth of understory fine fuels to support more extensive fires across the study area. Although fire frequencies increased during the 20th century, fire&ndash;climate relationships weakened, suggesting increased human-caused ignitions may override regional climate drivers. Our dataset presents a continuous record of frequent surface fires over the past 400 years, providing a valuable opportunity to compare dendrochronology-based reconstructions with satellite and documentary records. &nbsp;</p

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

Atmospheric Air Pollution by Stationary Sources in Ulan-Ude (Buryatia, Russia) and Its Impact on Public Health

For the first time in the territory of the Russian Far East, a study related to the establishment of correlations between air quality and public health in Ulan-Ude (Buryatia, Russia) was carried out. This study is based on the analysis of official medical statistics on morbidity over several years, the data on the composition and volume of emissions of harmful substances into the air from various stationary sources, and laboratory measurements of air pollutants in different locations in Ulan-Ude. This study confirmed that the morbidity of the population in Ulan-Ude has been increasing every year and it is largely influenced by air pollutants, the main of which are benzo(a)pyrene, suspended solids, PM2.5, PM10, and nitrogen dioxide. It was found that the greatest contribution to the unfavorable environmental situation is made by three types of stationary sources: large heating networks, autonomous sources (enterprises and small businesses), and individual households. The main air pollutants whose concentrations exceed the limits are benzo(a)pyrene, formaldehyde, suspended particles PM2.5, PM10, and nitrogen dioxide. A comprehensive assessment of the content of various pollutants in the atmospheric air showed that levels of carcinogenic and non-carcinogenic risks to public health exceeded allowable levels. Priority pollutants in the atmosphere of Ulan-Ude whose concentrations create unacceptable levels of risk to public health are benzo(a)pyrene, suspended solids, nitrogen dioxide, PM2.5, PM10, formaldehyde, and black carbon. The levels of morbidity in Ulan-Ude were higher than the average for Buryatia by the main disease classes: respiratory organs&mdash;by 1.19 times, endocrine system&mdash;by 1.25 times, circulatory system&mdash;by 1.11 times, eye diseases&mdash;by 1.06 times, neoplasms&mdash;by 1.47 times, congenital anomalies, and deformations and chromosomal aberrations&mdash;by 1.63 times. There is an increase in the incidence of risk-related diseases of respiratory organs and the circulatory system. A strong correlation was found between this growth of morbidity and atmospheric air pollution in Ulan-Ude