Olga V. Tutubalina

Monthly burned area and forest fire carbon emission estimates for the Russian Federation from SPOT VGT

Abstract Russian boreal forests contain around 25% of all global terrestrial carbon, some of which is released to the atmosphere when the forests burn. Whilst it is well known that fire is widespread in the boreal environment, there is a lack of good quality quantitative data on the extent of fire activity in Russian forests and on its interannual variation. This study provides one of the first comprehensive monthly satellite-based studies of fires occurring across the entire Russian Federation using a single, standardised methodology designed to map burned areas down to a size of 2 km 2 . Using data from SPOT VEGETATION (VGT), we detect newly burned pixels via a series of multi-temporal spectral reflectance differencing criteria. For the year 2001, the method is applied to 21 VGT 10-day syntheses (S10) scenes covering the Russian fire season. We map 2764 fires with a total area of 41,782 km 2 , and our methodology successfully detects all fires present in a comparison Landsat ETM+ data set, although it underestimates their size by on average of 18%. Using frequency–size relations, we estimate that 3790 fires of 1–2-km 2 area are likely to have remained unobserved by our method across the entire Russian region. Taking these corrections into account, we calculate the total burned area for the Russian Federation in 2001 as 51,546 km 2 , with 38,512 km 2 occurring in forest and 13,034 km 2 in other land use classes. Fire activity is strongest in August in Eastern Siberia and the northern part of the Russian Far East, and in May and October in the southern part of the Russian Far East. Using these data, we estimate direct carbon emissions from these Russian forest fires to be 39.3–55.4 Mt, five to eight times that from the 2001 North American boreal forest fires and around 11–17% of that years Russian industrial carbon emissions. This methodology will, in the future, be applied to the full VGT archive to quantify burned area and direct carbon emissions over a 5-year period in order to better assess the interannual variation in burned area and emissions and the relation to local climate.

Monitoring of Bashkara Glacier lakes (Central Caucasus, Russia) and modelling of their potential outburst

Glacier lakes pose threat to downstream settlements and infrastructure. In recent decades the number and area of lakes have been growing at an accelerating rate due to worldwide glacier shrinkage. In the Russian Caucasus this process is understudied. We present results obtained during a 12-year (1999–2010) continuous field monitoring of the Bashkara proglacial lakes group, which we identified as the place with the highest GLOF risk in the region. Recession of the parent Bashkara Glacier was the main driver of the rapid expansion of the lower Lake Lapa. The upper Lake Bashkara has not been enlarging, but its water level has shown significant inter- and intra-annual fluctuations. The lake outburst probability has increased in recent years, and in 2008 we observed surface overflow over the moraine dam. Taking into account that in the late 1950s lake outbursts at this site led to large-scale glacial debris flows, we have simulated a potential outburst using River and FLO-2D software and carried out hazard zonation. An early warning system has been designed and established at Lake Bashkara, and measures to mitigate risk have been proposed. Rapid change of proglacial lakes requires regular monitoring in ‘hot spot’ areas where the GLOF hazard is high and is dynamically changing.

Vegetation degradation in a permafrost region as seen from space: Noril'sk (1961–1999)

Abstract The presence and distribution of airborne and surface contaminants can often be inferred from their effects on vegetation, and this is particularly true in areas of frozen ground where the vegetation is especially vulnerable. In this paper, we take as a study area the region around the city of Norilsk in northern Siberia. Non-ferrous metal smelting has been carried out extensively in Norilsk since the 1930s, and it is now one of the worlds largest producers of nickel. The principal contaminants, which are extensive, are sulphur dioxide and heavy metals. Heat contamination from buildings and industrial activity is also significant in the immediate surroundings of the city where it has led to degradation of permafrost. We describe two approaches to the use of satellite imagery to monitor vegetation degradation in the Norilsk region. The first of these compares a panchromatic spy satellite image from 1961 with a multispectral satellite image acquired 34 years later to quantify the gross changes in land cover around Norilsk. This analysis shows a decrease of approximately 80 km 2 in the vegetated area around the city. The second approach is a regional multitemporal study based on the use of the Normalised Difference Vegetation Index, to which we apply a new correction for phenological variation. This analysis is used to identify a previously unreported area of vegetation decrease to the southwest of Norilsk.

Accelerated glacier shrinkage in the Ak-Shyirak massif, Inner Tien Shan, during 2003–2013

The observed increase in summer temperatures and the related glacier downwasting has led to a noticeable decrease of frozen water resources in Central Asia, with possible future impacts on the economy of all downstream countries in the region. Glaciers in the Ak-Shyirak massif, located in the Inner Tien Shan, are not only affected by climate change, but also impacted by the open pit gold mining of the Kumtor Gold Company. In this study, glacier inventories referring to the years 2003 and 2013 were created for the Ak-Shyirak massif based on satellite imagery. The 193 glaciers had a total area of 351.2±5.6km(2) in 2013. Compared to 2003, the total glacier area decreased by 5.9±3.4%. During 2003-2013, the shrinkage rate of Ak-Shyirak glaciers was twice than that in 1977-2003 and similar to shrinkage rates in Tien Shan frontier ranges. We assessed glacier volume in 2013 using volume-area (VA) scaling and GlabTop modelling approaches. Resulting values for the whole massif differ strongly, the VA scaling derived volume is 30.0-26.4km(3) whereas the GlabTop derived volume accounts for 18.8-13.2km(3). Ice losses obtained from both approaches were compared to geodetically-derived volume change. VA scaling underestimates ice losses between 1943 and 2003 whereas GlabTop reveals a good match for eight glaciers for the period 2003-2012. In comparison to radio-echo soundings from three glaciers, the GlabTop model reveals a systematic underestimation of glacier thickness with a mean deviation of 16%. GlabTop tends to significantly underestimate ice thickness in accumulation areas, but tends to overestimate ice thickness in the lowermost parts of glacier snouts. Direct technogenic impact is responsible for about 7% of area and 5% of mass loss for glaciers in the Ak-Shyirak massif during 2003-2013. Therefore the increase of summer temperature seems to be the main driver of accelerated glacier shrinkage in the area.

Glacial lake inventory and lake outburst potential in Uzbekistan

Climate change has been shown to increase the number of mountain lakes across various mountain ranges in the World. In Central Asia, and in particular on the territory of Uzbekistan, a detailed assessment of glacier lakes and their evolution over time is, however lacking. For this reason we created the first detailed inventory of mountain lakes of Uzbekistan based on recent (2002-2014) satellite observations using WorldView-2, SPOT5, and IKONOS imagery with a spatial resolution from 2 to 10m. This record was complemented with data from field studies of the last 50years. The previous data were mostly in the form of inventories of lakes, available in Soviet archives, and primarily included localized in-situ data. The inventory of mountain lakes presented here, by contrast, includes an overview of all lakes of the territory of Uzbekistan. Lakes were considered if they were located at altitudes above 1500m and if lakes had an area exceeding 100m2. As in other mountain regions of the World, the ongoing increase of air temperatures has led to an increase in lake number and area. Moreover, the frequency and overall number of lake outburst events have been on the rise as well. Therefore, we also present the first outburst assessment with an updated version of well-known approaches considering local climate features and event histories. As a result, out of the 242 lakes identified on the territory of Uzbekistan, 15% are considered prone to outburst, 10% of these lakes have been assigned low outburst potential and the remainder of the lakes have an average level of outburst potential. We conclude that the distribution of lakes by elevation shows a significant influence on lake area and hazard potential. No significant differences, by contrast, exist between the distribution of lake area, outburst potential, and lake location with respect to glaciers by regions.

Soil nutrient’s spatial variability in forest–tundra ecotones on the Kola Peninsula, Russia

This article addresses spatial variability in soil nutrients in altitudinal and latitudinal forest–tundra ecotones in the Kola Peninsula, Russia. Higher total carbon, nitrogen, and bio-available nutrients were found in the organic horizons of latitudinal ecotone against the background of lower nutrients in soil-forming rock. This is supposedly related to higher contribution of nutrient-rich plants in latitudinal ecotone and intense downward within-profile matter migration in the altitudinal ecotone. Elevated bio-available soil nutrients in spruce forests compared with birch forests and tundra sites, and in birch forests compared with tundra against the background of different trends in the soil-forming rock were attributed to the effects of predominant plants. The effects of predominant plants on soil nutrients were distinctly pronounced at the level of site patches. Soil-forming rock effects on soil nutrients were clear at the level of zones/belts and the whole ecotones. Strong negative correlations between the soil nutrients and altitudes were explained by replacement of vascular plants by low-ash lichens at higher elevations.

Application of hyperspectural images and ground data for precision farming

Crops, like other plants, clearly react to various changes in both natural and anthropogenic factors (herbicides, pesticides, fertilizers, etc.), which affects the amount of phytomass, its fractional composition, and developmental and physiological state of the plant, and, accordingly, is reflected in the spectral image. Data on spectral characteristics of plants allow users to determine quickly and with a high degree of reliability various indicators of the state of agricultural crops and thus improve the efficiency of agrotechnical practices and the use of land resources and facilitate the implementation of the precision farming concept. Reflective properties of plants (and hence crops) carry a large amount of meaningful information about the species, stage of development, and morpho-physiological state, allowing determination of the interrelations between the spectrometric characteristics and temporal physiological parameters. The paper presents the results of monitoring of the state of winter wheat and corn in experimental fields in southern and central Russia in the spring and summer of 2016.

Dendrogeomorphic reconstruction of lahar activity and triggers: Shiveluch volcano, Kamchatka Peninsula, Russia

Lahars are highly concentrated, water-saturated volcanic hyperconcentrated flows or debris flows containing pyroclastic material and are a characteristic mass movement process on volcanic slopes. On Kamchatka Peninsula (Russian Federation), lahars are widespread and may affect remote settlements. Historical records of past lahar occurrences are generally sparse and mostly limited to events which damaged infrastructure on the slopes or at the foot of volcanoes. In this study, we present a tree-ring-based reconstruction of spatiotemporal patterns of past lahar activity at Shiveluch volcano. Using increment cores and cross sections from 126 Larix cajanderi trees, we document 34 events covering the period AD 1729–2012. Analyses of the seasonality of damage in trees reveal that 95% of all lahars occurred between October and May and thus point to the predominant role of the sudden melt of the snow cover by volcanic material. These observations suggest that most lahars were likely syn-eruptive and that lahar activity is largely restricted to periods of volcanic activity. By contrast, rainfall events do not seem to play a significant role in lahar triggering.

Mapping the Anapa bay bar geosystems on the basis of satellite remote sensing and ground data

Our study is focused on the Anapa Bay Bar, a 43-km long body of sand on the Black Sea coast, which stretches from the Russian town of Anapa to the Zhelezny Rog Cape on the Taman’ peninsula. It is a major recreational resource and a host to unique ecosystems of beaches and partially vegetated sand dunes. Due to large recreational pressure, it is important to identify features of the bay bar that have to be preserved in order to keep this resource sustainable. We have conducted landscape and morphological mapping with WorldView-2 images. Methods included field research, analysis of multitemporal stereopairs and automated image interpretation to create maps of key areas of the Anapa Bay Bar. In our paper we showcase the map for a section of the Anapa Bay Bar created through visual image interpretation. It presents all morphological elements such as beaches, sand dunes, sand ridges and lowlands adjoining lagoons. Each element has its specific vegetation and sustainability against recreational pressure. We also present results of automated image analysis of seasonal dynamics of the beach and dunes on the basis of multitemporal imagery.

Linear spectral mixture modelling of arctic vegetation using ground spectroradiometry

An experimental linear mixture modelling using ground spectroradiometric measurements in the Kola Peninsula, Russia has been carried out to create a basis for mapping vegetation and non-vegetation components in the tundra-taiga ecotone using satellite imagery. We concentrated on the ground level experiment with the goal to use it further for the classification of multispectral satellite imagery through spectral unmixing. This experiment was performed on the most detailed level of remote sensing research which is free from atmospheric effects and easy to understand. We have measured typical ecotone components, including Cetraria nivalis, Betula tortuosa, Empetrum nigrum, Betula nana, Picea abies and rocks (nepheline syenite). The result of the experiment shows that the spectral mixture is indeed formed linearly but different components have different influence. Typical spectral thresholds for each component were found which are significant for vegetation mapping. Spectral unmixing of ground level data was performed and accuracy was estimated. The results add new information on typical spectral thresholds which can potentially be applied for multispectral satellite imagery when upscaling from high resolution to coarser resolution.