scholarly journals Spatial differentiation and temporal dynamics of drained raised bogs in Western Siberia

2021 ◽  
Vol 333 ◽  
pp. 02015
Author(s):  
Anna Sinyutkina
Keyword(s):  
Vegetation Index ◽  
Western Siberia ◽  
Temporal Dynamics ◽  
Spatial Differentiation ◽  
Temporal Analysis ◽  
Taiga Zone ◽  
Raised Bogs ◽  
Normalised Difference Vegetation Index ◽  
Key Sites ◽  
Landsat Satellite

This study analysed the influence of drainage on the vegetation cover of raised bogs in the taiga zone of Western Siberia. The study was based on a temporal analysis of Landsat satellite imagery data using the normalised difference vegetation index (NDVI) for the period from 1975–2020. We investigated four key sites within drained raised bogs. The analysis was not carried out using absolute NDVI values; rather, the ratio of the NDVI values of drained bogs to the NDVI values of a similar pristine bog was used. Four stages of the vegetation dynamics of drained bogs were determined. In the first stage, including the period before drainage, the NDVI values were close to those of the pristine site, which confirms that there are similar conditions before drainage. The second stage, from 1989–2001(2002), is characterised by a decrease in NDVI values relative to the pristine bog. This was probably due to the degradation of moss vegetation, which is a sensitive indicator of a decrease in the water table level in the absence of a significant growth of the tree layer. Furthermore, since the 2000s, there has been an increase in the NDVI values and they have stabilised at the level of a pristine bog.

scholarly journals Investigating peat deposits with ground-penetrating radar – a case study of drained bogs in Western Siberia, Russia

2021 ◽  
Vol 258 ◽  
pp. 12007
Author(s):  
Anna Sinyutkina
Keyword(s):  
Ground Penetrating Radar ◽  
Spatial Differentiation ◽  
Displacement Sensor ◽  
Peat Deposit ◽  
Taiga Zone ◽  
Peat Accumulation ◽  
Raised Bogs ◽  
Peat Deposits ◽  
Key Sites ◽  
Ground Penetrating

This paper deals with the assessment of the peat deposit transformation of two drained raised bogs (the Bakchar bog drained for forestry and the Ust-Bakchar bog drained for peat extraction) within the Western Siberian taiga zone. Specifically, the objectives of this study were to: 1) characterise the peat deposits of key sites with the use of ground-penetrating radar (GPR) and manual data; 2) estimate the spatial differentiation of modern peat accumulation rates at the microhabitat level. We used the GPR system “OKO-2” with 250, 700, and 1700 MHz shielded antennas and a displacement sensor. We concluded that the use of this GPR complex allowed the assessment of the total depth of the peat deposit, the depth of the fibric peat layer, and the thickness of the layer formed after drainage. We paid attention to defining the patterns of layers formed at depth after drainage within hummocks or hollow microhabitats. The peat accumulation after drainage was not continual throughout all mire surface, which was most typical for plots of the Ust-Bakchar bog. The modern peat accumulation increased 1.3–2.2 times from hollows to hummocks and it was 2–4 times higher within the Bakchar bog than in the Ust-Bakchar bog.

Assessment of changes in the state of the rangelands of Inner Mongolia, China between 1998 and 2007 using remotely sensed data

2012 ◽  
Vol 34 (1) ◽  
pp. 103 ◽  
Author(s):  
Z. M. Hu ◽  
S. G. Li ◽  
J. W. Dong ◽  
J. W. Fan
Keyword(s):  
Inner Mongolia ◽  
Vegetation Index ◽  
Net Primary Productivity ◽  
Temporal Dynamics ◽  
Remotely Sensed ◽  
The State ◽  
Mean Annual Precipitation ◽  
Aboveground Net Primary Productivity ◽  
Remotely Sensed Data ◽  
Normalised Difference Vegetation Index

The spatial annual patterns of aboveground net primary productivity (ANPP) and precipitation-use efficiency (PUE) of the rangelands of the Inner Mongolia Autonomous Region of China, a region in which several projects for ecosystem restoration had been implemented, are described for the years 1998–2007. Remotely sensed normalised difference vegetation index and ANPP data, measured in situ, were integrated to allow the prediction of ANPP and PUE in each 1 km2 of the 12 prefectures of Inner Mongolia. Furthermore, the temporal dynamics of PUE and ANPP residuals, as indicators of ecosystem deterioration and recovery, were investigated for the region and each prefecture. In general, both ANPP and PUE were positively correlated with mean annual precipitation, i.e. ANPP and PUE were higher in wet regions than in arid regions. Both PUE and ANPP residuals indicated that the state of the rangelands of the region were generally improving during the period of 2000–05, but declined by 2007 to that found in 1999. Among the four main grassland-dominated prefectures, the recovery in the state of the grasslands in the Erdos and Chifeng prefectures was highest, and Xilin Gol and Chifeng prefectures was 2 years earlier than Erdos and Hunlu Buir prefectures. The study demonstrated that the use of PUE or ANPP residuals has some limitations and it is proposed that both indices should be used together with relatively long-term datasets in order to maximise the reliability of the assessments.

scholarly journals Analysis of vegetation cover area as an urban environmental quality factor

2019 ◽  
Vol 36 (2) ◽  
pp. 95-107
Author(s):  
David Andrés Calvache ◽  
Angie Navarro ◽  
Álvaro Ceballos F.
Keyword(s):  
Environmental Quality ◽  
Vegetation Cover ◽  
Vegetation Index ◽  
Temporal Analysis ◽  
Urban Morphology ◽  
Population Exposure ◽  
Residential Energy ◽  
Multi Temporal ◽  
Landsat Satellite ◽  
The City

The process of urbanization modifies and eliminates biological components of urban morphology by replacing vegetation cover with gray surfaces. In this study, we aimed to identify the changes in vegetation cover in the city of San Juan de Pasto between the periphery and commune 1, which has the lowest vegetation cover in the city. We performed a multi-temporal analysis with LANDSAT satellite images over a period of 27 years (1989-2016) using the soil-adjusted vegetation index (SAVI) to determine the loss of urban vegetation cover (UVC). We estimated the urban environmental quality index (UEQI) based on the methodology proposed by the Ministry of Environment and Sustainable Development of Colombia (MinAmbiente), obtaining a score of 42 points that indicates low environmental quality. Furthermore, we calculated a new UEQI by mathematically extrapolating and correlating the theoretical benefits of UVC with environmental quality indicators, such as air quality, urban population exposure to noise exceeding the permitted levels, and residential energy consumption per capita. We found an improvement in the score of all the indicators and, consequently, the UEQI. We obtained a high projected environmental quality score of 60, demonstrating that UVC is a transforming factor of urban environmental quality due to the benefits provided by vegetation cover.

scholarly journals Assessment of Urban Expansion and Associated Spatial Transformation of Chandannagar City, West Bengal

2020 ◽  
Vol 7 (4) ◽  
pp. 109-121
Author(s):  
Giyasuddin Siddique ◽  
Subhendu Ghosh ◽  
Arindam Roy
Keyword(s):  
Land Use ◽  
Vegetation Index ◽  
Temporal Dynamics ◽  
Urban Expansion ◽  
Annual Growth Rate ◽  
Spatial Transformation ◽  
Remotely Sensed Data ◽  
Water Index ◽  
Normalised Difference Vegetation Index ◽  
The City

The Chandannagar city, as a former French colony and a historic trading centre, has witnessed a steady growth throughout the French colonial era, and the process is still in action even today. Such urban extension has altered the land use/cover (LULC) fabric both in the core and fringe areas by transforming the natural landscape. The prime goals of the study are to assess the magnitude of urban expansion of the city from 1991 to 2016 and its consequent spatial transformation by using geospatial techniques. Three indices, that is, Built-up Index (BUI), Normalised Difference Vegetation Index (NDVI) and Modified Normalised Difference Water Index (MNDWI) are employed to perceive the spatio-temporal dynamics of LULC from the remotely sensed data. Annual Growth Rate (AGR) and Land Use Integrated Index (LDI) are used to evaluate the rate, magnitude, and nature of changes. The results reveal that the rapid increase in built-up area from 7.9 sq. Km. in 1991 to 14.45 sq. Km. in 2016 has transformed nearly 51.52% of the non-forest vegetation covers and 58.18% of the water bodies of the city during the observation period.

scholarly journals Status of Phenological Research Using Sentinel-2 Data: A Review

2020 ◽  
Vol 12 (17) ◽  
pp. 2760
Author(s):  
Gourav Misra ◽  
Fiona Cawkwell ◽  
Astrid Wingler
Keyword(s):  
Vegetation Index ◽  
Temporal Frequency ◽  
Short Wave ◽  
Current State ◽  
Red Edge ◽  
Natural Grasslands ◽  
Wide Range ◽  
Normalised Difference Vegetation Index ◽  
Satellite Sensors ◽  
Sentinel 2

Remote sensing of plant phenology as an indicator of climate change and for mapping land cover has received significant scientific interest in the past two decades. The advancing of spring events, the lengthening of the growing season, the shifting of tree lines, the decreasing sensitivity to warming and the uniformity of spring across elevations are a few of the important indicators of trends in phenology. The Sentinel-2 satellite sensors launched in June 2015 (A) and March 2017 (B), with their high temporal frequency and spatial resolution for improved land mapping missions, have contributed significantly to knowledge on vegetation over the last three years. However, despite the additional red-edge and short wave infra-red (SWIR) bands available on the Sentinel-2 multispectral instruments, with improved vegetation species detection capabilities, there has been very little research on their efficacy to track vegetation cover and its phenology. For example, out of approximately every four papers that analyse normalised difference vegetation index (NDVI) or enhanced vegetation index (EVI) derived from Sentinel-2 imagery, only one mentions either SWIR or the red-edge bands. Despite the short duration that the Sentinel-2 platforms have been operational, they have proved their potential in a wide range of phenological studies of crops, forests, natural grasslands, and other vegetated areas, and in particular through fusion of the data with those from other sensors, e.g., Sentinel-1, Landsat and MODIS. This review paper discusses the current state of vegetation phenology studies based on the first five years of Sentinel-2, their advantages, limitations, and the scope for future developments.

scholarly journals Spatial-Temporal Analysis of the Forest Fragments Surrounding a Conservation Unit in the Southern Region of Brazil

2020 ◽  
Vol 3 (1) ◽  
pp. 48
Author(s):  
Bianca Fernandes ◽  
Ligia Batista
Keyword(s):  
Nearest Neighbor ◽  
Temporal Analysis ◽  
Management Plan ◽  
Edge Density ◽  
Forest Fragments ◽  
Conservation Unit ◽  
Border Effect ◽  
Action Strategies ◽  
Landsat Satellite ◽  
High Degree

In recent years, anthropogenic actions have intensified forest fragmentation, causing several damages to the landscape’s natural components, propagating the loss of biodiversity. This study aims to present an analysis of the forest fragments in a conservation unit located at southern of Brazil. The evaluation was carried out for the years 1998, 2008, and 2018, by using landscape metrics and classification of remote sensing imagery of the Landsat satellite. The following metrics were analyzed: area and edge, shape, core area, and aggregation. The results indicated an increase of 16.88% in the total area of vegetation, and the percentage of fragments increased from 16.16% to 18.89%. The number of fragments decreased, resulting in an increase of the mean area in 5.4 ha. The percentage of vegetation under border effect changed from 40.2% to 37.1%. In 1998, the average nearest neighbor distance was 155.4 m, and in 2018, 149.7 m. However, this distance is still classified as a high degree of isolation, which hinders the movement of organisms and the dispersion of species. Thus, all the analyzed metrics indicated a decrease in the fragmentation, except for the edge density metric, in which its increase of 1.86 pointed to a lower degree of conservation during the analyzed period. A study of this nature is important as it provides subsidies for future researches and can contribute to action strategies to be adopted in the management plan of the area.

scholarly journals The Multiscale Monitoring of Peatland Ecosystem Carbon Cycling in the Middle Taiga Zone of Western Siberia: The Mukhrino Bog Case Study

Land ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 824
Author(s):  
Egor Dyukarev ◽  
Evgeny Zarov ◽  
Pavel Alekseychik ◽  
Jelmer Nijp ◽  
Nina Filippova ◽  
...  
Keyword(s):  
Carbon Cycling ◽  
Western Siberia ◽  
Carbon Accumulation ◽  
Middle Taiga ◽  
Taiga Zone ◽  
Field Station ◽  
Moss Species ◽  
Chamber Method ◽  
The Impact

The peatlands of the West Siberian Lowlands, comprising the largest pristine peatland area of the world, have not previously been covered by continuous measurement and monitoring programs. The response of peatlands to climate change occurs over several decades. This paper summarizes the results of peatland carbon balance studies collected over ten years at the Mukhrino field station (Mukhrino FS, MFS) operating in the Middle Taiga Zone of Western Siberia. A multiscale approach was applied for the investigations of peatland carbon cycling. Carbon dioxide fluxes at the local scale studied using the chamber method showed net accumulation with rates from 110, to 57.8 gC m−2 at the Sphagnum hollow site. Net CO2 fluxes at the pine-dwarf shrubs-Sphagnum ridge varied from negative (−32.1 gC m−2 in 2019) to positive (13.4 gC m−2 in 2017). The cumulative May-August net ecosystem exchange (NEE) from eddy-covariance (EC) measurements at the ecosystem scale was −202 gC m−2 in 2015, due to the impact of photosynthesis of pine trees which was not registered by the chamber method. The net annual accumulation of carbon in the live part of mosses was estimated at 24–190 gC m−2 depending on the Sphagnum moss species. Long-term carbon accumulation rates obtained by radiocarbon analysis ranged from 28.5 to 57.2 gC m−2 yr−1, with local extremes of up to 176.2 gC m−2 yr−1. The obtained estimates of various carbon fluxes using EC and chamber methods, the accounting for Sphagnum growth and decomposition, and long-term peat accumulation provided information about the functioning of the peatland ecosystems at different spatial and temporal scales. Multiscale carbon flux monitoring reveals useful new information for forecasting the response of northern peatland carbon cycles to climatic changes.

scholarly journals Mapping the Spatial-Temporal Dynamics of Vegetation Response Lag to Drought in a Semi-Arid Region

2019 ◽  
Vol 11 (16) ◽  
pp. 1873 ◽  
Author(s):  
Li Hua ◽  
Huidong Wang ◽  
Haigang Sui ◽  
Brian Wardlow ◽  
Michael J. Hayes ◽  
...  
Keyword(s):  
Vegetation Index ◽  
Temporal Dynamics ◽  
Risk Mitigation ◽  
Scientific Information ◽  
Gaussian Function ◽  
Drought Risk ◽  
Severe Drought ◽  
Similar Response ◽  
Vegetation Types ◽  
Data Set

Drought, as an extreme climate event, affects the ecological environment for vegetation and agricultural production. Studies of the vegetative response to drought are paramount to providing scientific information for drought risk mitigation. In this paper, the spatial-temporal pattern of drought and the response lag of vegetation in Nebraska were analyzed from 2000 to 2015. Based on the long-term Daymet data set, the standard precipitation index (SPI) was computed to identify precipitation anomalies, and the Gaussian function was applied to obtain temperature anomalies. Vegetation anomaly was identified by dynamic time warping technique using a remote sensing Normalized Difference Vegetation Index (NDVI) time series. Finally, multilayer correlation analysis was applied to obtain the response lag of different vegetation types. The results show that Nebraska suffered severe drought events in 2002 and 2012. The response lag of vegetation to drought typically ranged from 30 to 45 days varying for different vegetation types and human activities (water use and management). Grasslands had the shortest response lag (~35 days), while forests had the longest lag period (~48 days). For specific crop types, the response lag of winter wheat varied among different regions of Nebraska (35–45 days), while soybeans, corn and alfalfa had similar response lag times of approximately 40 days.

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