Modelling and mapping permafrost at high spatial resolution in Wapusk National Park, Hudson Bay Lowlands1This article is one of a series of papers published in this CJES Special Issue on the theme of Fundamental and applied research on permafrost in Canada.2Earth Science Sector Contribution 20110058.

2012 ◽  
Vol 49 (8) ◽  
pp. 925-937 ◽  
Author(s):  
Yu Zhang ◽  
Junhua Li ◽  
Xiping Wang ◽  
Wenjun Chen ◽  
Wendy Sladen ◽  
...  
Keyword(s):  
Land Cover ◽  
Layer Thickness ◽  
Spatial Resolution ◽  
Active Layer ◽  
High Spatial Resolution ◽  
Landsat Imagery ◽  
Field Measurements ◽  
Active Layer Thickness ◽  
Hudson Bay ◽  
Climate Data

Most spatial modelling of permafrost distribution and dynamics has been conducted at half-degree latitude/longitude or coarser resolution. Such coarse results are difficult to use for land managers and ecologists. Here we mapped permafrost distribution at 30 m × 30 m resolution for a region in the northwest Hudson Bay Lowlands using a process-based model. Land-cover types and leaf area indices were derived from Landsat imagery; peat thickness was estimated from elevation based on field measurements; and climate data were interpolated from station observations. The modelled active-layer thickness and permafrost extent compared well with field observations, demonstrating that modelling and mapping permafrost at a high spatial resolution is practical for terrains such as these lowlands. The map portrayed large variations in active-layer thickness, with land-cover type and peat thickness being the most important controlling variables. The modelled active-layer thickness on average increased by 37% during the twentieth century due to increases in air temperature and precipitation, and permafrost disappeared in some southern areas. The spatial scale of the permafrost maps developed in this study is close to that of the ecosystem and landscape features; therefore, the results are useful for land management and ecosystem assessment.

scholarly journals Modelling and mapping climate change impacts on permafrost at high spatial resolution for a region with complex terrain

2012 ◽  
Vol 6 (6) ◽  
pp. 4599-4636
Author(s):  
Y. Zhang ◽  
X. Wang ◽  
R. Fraser ◽  
I. Olthof ◽  
W. Chen ◽  
...  
Keyword(s):  
Climate Change ◽  
Layer Thickness ◽  
Spatial Resolution ◽  
Active Layer ◽  
Complex Terrain ◽  
High Spatial Resolution ◽  
Climate Change Impacts ◽  
Active Layer Thickness ◽  
Topographic Effects ◽  
Field Observations

Abstract. Most spatial modelling of climate change impacts on permafrost has been conducted at half-degree latitude/longitude or coarser spatial resolution. At such coarse resolution, topographic effects on insolation cannot be considered accurately and the modelling results are difficult to use for land managers and ecologists. Here we mapped climate change impacts on permafrost from 1968 to 2100 at 10 m resolution using a process-based model for Ivvavik National Park, a region with complex terrain in northern Yukon, Canada. Soil and drainage conditions were defined based on ecosystem types, which were mapped using SPOT imagery, a digital elevation model and field observations. Leaf area indices were mapped using Landsat imagery and the ecosystem map. Climate distribution was estimated based on elevation and station observations, and the effects of topography on insolation were estimated based on slope, aspect and viewshed. To reduce computation time, we clustered climate distribution and topographic effects on insolation into discrete types. The modelled active-layer thickness and permafrost distribution were comparable with field observations and other studies, demonstrating that it is practical to model and map climate change impacts on permafrost at high spatial resolution for areas with complex terrain. The map portrayed large variations in active-layer thickness, with ecosystem types being the most important controlling variable, followed by climate, including topographic effects on insolation. This study also shows that climate scenarios and ground conditions are the major sources of uncertainty for high resolution permafrost mapping.

scholarly journals Permafrost temperature and active-layer thickness of Yakutia with 0.5-degree spatial resolution for model evaluation

2013 ◽  
Vol 5 (2) ◽  
pp. 305-310 ◽  
Author(s):  
C. Beer ◽  
A. N. Fedorov ◽  
Y. Torgovkin
Keyword(s):  
Layer Thickness ◽  
Spatial Resolution ◽  
Active Layer ◽  
Land Surface ◽  
Grid Cell ◽  
Active Layer Thickness ◽  
East Siberia ◽  
Permafrost Temperature ◽  
Surface Models ◽  
The Mean

Abstract. Based on the map of landscapes and permafrost conditions in Yakutia (Merzlotno-landshaftnaya karta Yakutskoi0 ASSR, Gosgeodeziya SSSR, 1991), rasterized maps of permafrost temperature and active-layer thickness of Yakutia, East Siberia were derived. The mean and standard deviation at 0.5-degree grid cell size are estimated by assigning a probability density function at 0.001-degree spatial resolution. The gridded datasets can be accessed at the PANGAEA repository (doi:10.1594/PANGAEA.808240). Spatial pattern of both variables are dominated by a climatic gradient from north to south, and by mountains and the soil type distribution. Uncertainties are highest in mountains and in the sporadic permafrost zone in the south. The maps are best suited as a benchmark for land surface models which include a permafrost module.

Estimation of active layer thickness from modeling and InSAR deformation data at QTP

2020 ◽  
Author(s):  
Rongxing Li ◽  
Tong Hao ◽  
Ping Lu ◽  
Gang Qiao ◽  
Lemin Chen ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Active Layer ◽  
Large Scale ◽  
Surface Deformation ◽  
Remote Sensing Data ◽  
Field Measurements ◽  
Active Layer Thickness ◽  
Quality Of Data ◽  
Spatial Coverage ◽  
Sbas Insar

<p>In context of global warming, permafrost, as an important component of cryosphere in the Qinghai-Tibetan Plateau (QTP) that is located in middle and low latitudes with a high radiation intensity of high Asia mountains, is particularly sensitive to climate changes. The active layer thickness (ALT) in a permafrost area is an important index to indicate its stability. Traditional methods for measuring ALT in QTP mainly rely on ground-based field surveys and accordingly are extremely time- consuming and labor-intensive. The field works provide a good quality of data at a single site, however, such measurements are limited in spatial coverage and difficult for multi-temporal acquisitions. In addition, the harsh environment in QTP is not suitable for large-scale field measurements. In this study, the ALT of permafrost in QTP is estimated using modelling and remote sensing data. Particularly, the surface deformation on permafrost, as detected by the long-term InSAR technique, is considered as an input to the inversion model of ALT. The time-series deformation results over an experimental permafrost area were obtained by the SBAS-InSAR technique. Then, combined with the soil characteristics of soil moisture and soil thermal conductivity in the Stefan model, the melting thickness was estimated. Finally, the resulting ALT was tested and verified against a set of in-situ borehole measurements of depth-temperature.</p>

scholarly journals Modelling and mapping climate change impacts on permafrost at high spatial resolution for an Arctic region with complex terrain

2013 ◽  
Vol 7 (4) ◽  
pp. 1121-1137 ◽  
Author(s):  
Y. Zhang ◽  
X. Wang ◽  
R. Fraser ◽  
I. Olthof ◽  
W. Chen ◽  
...  
Keyword(s):  
Climate Change ◽  
Layer Thickness ◽  
Spatial Resolution ◽  
Active Layer ◽  
Complex Terrain ◽  
Climate Change Impacts ◽  
Arctic Region ◽  
Slope Aspect ◽  
Active Layer Thickness ◽  
Topographic Effects

Abstract. Most spatial modelling of climate change impacts on permafrost has been conducted at half-degree latitude/longitude or coarser spatial resolution. At such coarse resolution, topographic effects on insolation cannot be considered accurately and the results are not suitable for land-use planning and ecological assessment. Here we mapped climate change impacts on permafrost from 1968 to 2100 at 10 m resolution using a process-based model for Ivvavik National Park, an Arctic region with complex terrain in northern Yukon, Canada. Soil and drainage conditions were defined based on ecosystem types, which were mapped using SPOT imagery. Leaf area indices were mapped using Landsat imagery and the ecosystem map. Climate distribution was estimated based on elevation and station observations, and the effects of topography on insolation were calculated based on slope, aspect and viewshed. To reduce computation time, we clustered climate distribution and topographic effects on insolation into discrete types. The modelled active-layer thickness and permafrost distribution were comparable with field observations and other studies. The map portrayed large variations in active-layer thickness, with ecosystem types being the most important controlling variable, followed by climate, including topographic effects on insolation. The results show deepening in active-layer thickness and progressive degradation of permafrost, although permafrost will persist in most of the park during the 21st century. This study also shows that ground conditions and climate scenarios are the major sources of uncertainty for high-resolution permafrost mapping.

scholarly journals Permafrost temperature and active-layer thickness of Yakutia with 0.5 degree spatial resolution for model evaluation

2013 ◽  
Vol 6 (1) ◽  
pp. 153-162 ◽  
Author(s):  
C. Beer ◽  
A. N. Fedorov ◽  
Y. Torgovkin
Keyword(s):  
Layer Thickness ◽  
Spatial Resolution ◽  
Active Layer ◽  
Land Surface ◽  
Grid Cell ◽  
Active Layer Thickness ◽  
East Siberia ◽  
Permafrost Temperature ◽  
Surface Models ◽  
The Mean

Abstract. Based on the map of landscapes and permafrost conditions in Yakutia (Merzlotno-landshaftnaya karta Yakutskoi0 ASSR, Gosgeodeziya SSSR, 1991), rasterized maps of permafrost temperature and active-layer thickness of Yakutia, East Siberia were derived. The mean and standard deviation at 0.5 degree grid cell size are estimated by assigning a probability density function at 0.001 degree spatial resolution. The gridded datasets can be accessed at the PANGAEA repository (doi:10.1594/PANGAEA.808240). Spatial pattern of both variables are dominated by a climatic gradient from north to south, and by mountains and the soil type distribution. Uncertainties are highest in mountains and in the isolated permafrost zone in the south. The maps are best suited as a benchmark for land surface models which include a permafrost module.

scholarly journals Active Layer Thickness Estimation from X-Band SAR Backscatter Intensity

2016 ◽  
Author(s):  
Barbara Widhalm ◽  
Annett Bartsch ◽  
Marina Leibman ◽  
Artem Khomutov
Keyword(s):  
Land Cover ◽  
Layer Thickness ◽  
Active Layer ◽  
Satellite Data ◽  
Active Layer Thickness ◽  
Vegetation Types ◽  
Backscatter Intensity ◽  
X Band ◽  
Spatial Coverage ◽  
The Relationship

Abstract. The active layer above the permafrost, which seasonally thaws during summer is an important parameter for monitoring the state of permafrost. Its thickness is typically measured locally. A range of methods, which utilize information from satellite data exist. Their applicability has been demonstrated mostly for shallow depths below 70 cm. Some permafrost areas including central Yamal are characterized by higher Active Layer Thickness (ALT). The relationship between ALT and X-Band SAR backscatter of TerraSAR-X has been investigated in order to explore the possibility of delineating ALT on a continuous and larger spatial coverage in this area. This study shows that the mutual dependency of ALT and TerraSAR-X backscatter on land cover types induces a connection of both parameters. A range of 5 dB can be observed for an ALT range of 100 cm (40–140 cm) and an R2 of 0.66 has been determined over the calibration sites. An increase of ALT with increasing backscatter can be especially determined for ALT > 70 cm. The RMSE over a comparably heterogeneous validation site with maximum ALT of > 150 cm is in the range of 20–22 cm. Deviations are larger for measurement locations with mixed vegetation types.

scholarly journals Classification of Very-High-Spatial-Resolution Aerial Images Based on Multiscale Features with Limited Semantic Information

2021 ◽  
Vol 13 (3) ◽  
pp. 364
Author(s):  
Han Gao ◽  
Jinhui Guo ◽  
Peng Guo ◽  
Xiuwan Chen
Keyword(s):  
Deep Learning ◽  
Land Cover ◽  
Spatial Resolution ◽  
Large Scale ◽  
High Spatial Resolution ◽  
Training Data ◽  
Aerial Images ◽  
Rural Landscapes ◽  
Feature Representations ◽  
Object Based

Recently, deep learning has become the most innovative trend for a variety of high-spatial-resolution remote sensing imaging applications. However, large-scale land cover classification via traditional convolutional neural networks (CNNs) with sliding windows is computationally expensive and produces coarse results. Additionally, although such supervised learning approaches have performed well, collecting and annotating datasets for every task are extremely laborious, especially for those fully supervised cases where the pixel-level ground-truth labels are dense. In this work, we propose a new object-oriented deep learning framework that leverages residual networks with different depths to learn adjacent feature representations by embedding a multibranch architecture in the deep learning pipeline. The idea is to exploit limited training data at different neighboring scales to make a tradeoff between weak semantics and strong feature representations for operational land cover mapping tasks. We draw from established geographic object-based image analysis (GEOBIA) as an auxiliary module to reduce the computational burden of spatial reasoning and optimize the classification boundaries. We evaluated the proposed approach on two subdecimeter-resolution datasets involving both urban and rural landscapes. It presented better classification accuracy (88.9%) compared to traditional object-based deep learning methods and achieves an excellent inference time (11.3 s/ha).

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