Brief Communication: Evaluation and comparisons of permafrost map over Qinghai-Tibet Plateau based on inventory of in-situ evidence

Abstract. Many maps have been produced to estimate permafrost distribution over the Qinghai-Tibet Plateau, however, the evaluation and comparisons of them are poorly understood due to limited evidence. Using a large number data from various sources, we present the inventory of permafrost presence/absence with 1475 sites/plots over the QTP. Based on the in-situ measurements, our evaluation results showed a wide range of map performance with the overall accuracy of about 59–82 %, and the estimated permafrost region (1.42–1.84 × 106 km2) and area (0.76–1.25 × 106 km2) are extremely large. The low agreement in areas near permafrost boundary and fragile landscapes require improved method considering more controlling factors at both medium-large and local scales.

Download Full-text

Brief communication: Evaluation and inter-comparisons of Qinghai–Tibet Plateau permafrost maps based on a new inventory of field evidence

The Cryosphere ◽

10.5194/tc-13-511-2019 ◽

2019 ◽

Vol 13 (2) ◽

pp. 511-519 ◽

Cited By ~ 5

Author(s):

Bin Cao ◽

Tingjun Zhang ◽

Qingbai Wu ◽

Yu Sheng ◽

Lin Zhao ◽

...

Keyword(s):

Kappa Coefficient ◽

Controlling Factors ◽

In Situ Measurements ◽

Tibet Plateau ◽

Field Evidence ◽

Wide Range ◽

Communication Evaluation ◽

Qinghai Tibet Plateau ◽

Variable Landscapes

Abstract. Many maps have been produced to estimate permafrost distribution over the Qinghai–Tibet Plateau (QTP), but the errors and biases among them are poorly understood due to limited field evidence. Here we evaluate and inter-compare the results of six different QTP permafrost maps with a new inventory of permafrost presence or absence comprising 1475 field sites compiled from various sources. Based on the in situ measurements, our evaluation results showed a wide range of map performance, with Cohen's kappa coefficient from 0.21 to 0.58 and an overall accuracy between about 55 % and 83 %. The low agreement in areas near the boundary between permafrost and non-permafrost and in spatially highly variable landscapes highlights the need for improved mapping methods that consider more controlling factors at both medium–large and local scales.

Download Full-text

Supplementary material to "Brief Communication: Evaluation and comparisons of permafrost map over Qinghai-Tibet Plateau based on inventory of in-situ evidence"

10.5194/tc-2018-190-supplement ◽

2018 ◽

Author(s):

Bin Cao ◽

Tingjun Zhang ◽

Qinghai Wu ◽

Yu Sheng ◽

Lin Zhao ◽

...

Keyword(s):

Tibet Plateau ◽

Supplementary Material ◽

Communication Evaluation ◽

Qinghai Tibet Plateau

Download Full-text

In Situ Measurements of Organic Carbon in Soil Profiles Using vis-NIR Spectroscopy on the Qinghai–Tibet Plateau

Environmental Science & Technology ◽

10.1021/es504272x ◽

2015 ◽

Vol 49 (8) ◽

pp. 4980-4987 ◽

Cited By ~ 52

Author(s):

Shuo Li ◽

Zhou Shi ◽

Songchao Chen ◽

Wenjun Ji ◽

Lianqing Zhou ◽

...

Keyword(s):

Organic Carbon ◽

Nir Spectroscopy ◽

In Situ Measurements ◽

Tibet Plateau ◽

Soil Profiles ◽

Qinghai Tibet Plateau

Download Full-text

Non-growing season soil CO2 flux and its contribution to annual soil CO2 emissions in two typical grasslands in the permafrost region of the Qinghai-Tibet Plateau

European Journal of Soil Biology ◽

10.1016/j.ejsobi.2015.10.004 ◽

2015 ◽

Vol 71 ◽

pp. 45-52 ◽

Cited By ~ 17

Author(s):

Tao Zhang ◽

Genxu Wang ◽

Yan Yang ◽

Tianxu Mao ◽

Xiaopeng Chen

Keyword(s):

Co2 Emissions ◽

Co2 Flux ◽

Growing Season ◽

Tibet Plateau ◽

Permafrost Region ◽

Soil Co2 ◽

Soil Co2 Flux ◽

Soil Co2 Emissions ◽

Qinghai Tibet Plateau

Download Full-text

Water regime shifts in the active soil layer of the Qinghai–Tibet Plateau permafrost region, under different levels of vegetation

Geoderma ◽

10.1016/j.geoderma.2008.12.008 ◽

2009 ◽

Vol 149 (3-4) ◽

pp. 280-289 ◽

Cited By ~ 18

Author(s):

Wang Genxu ◽

Li Shengnan ◽

Hu Hongchang ◽

Li Yuanshou

Keyword(s):

Water Regime ◽

Soil Layer ◽

Regime Shifts ◽

Tibet Plateau ◽

Permafrost Region ◽

Qinghai Tibet Plateau ◽

Different Levels

Download Full-text

Validation of modeled snow properties in Afghanistan, Pakistan, and Tajikistan

10.5194/tc-2019-150 ◽

2019 ◽

Author(s):

Edward H. Bair ◽

Karl Rittger ◽

Jawairia A. Ahmad ◽

Doug Chabot

Keyword(s):

Snow Depth ◽

Snow Water Equivalent ◽

Median Number ◽

In Situ Measurements ◽

Snow Properties ◽

Wide Range ◽

Spatial Estimates ◽

Snow Water ◽

Critical Layers

Abstract. Ice and snowmelt feed the Indus and Amu Darya rivers, yet there are limited in situ measurements of these resources. Previous work in the region has shown promise using snow water equivalent (SWE) reconstruction, which requires no in situ measurements, but validation has been a problem until recently when we were provided with daily manual snow depth measurements from Afghanistan, Tajikistan, and Pakistan by the Aga Khan Agency for Habitat (AKAH). For each station, accumulated precipitation and SWE were derived from snow depth using the SNOWPACK model. High-resolution (500 m) reconstructed SWE estimates from the ParBal model were then compared to the modeled SWE at the stations. The Alpine3D model was then used to create spatial estimates at 25 km to compare with estimates from other snow models. Additionally, the coupled SNOWPACK and Alpine3D system has the advantage of simulating snow profiles, which provide stability information. Following previous work, the median number of critical layers and percentage of facets across all of the pixels containing the AKAH stations was computed. For SWE at the point scale, the reconstructed estimates showed a bias of −42 mm (−19 %) at the peak. For the coarser spatial SWE estimates, the various models showed a wide range, with reconstruction being on the lower end. For stratigraphy, a heavily faceted snowpack is observed in both years, but 2018, a dry year, according to most of the models, showed more critical layers that persisted for a longer period.

Download Full-text