scholarly journals Climate Change and Livestock Management Drove Extensive Vegetation Recovery in the Qinghai-Tibet Plateau

2021 ◽  
Vol 13 (23) ◽  
pp. 4808
Author(s):  
Enqin Liu ◽  
Xiangming Xiao ◽  
Huaiyong Shao ◽  
Xin Yang ◽  
Yali Zhang ◽  
...  
Keyword(s):  
Climate Change ◽  
Tibet Plateau ◽  
Positive Trend ◽  
Vegetation Degradation ◽  
Livestock Population ◽  
Northern Tibet ◽  
Rate Of Increase ◽  
The Impact ◽  
Qinghai Tibet Plateau ◽  
Impacts Of Climate Change

The vegetation of the Qinghai-Tibet Plateau (QTP), China, is diverse and sensitive to climate change. Because of extensive grassland degradation in the QTP, several ecological restoration projects, which affect the livestock population, have been implemented in the QTP. Although many studies have reported the impacts of climate change on vegetation in the QTP, our knowledge on the impacts of both climate change and livestock on vegetation remains very limited. Here, we investigated the impacts of climate change and livestock population on vegetation growth by using the annual maximum normalized difference vegetation index (NDVImax) and growing-season climate data from 1981 to 2019. We analyzed the relationship between NDVImax and climate and livestock population using the modified Mann-Kendall trend Test and Pearson correlation analysis. For the entire QTP, NDVImax had a two-phase trend, with a slow rise during 1981–2000 and a rapid rise during 2000–2019. Overall, NDVImax in the QTP increased and decreased in 63.7% and 6.7% of the area in 2000–2019. In areas with significant changes in NDVImax, it was strongly correlated with relative humidity and vapor pressure. The small positive trend in NDVImax during 1981–2000 was influenced by warmer and wetter climate, and the overgrazing by a large population of livestock slowed down the rate of increase in NDVImax. Livestock population for Qinghai and Tibet in recent years has been lower than in the 1980s.The warmer and wetter climate and substantial drops in the livestock population contributed to large recovery in vegetation during 2001–2019. Vegetation degradation in Qinghai during 1981–2000 and central-northern Tibet during 2000–2019 was driven mainly by drier and hotter climatic. Although 63.7% of the area in the QTP became greener, the vegetation degradation in central-northern Tibet should not be ignored and more measures should be taken to alleviate the impact of warming and drying climate. Our findings provide a better understanding of the factors that drove changes in vegetation in the QTP.

scholarly journals The Impact of Climate Change on the Surface Albedo over the Qinghai-Tibet Plateau

2021 ◽  
Vol 13 (12) ◽  
pp. 2336
Author(s):  
Chaonan Chen ◽  
Li Tian ◽  
Lianqi Zhu ◽  
Yuanke Zhou
Keyword(s):  
Climate Change ◽  
Solar Radiation ◽  
Land Surface ◽  
Meteorological Data ◽  
Growing Season ◽  
High Elevation ◽  
Tibet Plateau ◽  
Decrease Rate ◽  
The Impact ◽  
Qinghai Tibet Plateau

Albedo is a characterization of the Earth’s surface ability to reflect solar radiation, and control the amount of solar radiation absorbed by the land surface. Within the context of global warming, the temporal and spatial changes of the albedo and its response to climate factors remain unclear. Based on MCD43A3 (V005) albedo and meteorological data (i.e., temperature and precipitation), we analyzed the spatiotemporal variations of albedo (2000–2016) and its responses to climate change during the growing season on the Qinghai-Tibet Plateau (QTP). The results indicated an overall downward trend in the annual albedo during the growing season, the decrease rate was 0.25%/decade, and the monthly albedo showed a similar trend, especially in May, when the decrease rate was 0.53%/decade. The changes also showed regional variations, such as for the annual albedo, the areas with significant decrease and increase in albedo were 181.52 × 103 km2 (13.10%) and 48.82 × 103 km2 (3.52%), respectively, and the intensity of albedo changes in low-elevation areas was more pronounced than in high-elevation areas. In addition, the annual albedo-temperature/precipitation relationships clearly differed at different elevations. The albedo below 2000 m and at 5000–6000 m was mainly negatively correlated with temperature, while at 2000–4000 m it was mainly negatively correlated with precipitation. The contemporaneous temperature could negatively impact the monthly albedo in significant ways at the beginning of the growing season (May and June), whereas in the middle of the growing season (July and August), the albedo was mainly negatively correlated with precipitation, and at the end of the growing season (September), the albedo showed a weak correlation with temperature/precipitation.

The impact of climate change and anthropogenic activities on alpine grassland over the Qinghai-Tibet Plateau

2014 ◽  
Vol 189-190 ◽  
pp. 11-18 ◽  
Author(s):  
Baoxiong Chen ◽  
Xianzhou Zhang ◽  
Jian Tao ◽  
Jianshuang Wu ◽  
Jingsheng Wang ◽  
...  
Keyword(s):  
Climate Change ◽  
Anthropogenic Activities ◽  
Alpine Grassland ◽  
Tibet Plateau ◽  
Impact Of Climate Change ◽  
The Impact ◽  
Qinghai Tibet Plateau

The Impact of Climate Change on Storage-Yield Curves for Multi-Reservoir Systems

1999 ◽  
Vol 30 (2) ◽  
pp. 129-146 ◽  
Author(s):  
N. R. Nawaz ◽  
A. J. Adeloye ◽  
M. Montaseri
Keyword(s):  
Climate Change ◽  
Surface Fluxes ◽  
Runoff Coefficient ◽  
Impact Study ◽  
Yield Functions ◽  
Reservoir Systems ◽  
English System ◽  
Multiple Reservoir ◽  
The Impact ◽  
Impacts Of Climate Change

In this paper, we report on the results of an investigation into the impacts of climate change on the storage-yield relationships for two multiple-reservoir systems, one in England and the other in Iran. The impact study uses established protocol and obtains perturbed monthly inflow series using a simple runoff coefficient approach which accounts for non-evaporative losses in the catchment, and a number of recently published GCM-based scenarios. The multi-reservoir analysis is based on the sequent-peak algorithm which has been modified to analyse multiple reservoirs and to accommodate explicitly performance norms and reservoir surface fluxes, i.e. evaporation and rainfall. As a consequence, it was also possible to assess the effect of including reservoir surface fluxes on the storage-yield functions. The results showed that, under baseline conditions, consideration of net evaporation will require lower storages for the English system and higher storages for the Iranian system. However, with perturbed hydroclimatology different impacts were obtained depending on the systems' yield and reliability. Possible explanations are offered for the observed behaviours.

scholarly journals Spatial and Temporal Differences in Alpine Meadow, Alpine Steppe and All Vegetation of the Qinghai-Tibetan Plateau and Their Responses to Climate Change

2021 ◽  
Vol 13 (4) ◽  
pp. 669
Author(s):  
Hanchen Duan ◽  
Xian Xue ◽  
Tao Wang ◽  
Wenping Kang ◽  
Jie Liao ◽  
...  
Keyword(s):  
Climate Change ◽  
Alpine Meadow ◽  
Global Climate ◽  
Growing Season ◽  
Tibet Plateau ◽  
Vegetation Types ◽  
Analysis Method ◽  
Alpine Steppe ◽  
Qinghai Tibet Plateau ◽  
Variation Trends

Alpine meadow and alpine steppe are the two most widely distributed nonzonal vegetation types in the Qinghai-Tibet Plateau. In the context of global climate change, the differences in spatial-temporal variation trends and their responses to climate change are discussed. It is of great significance to reveal the response of the Qinghai-Tibet Plateau to global climate change and the construction of ecological security barriers. This study takes alpine meadow, alpine steppe and the overall vegetation of the Qinghai-Tibet Plateau as the research objects. The normalized difference vegetation index (NDVI) data and meteorological data were used as the data sources between 2000 and 2018. By using the mean value method, threshold method, trend analysis method and correlation analysis method, the spatial and temporal variation trends in the alpine meadow, alpine steppe and the overall vegetation of the Qinghai-Tibet Plateau were compared and analyzed, and their differences in the responses to climate change were discussed. The results showed the following: (1) The growing season length of alpine meadow was 145~289 d, while that of alpine steppe and the overall vegetation of the Qinghai-Tibet Plateau was 161~273 d, and their growing season lengths were significantly shorter than that of alpine meadow. (2) The annual variation trends of the growing season NDVI for the alpine meadow, alpine steppe and the overall vegetation of the Qinghai-Tibet Plateau increased obviously, but their fluctuation range and change rate were significantly different. (3) The overall vegetation improvement in the Qinghai-Tibet Plateau was primarily dominated by alpine steppe and alpine meadow, while the degradation was primarily dominated by alpine meadow. (4) The responses between the growing season NDVI and climatic factors in the alpine meadow, alpine steppe and the overall vegetation of the Qinghai-Tibet Plateau had great spatial heterogeneity in the Qinghai-Tibet Plateau. These findings provide evidence towards understanding the characteristics of the different vegetation types in the Qinghai-Tibet Plateau and their spatial differences in response to climate change.

Extreme weather highlights longer-term Canada concerns

2022 ◽  
Keyword(s):  
Climate Change ◽  
Indigenous Peoples ◽  
Clean Energy ◽  
Focused Attention ◽  
Content Type ◽  
Weather Patterns ◽  
Extreme Cold ◽  
The Impact ◽  
Ways Of Life ◽  
Impacts Of Climate Change

Significance The extreme cold comes as the province is still dealing with the damage caused by unprecedented levels of heat and wildfires last summer and then record levels of rainfall and flooding in November. Its experience has focused attention on Canada’s wider vulnerability to the impact of shifting weather patterns and climate change. Impacts The natural resource sectors that are vital to Canada’s economy face an increasingly difficult environment for extraction. Indigenous peoples across the country will see their traditional ways of life further disrupted by climate change. The increasingly evident impacts of climate change on day-to-day life will see voters demand greater action from government. Significant investment in green initiatives, clean energy and climate resiliency initiatives will boost green industries.

Spatial variability of topsoil δ13C across Qinghai-Tibet Plateau

2021 ◽  
Author(s):  
Yunsen Lai ◽  
Shaoda Li ◽  
Xiaolu Tang ◽  
Xinrui Luo ◽  
Liang Liu ◽  
...  
Keyword(s):  
Climate Change ◽  
Machine Learning ◽  
Spatial Variability ◽  
Soil Carbon ◽  
Tibet Plateau ◽  
Learning Approach ◽  
Carbon Turnover ◽  
Machine Learning Approach ◽  
Qinghai Tibet Plateau ◽  
Soil Carbon Turnover

<p>Soil carbon isotopes (δ<sup>13</sup>C) provide reliable insights at the long-term scale for the study of soil carbon turnover and topsoil δ<sup>13</sup>C could well reflect organic matter input from the current vegetation. Qinghai-Tibet Plateau (QTP) is called “the third pole of the earth” because of its high elevation, and it is one of the most sensitive and critical regions to global climate change worldwide. Previous studies focused on variability of soil δ<sup>13</sup>C at in-site scale. However, a knowledge gap still exists in the spatial pattern of topsoil δ<sup>13</sup>C in QTP. In this study, we first established a database of topsoil δ<sup>13</sup>C with 396 observations from published literature and applied a Random Forest (RF) algorithm (a machine learning approach) to predict the spatial pattern of topsoil δ<sup>13</sup>C using environmental variables. Results showed that topsoil δ<sup>13</sup>C significantly varied across different ecosystem types (p < 0.05).  Topsoil δ<sup>13</sup>C was -26.3 ± 1.60 ‰ for forest, 24.3 ± 2.00 ‰ for shrubland, -23.9 ± 1.84 ‰ for grassland, -18.9 ± 2.37 ‰ for desert, respectively. RF could well predict the spatial variability of topsoil δ<sup>13</sup>C with a model efficiency (pseudo R<sup>2</sup>) of 0.65 and root mean square error of 1.42. The gridded product of topsoil δ<sup>13</sup>C and topsoil β (indicating the decomposition rate of soil organic carbon, calculated by δ<sup>13</sup>C divided by logarithmically converted SOC) with a spatial resolution of 1000 m were developed. Strong spatial variability of topsoil δ<sup>13</sup>C was observed, which increased gradually from the southeast to the northwest in QTP. Furthermore, a large variation was found in β, ranging from -7.87 to -81.8, with a decreasing trend from southeast to northwest, indicating that carbon turnover rate was faster in northwest QTP compared to that of southeast. This study was the first attempt to develop a fine resolution product of topsoil δ<sup>13</sup>C for QTP using a machine learning approach, which could provide an independent benchmark for biogeochemical models to study soil carbon turnover and terrestrial carbon-climate feedbacks under ongoing climate change.</p>

scholarly journals Characterizing Hydrological Connectivity of Artificial Ditches in Zoige Peatlands of Qinghai-Tibet Plateau

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1364 ◽  
Author(s):  
Zhiwei Li ◽  
Peng Gao ◽  
Yuchi You
Keyword(s):  
Google Earth ◽  
Tibet Plateau ◽  
Annual Rainfall ◽  
Water Volume ◽  
Hydrological Connectivity ◽  
Total Water ◽  
Zoigê Basin ◽  
The Impact ◽  
Qinghai Tibet Plateau ◽  
Peatland Degradation

Peats have the unique ability of effectively storing water and carbon. Unfortunately, this ability has been undermined by worldwide peatland degradation. In the Zoige Basin, located in the northeastern Qinghai-Tibet Plateau, China, peatland degradation is particularly severe. Although climate change and (natural and artificial) drainage systems have been well-recognized as the main factors catalyzing this problem, little is known about the impact of the latter on peatland hydrology at larger spatial scales. To fill this gap, we examined the hydrological connectivity of artificial ditch networks using Google Earth imagery and recorded hydrological data in the Zoige Basin. After delineating from the images of 1392 ditches and 160 peatland patches in which these ditches were clustered, we calculated their lengths, widths, areas, and slopes, as well as two morphological parameters, ditch density (Dd) and drainage ability (Pa). The subsequent statistical analysis and examination of an index defined as the product Dd and Pa showed that structural hydrological connectivity, which was quantitatively represented by the value of this index, decreased when peatland patch areas increased, suggesting that ditches in small patches have higher degrees of hydrological connectivity. Using daily discharge data from three local gauging stations and Manning’s equation, we back-calculated the mean ditch water depths (Dm) during raining days of a year and estimated based on Dm the total water volume drained from ditches in each patch (V) during annual raining days. We then demonstrated that functional hydrological connectivity, which may be represented by V, generally decreased when patch areas increased, more sensitive to changes of ditch number and length in larger peatland patches. Furthermore, we found that the total water volume drained from all ditches during annual raining days only took a very small proportion of the total volume of stream flow out of the entire watershed (0.0012%) and this nature remained similar for the past 30 years, suggesting that during annual rainfall events, water drained from connected ditches is negligible. This revealed that the role of connected artificial ditches in draining peatland water mainly takes effect during the prolonged dry season of a year in the Zoige Basin.

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