scholarly journals An 8500-year palynological record of vegetation, climate change and human activity in the Bosten Lake region of Northwest China

2019 ◽  
Vol 516 ◽  
pp. 166-178 ◽  
Author(s):  
Pavel E. Tarasov ◽  
Dieter Demske ◽  
Christian Leipe ◽  
Tengwen Long ◽  
Stefanie Müller ◽  
...  
Keyword(s):  
Climate Change ◽  
Human Activity ◽  
Northwest China ◽  
Bosten Lake ◽  
Lake Region

scholarly journals Impact of climate change and human activity on the runoff in the upper reaches of the Shiyang River, Northwest China

2014 ◽  
Author(s):  
Peng Li ◽  
Jianhua Xu ◽  
Zhongsheng Chen ◽  
Benfu Zhao
Keyword(s):  
Climate Change ◽  
Human Activity ◽  
Climatic Factors ◽  
Meteorological Data ◽  
Northwest China ◽  
Potential Evaporation ◽  
The Past ◽  
Shiyang River Basin ◽  
Runoff Change ◽  
Increasing Trend

Based on the hydrological and meteorological data of the upper reaches of Shiyang River basin in Northwest China from 1960 to 2009, this paper analyzed the change in runoff and its related climatic factors, and estimated the contribution of climate change and human activity to runoff change by using the moving T test, cumulative analysis of anomalies and multiple regression analysis. The results showed that temperature revealed a significant increasing trend, and potential evaporation capacity decreased significantly, while precipitation increased insignificantly in the past recent 50 years. Although there were three mutations in 1975, 1990 and 2002 respectively, runoff presented a slight decreasing trend in the whole period. The contributions of climate change and human activity to runoff change during the period of 1976-2009 were 45% and 55% respectively.

scholarly journals Separating the impacts of climate change and human activities on actual evapotranspiration in Aksu River Basin ecosystems, Northwest China

2018 ◽  
Vol 49 (6) ◽  
pp. 1740-1752 ◽  
Author(s):  
Peng Yang ◽  
Jun Xia ◽  
Chesheng Zhan ◽  
Xuejuan Chen ◽  
Yunfeng Qiao ◽  
...  
Keyword(s):  
Climate Change ◽  
Wind Speed ◽  
River Basin ◽  
Human Activity ◽  
Arable Land ◽  
Northwest China ◽  
Actual Evapotranspiration ◽  
Forest Land ◽  
Aksu River Basin ◽  
Impacts Of Climate Change

Abstract Separating the impacts of climate change and human activity on actual evapotranspiration (ET) is important for reducing comprehensive risk and improving the adaptability of water resource systems. In this study, the spatiotemporal distribution of actual ET in the Aksu River Basin, Northwest China, during the period 2000–2015 was evaluated using the Vegetation Interfaces Processes model and Moderate Resolution Imaging Spectroradiometer-Normalized Difference Vegetation Index. The impact of climate change and human activity on actual ET were separated and quantified. The results demonstrated that: (1) the annual pattern of actual ET per pixel exhibited the highest values for arable land (average 362.4 mm/a/pixel), followed by forest land and grassland (average of 159.6 and 142.8 mm/a/pixel, respectively). Significant increasing linear trends (p < 0.05) of 3.2 and 1.8 mm/a were detected in the arable land and forest land time series, respectively; (2) precipitation was the most significant of the selected climate factors (precipitation, average temperature, sunshine duration, and wind speed) for all ecosystems. The second most significant was wind speed; (3) human activity caused 89%, 98%, and 80% of the changes in actual ET of forest, grass, and arable land, respectively, while climate change caused 11%, 2%, and 20% of the changes in actual ET, in the Aksu River Basin during 2000–2015.

The impact of climate change and human activity on the ecological status of Bosten Lake, NW China, revealed by a diatom record for the last 2000 years

The Holocene ◽  
2019 ◽  
Vol 29 (12) ◽  
pp. 1871-1884 ◽  
Author(s):  
Luciane Fontana ◽  
Mingjie Sun ◽  
Xiaozhong Huang ◽  
Lixiong Xiang
Keyword(s):  
Climate Change ◽  
Human Activity ◽  
Little Ice Age ◽  
Tang Dynasty ◽  
Late Holocene ◽  
Ecological Status ◽  
Ice Age ◽  
Bosten Lake ◽  
Continuous Increase ◽  
The Impact

We present a 2000-year high-resolution diatom record from Bosten Lake (Yanqi Basin, Xinjiang), which is the largest inland freshwater lake in China. Our aims were to investigate the influence of climate change and human activity on its aquatic ecology during the late Holocene. During AD 280–480, a low water level and high salinity occurred, based on the dominance of epipelic and brackish diatoms. In addition, the diatom stratigraphy, combined with records of mean grain size and carbonate content, suggests that the lake experienced a high level of eolian input from the surrounding dunes. We hypothesize that during this interval, Loulan Kingdom, an important city of the Han Dynasty, located downstream of Bosten Lake, was abandoned due to the increasing scarcity of water resources and related harsh environmental conditions, including stronger eolian activity, which were the consequences of climate change. The dominance of meso-eutrophic small fragilarioid diatoms coincides with warm and arid intervals which also correspond to intensified human activity. These intervals correspond to the development of the Tang Dynasty (from ~AD 600), the ‘Medieval Warm Period’ (AD 1000–1200), and the last ~200 years. A shift from meso-eutrophic/benthic diatoms to oligotrophic/planktonic diatoms occurred during an interval of enhanced precipitation throughout the humid ‘Little Ice Age’ (AD 1600–1800). A return to markedly eutrophic conditions and a decreasing lake level occurred after the ‘Little Ice Age’, reflecting the more arid regional environment of the last 200 years. The high variability of the proxies suggests that both climate change and human activity were the major drivers of the ecological status of Bosten Lake during the late Holocene. We suggest that both the continuous increase of human activity and ongoing global warming will cause the major eutrophication or salinization of the freshwater lakes in the arid zone of northwest China.

scholarly journals Impact of climate change and human activity on the runoff in the upper reaches of the Shiyang River, Northwest China

2014 ◽  
Author(s):  
Peng Li ◽  
Jianhua Xu ◽  
Zhongsheng Chen ◽  
Benfu Zhao
Keyword(s):  
Climate Change ◽  
Human Activity ◽  
Climatic Factors ◽  
Meteorological Data ◽  
Northwest China ◽  
Potential Evaporation ◽  
The Past ◽  
Shiyang River Basin ◽  
Runoff Change ◽  
Increasing Trend

Based on the hydrological and meteorological data of the upper reaches of Shiyang River basin in Northwest China from 1960 to 2009, this paper analyzed the change in runoff and its related climatic factors, and estimated the contribution of climate change and human activity to runoff change by using the moving T test, cumulative analysis of anomalies and multiple regression analysis. The results showed that temperature revealed a significant increasing trend, and potential evaporation capacity decreased significantly, while precipitation increased insignificantly in the past recent 50 years. Although there were three mutations in 1975, 1990 and 2002 respectively, runoff presented a slight decreasing trend in the whole period. The contributions of climate change and human activity to runoff change during the period of 1976-2009 were 45% and 55% respectively.

scholarly journals A Multi-Perspective Assessment Method with a Dynamic Benchmark for Human Activity Impacts on Alpine Ecosystem under Climate Change

2022 ◽  
Vol 14 (1) ◽  
pp. 208
Author(s):  
Fuguang Zhang ◽  
Biao Zeng ◽  
Taibao Yang ◽  
Yuxuan Zheng ◽  
Ying Cao
Keyword(s):  
Climate Change ◽  
Human Activity ◽  
Net Primary Production ◽  
Regional Scale ◽  
Northwest China ◽  
Assessment Method ◽  
Alpine Ecosystems ◽  
Alpine Ecosystem ◽  
Assessment Period ◽  
The Impact

Intense human activities and rapid climate changes both have obvious impacts on alpine ecosystems. However, the magnitudes and directions of the impacts by these two drivers remain uncertain due to a lack of a reasonable assessment method to distinguish between them. The impact of natural resilience is also generally included in the dynamics of a disturbed ecosystem and is liable to be mixed into the impact of human activity. It is urgent that we quantitatively discriminate human activity impacts on the ecosystem under climate change, especially for fast-developing alpine regions. Here, we propose an assessment method to determine human activity impacts under a dynamic climate, taking the potential net primary production (NPP) of an ecosystem as a benchmark. The potential NPP (NPPP) series under the changing climate was retrieved by an improved integrated biosphere simulator based on the initial disturbed ecosystem status of the assessment period. The actual NPP (NPPA) series monitored by remote sensing was considered as the results derived from the joint impacts of climate change, natural resilience and human activity. Then, the impact of human activity was quantified as the difference between the NPPP and NPPA. The contributions of human activity and natural forces to ecosystem NPP dynamics were then calculated separately and employed to explore the dominant driver(s). This assessment method was demonstrated in a typical alpine ecosystem in Northwest China. The results indicate that this method capably revealed the positive impacts of local afforestation and land-use optimization and the negative impacts caused by grazing during the assessment period of 2001–2017. This assessment method provides a quantitative reference for assessing the performances of ecological protections or human damage to alpine ecosystems at the regional scale.

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