scholarly journals Changes in China’s lakes: Climate and human impacts

2019 ◽  
Author(s):  
Shengli Tao ◽  
Jingyun Fang ◽  
Suhui Ma ◽  
Qiong Cai ◽  
Xinyu Xiong ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Population Distribution ◽  
Driving Forces ◽  
Human Impacts ◽  
Critical Role ◽  
The Tibetan Plateau ◽  
Lake Area ◽  
Landsat Images ◽  
Climatic Control ◽  
Economic Boom

Abstract Lakes have played a critical role in providing water and ecosystem services for people and other organisms in China for millennia. However, accelerating climate change and economic boom have resulted in unprecedented changes in these valuable lakes. Using Landsat images covering the entity of the country, we explored the changes in China’s lakes and the associated driving forces over the last 30 years (i.e., mid-1980s to 2015). We discovered that China’s lakes have changed with divergent regional trends: in the sparsely populated Tibetan Plateau, lakes are abundant, and the lake area has increased dramatically from 38,596 km2 to 46,831 km2 (i.e., increased by 8235 km2, or 21.3%), whereas in the densely populated northern and eastern regions, lakes are relatively scarce, and the lake area has decreased from 36,659 km2 to 33,657 km2 (i.e., decreased by 3002 km2, or 8.2%). In particular, severe lake decreases occurred in the Mongolia-Xinjiang Plateau and the Eastern Plain (–2151 km2). Statistical analyses indicated that climate was the most important factor controlling lake changes in the Tibetan Plateau, the Yun-Gui Plateau and the Northeast Plain. However, the strength of climatic control on lake changes was low in the Eastern Plain and the Mongolia-Xinjiang Plateau, where human activities, e.g., impoldering, irrigation, and mining, have caused serious impacts on lakes. Further lake changes will exacerbate regional imbalances between lake resources and population distribution and thus may increase the risk of water resource crises in China.

scholarly journals Long-Term Lake Area Change and Its Relationship with Climate in the Endorheic Basins of the Tibetan Plateau

2021 ◽  
Vol 13 (24) ◽  
pp. 5125
Author(s):  
Junxiao Wang ◽  
Mengyao Li ◽  
Liuming Wang ◽  
Jiangfeng She ◽  
Liping Zhu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Large Scale ◽  
Driving Forces ◽  
Atlantic Multidecadal Oscillation ◽  
The Tibetan Plateau ◽  
Lake Area ◽  
Climate Variables ◽  
Landsat Images ◽  
Area Change ◽  
Local Climate

Lakes are sensitive indicators of climate change in the Tibetan Plateau (TP), which have shown high temporal and spatial variability in recent decades. The driving forces for the change are still not entirely clear. This study examined the area change of the lakes greater than 1 km2 in the endorheic basins of the Tibetan Plateau (EBTP) using Landsat images from 1990 to 2019, and analysed the relationships between lake area and local and large-scale climate variables at different geographic scales. The results show that lake area in the EBTP has increased significantly from 1990 to 2019 at a rate of 432.52 km2·year−1. In the past 30 years, lake area changes in the EBTP have mainly been affected by local climate variables such as precipitation and temperature. At a large scale, Indian Summer Monsoon (ISM) has correlations with lake area in western sub-regions in the Inner Basin (IB). While Atlantic Multidecadal Oscillation (AMO) has a significant connection with lake area, the North Atlantic Oscillation (NAO) does not. We also found that abnormal drought (rainfall) brought by the El Niño/La Niña events are significantly correlated with the lake area change in most sub-regions in the IB.

scholarly journals Monitoring 40-Year Lake Area Changes of the Qaidam Basin, Tibetan Plateau, Using Landsat Time Series

2019 ◽  
Vol 11 (3) ◽  
pp. 343 ◽  
Author(s):  
Huiying Li ◽  
Dehua Mao ◽  
Xiaoyan Li ◽  
Zongming Wang ◽  
Cuizhen Wang
Keyword(s):  
Tibetan Plateau ◽  
Structural Equation ◽  
Environmental Changes ◽  
Human Impacts ◽  
Qaidam Basin ◽  
Salt Lakes ◽  
Anthropogenic Factors ◽  
The Tibetan Plateau ◽  
Lake Area ◽  
Landsat Images

Areal changes of high-altitude inland lakes on the Qaidam Basin (QB) of the Tibetan Plateau are reliable indicators of climate change and anthropogenic disturbance. Due to the physical difficulties to access, our knowledge of the spatial patterns and processes of climatic and human impacts on the Basin has been limited. Focusing on lake area changes, this study used long-term Landsat images to map the patterns of lakes and glaciers in 1977, 1990, 2000, and 2015, and to monitor the spatially explicit changes of lakes between 1977 and 2015. Results revealed that the total number of lakes (area > 0.5 km2) increased by 18, while their total area expanded by 29.8%, from 1761.5 ± 88.1 km2 to 2285.9 ± 91.4 km2. Meanwhile, glaciers have decreased in area by 259.16 km2 in the past four decades. The structural equation model (SEM) was applied to examine the integrative effects of natural and anthropogenic factors on lake area. Precipitation change exhibited the most significant influence on lake area in the QB from 1977 to 2000, while human activities also played an important role in the expansion of lakes in the QB in the period 2000–2015. In particular, extensive exploitation of salt lakes as mining resources resulted in severe changes in lake area and landscape. The continuously expanding salt lakes inundated the road infrastructure nearby, posing great threats to road safety. This study shed new light on the impacts of recent environmental changes and human interventions on lakes in the Qaidam Basin, which could assist policy-making for protecting the lakes and for strengthening the ecological improvement of this vast, arid basin.

scholarly journals Contrasting Evolution Patterns of Endorheic and Exorheic Lakes on the Central Tibetan Plateau and Climate Cause Analysis during 1988–2017

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1962
Author(s):  
Zhilong Zhao ◽  
Yue Zhang ◽  
Zengzeng Hu ◽  
Xuanhua Nie
Keyword(s):  
Climate Change ◽  
Tibetan Plateau ◽  
Climatic Factors ◽  
Global Climate ◽  
Rapid Expansion ◽  
Annual Precipitation ◽  
The Tibetan Plateau ◽  
Lake Area ◽  
Climate Change Research ◽  
Mean Temperature

The alpine lakes on the Tibetan Plateau (TP) are indicators of climate change. The assessment of lake dynamics on the TP is an important component of global climate change research. With a focus on lakes in the 33° N zone of the central TP, this study investigates the temporal evolution patterns of the lake areas of different types of lakes, i.e., non-glacier-fed endorheic lakes and non-glacier-fed exorheic lakes, during 1988–2017, and examines their relationship with changes in climatic factors. From 1988 to 2017, two endorheic lakes (Lake Yagenco and Lake Zhamcomaqiong) in the study area expanded significantly, i.e., by more than 50%. Over the same period, two exorheic lakes within the study area also exhibited spatio-temporal variability: Lake Gaeencuonama increased by 5.48%, and the change in Lake Zhamuco was not significant. The 2000s was a period of rapid expansion of both the closed lakes (endorheic lakes) and open lakes (exorheic lakes) in the study area. However, the endorheic lakes maintained the increase in lake area after the period of rapid expansion, while the exorheic lakes decreased after significant expansion. During 1988–2017, the annual mean temperature significantly increased at a rate of 0.04 °C/a, while the annual precipitation slightly increased at a rate of 2.23 mm/a. Furthermore, the annual precipitation significantly increased at a rate of 14.28 mm/a during 1995–2008. The results of this study demonstrate that the change in precipitation was responsible for the observed changes in the lake areas of the two exorheic lakes within the study area, while the changes in the lake areas of the two endorheic lakes were more sensitive to the annual mean temperature between 1988 and 2017. Given the importance of lakes to the TP, these are not trivial issues, and we now need accelerated research based on long-term and continuous remote sensing data.

scholarly journals Atmospheric processes of persistent organic pollutants over a remote lake of the central Tibetan Plateau: Implications for regional cycling

2016 ◽  
Author(s):  
Jiao Ren ◽  
Xiaoping Wang ◽  
Chuanfei Wang ◽  
Ping Gong ◽  
Tandong Yao
Keyword(s):  
Tibetan Plateau ◽  
Organic Pollutants ◽  
Persistent Organic Pollutants ◽  
Secondary Source ◽  
The Tibetan Plateau ◽  
Lake Area ◽  
Nam Co ◽  
Surface Exchange ◽  
Atmospheric Processes ◽  
Water Gas

Abstract. Atmospheric processes (air-surface exchange, and atmospheric deposition and degradation) are crucial for understanding the global cycling and fate of persistent organic pollutants (POPs). However, such assessment over the Tibetan Plateau (TP) remains uncertain. More than 50 % of the Chinese lakes are located on the TP, which exerts a remarkable influence on the regional water, energy, and chemical cycling. In this study, air and water samples were simultaneously collected in Nam Co, a large lake on the TP, to test whether the lake is a "secondary source" or "sink" of POPs. Lower concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were observed in the atmosphere and lake water of Nam Co, while the levels of polycyclic aromatic hydrocarbons (PAHs) were relatively higher. Results of fugacity ratios and chiral signatures both suggest that the lake acted as the net sink of atmospheric hexachlorocyclohexanes (HCHs), following their long-range transport driven by the Indian Monsoon. Different behaviors were observed in the PAHs, which primarily originated from local biomass burning. Acenaphthylene, acenaphthene, and fluorene showed volatilization from the lake to the atmosphere; while other PAHs were deposited into the lake due to the integrated deposition process (wet/dry and air-water gas deposition) and limited atmospheric degradation. As the dominant PAH compound, phenanthrene exhibited a seasonal reversal of air-water gas exchange, which was likely related to the melting of the lake ice in May. The annual input of HCHs from air to the entire lake area (2015 km2) was estimated as 1.9 kg year−1, while those estimated for PAHs can potentially reach up to 550 kg year−1. This study highlights the significance of PAH deposition on the regional carbon cycling in the oligotrophic lakes of the TP.

scholarly journals Snow distribution over the Namco lake area of the Tibetan Plateau

2009 ◽  
Vol 13 (11) ◽  
pp. 2023-2030 ◽  
Author(s):  
M. Li ◽  
Y. Ma ◽  
Z. Hu ◽  
H. Ishikawa ◽  
Y. Oku
Keyword(s):  
Tibetan Plateau ◽  
The Tibetan Plateau ◽  
Lake Area ◽  
State Variable ◽  
Nested Grids ◽  
Snow Distribution ◽  
Surface Skin Temperature ◽  
Modified Surface ◽  
Meteorological Observations

Abstract. The mesoscale snow distribution over the Namco lake area of the Tibetan Plateau on October 2005 has been investigated in this paper. The base and revised experiments were conducted using the Weather Research Model (WRF) with three nested grids that included a 1 km finest grid centered on the Namco station. Our simulation ran from 6 October through to 10 October 2005, which was concurrent with long term meteorological observations. Evaluation against boundary layer meteorological tower measurements and flux observations showed that the model captured the observed 2 m temperature and 10 m winds reasonably well in the revised experiment. The results suggest that output snow depth maximum amounts from two simulated experiments were centered downwind of the Namco lakeshore. Modified surface state variable, for example, surface skin temperature on the lake help to increase simulated credibility.

Assessing phenological change and climatic control of alpine grasslands in the Tibetan Plateau with MODIS time series

2014 ◽  
Vol 59 (1) ◽  
pp. 11-23 ◽  
Author(s):  
Cuizhen Wang ◽  
Huadong Guo ◽  
Li Zhang ◽  
Shuangyu Liu ◽  
Yubao Qiu ◽  
...  
Keyword(s):  
Time Series ◽  
Tibetan Plateau ◽  
The Tibetan Plateau ◽  
Alpine Grasslands ◽  
Climatic Control

scholarly journals Snow distribution over the Namco lake area of the Tibetan Plateau

2009 ◽  
Vol 6 (1) ◽  
pp. 843-857 ◽  
Author(s):  
M. Li ◽  
Y. Ma ◽  
Z. Hu ◽  
H. Ishikawa ◽  
Y. Oku
Keyword(s):  
Tibetan Plateau ◽  
The Tibetan Plateau ◽  
Lake Area ◽  
Research Model ◽  
Nested Grids ◽  
Snow Distribution ◽  
Surface Skin Temperature ◽  
Modified Surface ◽  
Meteorological Observations

Abstract. The mesoscale snow distribution over the Namco lake area of the Tibetan Plateau on October 2005 has been investigated in this paper. The control and sensitive experiments were conducted using Weather Research Model (WRF) with three nested grids that included a 1 km finest grid centered on the Namco station. Our simulation ran from 6 October through 10 October 2005, which was concurrent with long term meteorological observations. Evaluation against boundary layer meteorological tower measurements and flux observations showed that the model captured the observed 2 m temperature and 10 m winds reasonably well in the sensitive experiment. The results suggested that output snow depth maximum amounts from two simulated experiments were centered downwind shore of Namco lake. Modified surface parameters for example surface skin temperature on the lake help to increase simulated credibility.

Generation of an improved precipitation data set from multisource information over the Tibetan Plateau

2021 ◽  
Author(s):  
Zhongkun Hong ◽  
Zhongying Han ◽  
Xueying Li ◽  
Di Long ◽  
Guoqiang Tang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Mean Squared Error ◽  
Critical Role ◽  
Reanalysis Data ◽  
The Tibetan Plateau ◽  
Efficiency Coefficient ◽  
Precipitation Data ◽  
Distributed Hydrological Model ◽  
Data Set ◽  
Daily Streamflow

AbstractPrecipitation over the Tibetan Plateau (TP) known as Asia’s water tower plays a critical role in regional water and energy cycles, largely affecting water availability for downstream countries. Rain gauges are indispensable in precipitation measurement, but are quite limited in the TP that features complex terrain and the harsh environment. Satellite and reanalysis precipitation products can provide complementary information for ground-based measurements, particularly over large poorly gauged areas. Here we optimally merged gauge, satellite, and reanalysis data by determining weights of various data sources using artificial neural networks (ANNs) and environmental variables including elevation, surface pressure, and wind speed. A Multi-Source Precipitation (MSP) data set was generated at a daily timescale and a spatial resolution of 0.1° across the TP for the 1998–2017 period. The correlation coefficient (CC) of daily precipitation between the MSP and gauge observations was highest (0.74) and the root mean squared error was the second lowest compared with four other satellite products, indicating the quality of the MSP and the effectiveness of the data merging approach. We further evaluated the hydrological utility of different precipitation products using a distributed hydrological model for the poorly gauged headwaters of the Yangtze and Yellow rivers in the TP. The MSP achieved the best Nash-Sutcliffe efficiency coefficient (over 0.8) and CC (over 0.9) for daily streamflow simulations during 2004–2014. In addition, the MSP performed best over the ungauged western TP based on multiple collocation evaluation. The merging method could be applicable to other data-scarce regions globally to provide high quality precipitation data for hydrological research.

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