Spatio-temporal patterns of hydrological processes and their responses to human activities in the Poyang Lake basin, China

2011 ◽  
Vol 56 (2) ◽  
pp. 305-318 ◽  
Author(s):  
Qiang Zhang ◽  
Peng Sun ◽  
Tao Jiang ◽  
Xinjun Tu ◽  
Xiaohong Chen
2021 ◽  
Vol 13 (24) ◽  
pp. 5081
Author(s):  
Yiming Wang ◽  
Zengxin Zhang ◽  
Xi Chen

Understanding the driving mechanism of vegetation changes is essential for vegetation restoration and management. Vegetation coverage in the Poyang Lake basin (PYLB) has changed dramatically under the context of climate change and human activities in recent decades. It remains challenging to quantify the relative contribution of natural and anthropogenic factors to vegetation change due to their complicated interaction effects. In this study, we selected the Normalized Difference Vegetation Index (NDVI) as an indicator of vegetation growth and used trend analysis and the Mann-Kendall test to analyze its spatiotemporal change in the PYLB from 2000 to 2020. Then we applied the Geodetector model, a novel spatial analysis method, to quantify the effects of natural and anthropogenic factors on vegetation change. The results showed that most regions of the basin were experiencing vegetation restoration and the overall average NDVI value in the basin increased from 0.756 to 0.809 with an upward yearly trend of +0.0026. Land-use type exerted the greatest influence on vegetation change, followed by slope, elevation, and soil types. Except for conversions to construction land, most types of land use conversion induced an increase in NDVI in the basin. The influence of one factor on vegetation NDVI was always enhanced when interacting with another. The interaction effect of land use types and population density was the largest, which could explain 45.6% of the vegetation change, indicating that human activities dominated vegetation change in the PYLB. Moreover, we determined the ranges or types of factors most suitable for vegetation growth, which can be helpful for decision-makers to optimize the implementation of ecological projects in the PYLB in the future. The results of this study could improve the understanding of the driving mechanisms of vegetation change and provide a valuable reference for ecological restoration in subtropical humid regions.


The Holocene ◽  
2021 ◽  
pp. 095968362110477
Author(s):  
Maofeng He ◽  
Fengxian Bu ◽  
Claudio O Delang ◽  
Jialin Xie ◽  
Quan Ye ◽  
...  

Climate change and human activities have been an important part of studies regarding historical environmental changes in China over the past 2000 years. In this study, we focused on environmental changes, that is, natural disasters and human activities, in the Poyang Lake Basin over the past 2000 years, to analyze interactions between land use cover changes and human activities from the perspective of regional sustainable development. We collected historical records of climate and hydrology, floods and droughts, and rivers and lakes in the Poyang Lake area, and established time sequences for the floods and droughts, lake water level and lake area, amount of farming land, and population, in order to discuss interactions between changes in the environment and the climate, with emphasis on the impacts of extreme events on lake and river basin environment changes. The following results were obtained. First, climate changes in historical periods had wide-ranging and far-reaching impacts on agricultural production, especially disasters caused by climate change. Among the changes in the Poyang Lake basin environment, including river network systems, lake water levels, etc., changes in lake water volume are direct evidence of climate change, adaptation to climate change, and obvious phased characteristics. Second, in the process of changes to the lake and river network in the Poyang Lake Basin, social and economic development is accompanied by evolution of the lake. Increases and decreases in population, the scale of agricultural production, and lake environment changes have direct and significant interactions. Third, the Poyang Lake basin’s environmental changes during the historical period are mainly reflected in the pressure feedback mode of “population–agriculture” in the lake environment.


2021 ◽  
Vol 123 ◽  
pp. 103019
Author(s):  
Xiangyong Lei ◽  
Lu Gao ◽  
Jianhui Wei ◽  
Miaomiao Ma ◽  
Ligang Xu ◽  
...  

2018 ◽  
Vol 136 (1-2) ◽  
pp. 15-30 ◽  
Author(s):  
Chaojun Gu ◽  
Xingmin Mu ◽  
Peng Gao ◽  
Guangju Zhao ◽  
Wenyi Sun ◽  
...  

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1654
Author(s):  
Xiaodong Chu ◽  
Hao Wang ◽  
Fangwen Zheng ◽  
Cheng Huang ◽  
Chunxia Xu ◽  
...  

In December of 2019, a total of 114 river water samples were collected from 38 sampling sites in the Xiujiang River of the Poyang Lake Basin for three consecutive days. The temperature (T), pH, dissolved oxygen (DO), chemical oxygen demand (CODCr), five-day biochemical oxygen demand (BOD5), total nitrogen (TN), ammonia nitrogen (NH4+-N), total phosphorus (TP), and concentrations of heavy metals (Cr, Cu, Zn and As) of the samples were measured. The results showed that the average concentrations of heavy metals in the mainstream of the Xiujiang River were Cu > Zn > Cr > As, and those in the main tributary of Xiujiang River (named as the Liaohe tributary) were Zn > Cu > Cr > As, which met the class III of the Environmental Quality Standards for Surface Water in China. However, it was founded that TN and NH4+-N in some agricultural areas had not met the class III standard of surface water. Hierarchical clustering analysis grouped sampling sites into four clusters. Clusters 1, cluster 2, cluster 3, and cluster 4 corresponded to an urban industrial area, rural mountainous area, primitive mountainous area, and agricultural area, respectively. The majority of the sampling sites were classified as mountainous rural areas less impacted by human activities, while the Liaohe tributary were urban industrial areas impacted more by human activities. Principal component analysis and correlation analysis results showed that variation of heavy metals and nutrient elements in Xiujiang River is related to the heterogeneity of human activities, which is mainly affected by urban industrial and agricultural pollution, and natural environments of the river with different background values. The results obtained in the current study will potentially provide a scientific basis for the protection and management of freshwater resources and aquatic ecosystems in the Xiujiang River and Poyang Lake Basin.


2020 ◽  
Vol 12 (3) ◽  
pp. 944 ◽  
Author(s):  
Ruonan Wang ◽  
Wenqi Peng ◽  
Xiaobo Liu ◽  
Cuiling Jiang ◽  
Wenqiang Wu ◽  
...  

Spatial and temporal variations in hydrological series are affected by both climate change and human activities. A scientific understanding of the impacts of these two main factors on runoff will help to understand the response mechanism of the water cycle in a changing environment. This study focused on Poyang Lake Basin, which contains China’s largest freshwater lake. Several approaches, including the Mann-Kendall trend test, cumulative anomaly method, Hurst exponent analysis, and slope change ratio of cumulative quantity (SCRCQ) method, were adopted to explore the characteristics of runoff variations and the respective impacts of climate change and human activities on runoff variations in the five subbasins. The results indicated that (1) from 1961 to 2015, the runoff throughout the basin fluctuated, and it decreased significantly in the 2000s. (2) Different baseline periods and measurement periods were identified for each subbasin to analyse the spatial and temporal responses of runoff to climate change and human activities. (3) The runoff of each subbasin will exhibit anti-persistent features with different persistence times in the future. (4) Compared with those in the baseline period, in the first measurement period, precipitation was the main factor driving the runoff increase in the Ganjiang, Fuhe, Xinjiang and Raohe subbasins, with contribution rates of 50.91–63.47%, and human activities played a supplementary role. However, in the second measurement period, as human activities intensified, they became the leading factor causing changes in runoff, with contribution rates between 59.57% and 92.49%. Considering water shortages and the intensification of human activities, the impacts of human activities on runoff variations will require more attention in the future.


2016 ◽  
Vol 30 (14) ◽  
pp. 2562-2576 ◽  
Author(s):  
Qiang Zhang ◽  
Jianyu Liu ◽  
Vijay P. Singh ◽  
Xihui Gu ◽  
Xiaohong Chen

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