scholarly journals Effects of land use/land cover and climate changes on terrestrial net primary productivity in the Yangtze River Basin, China, from 2001 to 2010

2014 ◽  
Vol 119 (6) ◽  
pp. 1092-1109 ◽  
Author(s):  
Yulong Zhang ◽  
Conghe Song ◽  
Kerong Zhang ◽  
Xiaoli Cheng ◽  
Lawrence E. Band ◽  
...  
Keyword(s):  
Land Use ◽  
Primary Productivity ◽  
Yangtze River ◽  
Climate Changes ◽  
Net Primary Productivity ◽  
Yangtze River Basin ◽  
Land Use Land Cover ◽  
The Yangtze River ◽  
The Yangtze River Basin ◽  
Effects Of Land Use

scholarly journals Changes in Forest Net Primary Productivity in the Yangtze River Basin and Its Relationship with Climate Change and Human Activities

2019 ◽  
Vol 11 (12) ◽  
pp. 1451
Author(s):  
Fengying Zhang ◽  
Zengxin Zhang ◽  
Rui Kong ◽  
Juan Chang ◽  
Jiaxi Tian ◽  
...  
Keyword(s):  
Climate Change ◽  
Spatial Distribution ◽  
River Basin ◽  
Primary Productivity ◽  
Yangtze River ◽  
Net Primary Productivity ◽  
Yangtze River Basin ◽  
The Yangtze River ◽  
The Yangtze River Basin ◽  
Lower Yangtze

Net Primary Productivity (NPP) is a basis of material and energy flows in terrestrial ecosystems, and it is also an important component in the research on carbon cycle and carbon budget. This paper evaluated the spatial distribution pattern and temporal change trends for forest NPP simulated by the LPJ (Lund-Potsdam-Jena) model and NDVI (normalized difference vegetation index) in the Yangtze River basin from 1982 to 2013. The results revealed that: (1) the spatial distribution of the forest NPP and NDVI in the Yangtze River basin has gradually decreased from the southeast coast to the northwest. The forest NPP and NDVI in the mid-lower Yangtze were higher than that of the upper Yangtze; (2) the forest NPP and NDVI in most areas of the Yangtze River basin were positively correlated with the temperature and precipitation. Moreover, the correlations among the temperature with the forest NPP and NDVI were stronger than that of correlations among precipitation with forest NPP and NDVI. Moreover, the extreme drought event in the year of 2004–2005 led the NPP to decrease in the middle and lower Yangtze River basin; (3) human activity such as major ecological projects would have a certain impact on the NPP and NDVI. The increase in forest areas from 2000 to 2010 was larger than that from 1990 to 2000. Moreover, the increasing rate for the NDVI was higher than that of NPP, especially after the year 2000, which indicates that the major ecological projects might have great impacts on the vegetation dynamics. Moreover, more attention should be paid on the joint impacts of human activity and climate change on terrestrial NPP and NDVI.

scholarly journals The Effect of the Grain for Green Program on Ecosystem Health in the Upper Reaches of the Yangtze River Basin: A Case Study of Eastern Sichuan, China

2019 ◽  
Vol 16 (12) ◽  
pp. 2112 ◽  
Author(s):  
Rui Han ◽  
Luo Guo ◽  
NuanYin Xu ◽  
Dan Wang
Keyword(s):  
Land Use ◽  
River Basin ◽  
Yangtze River ◽  
Ecosystem Health ◽  
Yangtze River Basin ◽  
Vegetation Coverage ◽  
The Yangtze River ◽  
Grain For Green ◽  
The Yangtze River Basin ◽  
Eastern Sichuan

The Eastern Sichuan Region (ESR) is one of the key pilot regions for Grain for Green Program (GGP) implementation in the upper reaches of the Yangtze River basin in China. Therefore, monitoring the effect of the GGP on the ecosystem in the ESR is important. In this study, the Mann–Kendall Trend Test Model was used to ascertain the changes in vegetation coverage. The transfer matrix was used to explore the changes in Land Use/Land Cover (LULC). LULC change direction model (LCDM) was used to preliminarily assess the impact of LULC changes on the ecosystem. The Pressure–State–Response model (PSR), reflecting the human pressure and the ecosystem state, was applied to analyze the spatial–temporal characteristics of the ecosystem health index (EHI). The time span of this study was from 1990 to 2015. The results show that the vegetation coverage changed significantly (p < 0.05), and ecosystem function developed towards positive because of the increase in the coverage of forestland and water land and decrease in the coverage of farmland. The spatial distribution of the EHI was influenced by the pattern of land use. The eastern region, associated with a large area of forestland and grassland, has a low population density and a low degree of land use exploitation, resulting in a high EHI value. The situation was completely opposite in the western region. Regarding the temporal scale, in spite of the decreasing pressure indicator, most counties had experienced an increase in the EHI. There was a clear correlation between the increased EHI values and the restored areas at the third stage (2000–2005) (p < 0.05, r2 = 0.164), but this correlation disappeared at the latter stage (2005–2015) (p > 0.05). The changes showed significant variations in time and area because of differences in the process and the intensity of the implication of the GGP.

scholarly journals Spatiotemporal Characteristics of the Water Quality and Its Multiscale Relationship with Land Use in the Yangtze River Basin

2021 ◽  
Vol 13 (16) ◽  
pp. 3309
Author(s):  
Jian Wu ◽  
Sidong Zeng ◽  
Linhan Yang ◽  
Yuanxin Ren ◽  
Jun Xia
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Temporal Variation ◽  
Yangtze River ◽  
Stream Water ◽  
Yangtze River Basin ◽  
The Yangtze River ◽  
Stream Water Quality ◽  
The Yangtze River Basin

The spatiotemporal characteristics of river water quality are the key indicators for ecosystem health evaluation in basins. Land use patterns, as one of the main driving forces of water quality change, affect stream water quality differently with the variations in the spatiotemporal scales. Thus, quantitative analysis of the relationship between different land cover types and river water quality contributes to a better understanding of the effects of land cover on water quality, the landscape planning of water quality protection, and integrated water resources management. Based on water quality data of 2006–2018 at 18 typical water quality stations in the Yangtze River basin, this study analyzed the spatial and temporal variation characteristics of water quality by using the single-factor water quality identification index through statistical analysis. Furthermore, the Spearman correlation analysis method was adopted to quantify the spatial-scale and temporal-scale effects of various land uses, including agricultural land (AL), forest land (FL), grassland (GL), water area (WA), and construction land (CL), on the stream water quality of dissolved oxygen (DO), chemical oxygen demand (CODMn), and ammonia (NH3-N). The results showed that (1) in terms of temporal variation, the water quality of the river has improved significantly and the tributaries have improved more than the main rivers; (2) in the spatial variation respect, the water quality pollutants in the tributaries are significantly higher than those in the main stream, and the concentration of pollutants increases with the decrease of the distance from the estuary; and (3) the correlation between DO and land use is low, while that between NH3-N, CODMn, and land use is high. CL and AL have a negative effect on water quality, while FL and GL have a purifying effect on water quality. In particular, AL and CL have a significant positive correlation with pollutants in water. Compared with NH3-N, CODMn has a higher correlation with land use at a larger scale. The results highlight the spatial scale and seasonal dependence of land use on water quality, which can provide a scientific basis for land management and seasonal pollution control.

scholarly journals Impacts of land use/cover change and reforestation on summer rainfall for the Yangtze River Basin

2020 ◽  
Author(s):  
Wei Li ◽  
Lu Li ◽  
Jie Chen ◽  
Qian Lin ◽  
Hua Chen
Keyword(s):  
Land Use ◽  
River Basin ◽  
Yangtze River ◽  
Yangtze River Basin ◽  
Daily Rainfall ◽  
Summer Rainfall ◽  
Rainfall Amount ◽  
The Yangtze River ◽  
The Yangtze River Basin ◽  
Land Use And Cover

Abstract. Land use and cover has been significantly changed all around the world during the last decade. In particular, the Returning Farmland to Forest Program (RFFP) have resulted in significant changes in regional land use and cover, especially in China. The land use and cover change (LUCC) may lead to the change in regional climate. In this study, we take the Yangtze river basin as a case study and analyze the impacts of LUCC and reforestation on summer rainfall amount and extremes based on the Weather Research and Forecasting model. Firstly, two observed land use and cover scenarios (1990 and 2010) were chosen to investigate the impacts of LUCC on the summer rainfall during the last decade. Secondly, two hypothetical reforestation scenarios (i.e., scenarios of 20 % and 50 % cropland changed to be forest) were taken based on the control year of 2010 to test the sensitivity of summer rainfall (amount and extremes) to reforestation. The results showed that LUCC between 1990 and 2010 decreased average summer rainfall, while increased extreme summer daily rainfall in the Yangtze River basin. The extreme summer daily rainfall increased up to 50 mm, which was mainly observed in the midstream and downstream. Reforestation could increase summer rainfall amount and extremes, and the effects were more pronounced at the local scale where suffered reforestation than at the whole basin. Moreover, the effects of reforestation were influenced by the reforestation proportion. In this study, the average summer rainfall increased more for the scenario of 20 % croplands changed to forests than that for the scenario of 50 %, while the high-intensity short-duration rainfall increased more for the scenario of 50 % croplands changed to forests than that for the scenario of 20 %. Although a comprehensive assessment of the impacts of LUCC on summer rainfall amount and extremes was conducted, further studies are needed to better investigate the uncertainty.

Response of Hydrologic Processes to Future Climate Changes in the Yangtze River Basin

2014 ◽  
Vol 19 (1) ◽  
pp. 211-222 ◽  
Author(s):  
Qin Ju ◽  
Zhongbo Yu ◽  
Zhenchun Hao ◽  
Gengxin Ou ◽  
Zhiyong Wu ◽  
...  
Keyword(s):  
River Basin ◽  
Yangtze River ◽  
Climate Changes ◽  
Yangtze River Basin ◽  
Future Climate ◽  
The Yangtze River ◽  
Hydrologic Processes ◽  
The Yangtze River Basin
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