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Control factors and scale analysis of annual river water, sediments and carbon transport in China.

Song C, Wang G, Sun X, Chang R, Mao T - Sci Rep (2016)

Bottom Line: Multiple spatial scale analyses indicated that Rc increased from the small to medium scale by 20% and then decreased at the sizable scale by 20%.TSSC decreased from the small to sizeable scale but increase from the sizeable to large scales; however, TSSL significantly decreased from small (768 g·m(-2)·a(-1)) to medium spatial scale basins (258 g·m(-2)·a(-1)), and TOCL decreased from the medium to large scale.Our results will improve the understanding of water, sediment and carbon transport processes and contribute better water and land resources management strategies from different spatial scales.

View Article: PubMed Central - PubMed

Affiliation: Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, China.

ABSTRACT
Under the context of dramatic human disturbances on river system, the processes that control the transport of water, sediment, and carbon from river basins to coastal seas are not completely understood. Here we performed a quantitative synthesis for 121 sites across China to find control factors of annual river exports (Rc: runoff coefficient; TSSC: total suspended sediment concentration; TSSL: total suspended sediment loads; TOCL: total organic carbon loads) at different spatial scales. The results indicated that human activities such as dam construction and vegetation restoration might have a greater influence than climate on the transport of river sediment and carbon, although climate was a major driver of Rc. Multiple spatial scale analyses indicated that Rc increased from the small to medium scale by 20% and then decreased at the sizable scale by 20%. TSSC decreased from the small to sizeable scale but increase from the sizeable to large scales; however, TSSL significantly decreased from small (768 g·m(-2)·a(-1)) to medium spatial scale basins (258 g·m(-2)·a(-1)), and TOCL decreased from the medium to large scale. Our results will improve the understanding of water, sediment and carbon transport processes and contribute better water and land resources management strategies from different spatial scales.

No MeSH data available.


Related in: MedlinePlus

Total suspended sediments load (TSSL) variations along scale under different classes of environmental factors.Boxes are the 25th and 75th percentiles quantiles. Small: <15000 km2; Medium: 15000–100000 km2; Sizeable: 100000–350000 km2; Large: 350000–700000 km2; Great: >700000 km2. Coloured dots and lines show TSSL under the different classes of averment factors change with spatial scales. Abbreviations of the variables as shows in Table 1. Classifications criteria as shows in Table 2.
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f6: Total suspended sediments load (TSSL) variations along scale under different classes of environmental factors.Boxes are the 25th and 75th percentiles quantiles. Small: <15000 km2; Medium: 15000–100000 km2; Sizeable: 100000–350000 km2; Large: 350000–700000 km2; Great: >700000 km2. Coloured dots and lines show TSSL under the different classes of averment factors change with spatial scales. Abbreviations of the variables as shows in Table 1. Classifications criteria as shows in Table 2.

Mentions: The last analysis step was to perform a more comprehensive analysis to summarize the spatial scale effects of the selected primary control factors on the response variables. The effect of the primary control factors on the Rc, TSSC, TSSL, and TOCL are illustrated with box and average line plots (Figures 4, 5, 6, 7). Each box plot includes a scatterplot of carbon or water variables as environmental control factors, with different classes and trend lines included for each spatial scale. The box plots show that multiple control factors had scale effects on each class as well as the Rc, TSSC, TSSL, and TOCL. The inorganic carbon variables were not included because of data limitations. We used the “ggplot2” package in R35 to plot these graphics.


Control factors and scale analysis of annual river water, sediments and carbon transport in China.

Song C, Wang G, Sun X, Chang R, Mao T - Sci Rep (2016)

Total suspended sediments load (TSSL) variations along scale under different classes of environmental factors.Boxes are the 25th and 75th percentiles quantiles. Small: <15000 km2; Medium: 15000–100000 km2; Sizeable: 100000–350000 km2; Large: 350000–700000 km2; Great: >700000 km2. Coloured dots and lines show TSSL under the different classes of averment factors change with spatial scales. Abbreviations of the variables as shows in Table 1. Classifications criteria as shows in Table 2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4863175&req=5

f6: Total suspended sediments load (TSSL) variations along scale under different classes of environmental factors.Boxes are the 25th and 75th percentiles quantiles. Small: <15000 km2; Medium: 15000–100000 km2; Sizeable: 100000–350000 km2; Large: 350000–700000 km2; Great: >700000 km2. Coloured dots and lines show TSSL under the different classes of averment factors change with spatial scales. Abbreviations of the variables as shows in Table 1. Classifications criteria as shows in Table 2.
Mentions: The last analysis step was to perform a more comprehensive analysis to summarize the spatial scale effects of the selected primary control factors on the response variables. The effect of the primary control factors on the Rc, TSSC, TSSL, and TOCL are illustrated with box and average line plots (Figures 4, 5, 6, 7). Each box plot includes a scatterplot of carbon or water variables as environmental control factors, with different classes and trend lines included for each spatial scale. The box plots show that multiple control factors had scale effects on each class as well as the Rc, TSSC, TSSL, and TOCL. The inorganic carbon variables were not included because of data limitations. We used the “ggplot2” package in R35 to plot these graphics.

Bottom Line: Multiple spatial scale analyses indicated that Rc increased from the small to medium scale by 20% and then decreased at the sizable scale by 20%.TSSC decreased from the small to sizeable scale but increase from the sizeable to large scales; however, TSSL significantly decreased from small (768 g·m(-2)·a(-1)) to medium spatial scale basins (258 g·m(-2)·a(-1)), and TOCL decreased from the medium to large scale.Our results will improve the understanding of water, sediment and carbon transport processes and contribute better water and land resources management strategies from different spatial scales.

View Article: PubMed Central - PubMed

Affiliation: Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, China.

ABSTRACT
Under the context of dramatic human disturbances on river system, the processes that control the transport of water, sediment, and carbon from river basins to coastal seas are not completely understood. Here we performed a quantitative synthesis for 121 sites across China to find control factors of annual river exports (Rc: runoff coefficient; TSSC: total suspended sediment concentration; TSSL: total suspended sediment loads; TOCL: total organic carbon loads) at different spatial scales. The results indicated that human activities such as dam construction and vegetation restoration might have a greater influence than climate on the transport of river sediment and carbon, although climate was a major driver of Rc. Multiple spatial scale analyses indicated that Rc increased from the small to medium scale by 20% and then decreased at the sizable scale by 20%. TSSC decreased from the small to sizeable scale but increase from the sizeable to large scales; however, TSSL significantly decreased from small (768 g·m(-2)·a(-1)) to medium spatial scale basins (258 g·m(-2)·a(-1)), and TOCL decreased from the medium to large scale. Our results will improve the understanding of water, sediment and carbon transport processes and contribute better water and land resources management strategies from different spatial scales.

No MeSH data available.


Related in: MedlinePlus