Compared with previous studies,the research attempted to establish the appropriate quantitative models to explain the relations between settlement density Diand geographic factors,which could make a scientific guidanc...Compared with previous studies,the research attempted to establish the appropriate quantitative models to explain the relations between settlement density Diand geographic factors,which could make a scientific guidance to the mountain settlements planning. Five factors,including slope,relief amplitude,distance to river, distance to cultivated land, and distance to road, were identified through principal component analysis( PCA). The inherent relations between five factors and Di( settlement density)were modeled by regression analysis. The results are as follows.( 1) The associations among Diand slope,relief amplitude,river,road are better modeled by the exponential decay line; with the buffer distance of slope, relief amplitude, distance to river and distance to road increasing, Didecreases.( 2) The associations between Diand cultivated land are better modeled by the quadratic polynomial line; with the buffer distance of cultivated land increasing,Diincreases first, and then dramatically decreases.( 3) The area within 500 m from the road,within 500 m from the cultivated land,within 1 600 m from the river,within the relief amplitude of 30-200 m,and the area within the slope of 0°-10° are the fitting land for settlements,and it is very important to lay the mountain settlements on those optimized regions.展开更多
1 Introduction The Sendai Framework for Disaster Risk Reduction 2015–2030 shifts the focus from managing disasters to reducing risks.Such a shift requires a better understanding of risk in all its dimensions of envir...1 Introduction The Sendai Framework for Disaster Risk Reduction 2015–2030 shifts the focus from managing disasters to reducing risks.Such a shift requires a better understanding of risk in all its dimensions of environment,hazards,exposure,and vulnerability;a disaster risk governance that展开更多
Ultraviolet(UV) radiation has significant effects on ecosystems, environments, and human health, as well as atmospheric processes and climate change. Two ultraviolet radiation datasets are described in this paper. O...Ultraviolet(UV) radiation has significant effects on ecosystems, environments, and human health, as well as atmospheric processes and climate change. Two ultraviolet radiation datasets are described in this paper. One contains hourly observations of UV radiation measured at 40 Chinese Ecosystem Research Network stations from 2005 to 2015. CUV3 broadband radiometers were used to observe the UV radiation, with an accuracy of 5%, which meets the World Meteorology Organization's measurement standards. The extremum method was used to control the quality of the measured datasets. The other dataset contains daily cumulative UV radiation estimates that were calculated using an all-sky estimation model combined with a hybrid model. The reconstructed daily UV radiation data span from 1961 to 2014. The mean absolute bias error and root-mean-square error are smaller than 30% at most stations, and most of the mean bias error values are negative, which indicates underestimation of the UV radiation intensity. These datasets can improve our basic knowledge of the spatial and temporal variations in UV radiation. Additionally, these datasets can be used in studies of potential ozone formation and atmospheric oxidation, as well as simulations of ecological processes.展开更多
Journal of Plant Ecology(JPE)decided to establish awards of JPE Best Papers,in order to thank and encourage authors to submit their valuable research to JPE.This award will be given annually to the first author(s)of 2...Journal of Plant Ecology(JPE)decided to establish awards of JPE Best Papers,in order to thank and encourage authors to submit their valuable research to JPE.This award will be given annually to the first author(s)of 2–5 papers selected by the editors,according to the citation data as well as the impact in the field of plant ecology.We will place extra emphasis on authors who had completed graduate studies not more than 5 years before submission of the paper,to encourage more early-career scientists to submit their work to JPE.It will come with a‘JPE Best Paper’certificate,as well as a price money of Chinese RMB 5000.展开更多
基金National Natural Science Foundation of China(No.41101552)West Light Foundation of the Chinese Academy of Sciences(No.2013)+1 种基金Geographic National Condition Monitoring Engineering Research Center of Sichuan Province,China(No.GC201418)Key Laboratory of Geo-spatial Information Technology of Ministry of Land and Resources Open Fund,Chengdu University of Technology,China(No.KLGSIT2015-08)
文摘Compared with previous studies,the research attempted to establish the appropriate quantitative models to explain the relations between settlement density Diand geographic factors,which could make a scientific guidance to the mountain settlements planning. Five factors,including slope,relief amplitude,distance to river, distance to cultivated land, and distance to road, were identified through principal component analysis( PCA). The inherent relations between five factors and Di( settlement density)were modeled by regression analysis. The results are as follows.( 1) The associations among Diand slope,relief amplitude,river,road are better modeled by the exponential decay line; with the buffer distance of slope, relief amplitude, distance to river and distance to road increasing, Didecreases.( 2) The associations between Diand cultivated land are better modeled by the quadratic polynomial line; with the buffer distance of cultivated land increasing,Diincreases first, and then dramatically decreases.( 3) The area within 500 m from the road,within 500 m from the cultivated land,within 1 600 m from the river,within the relief amplitude of 30-200 m,and the area within the slope of 0°-10° are the fitting land for settlements,and it is very important to lay the mountain settlements on those optimized regions.
文摘1 Introduction The Sendai Framework for Disaster Risk Reduction 2015–2030 shifts the focus from managing disasters to reducing risks.Such a shift requires a better understanding of risk in all its dimensions of environment,hazards,exposure,and vulnerability;a disaster risk governance that
文摘Ultraviolet(UV) radiation has significant effects on ecosystems, environments, and human health, as well as atmospheric processes and climate change. Two ultraviolet radiation datasets are described in this paper. One contains hourly observations of UV radiation measured at 40 Chinese Ecosystem Research Network stations from 2005 to 2015. CUV3 broadband radiometers were used to observe the UV radiation, with an accuracy of 5%, which meets the World Meteorology Organization's measurement standards. The extremum method was used to control the quality of the measured datasets. The other dataset contains daily cumulative UV radiation estimates that were calculated using an all-sky estimation model combined with a hybrid model. The reconstructed daily UV radiation data span from 1961 to 2014. The mean absolute bias error and root-mean-square error are smaller than 30% at most stations, and most of the mean bias error values are negative, which indicates underestimation of the UV radiation intensity. These datasets can improve our basic knowledge of the spatial and temporal variations in UV radiation. Additionally, these datasets can be used in studies of potential ozone formation and atmospheric oxidation, as well as simulations of ecological processes.
文摘Journal of Plant Ecology(JPE)decided to establish awards of JPE Best Papers,in order to thank and encourage authors to submit their valuable research to JPE.This award will be given annually to the first author(s)of 2–5 papers selected by the editors,according to the citation data as well as the impact in the field of plant ecology.We will place extra emphasis on authors who had completed graduate studies not more than 5 years before submission of the paper,to encourage more early-career scientists to submit their work to JPE.It will come with a‘JPE Best Paper’certificate,as well as a price money of Chinese RMB 5000.