This research considers the mathematical relationship between concentration of Chla and seven environmental factors, i.e. Lake water temperature (T), Secci-depth (SD), pH, DO, CODMn, Total Nitrogen (TN), Total Phospho...This research considers the mathematical relationship between concentration of Chla and seven environmental factors, i.e. Lake water temperature (T), Secci-depth (SD), pH, DO, CODMn, Total Nitrogen (TN), Total Phosphorus (TP). Stepwise linear regression of 1997 to 1999 monitoring data at each sampling point of Qiandaohu Lake yielded the multivariate regression models presented in this paper. The concentration of Chla as simulation for the year 2000 by the regression model was similar to the observed value. The suggested mathematical relationship could be used to predict changes in the lakewater environment at any point in time. The results showed that SD, TP and pH were the most significant factors affecting Chla concentration.展开更多
Ecological degradation is a common problem around the world which has a profound impact on the sustainable development of mankind.This paper selects Lashihai basin as the study case,and uses Logistic stepwise regressi...Ecological degradation is a common problem around the world which has a profound impact on the sustainable development of mankind.This paper selects Lashihai basin as the study case,and uses Logistic stepwise regression to simulate the original ecology of the potential vegetation in the area as a reference system for the definition and analysis of the subsequent degree of ecological degradation and its distribution characteristics.The analysis yields four main results.(1)The strong human disturbance areas in the Lashihai region are concentrated in the Lashihai basin,and the main impact factors are roads,residential areas and cultivated lands.(2)Besides lake,there are eight potential vegetation types in Lashihai,among which evergreen coniferous forest is the dominant community,and the other seven planting types of potential vegetation include warm meadow,grass,beach grass,evergreen broad-leaved shrubbery,deciduous broad-leaved shrubbery,warm steppe and alpine grassland.(3)The elevation and average phosphorus content have significant effects on the distribution of potential vegetation,while the different vegetation types have differential sensitivities to environmental factors.(4)On the whole,the degree of ecological degradation in the basin is relatively light,in which the proportion of non-degraded areas accounts for nearly half,the area of mild degradation is about one-fourth,the moderately degraded area is concentrated in areas with strong human disturbance,accounting for only 18.64%,and the severe degradation is rare,occupying an area of only 3.17%.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 69673044) the Environmental Protection Bureau of Hangzhou (No. 9901), China
文摘This research considers the mathematical relationship between concentration of Chla and seven environmental factors, i.e. Lake water temperature (T), Secci-depth (SD), pH, DO, CODMn, Total Nitrogen (TN), Total Phosphorus (TP). Stepwise linear regression of 1997 to 1999 monitoring data at each sampling point of Qiandaohu Lake yielded the multivariate regression models presented in this paper. The concentration of Chla as simulation for the year 2000 by the regression model was similar to the observed value. The suggested mathematical relationship could be used to predict changes in the lakewater environment at any point in time. The results showed that SD, TP and pH were the most significant factors affecting Chla concentration.
基金The Basic Scientific Research Fund of Central Public Welfare Scientific Research Institutes(2021-9070b)。
文摘Ecological degradation is a common problem around the world which has a profound impact on the sustainable development of mankind.This paper selects Lashihai basin as the study case,and uses Logistic stepwise regression to simulate the original ecology of the potential vegetation in the area as a reference system for the definition and analysis of the subsequent degree of ecological degradation and its distribution characteristics.The analysis yields four main results.(1)The strong human disturbance areas in the Lashihai region are concentrated in the Lashihai basin,and the main impact factors are roads,residential areas and cultivated lands.(2)Besides lake,there are eight potential vegetation types in Lashihai,among which evergreen coniferous forest is the dominant community,and the other seven planting types of potential vegetation include warm meadow,grass,beach grass,evergreen broad-leaved shrubbery,deciduous broad-leaved shrubbery,warm steppe and alpine grassland.(3)The elevation and average phosphorus content have significant effects on the distribution of potential vegetation,while the different vegetation types have differential sensitivities to environmental factors.(4)On the whole,the degree of ecological degradation in the basin is relatively light,in which the proportion of non-degraded areas accounts for nearly half,the area of mild degradation is about one-fourth,the moderately degraded area is concentrated in areas with strong human disturbance,accounting for only 18.64%,and the severe degradation is rare,occupying an area of only 3.17%.
