环境因子对大伙房水库叶绿素α的影响研究

Influence of Environmental Factors on Chlorophyll-α in Dahuofang Reservoir

为研究叶绿素α浓度动态特征以及环境因子对叶绿素α浓度动态特征的影响,该文利用环境卫星时间序列影像作为数据源,分析大伙房水库叶绿素α浓度的分布特征;并结合环境因子数据,采用相关分析和偏相关分析方法,研究环境因子和叶绿素α浓度之间的关联程度,利用逐步回归分析方法,探讨叶绿素α浓度对环境因子的影响程度,预测叶绿素α浓度变化。叶绿素α浓度反演结果表明,大伙房水库叶绿素α浓度具有空间分异性,表现为水库上游浓度较高,为0.0204 mg/L,中游和下游浓度较低,分别为0.0124、0.0088 mg/L。Peαrson相关性分析及偏相关性分析结果表明,叶绿素α浓度变化的显著影响因子为风速变化,水库上游、中游、下游的叶绿素α浓度变化与风速变化的相关系数分别为0.726、0.559、0.467,偏相关系数分别为0.772、0.488、0.467。逐步回归分析结果表明,水温变化、风速变化是影响叶绿素α浓度变化的主要因素,上游水温变化的标准化系数为0.278,中游、下游、全库区风速变化的标准化系数分别为0.646、0.508、0.246。

In order to understand the dynamic characteristics of chlorophyll-αconcentration and the influence of environmental factors on the dynamic characteristics of chlorophyll-αconcentration,this article uses environmental satellite time series images as data sources to analyze the distribution characteristics of chlorophyll-αconcentration in Dahuofang Reservoir.Combined with environmental factor data,the correlation between environmental factors and chlorophyll a concentration is studied by using the correlation analysis and partial correlation analysis and the influence of chlorophyll-αconcentration on environmental factors was discussed by using stepwise regression analysis.The results show that the concentration of chlorophyll-αin the Reservoir has spatial differentiation,the upstream area is higher,0.0204 mg/L,the middle area and the downstream area is lower,0.0124 mg/L and 0.0088 mg/L respectively.Pearson correlation analysis and partial correlation analysis show that the significant influence factor of chlorophyll-αchange amount is the amount of wind speed change.The correlation coefficient in the upstream area,the middle area and the downstream area is respectively 0.726,0.559 and 0.467.The partial correlation coefficient in the upstream area,the middle area and the downstream area is respectively 0.772,0.488 and0.467.Stepwise regression analysis shows that water temperature change and wind speed change are the main factors affecting change of chlorophyll-α.The normalization coefficient of the water temperature change in the upstream area is 0.278,the normalization coefficients of the wind speed change in the middle,downstream and whole reservoir areas are 0.646,0.508 and0.246 respectively.