博斯腾湖COD_(Cr)污染现状及影响因素分析

Analysis of CODcr Pollution Status and Influencing Factors in Bosten Lake

近几年博斯腾湖COD_(Cr)污染问题突出,制约了区域社会经济的可持续发展。目前有关博斯腾湖COD_(Cr)的研究,主要集中于非长序列的COD_(Cr)时空特征分析,而对造成这种时空特征的成因缺乏定量化分析研究。鉴于此,在收集分析博斯腾湖COD_(Cr)长序列变化特征的基础上,通过统计分析和模型模拟等方法,系统探讨了博斯腾湖COD_(Cr)污染的主要影响因素及其作用机理。主要研究结论为:入湖负荷和湖泊水位对COD_(Cr)的影响存在共轭作用,主导作用取决于水位阈值;当水位低于1047.1 m,水位稀释作用占主导,当水位高于1047.1 m时,入湖负荷占主导;湖泊水动力条件主要受风生流控制,近年来风速呈上升趋势,增强了湖区内部的水循环,进而影响西部湖区COD_(Cr)浓度;湖泊藻类浓度与水位呈负相关,而与COD_(Cr)浓度呈正相关,COD_(Cr)与藻类浓度显著相关性的内在机制是两者均受水位影响。该研究为博斯腾湖COD_(Cr)污染治理提供了科学依据,同时提出未来研究的关注点是加强对底泥、水温和溶解氧的垂向相关数据的监测,以进一步分析底泥对水体COD_(Cr)的影响。

In recent years,the COD_(Cr)pollution problem of Bosten Lake has been prominent,which has restricted the sustainable development of regional social economy.At present,the research on COD_(Cr)in Bosten Lake has mainly focused on the analysis of the spatiotemporal characteristics of COD_(Cr)in non-long sequences,but there has been a lack of quantitative analysis of the causes of such spatiotemporal characteristics.In view of this,the long series characteristics of COD_(Cr)changes in Bosten Lake had been collected and analyzed.Then the main influencing factors and mechanism of COD_(Cr)pollution in Bosten Lake had been systematically discussed through statistic analysis analysis and model simulation.The main conclusions were that there was a conjugation effect on the influence of inflow load and lake water level on COD_(Cr),and the dominant effect depended on the water level threshold.When the water level was lower than 1047.1 m,the water level dilution was dominant,and when the water level was higher than 1047.1 m,the inflow load was dominant.The hydrodynamic conditions of lakes were mainly controlled by wind-driven currents.In recent years,the wind speed has shown an upward trend,which has enhanced the water cycle in the lake area,and then affected the COD_(Cr)concentration in the western lake area.The algae concentration in the lake was negatively correlated with the water level and positively correlated with the COD_(Cr)concentration,and the internal mechanism of the significant correlation between COD_(Cr)and the algae concentration was that both were affected by the water level.This study has provided a scientific basis for the treatment of COD_(Cr)pollution in Bosten Lake,and proposed that the focus of future research is to strengthen the monitoring of vertical correlation data of sediment,water temperature and dissolved oxygen,so as to further analyze the impact of sediment on COD_(Cr)in water.