基于MERIS影像的洪泽湖叶绿素a浓度时空变化规律分析

发布时间：2018-01-28 09:32

  本文关键词： 叶绿素a 洪泽湖 时空变化 MERIS 气候变化 淮河　出处：《环境科学》2017年09期 　论文类型：期刊论文

【摘要】：叶绿素a(Chl-a)浓度是衡量藻类生物量及评价水体营养状态的重要指标.基于洪泽湖2016年7月、2016年12月共49个实测水质参数与同步光谱数据,验证了5种可应用于MERIS/OLCI数据的Chl-a遥感估算模型(包括波段比值模型、三波段模型、FLH模型、MCI模型以及UMOC模型)在洪泽湖水域的适用性.结果表明,UMOC模型是最适用于洪泽湖水域的Chl-a浓度估算模型,其平均相对误差为32.30%,低于波段比值模型的75.17%,三波段模型的62.44%,FLH模型的45.87%和MCI模型的56.95%.进而利用UMOC模型,结合MERIS数据,获取了洪泽湖2002~2012年Chl-a浓度遥感估算产品,并分析了洪泽湖Chl-a浓度的时空变化规律.洪泽湖Chl-a浓度具有明显的时空差异性.依据水体像元长时间序列月平均Chl-a浓度的差异,将洪泽湖水体分为了区域A、区域B和区域C这3种类型.区域B和区域C水体无明显的变化趋势,区域A则显著增加.与气象因子的相关性分析表明,区域B和区域C年平均Chl-a的波动主要受年降水量的影响,反映了该2个区域Chl-a浓度的变化主要受湖流强度的控制,区域A年平均Chl-a浓度的变化与年平均风速呈显著负相关性,风速下降的气候大背景可能会加重这一区域的富营养化程度,威胁南水北调的水质安全.此外,在汛期(7~9月)洪泽湖水体Chl-a浓度与离淮河入湖口的距离呈显著的正相关关系,证明了这一时期淮河对洪泽湖藻类浓度具有明显的抑制作用.
[Abstract]:Chlorophyll a Chl-a) concentration is an important index to measure algal biomass and evaluate the nutrient status of water body based on Hongze Lake in July 2016. In December 2016, 49 measured water quality parameters and synchronous spectral data were measured, and five Chl-a remote sensing estimation models (including band ratio model) were verified. The applicability of MCI model and UMOC model in Hongze Lake waters is shown. UMOC model is the most suitable model for estimating the concentration of Chl-a in Hongze Lake. Its average relative error is 32.30, which is lower than that of the ratio model of wave band 75.17%. 62.44 of the three-band model and 45.87% of the FLH model and 56.95of the MCI model. Then the UMOC model is used to combine the MERIS data. The remote sensing estimation products of Chl-a concentration from 2002 to 2012 in Hongze Lake were obtained. The temporal and spatial variation of Chl-a concentration in Hongze Lake was also analyzed. The Chl-a concentration of Hongze Lake had obvious difference in time and space. According to the difference of the monthly average Chl-a concentration in the long time series of water bodies, the variation of Chl-a concentration in Hongze Lake was analyzed. The water body of Hongze Lake is divided into three types: area A, region B and region C. there is no obvious change trend in area B and C, but there is a significant increase in area A. the correlation analysis with meteorological factors shows that the water body of Hongze Lake can be divided into three types. The fluctuation of average annual Chl-a in region B and C is mainly affected by annual precipitation, which indicates that the variation of Chl-a concentration in these two regions is mainly controlled by the intensity of lake flow. The variation of annual average Chl-a concentration in A area is significantly negatively correlated with the annual average wind speed, and the climate background of wind speed decline may aggravate the eutrophication degree of this area. In addition, there is a significant positive correlation between the concentration of Chl-a in Hongze Lake and the distance from the entrance of the Huaihe River to the mouth of the Huai River during the flood season from 7 to September. It is proved that the Huaihe River has obvious inhibitory effect on algae concentration in Hongze Lake during this period.
【作者单位】： 南京师范大学虚拟地理环境教育部重点实验室;江苏省地理信息资源开发与利用协同创新中心;
【基金】：国家自然科学基金项目(41671340) 国家重点研发计划项目(2017YFB0503902)
【分类号】：X524;X87
【正文快照】： 南京210023)叶绿素a(Chl-a)浓度是藻类生物量重要指标,是水质的重要表征参数,也是我国水环境必须监测的指标[1].湖泊Chl-a浓度的调查不仅可以确定水体的营养状态,为湖泊治理和渔业资源管理提供基础信息,而且有助于深刻理解和研究湖泊生态系统的生物地球化学循环过程以及其对气，

本文编号：1470396