藻类垂向分布对内陆湖泊叶绿素a反演算法影响的模拟研究

利用高斯模型模拟不同的藻类垂向分布结构,研究其对于典型叶绿素a反演算法波段比值法的影响.结果显示,藻类垂向分布不均一性导致了叶绿素a浓度反演结果与藻类生物量间不存在一一对应的关系;藻类分布集中于水面以及水下0.5 m水深时会严重干扰波段比值反演算法的准确性,说明当水体表面存在藻华现象时,将导致反演算法失效;若排除此类情况,波段比值法与水体表层0.25 m处叶绿素a浓度、0~0.25 m、0~0.5 m水深范围内平均叶绿素a浓度值之间具有独立于藻类生物量以及藻类垂向分布的相关性;内陆湖泊叶绿素a反演算法与藻类垂向分布模型相结合,是获取藻类生物量的必要条件.

Influence of algae vertical profiles on chlorophyll-a retrieval algorithm in inland lakes: Hydrolight simulation

Now the influence of algae vertical profiles on chlorophyll-a retrieval algorithm in inland lakes needs more attentions in the research field of Case 2 water color remote sensing. In our study, we used the Gaussian model to describe the algae vertical profiles and analyzed the influence of algae vertical profiles on band ratio algorithm via Hydrolight simulation. It indicated that there was no uniform relationship between reflectance of water surface and the algae biomass because of different algae vertical profiles; algae blooms at the water surface could lead to the failing of retrieval algorithm; excluding algal bloom case, there were good correlation between band ratio algorithm and chlorophyll-a concentration at 0.25m water depth or average chlorophyll-a concentrations at 0~0.25 / 0~0.5m water depth, which did not concern algae biomass and algae vertical profiles; integrate consideration on chlorophyll-a concentration retrieved from remote sensing algorithm and algae vertical profiles should be an executable approach to obtain algae biomass of inland lakes.