赣南稀土矿区河流富营养化评价及时空格局

Evaluation of River Eutrophication and Spatio-temporal Patterns in Rare Earth Mining Areas of Gannan

由于人类活动的不断加剧,大量污染物随地表径流进入河流与湖泊,河流与湖泊水质急剧下降,富营养化问题日益凸显.文章采用Landsat-8遥感影像和富营养化遥感评价因子构建赣南稀土矿区河流水体富营养状态遥感评价模型,结合地面实测数据,对模型的精度和适用性进行评价;利用2013-2020年获取的赣南稀土矿区河流水体Landsat-8数据对水体进行富营养状态遥感监测并分析其时空分布.结果表明:(Ⅰ)采用叶绿素浓度作为水体富营养化状态遥感评价的水质因子可以准确反映水体富营养化状态;(Ⅱ)利用2013-2018年鄱阳湖地面实测数据中验证数据对模型进行精度评价,模型MAD为4.48,RMSE为5.29,MAPE为9.59%;(Ⅲ)桃江水体富营养状态占比在2013-2020年期间呈现上升-下降-上升-下降趋势.文章将推进Landsat-8影像数据在内陆水体富营养化状态监测中的利用,为内陆水环境质量评价提供技术支持.

Due to the increasing human activities,many pollutants enter rivers and lakes with surface runoff,and the water quality of rivers and lakes decreases sharply,and the problem of eutrophication becomes more and more prominent.In this paper,a remote sensing evaluation model of eutrophication status of river water bodies in rare earth mining areas is constructed using Landsat-8 remote sensing images and eutrophication remote sensing evaluation factors,and the accuracy and applicability of the model are evaluated by combining with ground truth data.The remote sensing monitoring of eutrophic status of water bodies and analysis of their spatial and temporal distribution were carried out using Landsat-8 data of river water bodies in Gannan rare earth mining area acquired from 2013 to 2020.The results show that􀃬(Ⅰ)using chlorophyll concentration as the water quality factor for remote sensing evaluation of eutrophication status of water bodies can accurately reflect the eutrophication status of water bodies;(Ⅱ)using the validation data in the ground truth data of Poyang Lake from 2013-2018 to evaluate the accuracy of the model,the model MAD is 4.48,RMSE is 5.29 and MAPE is 9.59%;(Ⅲ)the percentage of eutrophic status of Taojiang River water bodies shows an increasing-decreasing-rising-decreasing trend during the period of 2013-2020.This paper will promote the use of Landsat-8 image data in monitoring the eutrophication status of inland water bodies and provide technical support for the evaluation of inland water environmental quality.