| 面向GOCI数据的太湖总磷浓度反演及其日内变化研究 |
| 摘要点击 2390 全文点击 985 投稿时间：2015-06-09 修订日期：2015-10-16 |
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| 中文关键词 GOCI影像 太湖 总磷 遥感反演 时空变化 |
| 英文关键词 GOCI data Taihu Lake total phosphorus remote sensing inversion spatial-temporal change |
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| 中文摘要 |
| 总磷浓度是水质评价的一个重要指标,是水体富营养化、蓝藻水华暴发的重要影响因素,遥感技术具有范围广、时效高的优势,利用卫星遥感监测总磷浓度,对于水质和富营养化的研究有着重要意义. 利用2013~2014年3次地面实验数据,构建了基于GOCI影像的总磷反演模型,为了检验模型的适用性,选取2014年春、夏、秋、冬各1日GOCI影像,对太湖总磷浓度的日内变化进行分析. 结果表明,利用GOCI数据8个波段的波段组合作为变量,进行逐步回归分析所建立的模型具有较高的反演精度,模型的决定系数为0.898,平均绝对误差百分比为14.296%,均方根误差为0.026mg ·L-1. 同时,利用地面实测样点与同步卫星影像对模型进行了精度分析, 2014年8月5日和2014年10月24日同步影像的验证精度分别为:平均绝对误差百分比为33.642%和22.551%,均方根误差为0.076 mg ·L-1和0.028 mg ·L-1. 对4个季节中4 d的30幅影像对比分析表明,不同季节总磷浓度的绝对含量存在差异,但是,总磷浓度的时空分布及从早晨到下午的差异性存在相似性. 从空间分布上看,梅梁湾、竺山湾、贡湖湾及西南部沿岸小梅港、长兜港总磷浓度长期偏高,各个区域的总磷浓度变化受到风向、风速等因素的影响; 从时间变化上看,早上总磷浓度最高,随后逐渐降低,反映了总磷浓度受到温度和光照影响的效果. |
| 英文摘要 |
| The TP concentration is an important index of water quality and an important influencing factor of eutrophication and algae blooms. Remote sensing technology has advantages of wide scope and high time limited efficacy. Monitoring the concentration of TP by satellite remote sensing is important for the study of water quality and eutrophication. In situ datasets collected during the three times of experiments in Taihu Lake between 2013 and 2014 were used to develop the TP inversion model based on GOCI data. The GOCI data in spring, summer, autumn and winter in 2014 were selected to analyze the time and space changes of TP concentration in Taihu Lake. The results showed that the TP algorithm was built up based on the variables, which was to use the eight band combination of GOCI data as variable, and build model using Multi factor linear regression method. The algorithm achieved more accurate TP estimation with R2=0.898, MAPE=14.296%, RMSE=0.026 mg ·L-1. Meantime, a analysis on the precision of the model by using the measured sample points and the synchronous satellite images with MAPE=33.642%, 22.551%,RMSE=0.076 mg ·L-1, 0.028 mg ·L-1 on August 5, 2014 and October 24, 2014. Through the analysis of the 30 images on the four days of the four seasons, it showed that the absolute concentration of total phosphorus was different in different seasons. But temporal and spatial distribution of total phosphorus concentration was similar in the morning and afternoon. In spatial distribution, the TP concentration in Meiliang Bay, Zhushan Bay, Gonghu Bay, Xiaomei Port and Changdou Port in the southwest coast was at a continuously high position. The TP concentration change in different regions was influenced by wind direction, wind speed and other factors. The TP concentration highest in the morning, and then gradually decreased, this phenomenon reflected that the TP concentration was affected by temperature and light. |
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