CAJ | 학술논문

利用Shimadzu UV2450分光光度计测量了含有不同叶绿素浓度的湖水样本在可见光和近红外区域的透射光谱，并使用实验室手段测量了水体的叶绿素含量。分析了湖水样本的透射光谱特性，同时引入二维相关光谱技术，利用叶绿素浓度值作为微扰量，得到水体叶绿素的动态光谱，进而结合二维同步谱图和异步谱图确定表征水体叶绿素浓度的特征波段。综合观察二维相关光谱中的同步谱图和异步谱图，更加精确地阐明了水体光谱特征，同时剔除水体中其他物质对于光谱信息的影响，更有效、全面地提取反映水体叶绿素信息的敏感波段。利用所选特征波段构建归一化水体叶绿素指数，将特征波段与叶绿素指数分别与水体叶绿素浓度建立线性预测模型。结果显示，归一化水体叶绿素指数的预测模型测定R2达到0.7712，均方根误差是45.5098 mg · L -1，预测R2达到0.7658，均方根误差是39.5038 mg · L -1。模型精度较利用特征波段建立的多元线性回归模型有了较大的提高，达到了实用水平。
이용Shimadzu UV2450분광광도계측량료함유불동협록소농도적호수양본재가견광화근홍외구역적투사광보，병사용실험실수단측량료수체적협록소함량。분석료호수양본적투사광보특성，동시인입이유상관광보기술，이용협록소농도치작위미우량，득도수체협록소적동태광보，진이결합이유동보보도화이보보도학정표정수체협록소농도적특정파단。종합관찰이유상관광보중적동보보도화이보보도，경가정학지천명료수체광보특정，동시척제수체중기타물질대우광보신식적영향，경유효、전면지제취반영수체협록소신식적민감파단。이용소선특정파단구건귀일화수체협록소지수，장특정파단여협록소지수분별여수체협록소농도건립선성예측모형。결과현시，귀일화수체협록소지수적예측모형측정R2체도0.7712，균방근오차시45.5098 mg · L -1，예측R2체도0.7658，균방근오차시39.5038 mg · L -1。모형정도교이용특정파단건립적다원선성회귀모형유료교대적제고，체도료실용수평。
Twenty five samples were collected from 10 different ponds in Jiangsu Province of China .According to the different water status and surface area of each pond ,different numbers of water samples were collected .The present paper aims to detect chlorophyll content in water body based on hyperspectrum .The visible and near infrared spectral transmittance of the water sam-ples was measured by using a Shimadzu UV-2450 spectrograph .At the same time ,the chlorophyll content of each sample was measured using hot-ethanol extraction method in the laboratory .Then the spectral characteristics were analyzed for the water samples and the results showed that with chlorophyll concentration increasing ,spectral transmittance decreased gradually .There is an apparent transmission valley at 676 nm .And then two dimensional correlation spectrum technology was used to analyze the sensitive absorption band of chlorophyll in water body .Comprehensive observation of the spectral characteristics of water sam-ples can be carried out much accurately by analyzing two-dimensional correlation spectra of synchronous and asynchronous spec-trograms .And the effective spectral response bands of the chlorophyll content were found at 488 and 676 nm .Then the NDWCI (normalized difference water chlorophyll index ) was established with the transmittance of red band and blue band .Two regres-sion models were built to predict the chlorophyll concentration in water .One is a multiple linear regression model based on the o-riginal transmittances at 488 and 676 nm .The other is the linear regression model based on NDWCI .By comparison ,the model based on NDWCI was better .The R2 of its training model reached to 0.771 2 ,and the root mean square error of calibration was 45.509 9 mg · L -1 .The R2 of prediction model reached to 0.765 8 ,and the root mean square error of prediction was 39.503 8 mg · L -1 .It reached to a practical level to predict the chlorophyll content in water body rapidly .