Water Quality Parameters for Khadakwasala Dam derived using Landsat 8 OLI Surface Reflectance

Format of the Data: The data consists of images in .tiff format. Description: This dataset contains images representing the concentrations of Chlorophyll, Turbidity, Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD) and Dissolved Oxygen (DO) for the Khadakwasala Dam. The concentrations have been derived from various surface reflectance bands obtained from Landsat 8 OLI. The relationship between Landsat surface reflectance and optically sensitive water quality parameters such as turbidity and chlorophyll, using a stepwise regression model, is developed. Parameters that are optically non-sensitive, such as COD, BOD and DO, are not directly inferred from the surface reflectance. The process entails formulating a secondary interrelation between the optically sensitive and non-sensitive parameters. Equations Used: Chlorophyll=-0.1551*B3/B2 - 0.9551*B4 + 1.5376*(B3+B4) - 2.1244*B2 - 0.4921*B5 + 0.3683*B2 + 0.3141 Turbidity =1.012*B2/B1 + 1.021 Where B1, B2, B3, B4 and B5 are Top of Atmospheric Surface Reflectance derived from Landsat 8 OLI surface reflectance bands COD = -233.1802*Chlorophyll - 17.1638*Turbidity + 89.4429 BOD = -0.869*Turbidity + 5.6707 DO = -0.6339*Turbidity + 8.9572 Where Chlorophyll and Turbidity derived in eralier equation above using Surface Reflectance bands of Landsat 8 OLI Time Span for Availability From: 20th October 2022 To: 22nd April 2023 Nomenclature The files in this dataset follow the naming convention: Water Quality Parameter_YEARMMDD_Khadakwasala.tiff Caution Note: These equations are specific to the conditions at the Khadakwasala Dam and may not accurately predict concentrations for other water bodies. Users should exercise caution when applying these equations to different contexts. Acknowledgement: Thanks to Water Resource Department Maharashtra, India Pune Division for permission to access the site for the periodic water sampling for testing purpose.数据格式： 本数据集包含.tiff格式的图像。 数据集说明： 本数据集涵盖了哈达瓦萨大坝（Khadakwasala Dam）的叶绿素、浊度、化学需氧量（Chemical Oxygen Demand, COD）、生化需氧量（Biochemical Oxygen Demand, BOD）以及溶解氧（Dissolved Oxygen, DO）的浓度影像。上述水质浓度值由Landsat 8 OLI获取的多组地表反射波段推导得出。 研究通过逐步回归模型，建立了Landsat地表反射率与浊度、叶绿素这类光学敏感型水质参数之间的关联关系。而COD、BOD、DO这类光学非敏感参数无法直接通过地表反射率推导得到，因此需要构建光学敏感与非敏感参数之间的二级互相关联关系。 所用计算公式： 叶绿素浓度 = -0.1551*B3/B2 - 0.9551*B4 + 1.5376*(B3+B4) - 2.1244*B2 - 0.4921*B5 + 0.3683*B2 + 0.3141 浊度 = 1.012*B2/B1 + 1.021 其中B1、B2、B3、B4、B5为基于Landsat 8 OLI地表反射波段获取的大气顶部地表反射率（Top of Atmospheric Surface Reflectance）。 化学需氧量（COD） = -233.1802*叶绿素浓度 - 17.1638*浊度 + 89.4429 生化需氧量（BOD） = -0.869*浊度 + 5.6707 溶解氧（DO） = -0.6339*浊度 + 8.9572 注：上述叶绿素与浊度浓度值通过前文所述的Landsat 8 OLI地表反射波段公式推导得出。 数据可用时间范围： 起始：2022年10月20日 终止：2023年4月22日 命名规范： 本数据集内的文件遵循如下命名规则： 水质参数_年份月份日期_Khadakwasala.tiff 注意事项： 本套计算公式仅适配哈达瓦萨大坝的当地环境条件，无法准确预测其他水体的水质浓度。使用者将该公式应用于其他场景时需谨慎操作。 致谢： 感谢印度马哈拉施特拉邦水资源部浦那分部允许开展周期性现场水样采集与检测工作。