Egypt is a highly populated country of about 85 million inhabitants that are concentrated on the Nile Delta and on the flood plain of the Nile River. More than 90% of this population relies on the Nile River in their ...Egypt is a highly populated country of about 85 million inhabitants that are concentrated on the Nile Delta and on the flood plain of the Nile River. More than 90% of this population relies on the Nile River in their water demand for domestic use. Currently, Egypt is facing a problem with the trans-boundary water budget coming from the Nile basin. This urges for managing the water quantity and quality to secure the water needs. This paper discusses the potential use of airborne hyperspectral data for water quality management in the form of detecting the oil contamination in the Nile River in integration with in-situ measurements including ASD spectroradiometer and eco-sounder multi-probe devices. The eco-sounder multi-probe device measured most of the water quality parameters and detected the existence of oil contamination at 1200 bb downstream of the study area. The airborne hyperspectral images were analyzed and calibrated with the spectral library determined from the in-situ spectroradiometer to map the patches of the oil contamination. The details of the findings and learning lessons are fully discussed in the paper.展开更多
油膜厚度是水面溢油量估算的一个关键参数。为了确定高光谱数据探测水面油膜厚度的可行性,在实验室内,以原油作为实验油品,以石英卤素灯模拟太阳光源,以ASD FieldSpec3作为光谱探测仪器,开展了不同厚度油膜模拟及其反射率光谱测量实验,...油膜厚度是水面溢油量估算的一个关键参数。为了确定高光谱数据探测水面油膜厚度的可行性,在实验室内,以原油作为实验油品,以石英卤素灯模拟太阳光源,以ASD FieldSpec3作为光谱探测仪器,开展了不同厚度油膜模拟及其反射率光谱测量实验,获取油膜厚度-反射率光谱数据27组。为了充分利用光谱信息,选择偏最小二乘法(partial least squares,PLS)进行油膜厚度-光谱反射率建模,样本数据中21组用于建模,6组用于验证。研究结果表明,当主成分分量个数为5时,PLS模型具有最佳效果,5个主成分分量累积解释了74%的自变量信息和99.8%的因变量信息,模型的预测能力达到92.8%,建模样本和验证样本的均方根误差(root mean squared error,RMSE)分别为0.01和0.04,说明所建立的PLS模型具有较好的预测能力和稳定性。通过与传统曲线拟合模型的对比,PLS模型在误差方面无论是建模样本还是验证样本均优于传统的经验模型,因而认为基于PLS模型可以实现高光谱数据水面油膜厚度估算。展开更多
The dynamics of contained oil spills is investigated based on multiphase CFD (Computational Fluid Mechanics) model. The oil slick shape behind the oil boom under water current is studied. The velocity field in the oil...The dynamics of contained oil spills is investigated based on multiphase CFD (Computational Fluid Mechanics) model. The oil slick shape behind the oil boom under water current is studied. The velocity field in the oil slick is compared with the velocity field in pure water flow. The thickness of the oil slick is studied quantitatively. It is found that there is a fixed linear relationship between the oil slick relative thickness and the Froude number for different oil, different current velocity, different boom draft and different volume of oil.展开更多
文摘Egypt is a highly populated country of about 85 million inhabitants that are concentrated on the Nile Delta and on the flood plain of the Nile River. More than 90% of this population relies on the Nile River in their water demand for domestic use. Currently, Egypt is facing a problem with the trans-boundary water budget coming from the Nile basin. This urges for managing the water quantity and quality to secure the water needs. This paper discusses the potential use of airborne hyperspectral data for water quality management in the form of detecting the oil contamination in the Nile River in integration with in-situ measurements including ASD spectroradiometer and eco-sounder multi-probe devices. The eco-sounder multi-probe device measured most of the water quality parameters and detected the existence of oil contamination at 1200 bb downstream of the study area. The airborne hyperspectral images were analyzed and calibrated with the spectral library determined from the in-situ spectroradiometer to map the patches of the oil contamination. The details of the findings and learning lessons are fully discussed in the paper.
文摘油膜厚度是水面溢油量估算的一个关键参数。为了确定高光谱数据探测水面油膜厚度的可行性,在实验室内,以原油作为实验油品,以石英卤素灯模拟太阳光源,以ASD FieldSpec3作为光谱探测仪器,开展了不同厚度油膜模拟及其反射率光谱测量实验,获取油膜厚度-反射率光谱数据27组。为了充分利用光谱信息,选择偏最小二乘法(partial least squares,PLS)进行油膜厚度-光谱反射率建模,样本数据中21组用于建模,6组用于验证。研究结果表明,当主成分分量个数为5时,PLS模型具有最佳效果,5个主成分分量累积解释了74%的自变量信息和99.8%的因变量信息,模型的预测能力达到92.8%,建模样本和验证样本的均方根误差(root mean squared error,RMSE)分别为0.01和0.04,说明所建立的PLS模型具有较好的预测能力和稳定性。通过与传统曲线拟合模型的对比,PLS模型在误差方面无论是建模样本还是验证样本均优于传统的经验模型,因而认为基于PLS模型可以实现高光谱数据水面油膜厚度估算。
基金Program of PetroChina Exploration and Development Research Institute (Grant No.06-01C-01-08)National Science & Technology Pillar Program (Grant No.2006BAK30B01)
文摘The dynamics of contained oil spills is investigated based on multiphase CFD (Computational Fluid Mechanics) model. The oil slick shape behind the oil boom under water current is studied. The velocity field in the oil slick is compared with the velocity field in pure water flow. The thickness of the oil slick is studied quantitatively. It is found that there is a fixed linear relationship between the oil slick relative thickness and the Froude number for different oil, different current velocity, different boom draft and different volume of oil.
