Considering the Haihe River Basin as an example, the DPeRS model was used to analyze the spatial distribution characteristics and pollution sources of the diffuse pollution by remote sensing pixel scale. Combined with the evaluation standard of surface water quality, a potential risk grading method for diffuse pollution was constructed to assess the potential risk of diffuse pollution in Haihe River Basin. The results showed that, in 2016, the diffuse discharge loads of total nitrogen (TN), total phosphorus (TP), ammonia nitrogen (NH-N), and chemical oxygen demand (COD) were 429.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
November 2014
Thermal plume from coastal nuclear power plant is a small-scale human activity, mornitoring of which requires high-frequency and high-spatial remote sensing data. The infrared scanner (IRS), on board of HJ-1B, has an infrared channel IRS4 with 300 m and 4-days as its spatial and temporal resolution. Remote sensing data aquired using IRS4 is an available source for mornitoring thermal plume.
View Article and Find Full Text PDFHuan Jing Ke Xue
September 2014
Guang Pu Xue Yu Guang Pu Fen Xi
December 2013
With the development of platforms and sensors, continuous repetition of remote sensing observation of the earth surface has been realized, and a mass of multi-source, multi-scale, multi-resolution remote sensing data has been accumulated. Those images have detailedly recorded the changing process of ground objects on the earth, which makes the long term global change research, such as change detection, based on remote sensing become possible, and greatly push forward the research on image processing and application. Although plenty of successful research has been reported, there are still enormous challenges in multi-temporal imagery change detection.
View Article and Find Full Text PDFHuan Jing Ke Xue
February 2011
Phycocyanin (PC) in the blue-green algae is usually used to detective the quantity of the blue-green algae, because of its special absorption at band 620 nm. A semi-analytical model retrieving phycocyanin concentrations is been built, based on a nested semi-empirical band ratio algorithm, using the data sets collected in September 19 and September 20, 2009 from Dianchi Lake. The empirical relationship between the specific absorption coefficient at band 620 nm [a(PC)* (620)] and the absorption coefficient at band 620 nm [a(PC) (620)] reduces the impact of the variability of a(PC)* (620) in the model built by Simis.
View Article and Find Full Text PDFHuan Jing Ke Xue
February 2011
A field investigation in Lake Dianchi was carried out in November, 2009, and a dataset including absorption coefficients and concentration of water components was collected. Absorption properties and its spatial distribution of Lake Dianchi have been systematically analyzed, the results show that: (1) Absorption spectral curve of total particles (a(p)) are similar with that of phytoplankton (a(ph)), which indicates that phytoplankton absorption dominates absorption of total suspended particles; (2) Significant relationships are found between a(ph) (440), a(ph) (624), a(ph) (675) and concentration of chla, and cyanophyta dominats the quantity of the algae in water columns; (3) There are more phytoplankton existed in northern lake than other areas because of higher level of eutrophication. Comparing with other water columns, discrepancies mainly appear as below: (1) The mean value of slope of absorption spectral curve of non-algal particles (S(d)) in Lake Dianchi is much bigger than that in other case-II waters; (2) The mean value of slope of absorption spectral curve of chromophoric dissolved organic matter (CDOM) S(g) in Lake Dianchi is much smaller than that in other case-II waters; (3) Specific absorption of phytoplankton (a(ph)*) at 440 nm and 675 nm is at intermediate level, and a(ph)* value is susceptible to different regions, seasons, population structure of phytoplankton and so on.
View Article and Find Full Text PDFRemote sensing reflectivity (R(rs)), total suspended matter (TSM), absorption and scattering properties of 32 sampling sites in situ were measured in June 2009. The inherent optical properties (IOPs), such as absorption and scattering properties of different components in Chaohu Lake, were analyzed according to these data. And specific scattering coefficient of suspended matters and the backscattering ratio which were the indispensable inherent optical parameters were identified.
View Article and Find Full Text PDFA hierarchical cluster analysis is applied to the data set of R(rs) spectra. Combing the inherent optical and measured water color characteristics, we determine factors of the variability for each class of R(rs) spectra. The R(rs) measured from Lake Taihu, Chaohu, Dianchi and Three Gorges Reservoir can be divided into three spectrally distinct classes: class 1, class 2 and class 3.
View Article and Find Full Text PDFZhonghua Wei Chang Wai Ke Za Zhi
November 2010
Objective: To evaluate the clinical value of laparoscopy-assisted modified Soave procedure for Hirschsprung disease in adults.
Methods: Twenty-eight patients with a preoperative diagnosis of Hirschsprung disease underwent laparoscopy-assisted modified Soave procedure between March 2005 and December 2009. Clinical data were retrospectively analyzed.