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Chlorophyll-a is a well-accepted index for phytoplankton abundance and population of primary producers in an aquatic environment. The relationships between chlorophyll-a and 18 chemical, physical and biological water quality variables in YuQiao Reservoir (YQR) in the Haihe River Basin in P.R. China were studied by using principal component analysis (PCA) coupled with a radial basis function network (RBF) model to predict chlorophyll-a levels. Principal component analysis was used to simplify the complexity of relations between water quality variables. Score values obtained by PC scores were used as independent variables in the RBF models. In the forecast, only five selected score values obtained by PC analysis were used for the prediction of chlorophyll-a levels. Correlative analysis between the modeled results and observed data indicates that the correlative coefficient is 0.61, and analysis of the forecast error rate shows that the average forecast error is 32.9%, proving the viability of the forecast model.

An experimental study was undertaken to highlight the potential applicability of biofilms as biomonitors forming simultaneously on natural and artificial substrata in Baiyngdian Lake(China).We investigated the responses of freshwater biofilm in 8 site of Baiyngdian Lake and compared with control site (a reservoir) to assess the relative health of water. Exposure to pollution and its impact on biofilms were assessed by measuring the biomass production, Chlorophyll concentration, the algal composition, extracellular enzyme activity of bacterial communities and Polysaccharide content. This relation between the biological characters of biofilms and water quality were discussed, and the relative health of regions were demonstrated by the degree of deviation based on bioflim indicator in the following order: Fu river (S4) < Duan cun (S8) < Nan Liuzhuang (S5) < Wang jiazai (S1) < Cai putai (S7) < Zao lingzhuang (S2)< Shao Chedian (S3).. The result indicated that biofilm can provide information for pollution detection and ecological health assessment of water, and biofilm on aritificial substrata was recommended for biomonitoring in the Baiyangdian Lake.

Supplying water to the ecological environment with certain quantity and quality is significant for the protection of diversity and the realization of sustainable development. The conception and connotation of eco-environmental water requirements, including the definition of the conception, the composition and characteristics of eco-environmental water requirements, are evaluated in this paper. The classification and estimation methods of eco-environmental water requirements are then proposed. On the basis of the study on the Huang-Huai-Hai Area, the present water use, the minimum and suitable water requirement are estimated and the corresponding water shortage is also calculated. According to the interrelated programs, the eco-environmental water requirements in the coming years (2010, 2030, 2050) are estimated. The result indicates that the minimum and suitable eco-environmental water requirements fluctuate with the differences of function setting and the referential standard of water resources, and so as the water shortage. Moreover, the study indicates that the minimum eco-environmental water requirement of the study area ranges from 2.84×10 10 m3 to 1.02×10 11 m 3 , the suitable water requirement ranges from 6.45×10 10 m 3 to 1.78×10 11 m 3 , the water shortage ranges from 9.1×10 9 m 3 to 2.16×10 10 m 3 under the minimum water requirement, and it is from 3.07×10 10 m 3 to 7.53×10 10 m 3 under the suitable water requirement. According to the different values of the water shortage, the water priority can be allocated. The ranges of the eco-environmental water requirements in the three coming years (2010, 2030, 2050) are 4.49×10 10 m 3 -1.73×10 11 m 3 , 5.99×10m 3 -2.09×10 11 m 3 , and 7.44×10 10 m 3 -2.52×10 11 m 3 , respectively.