[Scenario analysis of integrated model of nutrients in the Miyun Reservoir and its watershed].

Supported by the integrated model of nutrients for the Miyun Reservoir in part I, effects of different control measures were studied on the water quality of the reservoir. Four scenarios were assumed and analyzed. Results of the base case scenario showed that TN concentration of the Miyun Reservoir had highly exceeded the environmental quality standard for surface water, and TP was relatively better.

[Integrated model of nutrients for the Miyun Reservoir and its watershed].

In recent years, the Miyun Reservoir faces severe problems of water quality and quantity due to continuous drought. In order to simulate and predict the eutrophic status of the Miyun Reservoir and its watershed, an integrated model was developed based on GIS and RS technology, which was composed of non-point source (NPS) simulation model, aquatic ecological-hydrodynamic model, and river water quality model. Ecological-hydrodynamic model was developed through coupling water quality analysis simulation program (WASP) with environmental fluid dynamics Code (EFDC).

[Study on spatial site selection assessment of urban medical waste treatment facility].

Based on the principle of regional differentiation and gravity model, this paper proposes a GIS-based urban medical waste treatment facility spatial site selection assessment method. And the method is implemented by use of the third generation GIS database model, Geodatabase. Taking a city in Pearl River Delta as a case, based on its 46 basic units, two scenarios for medical waste central treatment are designed and analyzed by means of scenario analysis (SA) and then the better scenario is recommended.

[Markov Chain Monte Carlo scheme for parameter uncertainty analysis in water quality model].

Parameter identification plays an important role in environmental model application. Markov Chain Monte Carlo method was introduced to estimate parameter uncertainty, since usual Bayes discrete methods were not applicable to produce posterior distribution of complicated environmental model due to the limit of computation. In order to study the performance and efficiency of MCMC, two case studies were used.

Risk forecasting and evaluating model of environmental pollution accident.

Environmental risk (ER) factors come from ER source and they are controlled by the primary control mechanism (PCM) of environmental risk, due to the self failures or the effects of external environment risk trigger mechanism, the PCM could not work regularly any more, then, the ER factors will release environmental space, and an ER field is formed up. The forming of ER field does not mean that any environmental pollution accident (EPA) will break out; only the ER receptors are exposed in the ER field and damaged seriously, the potential ER really turns into an actual EPA. Researching on the general laws of evolving from environmental risk to EPA, this paper bring forwards a relevant concept model of risk forecasting and evaluating of EPA.

[Parameter optimization of water quality model: implementation of genetic algorithm and its control parameters analysis].

Parameter identification plays an important role in environmental model application. As a commonly used global optimization method, genetic algorithm (GA) has very simple structure, the key related to whether a practical issue can be solved using GA or not is algorithm design and selection of the control parameters. Based on the feature of parameter optimization of water quality model, orthogonal test method was proposed for reviewing effects of different control parameters of GA on the performance of water quality parameter optimization.

[Regular pattern of non-point source pollutants losses in Luxi watershed].

The losses of non-point pollutant combined with natural rainfall events were monitored at outlets of Luxi watershed and several field plots with different land use. The paper probes characteristics of the sediment and chemical losses during a single rainfall-runoff process. The impact of preceding precipitation is also discussed.

[GIS and scenario analysis aid to water pollution control planning of river basin].

The forward and backward algorithms for watershed water pollution control planning were summarized in this paper as well as their advantages and shortages. The spatial databases of water environmental function region, pollution sources, monitoring sections and sewer outlets were built with ARCGIS8.1 as the platform in the case study of Ganjiang valley, Jiangxi province.

[Development of MOIMS on environmental data distribution].

'Environmental WebGIS system for Ganjiang Watershed', based on 1:250,000 topographic spatial database and environmental database of Jiangxi province, was developed. In the system, a hybrid strategy was adopted. And the GIS analysis functions of MapObjects and Map server functions of MOIMS were integrated in the system.

[An artificial neural network model for lake color inversion using TM imagery].

The technology of artificial neural network was used for inversing water quality parameters from TM imagery data in the paper in order to study water quality and eutrophic status of lake. On the basis of satellite synchronous monitoring experiment, a BP neural network model was constructed, in which concentrations of SS, CODMn, DO, T-N, T-P and chlo-a were inversed from Landsat TM data and the accuracy of which was good, the relative error of which could be controlled below 25%. Moreover, the reasons of simulating error, ways of improving model and applications of the model were also analyzed in detail.

[Extract non-point pollution source information from a TM image by hierarchical classification].

The issue of the article is hierarchical classification that is used to extract land-use information relating to non-point source pollution from TM image. The result shows that it performs better than traditional maximum likelihood method. It is useful to extract information quickly and effectively with advantages of simplifying complex problem, giving prominence to key point and having more flexibility.