Development and Application of the Software for Water Ecological Index Screening

The objective of this article is to apply a program for ecological indicator screening base on a new method, which is the Comprehensive Method for Water Ecological Index Screening (CMWEIS). CMWEIS is based on the Principal Component Analysis (PCA) and Delphi Method (DM, a kind of expert investigation method). Not only the objective factors but also the subjective factors are considered. Using CMWEIS, the ecological indicators were sorted in the range of Liao River basin. 25 ecological indexes, 2 years' observed data of the main stream of Liao River were considered. Ten specialists were invited to answer the designed questionnaires. After 5 times of screening, the score of each ecological index was provided and 11 indexes were selected. CMWEIS considered both the objective characters of the indicators and the subjective adjustment of the specialists. So the indexes selected by WEIDSM could reflect the ecological status well and truly. The model was programmed by Visual Basic 6.0, so that all the statistical calculations were done by the computer. It could be expected that CMWEIS could give the sequence of ecological indicators quickly, so as to make ecological monitoring or evaluating more effectively.