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1、Journal of Ocean University of China (Oceanic and Coastal Sea Research) ISSN 1672-5182, October 30, 2006, Vol.5, No.4, pp.322-326 http: / www. ouc. edu. cn/xbywb/ E-maih xbywbouc edu. cn A High Precision Comprehensive Evaluation Method for Flood Disaster Loss Based on Improved Genetic Programming ZH
2、OU Yuliang 1)* , LU Guihua 1), JIN Juliang 2), TONG Fang 1), and ZHOU Ping 1 1 ) College of Water Resources and Environment, Hohai University, Nanjing 210098, P.R. China 2) College of Civil Engineering, Hefei University of Technology, Hefei 230009, P. R. China (Received March 29, 2006; accepted Augu
3、st 25, 2006) Abstract Precise comprehensive evaluation of flood disaster loss is significant for the prevention and mitigation of flood disasters. Here, one of the difficulties involved is how to establish a model capable of describing the complex relation be- tween the input and output data of the
4、system of flood disaster loss. Genetic programming (GP) solves problems by using ideas from genetic algorithm and generates computer programs automatically. In this study a new method named the evalua- tion of the grade of flood disaster loss (EGFD) on the basis of improved genetic programming (IGP)
5、 is presented (IGP- EGFD). The flood disaster area and the direct economic loss are taken as the evaluation indexes of flood disaster loss. Obvi- ously that the larger the evaluation index value, the larger the corresponding value of the grade of flood disaster loss is. Con- sequently the IGP code i
6、s designed to make the value of the grade of flood disaster be an increasing function of the index val- ue. The result of the application of the IGP-EGFD model to Henan Province shows that a good function expression can be obtained within a bigger searched function space; and the model is of high pr
7、ecision and considerable practical significance. Thus, IGP-EGFD can be widely used in automatic modeling and other evaluation systems. Key words automatic modeling; evaluation of flood disaster loss; genetic algorithm; genetic programming 1 Introduction Systems evaluation, which precedes system anal
8、ysis and follows systems decision-making and analysis, is a hinge of the systems engineering theory and methodol- ogy (Jin et al., 2002). Comprehensive evaluation of the grade of flood disaster loss (EGFD) aims at evalu- ating the grade of disaster loss caused by flood based on the existing evaluati
9、on model of flood disaster loss and the indexes values. Precise evaluation result can provide a scientific decision-making basis for flood dis- aster management, which is very significant in region- al social economic and ecological environmental devel- opment. Because the evaluation results of sing
10、le in- dexes in practical evaluation are often incompatible, the evaluation of flood disaster obtained by using flood disaster evaluation standard table directly lacks practi- cality. Hence many kinds of comprehensive evaluation models, such as the project pursuit method (Friedman and Turkey, 1974;
11、Jin et al., 2002), fuzzy compre- hensive evaluation method (Chen, 1990), grey clus- tering method (Xia, 2000) and logistic curve model (Jin et al., 2000) have been proposed successively. However, the complex mathematical expression desc- Corresponding author. Tel: 0086-25-83787741 E-mail: zy154600 1
12、63. tom ribing the relation between the flood disaster evalua- tion indexes and the evaluation grade should be speci- fied in advance on the basis of the knowledge of the flood disaster system being studied when using those models, so they lack flexibility. Genetic programming, GP for short, as one
13、of the automation wogramming techniques developing rapid- ly in recent years, is a kind of new evolutionary com- putation based on the extension and development of genetic algorithm; with the improvement on its theory and the application of its technique by efforts of many scholars, GP has successfu
14、l applications in modelling, prediction and classification, designing, auto-design- ing of multi-agent systems and biomedicine (Koza et al., 1993, 1994; Linet al., 1999; Chen et al., 2000; Whigham and Crapper, 2001; Cornelis et al., 2004). The specific realization of IGP for the evalua- tion of floo
15、d disaster loss in this paper is presented on the basis of all the research achievements mentioned above. GP has been realized by Prof. J. R. Koza in the programming language of Lisp; in recent years, many scholars have realized programming GP in the languages of C, C + +, Javal. 1, Smalltalk 80, ma
16、th- ematical, etc (Liu et al., 2001). For the sake of the practical engineering calculation, the IGP-EGFD mo- del in this paper is realized in the Fortran program- ming language. ZHOU Y. L. et al.: Evaluation for Flood Disaster Loss Based on Genetic Programming 323 2 Material and Methods The IGP-EGFD method includes six steps as fol- lows: Step 1 The standardization of the evaluation in- dexes set of the samples. Define the se
