| Traditional design and construction of ecological bank revetment systems rely more on experience,rather than a unified evaluation system.They also lacks quantitative analysis in the later effect appraisal.It has become an important research aspect to put forward the appropriate model of ecological bank revetment in river regulation and provide a systematic and comprehensive evaluation in the meanwhile.By analyzing the influencing factors of a typical ecological revetment system,this paper proposes a set of appraisal system on ecological revetment system and establishes an objective,accurate and operable evaluation model based on hierarchical analysis method(AHP)and approximation ideal solution sequencing method(TOPSIS).Through practical application in MaLin River,we came to the following main conclusions:(1)In the analysis of the main factors of typical ecological bank revetment,this paper constructed an index appraise system and mathematical model which combined with the opinions of industry experts.The index appraise system consider from three aspects:structural stability,ecological functionality and social economy.Nine indexes was selected,including slope coefficient,bank slope durability,bank slope impact resistance,species abundance,biological channel patency,vegetation coverage,construction and maintenance cost,landscape aesthetic function,leisure and entertainment function.For each of them,we put forward the evaluation criteria.All of these indexes have strong representativeness and maneuverability which can reflect the effect of ecological revetment measures systematically and comprehensively.(2)The AHP-TOPSIS evaluation mathematical model which combined the advantages of AHP and TOPSIS methods,is according to the characteristics of ecological revetment index system.The AHP-TOPSIS model defined the weight coefficients of each index of the evaluation system based on expert scoring method(Delphi)and AHP,then used the TOPSIS to normalize and sort the calculated evaluation index value to determine the advantages and disadvantages of each scheme’s effect.(3)AHP-TOPSIS evaluation model has been applied on evaluating the six ecological revetment schemes of Malin River Project.This paper demonstrated the models by living examples,illustrated the the concrete calculation method of the evaluation model and checked the rationality of the model.All of these evaluation results suggest that the following models score higher:Gebin revetment,Renault cushion,ecological concrete,plant revetment and self-embedded retaining wall,which is more suitable for popularizing in the field of river regulation,otherwise,simple dry masonry slope protection method is deprecated.Based on the analysis of the merits and demerits of above revetment models,the corresponding improvement Suggestions were put forward.In conclusion,the evaluation index system selected in this paper appear comprehensive,simple and operable.The AHP-TOPSIS evaluation model gives full play to the advantages of AHP and TOPSIS,it combines qualitative evaluation with quantitative calculation effectively,which makes the evaluation results of ecological revetment as accurate and objective as possible.The research result is practicable and well-adapted,which provide an effective theoretical guidance and technological support for the design,construction and quantitative evaluation of ecological bank revetment system,has the certain reference significance for the treatment of small and medium-sized river channels and ecological restoration. |
