Research on the road landscape evaluation system with the emphasis on the landscape ecology.doc

1、1Research on the road landscape evaluation system with the emphasis on the landscape ecologyAbstract. As the idea of the sustainable development wins support among the people, people have already realized that not only should the road have the transportation function, but we also should consider the

2、 rationality of the road construction from the multiple angles of the landscape ecology, and the visual art and so on. From the point of view of the landscape ecology, combined with the characteristics of the landscape ecology and the overall targets and requirements of the evaluation, this article

3、constructs a three-tier system of indicators, uses the fuzzy comprehensive evaluation model based on the analytic hierarchy process to evaluate the road landscape, and makes an empirical analysis with the evaluation of the road landscape from the Luoshi Road to the East Lake Road in the Second Loop

4、of Wuhan City as an example. Keywords: Landscape ecology; road landscape; evaluation method; indicator system 1. Introduction The modern traffic is developing towards the direction of 2the stereoscope, high speed, diversification, and networking, and at the same time, the road landscape has also und

5、ergone the fundamental changes. And the corresponding road landscape design is no longer to meet the demands of the flows of the people and the cars, but should pay more attention to the coordinated development of the environment, the economy, and the traffic. At the same time, the large-scale const

6、ruction of the roads causes great damage to the environment, which has become increasingly prominent, causing a great impact to the ecological environment, the landscape resources, and the visual environment of the regions along the roads. So the road systems, economic and applicable in the aestheti

7、cs, society, and ecological environment have become the focus of the current road planning and construction. The road landscape designing and evaluation require that the roads should become a part of the natural landscape, and that the roads and the surrounding environments should match to a proper

8、extent, and become the organic part of it. 2. The establishment of the evaluation index system For this research project, the methods of selecting the evaluation indexes are mainly the investigation and research method and the target decomposition method, to establish the 3evaluation index system of

9、 the road landscape. (Fig. 2-1) In the evaluation process, according to the characteristics of the landscape ecology and the overall objectives and requirements of the evaluation, this article constructs a three-tier system of indicators. The first tier is the final goal of the road landscape evalua

10、tion with the emphasis on the landscape ecology ? the overall landscape quality. And then it is decomposed into the second tier that can reflect the indexes ? the sub-indicator, and according to the principle, decompose again, until the single evaluation index at the bottom, and finally construct a

11、three-tier framework of the evaluation index structure of the quality of the road landscape. The sub-indexes of the quality of the road landscape evaluation mainly include three aspects: the quality of the ecological environment of the landscape, the quality of the functional environment of the land

12、scape, and the quality of the visual environment of the landscape. The quality of the ecological environment of the landscape mainly reflects the ecological conditions of the road environment, including the effects of the road on the topography and the landform, the impact on the ecological environm

13、ent, the influence on the natural landscape and other factors. The quality of the functional environment of 4the landscape mainly reflects the factors of the road itself, including the improvement of the road on the flows of the human resources and logistics, the road greening and the traffic engine

14、ering facilities. The quality of the visual environment of the landscape mainly reflects the coordination of the road and the landscape along the lines, and the visual effects of the road greening and the ancillary facilities and so on, including the landscape sensitivity, the impact on the people,

15、the coordination of the greening and the road characteristics and the road pavement route etc. Based on the three-tier evaluation index system, starting from the point of view of the landscape ecology, according to the characteristics of the road landscape, we select the following factors as the roa

16、d landscape evaluation indexes. 3. The fuzzy comprehensive evaluation model based on the analytic hierarchy process (AHP) The analytic hierarchy process (AHP) is the method to determine the weights of the factors with the use of the treatment of the multi-factor classification, and the basic idea is

17、 that the evaluators decompose the complex problems into the each interrelated and orderly hierarchy, so that all the hierarchies are systematic and orderly, in order to effectively 5analyze the problems and solve the problems. Express with the fixed quantity the relative importance of each of the t

18、wo different elements in each hierarchy, and conduct the simple comparison, judgment and calculation between them, and finally calculate the weights of all the related elements. The steps are as follows: 3-1. Define the problems By using the AHP method, first of all, have a clear understanding of th

19、e problems to be studied. Specific to the road landscape, we should comprehensively take into account the landscape ecological needs, and carry out the comprehensive evaluation of all the aspects of the road landscape vision, functions, environment, and ecology. 3-2. Construct the hierarchical struc

20、ture Based on the analysis of the problems to be studied, construct the factors into a tree hierarchy according to the system and hierarchical structure. (Fig. 3-1) 3-3. Compose the judgment matrix using the fuzzy comprehensive evaluation method The judgment matrix is to determine the matrix element

21、s through the multiple comparisons of the importance of the factors of this layer with a certain factor of the above layer 6as the evaluation criteria. According to the theory of the fuzzy comprehensive evaluation, combined with the hierarchy of the road landscape evaluation indexes, determine the j

22、udgment matrix: 3-3-1. Establish the set of the factors The collection of each of the factors influencing the values (scores) of the assessment objects is known as the factor set, i.e.: ; Among them, each element has the fuzziness. 3-3-2. Build the set of the weights The degree of importance of the

23、influence of various factors on the value of the evaluation objects is not the same, so the factors should be given the corresponding weights. Set the weights , which is known as the factor weight set. Usually, the weights should satisfy the conditions of the normalization and the non-negativity: (3

24、-1) In order to make the determined weights more reasonable, then, determine the weights using the analytic hierarchy process (AHP). Assume the influence of n factors for the comparison X=x1, x2, xn on the targets Z, and determine the proportion of 7them in the Z. Each time, select two factors xi an

25、d xj, and use aij to express the ratio of the influence of xi and xj on Z, and obtain the judgment matrix through the multiple comparisons A=(aij)nn. The two matrix elements represent the relative importance of the factors in the sub-indicator level to the Ai and Aj in terms of the total index A. Th

26、e judgment of the relative importance of Ai to Aj usually values from 1 9 and its reciprocal (Table 3-1) The way to calculate the weight value of the relative importance of various elements in this layer in terms of a certain element in the above layer is to find the eigenvector of the judgment matr

27、ix. First, work out the maximum values of the judgment matrix A, and then, use: (3-2) Work out the corresponding feature vector W. After the standardization, W is the hierarchy weight value of the corresponding elements in the same level compared with the certain factor in the above layer. Finally,

28、check the consistency of the judgment matrix, and then define: (3-3) In this equation: CI the coincidence indicator n the orders of the judgment matrix 8Compare the CI with the average random consistency index RI (in table 3-2), set CR=CI/RI and CR is called the random consistency ratio. When CR0.10

29、, the judgment matrix has the satisfactory consistency. Table 3-2 RI value of the judgment matrix 3-3-3. Establish the evaluation set In the evaluation of the road landscape environment, set the evaluation set: 3-3-4. Single factor fuzzy evaluation Conduct the evaluation from the single factor, and

30、determine the membership degree of the evaluation objects on the elements of the evaluation set, which is called the single factor fuzzy evaluation. In general, evaluate the target, according to the I factor ui in the factor set, and the membership degree of the j element vj in the evaluation set is

31、 ij, and the results can be expressed as a fuzzy set: (3-4) 3-3-5. The first-level fuzzy comprehensive evaluation If the degree of importance of the factors is the same, that is, all the weights ai in the weight set are the same, at this time, as long as we add the elements of every list in the R ma

32、trix, we can respectively obtain the “scores“ of all the 9elements in the evaluation set. If each factor weight ranges, then we need to conduct the calculation of the fuzzy matrix: (3-5) In this equation, the “?“ is the generalized fuzzy multiplication, and usually operate by the general rules of th

33、e matrix multiplication. 3-3-6. Multilevel fuzzy comprehensive evaluation Because the road landscape indicator system is a multi-level structure, therefore, it requires a multilevel fuzzy comprehensive evaluation. In the second-level comprehensive evaluation, the single factor evaluation matrix is a

34、s follows: (3-6) Then, the conclusion vector of the second-level evaluation criteria is: (3-7) In this equation, R二级- The single factor judgment matrix of the second-level comprehensive evaluation; Bi 一级- The matrix consisting of the conclusion vectors of the first-level comprehensive evaluation Ai-

35、 The weight vectors of the first-level evaluation Ri 一级- The first-level single factor evaluation matrix B 二级- The conclusion vector of the second-level comprehen 10sive evaluation A 二级- The weight vectors of the second-level evaluation bj二级- The degree of membership of the evaluation objects evalua

36、ted according to the second-level evaluation Similarly, the single factor evaluation matrix can be introduced of the multilevel fuzzy comprehensive evaluation above the second level, and the vector of the conclusion of the evaluation can be obtained. Usually according to the principle of the maximum

37、 membership degree, judge the final results of the evaluation of the grade of the road landscape. 4. Example verification 4-1. General situation of the items The design of the project starts from Wuhan University of Technology in the west, to the Donghu Garden Hotel in the east along the Luoshi Road

38、. The total length of the highway is 4.525km. As is shown in Figure (4-1), according to the characteristics of the project and the relative independence, divide the designing road sections into four engineering sections. The first section is in vertical cross section of Wuhan University of Technology, including the tunnel of the second ring line through Wuhan University of Technology. The second section is the Street Interchange Section, and the main