Introduction
Using greenways could be one of the ways which fulfill the improvement of urban streets. Greenways, as they are known, improve the pedestrianism and related qualities like climatic comfort, visual complexity and desirable serial visions. The objective of this research is to evaluate the capacity of Mâdies[1] network in Isfahan to function as greenway. This research aims to assess in what extent they can play as main part of a vast green network. Mâdies are several streams divided directly from Zayandeh-Rood River. They constitute the main part of the historic-natural structureof Isfahan. There are about 250 km of these manmade streams which are perfectly planned, designed and constructed according to the topographic characteristic of the plain of Isfahan. Originally, Mâdies were created to irrigate the farmlands surrounding the river in the plain of Isfahan since the Safavide period. Today their role is completely changed; in one hand due to the drought of Zayandeh-Rood River (source of water in Mâdies) and expansion of city and land use transformation from agricultural to different urban land uses in the other hand. By the way, today Mâdies could play a vital role in improvement of environmental qualities despite their changing role. They are fundamental elements of urban structure in the city and reinforce the organic and natural aspects of urban planning and design as basic parts of greenway characteristics. Therefore they could be considered as main structure of green network in the city of Isfahan. As it is known, greenways enhance quality environment, aesthetic, recreation, education, relaxation, and preservation of habitation. Greenways can help the protection of ecological continuity. They are managed, planned and designed for several functions such as environmental, recreational, cultural, aesthetic and other purposes. So we can extract greenway characteristic from existing definitions such as their linear form, organic design, social inclusiveness and their perfect adaption to the urban environment. Mâdies can play a central role as part of a structure which is greenway network. To do this, it is necessary to know in what extend they are apt to this function. This paper tried to define what the strengths are and weakness of Mâdies to fulfill the task of being greenways.
Materials and methods
The first step of the method consists on description and definition of Mâdies and greenways as two principle parts of this study. The identification of two abovementioned concepts was necessary to establish the categories of indicators which make possible the comparison between them. Describing and categorizing the main characteristics of greenways was the next step of the research. In this part greenways are summarized across principal sources and expert in the field. The next step was defining the criteria and indicators to evaluate in what extent Mâdiescould play the role of greenways in Isfahan. In-order to determine the indicators the main axis of precedent tables constitute the categories in which the indicators are extracted from different sources. The data is gathered through observation, noting and measurement. Table 1 shows the criteria, sub-criteria and indicators.
Table 1: Critera and indicators for assessment of Madies as greenways




Criteria


Indicators


Niasarm


Unit


Quantification and Measurement




A. Pedestrianism


A1. Interconnection of pedestrians and cars


96%


Length (m).


Length of common path (pedestrians and cars) transportation.




A2. Pavement facilitating pedestrian


34%


m2


More convenient pavement covered percentage among 3 types identified.




A3. Efficient width of pedestrian way


45%,


Width (m).


Width variation along Score of Niasarm.




A4. Noise pollution rate


34%


dB


Average noise pollution recorded in one week with Noise Dosimeter and Sound Label Meter




B.  Security


B1. Nightlife uses


5%


Number/ unit of length


Land uses having nightlife potentials




B2. Social control


35%


Individual/ unit of surface


Number of individuals in space over 2 Hours (2 times a day), (+10→4 pts; 10-6→3 pts; 5-4→2 pts; 3-1→1pt; 0→0 point(




B3. Night lighting


45%


Lux /unit of length


M2 of alighted spaces/total space along Mâdi




B4. Sense of security and control


40%


Number of positive responses


Positive responses in questionnaires




B5. Transparent fronts


25%


Unit/ length


Opening surfaces in m2/total surface




C. Safety


C1. Accident prone spots


90%


Number/ unit of length


Number of prone spots in length




C2. Sense of security in pathways


100%


Number of positive responses


Positive responses in questionnaires




D. Sociability


D1. Equipment and facilities


5%


Number in unit of surface /total


Average areas of Equipment and facilities measured in unit of surface/ total surface




D2. Programmed socio-petal spaces


5%


m2 of programmed spaces / m2 total


Average areas of programmed socio-petal spaces measured in m2 /total




D3.Public participation in maintenance


5%


Number of positive responses


Positive responses in questionnaires




D4. Place attachment rate


70%


Number of positive responses


Positive responses in questionnaires




E. Viability


E1. Inclusivity of space


25%


Percent


Diversity of different groups (sex, age) recorded in a week (2 times per day)




E2. Climatic comfort of space


100%


Percent


Creating a list and determining score of Mâdi




E3. Permeability of space


5%


Block length (m).


Length of blocks measured by GIS




F. Physical aspects


F1. Geometry


100%


Percent


Linear form (of green way)→Best point; semi-linear→0.5 point; non-linear→0 point




F2. Structural elements


50%


Number in length


Elements of greenway (Corridors and pause points); Mâdi has no visible pause point




F3. Network character


50%


Percent


Structure of Mâdi is branching, so is part of a network.




G. Place quality


G1. Adventure


5%


Number of positive responses


Positive responses in questionnaires




G2. Fun of space


100%


Number of positive responses


Positive responses in questionnaires




G3. Biodiversity


70%


Percent


Creating a list and determining score of Mâdi according to obtained information from the Park organization.




 
As it is shown in Table 3, the indicators are grouped in seven categories: pedestrianism, security, safety, sociability, viability, physical aspects and qualities of place. Then the Mâdi of Niasarm has been assessed through the set of indicators defined in Table 1. Quantification and measurement of each indicator is explained and several techniques like questionnaire, mapping, observation and survey are used.
Results: The findings show that to become greenway, Mâdi of Niasarm needs to be improved. In seven established categories the situation is satisfactory in just one category of Safety. In two other categories (pedestrianism and physical aspects) the results is above the average of 50%. Concerning the rest, the situation is not satisfactory. For example the category of Security is below the total average. Diagram 1 shows seven categories and their respected indicators.
 
 





Match the parameters of Madies relative to Greenway










Criteria and Indicator










Diagram 1: seven categories and their respected indicators





 
Conclusion: In conclusion as shown in results, the physical, functional and spatial similarity of Madies in Isfahan and greenway are proved; but according to this study, Mâdies do not function perfectly as a standard and greenway. The evaluation of Mâdi of Niasarm in this study in seven groups of criteria and 24 indicators shows that the efforts are necessary to make the existent Madies good greenways even if they are apt to be good ones. In some criteria such as C (Safety) Mâdi of Niasarm has approximate condition of a standard greenway. In three groups of A (Pedestrianism), F (Physical aspects) and G (Place quality) the score is above 50% and could be considered as acceptable.