evaluation of isfahan’s “mâdies” as greenways, with sustainable development approach; a case study of niasarm mâdi

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.