فصلنامه محیط شناسی
سال چهل و هشتم شماره 1 (پیاپی 101، بهار 1401)

Soil pollution and accumulation of heavy metals such as lead, cadmium, silver and mercury in agricultural products of industrial areas is one of the most important environmental issues that threaten the lives of plants, animals and humans. Harmful effects of these pollutants on living organisms, including disruption of biological activities, adverse effects on plants and humans due to their entry into the food chain have been proven. As well as, oil pollution is one of the most common of pollution in terrestrial and aquatic ecosystems. The development of the petrochemical industry and the non-observance of environmental requirements, have led to the introduction of large amounts of hydrocarbon pollutants into the environment in recent decades.Biomarkers include biological processes, species, or communities of living organisms that are used to assess the quality of the environment and how the environment changes over time. In recent years, the use of biomarkers to identify environmental pollutants, especially heavy metals and petroleum hydrocarbons, has increased. Collembolan arthropods are one of the most important soil decomposers with high species diversity and density, especially in forest ecosystems. These organisms are widely used organisms as biomarkers due to their short life cycle, high density and high susceptibility to various contaminants in terrestrial ecosystems. This research was aimed to identify the collembola fauna in soils contaminated with heavy metals and petroleum hydrocarbons in two industrial areas of Isfahan and to investigate the impact of these contaminants on the diversity and population abundance of these organisms as a biological indicator of soil contamination.

Soil samples were taken from the lands around Isfahan Oil Refinery and the area around Mobarakeh Steel factory, as contaminated areas to petroleum hydrocarbons and heavy metals respectively. Also, a sample of pristine soil (non-contaminated soil) was taken from the test areas as a control. Heavy metals concentration was measured by atomic absorption method and the amount of petroleum hydrocarbons in the samples was measured by Soxhlet method. The terrestrial arthropods were collected using Berlese funnel. To identify the Collembola species, microscopic slides were prepared and identified according to the taxonomic keys.

Diversity of Collembola in contaminated soilsThe results of chemical analysis of soils showed that there were different degrees of contamination with petroleum hydrocarbons and heavy metals including lead, cadmium and nickel in the sampled areas, and the soil of the control area was free of any contamination. The highest concentration of heavy metal in the studied soils was related to cadmium with 21.92 mg/kg and the lowest concentration of nickel was related to 42.85 mg/kg. Sampling was performed to collect collembolan arthropods throughout the year and a total of 11 species of collembola from 6 families and 2 suborders were collected (table 1).As shown in Figure 1a, Istomiella minor, Ceratophysella stercoraria, Hypogastrura sp.1, Entomobrya sp.1 and Onychiurus sp.2 species are more abundant in heavy metal contaminated area than uncontaminated soil (control). Also, Folsomia candida was not found in the soil samples around the steel factory. On the other, the diversity and abundance of Collembola species collected in soils contaminated with petroleum compounds around the oil refinery were similar to soils contaminated with heavy metals (Figure 1-b). In these soils, the highest abundance of collembolan communication is related to Hypogastura sp.1, I. minor and C. stercoraria, respectively. Also, the frequency percentage of F. candida, Pseudosinella sp.2 and Onychurus sp.1 was zero and no samples of these species were collected, which indicates the high sensitivity of these species to petroleum products and hydrocarbon compounds.Sampling was performed to isolate terrestrial Collembola in different seasons of the year. The results showed that these arthropods were active only in spring and summer. In both autumn and winter, no samples of Collembola were collected in either of the two areas contaminated with heavy metals and petroleum compounds. The interesting point in this study was that no significant difference was observed between the collembola population of contaminated soils and non-contaminated soils in spring. However, in summer, the population of non-contaminated soils was much higher than soils contaminated with heavy metals and petroleum compounds and a significant difference (p ≥ 0.05) was observed between them.As shown in Figure 2, the frequency of Hypogastrura sp.1 and Pseudosinella octoppuncta species in oil-contaminated soils is higher than their frequency in heavy metal-contaminated soils. The frequency of Hypogastrura sp.1 in oil-contaminated soils (40%) was significantly higher (p ≥ 0.05) than the frequency of this species in heavy metal-contaminated soils (12.5%) (Fig. 2). Therefore, Hypogastrura sp.1 is the most resistant species to petroleum products among the species studied in this research. Also, the I. minor showed the highest frequency (28.13%) in soils contaminated with heavy metals. Therefore, this species is the most resistant to heavy metals among the studied species.

The main purpose of this study was to compare the Collembola fauna in soils contaminated with heavy metals and petroleum compounds as a biological indicator in the some industrial regions of Isfahan. In this study, a total of 11 species belonging to 6 families from 2 suborders of Collembola were collected. F. candida was not isolated from contaminated soils with heavy metals, while this species has acceptable population abundance in pristine and non-polluted soils. These results indicate the high sensitivity of this species to heavy metals. Lead and cadmium have very destructive effects on the reproduction of F. candida and cause a significant reduction in reproduction of this species. According to Sandifer and Hopkin (1996), when the cadmium concentration in the soil reaches to 1.2 μg / kg, the reproduction of Folsomia species decreases dramatically. The soils studied in this study were also highly contaminated with cadmium and the concentration of this element in some samples was 21.92 mg / kg, which is several hundred times than the global pollution standard, this is why F. candida was not collected from these soils. Also the species F. candida, Pseudosinella sp.2 and Onchiusus sp.1 were not collected from soils contaminated with petroleum hydrocarbons. Studies by Fountain and Hopkin (2005) show the very high susceptibility of these species, especially F. candida, to chemical contaminants and introduce this species as a reliable biomarker against soil pollutants. In contrast, populations of some species such as I. minor, C. stercoraria and Hypogastrura sp.1 was higher in soils contaminated with heavy metals and petroleum compounds than in non-contaminated soils. These results may be due to the fact that some species of Collembola have the ability to detoxify and remove of poisonous chemicals from their bodies with repeated molting. In Conclusion, the genus Folsomia is one of the most well-known soil collembolan which whose species, due to non-migratory living and its low dependence on sub-habitats, make them important organisms for determining air and soil quality and tracking pollution. Among the identified species of this genus, F. candida has been considered as an ecological criterion and biological indicator of soil. In this study, this species was not isolated in soils contaminated with heavy metals and petroleum compounds and was introduced as the most sensitive species to chemicals. On the other hand, I. minor with a population frequency of about 25% in the studied soils was introduced as the most resistant species to chemical compounds.

Assessing human comfort outdoors is one of the key criteria in the design of building. One of the effective factors in creating comfort conditions is wind flow. The purpose of this study is to investigate the effect of urban blocks on wind flow for creating the comfortable condition. The ratio of buildings height to distance (H/W) and the orientation of buildings as the most important factors affecting wind flow were examined. The ratios of 0.5, 1, 1.5, and 2 were selected and orientations of 135° to 200° were examined. A residential complex in Tabriz was selected as a case study and weather information of the last 19 years (2002-2021) of Tabriz was extracted from the Meteorological Organization. Months of the year that were unfavorable in terms of comfort conditions were identified by using the Penwarden standard. Accordingly, January 6, 2021, was selected as one of the coldest days of the year, and to simulate different scenarios, Envi-met (4.4.5) software was used. The results show that the H/W ratios of 0.5 to 1 and the orientations of 200° to 185° and 135° are the most appropriate. In this research two important factors, H/W and their orientation were studied in a linear form. One of the limitations of the research is that only the comfort conditions in the outdoor environment of the buildings have been studied. Therefore, in future research, the arrangement of urban blocks to consume less energy inside buildings can be examined.

Urban greenspace is a very important and vital element in urban planning so that parks and urban greenspace are usually considered as a very important solution to improve the quality of social life. Urban parks and greenspaces provide valuable recreational opportunities for the residents of cities. Nowadays, determining the real value of environmental resources is an important issue in resource investment and pricing. Environmental economists believe that there is a necessity for economic and recreational valuation of non-market services and benefits, such as parks and green spaces. Estimating the recreational value of parks is also effective in improving environmental policies and increasing human well-being and eventually, it could lead to achieving sustainable development.There are various approaches to estimate the economic values of environmental resources. Common approaches such as market valuation are not applicable for the valuation of parks and green because of non-market services. The use of substitute market techniques is one of the price-based valuation methods for non-exchange ecological services of parks and green spaces, which refer to the expressed preferences in real markets. Contingent Valuation Method (CVM) is one of the most common and practical methods of economic valuation of non-market environmental services and resources based on the community demand for their protection and use. Regarding the growing demand for public resorts and recreation areas in cities, the study of effective factors on people's demands can help to predict the needs of urban recreation and entertainment. So, the present study has been conducted to estimate the economic valuation of recreational activities and the effective factors of the willingness of visitors to pay for Baharan Park in Meybod city located in Yazd province. If the value of environmental resources is estimated in monetary units, it would be comparable to the value of other resources goods, and services and it would help policymakers and planners for the necessary support of these ecosystems.

This study has conducted in Baharan Park located in Meybod city, Yazd province, Iran. The mean annual rainfall and temperature of this city are 60 mm and 19 °C, respectively (Meybod Meteorological Organization, 1398). The altitude of the study area is 1234 meters above sea level. Baharan Park is situated in the center of Meibod city, between 54°1'24" and 54°1'32" longitude and 32°12'32" and 32°12'59" latitude with an area of 23.2 hectares.Data were collected by completing 169 questionnaires, which were determined based on the Cochran method. The questionnaires include information about the personal, social, and economic characteristics of visitors and questions related to the willingness of the visitors to pay. The essential assumption in this method is that some variables such as "age", "household dimension", "monthly income", "duration of visit", "gender", "occupation", "level of education", "transportation vehicle", and "season" play the main role in the willingness or unwillingness of people to pay.In this study, the contingent valuation method was used to measure the willingness to pay and recreational value in parks and green spaces. Double-bounded Dichotomous Choice (DDC) was used among the different methods for evaluation of the willingness of visitors to pay. In the contingent valuation method, the model has a dependent variable with dichotomous qualitative choice. A logit regression model based on maximum likelihood is usually used for qualitative choice methods. Normal and logistical distributions are used in the probabilistic logit model. The predicted probability values of this model are between zero and one. This method requires determining and selecting a higher bid to the initial bid, which is given a higher value to the "yes" answer and a lower bid to the "no" answer. In this study, three bids (20,000, 30,000, and 50,000 Rials) were asked in the form of related questions.Then, a logit regression model and STATA and SHAZAM software were used in order to analyze the data. The dependent variable was the willingness to pay (in Rials) and the independent variables were socioeconomic characteristics including age, household size, monthly income, duration of visit, gender, occupation, level of education, transportation, season. Based on the contingent valuation model, the logit model was fitted using Cragg-Uhler, Esterlla, Maddala, and Mc Fadden coefficients. Also, likelihood ratio tests and variance heterogeneity tests were used to ensure the reliability of the estimated model results. Conventional methods such as Breusch-Pagan-Godfrey and White test cannot be used to check for the presence or absence of variance heterogeneity in logit patterns. In this regard, there is an LM2 statistic to test the variance heterogeneity in logit patterns.

The results of variance heterogeneity tests indicated that the model does not have variance heterogeneity. The value of the probability ratio statistic was 41.04. Since this value is higher than the value of probability value, the total estimated pattern is statistically significant at the 5% level. The Maddala, Esterlla, Cragg-Uhler, and Mc Fadden coefficients for the estimated logit model, were 0.21, 0.23, 0.28, and 0.17, respectively. The percentage of correct predictions was 71%, and so this pattern is reliable for subsequent analysis since the correct predictable value for logit patterns is 60%. The results of model estimation showed that between 15 independent variables, four variables are statistically significant (P <0.05). Visit duration (with the coefficient of 0.114), education level (with the coefficient of 0.065), transportation vehicles (with the coefficient of 0.056), and maximum offer amount (with the coefficient of 0.114), significantly affect the willingness of people to pay to enter and improve the condition and maintenance of the park.The average expected value of willingness to pay per visitor of Baharan Park was 2.2821. Also, the average willingness to pay for each visitor was evaluated at 38350 Rials to improve the condition and protection of Baharan Park in Meybod. The monthly and annually recreational value of this park is equal to 161070 and 1932840 Rials according to the average willingness to pay to each household.

In this study, the variable "education level" has a direct and significant relationship with the willingness of people to pay in Baharan Park. With an increasing educational level, the willingness to pay increases by 0.065 percent. Studies in this field show that the high level of education has led to their acceptance to pay for beauty functions because there is a positive relationship between education and recognizing the importance of the environment. People with higher education have more knowledge to protect natural ecosystems because of more information about the importance of natural resources.According to the results of this study, the variable "transportation vehicles" has a significant negative relationship with the willingness of people to visit Baharan Park. If people do not use a personal car, the willingness to pay will decrease by 0.056 percent. Most visitors prefer to travel to the recreational areas by car. The variable "maximum offer amount" has a negative significant relationship with the willingness of people (P <0.05). In other words, visitors are less willing to pay the entrance fee with the higher amount of bids to enter Baharan Park.The results of this study indicate that there is a willingness of visitors and tourists to pay in order to use and support the natural and cultural attractions of recreational areas. Therefore, due to the high potential of Baharan Park in attracting local and non-native tourists, the number of tourists and their willingness to pay will increase if the welfare facilities are created, the condition of the park is improved, and transportation is developed. Also, considering the recreational value of Baharan Park in Meybod city, planners and officials must change the economic attitude of tourists in the region to develop sustainable tourism and increase the number of visitors.

Eutrophication is a serious water quality issue that occurs due to the excess nutrient loads entering the water bodies. In a watershed, there are some areas with a particular type of soil, land use, vegetation, and topography where are at a greater risk of nutrient production and higher sediment loads, called Critical Source Areas (CSAs). Comprehensive modeling of the watershed system helps identify and quantify nutrient loads in CSAs which allows for recognizing and prioritizing effective nutrient reduction plans such as farm and watershed management strategies. Esteghlal Dam is the source of supplying 50% of the drinking water of Bandar Abbas, which has been affected by algal blooms due to the excess nutrient loads from the Minab watershed. The purpose of this study is to identify Critical Source Areas (CSAs) and study and prioritize management scenarios to reduce pollution load to the reservoir.

Study areaMinab basin is located at latitude 26°57'00" to 28°24'00" N and longitude 56°49'00" and 57°53'00" E. The Minab River flows southwesterly to the Minab Dam, and after the dam, it changes direction to the west and enters the Oman Sea. The reservoir of Esteghlal Dam has been suffered from algal blooms due to high pollution load from the watershed.Simulation ModelThe Soil & Water Assessment Tool (SWAT) enables to simulate the impact of different management practices on water, sediment, and agricultural pollutants in a watershed with diverse types of soils and land use. In the SWAT, the basin is divided into several sub-basins and each sub-basin is divided into a large number of Hydrologic Response Units (HRUs) based on topography, land use, and soil type. Daily runoff is estimated by the SCS curve number method. Erosion and sedimentation in each HRU are calculated based on the Modified Universal Soil Loss Equation (MUSLE) and the Bagnold Modified Sediment Transfer Equation. In order to simulate nutrient transfer in SWAT, various factors such as mineralization, decomposition, nitrogen and phosphorus uptake, erosion, and sedimentation rate should be taken into account. Accordingly, the entire basin of Esteghlal Dam was divided into 29 sub-basins and 1350 HRUs. In this study, we used the monthly observed data in 2018. Sensitivity analysisIn this study, we used the SUFI-2 algorithm to recognize the parameters with the greatest impact on the watershed outflow and water quality. Analyzes showed that the curve number has the greatest effect on the outflow of the basin. Among parameters affecting nutrient loads, algae mass percentage in form of phosphorus (AI2) and parameters related to the nitrogen cycle, such as (BC3) and (BC2) have the highest sensitivity.Model calibrationThe model was calibrated and validated in a multi-step process for 29 years from 1990 to 2018. Precipitation, evaporation, actual yield, evapotranspiration, and nutrient parameters were calibrated at the basin level. Critical Source AreasTo identify and compare CSAs, the simulated nutrient loads and runoff were analyzed at the level of each HRUs. Then, the average annual load per unit area of each HRU, total nitrogen (TN), and total phosphorus (TP) were estimated by calculating the weighted average in all land uses and considering cultivation patterns. By dividing these values by the total load of the basin, we find the percentage share of each land uses in producing TN and TP. Based on this, land uses that have more than 20% contribution in nutrient productions and runoff are selected as CSAs.Long-term Strategies to control nutrient loads 1-Management strategies on the farmConsidering the agricultural land use as a CSA in terms of total nitrogen load, we supposed that the use of nitrogen and phosphate fertilizers is simultaneously reduced by 25% and 50%. Furthermore, animal manure is decreased by 25% and 50%, respectively.2-Residential wastewater managementIt is assumed that pollution from the residential areas of Ziarat Ali, Nodej, Manojan, and Deh Barez has been reduced by 30 to 60 percent due to the operation of the Rudan WWT and the implementation of the first phase of the Minab WWT.3-Watershed management strategies (Filter Strip)A Filter Strip is a plant-covered strip that filters contaminants by reducing the flow rate and the sedimentation. Based on the watershed slope of 5 to 20% in critical sub-basins, the filter is defined with a width of 10 meters.4-Terracing CSAs This strategy is implemented in lands with a slope of 8 to 12 percent. In the SWAT, the strategy is applied by changing the average slope of the basin, CN , and USLEP parameters.

The calibration and validation process showed that the developed model has sound reliability to simulate the discharge and water quality at the basin level. The simulation results indicates that the annual inflow to the reservoir has decreased in recent years caused an increase in the concentration of nutrient loads. The highest flow is recorded at 25 m3/s in 1993. The long-term simulation average is 5.8 m3/s which is slightly higher than the observed of 5.65 m3/s. Also, in the short term (10-year interval) these values are 3.4 and 3.3 m3/s, respectively. The simulated nutrient concentrations showed that total nitrogen (TN) has been on the rise, from about 8 mg/L in 2002 to more than 19 mg/L in 2018. The concentration of total phosphorus (TP) has also increased to about 3 mg/L. The ratio of TP to TN is about 15%, while standards suggest the number is less than 10%. To determine the CSAs, we used two combined indices with different weights. The first index CI(1) considers equal weights of 0.33 for sediment load, TN, and TP. The second index CI(2) takes 0.2 for sediment load, 0.4 for TN, and 0.4 for TP into account, respectively. These weights were calculated using the entropy method. Crops have the highest share in total nitrogen production compared to other land uses. Animal husbandry also has the greatest share in sediment production and total phosphorus. Based on the first index, traditional animal husbandry is the most critical source in terms of pollution and sediment production. According to the results, Jaghin and Minab sub-basins have the highest potential for nutrient production and erosion.After examining the effect of each management strategy using the simulation model, there is a need to compare their effectiveness by scoring, weighing, and ranking them. The highest score for the reduction of organic nitrogen was for Terracing and the lowest score. The highest priority for reducing total nitrogen is to reduce chemical and animal fertilizers on the farm. Also, the highest priority in reducing phosphorus is the implementation of Filter Strip in CSAs. To determine the priority of management strategies, we utilized the Multi-Criteria Decision-Making approach based on the experts’ opinion and the results of the effectiveness of strategies as well as their implementation costs.Results showed that implementation of Filter Strip (with a minimum width of 10 meters) in CSAs has the highest priority in reducing nutrient loads and controlling Eutrophication. Then, terracing farmland on steep slopes was ranked as a second priority and strategy to control erosion and nutrient load production.

In this study, we used an integrated quantitative and qualitative simulation approach at the basin scale. We applied the SWAT model as a comprehensive process-oriented model to simulate the entire watershed. After identifying CSAs, we assessed the impact of each management scenario on reducing the nutrients. Finally, based on the nutrient load reduction and the investment and operating costs of each scenario, we select appropriate solutions using a multi-criteria decision-making approach. The results showed that agricultural and pastures (livestock) land uses in Jaghin and Minab sub-basins are CSAs. In addition, Filter Strip with a width of at least 10 meters and Fertilizer Reduction on Farms were recognized as the most effective strategies.Keywords: Water Quality Management, Comprehensive Watershed Simulation, Critical Sources Areas, Best Management Practices (BMPs), Esteghlal Dam Watershed

Urban development disturbs the natural infiltration of runoff by creating impermeable surfaces. With the increase of impermeable levels in the watersheds, the volume of runoff also increases and cities will be exposed to waterlogging and floods in the rainy season. Therefore, the level of groundwater resource is expected to have lowered gradually. Today’s main policy to face with this problem centers on using traditional flood systems like concrete channelization to convey runoff which increases the problem of groundwater recharge. So, it seems that Green Infrastructure Development (GID) could play a crucial role in the restoration of the disrupted hydrological cycle, lowering the runoff problem, and move toward towards urban sustainability.Materials and methods Study area Tehran is a metropolitan with an area of about 730 km2 and the population of more than 8.5 million people, located at the south part of Alborz Mountains. The city comprised of 22 districts. The middle districts and downtown areas are urbanized while the other districts have more open spaces and untouched lands. The slope of the most parts of the city is about 3-9 percent which is mainly from the north to the south. There are seven natural rivers streaming the city. These natural valley-rivers play important roles in natural ventilation and runoff conveying. Tehran has a diverse Land use. Apart from big green patches dispersed in the northern parts and the urban fringe areas, all patches of the city are manmade and impermeable. Tehran has faced rapid growth in the current decades. Rapid urbanization has worsened the natural hydrological cycle and put this megacity in jeopardy of water logging and flood. Flood risk is one of the second most important natural hazards in Tehran. The city is coated with impermeable surfaces like buildings, highways, roads, and parking lots. In rainy seasons rainfall rapidly turns into runoff flowing throughout the streets and finally leaves the urban watershed. Consequently, the level of groundwater supply is expected to have diminished.

The framework of this research has four steps. 1- Selection of relevant criteria and sub-criteria 2- Determining the weight of each of criteria and sub-criteria 2- reaching of decision matrix, 4- Prioritization of green infrastructure practices 3- Development of combination scenarios 4- Prioritization of combination scenarios. Each step is elaborated below.This step was done by reviewing scientific sources and interviewing experts and specialists. At this step, we tried to select criteria for multivariate decision models that are more repetitive in scientific texts and are in accordance with the geographical, climatic conditions and realities of the study area. Finally, the criteria in the process of introducing green infrastructure in Tehran with the aim of runoff control includes five main criteria namely: runoff quantity control, runoff quality control, cost, compatibility with city structure, and adaptation to the climate of the city.Expert panel and The Analytic Hierarchy Process (AHP) method were used to weight the selected criteria. In this regard, a questionnaire was first prepared in accordance with the standard structure of pairwise comparison, which is common in the hierarchical analysis method. Then, 15 faculty members, consulting engineers, and researchers in various fields related to the development of green infrastructure in urban areas were surveyed. Then the weight of criteria, sub-criteria, and inconsistency coefficients were calculated. Meanwhile, the responses of 6 participants had an inconsistency coefficient of more than one tenth and were excluded. Therefore, a total of 9 experts participated in the weighting process of the criteria. Expert Choice software was used in the process of calculating the weight of criteria and incompatibility coefficients.In order to compile the decision matrix and achieve the ability of the studied green infrastructure types, the review of scientific literature was performed. At this step, we referred to studies that examined the ability of green infrastructure in relation to each of the criteria.At this stage, the TOPSIS method was used to prioritize green infrastructure. TOPSIS is a multi-criteria decision-making method that is programmed based on the similarity of the solution to the ideal solution and the distance from the non-ideal solution. This technique can be used to rank, compare different options, select the best option and determine the distances between options. Based on the final decision matrix and the weight of the studied criteria, different forms of green infrastructure were prioritized. All calculations were performed to prioritize the options using R software and topsis package.Sensitivity analysis is performed to achieve assurance of results and to confirm that the weighting is non-biased. The method is that values are added or subtracted to each of the indicators and the model will be run again with the changes made and the results will be compared. In this study, PYSIS software was used to analyze the sensitivity of the results of this study. To ensure that the scores and weights were non-biased, sensitivity analysis was performed with 30% change in weights for 10,000 repetitions.To combine different forms of green infrastructure, five main functions of green infrastructure for runoff management were identified, including infiltration, storage, conveyance, irrigation, and rainwater collection. Based on these performances, different scenarios for combination of GI practices were identified and scored. The equation 1 was used for prioritizing the combination scenarios A= (S1 × D1)+(S2× D2)Where A is the final score of each compound, S1 is the final score of the green infrastructure expressed in the row, D1 is the green infrastructure score expressed in the row in the runoff management process, S2 is the green infrastructure score expressed in the column, D2 is the green infrastructure score in the column in the runoff management process.

Results revealed that permeable pavement with a score of 0.756 is the most suitable, while green atmosphere with 0.342 points was selected as the most unsuitable form of green infrastructure for the city of Tehran. Infiltration trenches, rain beds, rainwater harvesting system, detention ponds, bio-retention ponds, and green roofs were ranked second to seventh, respectively.The results of sensitivity analysis showed that with 30% change in coefficients and 10,000 times of model implementation, we did not see much change in the results of this research, and again permeable pavement has been introduced as the most appropriate option. The lack of change in the ranking of options in the sensitivity analysis indicated the low level of subjectivist bias.In the next step, in order to achieve appropriate scenarios, a combination of different forms of green infrastructure from Formula 1 was used and 112 possible combination scenarios were examined, scored and ranked. Finally, three preferred scenarios for each combination based on the hydrological performance were proposed.

In this study, a framework was proposed to use multi-objective prioritization of different forms of green infrastructure to control runoff in Tehran. The results showed that the permeable pavement is the most suitable form of green infrastructure for the city of Tehran, while the green swale is the most unsuitable. Infiltration trenches, rain gardens, rainwater collection reservoirs, ponds, biological ponds and green roofs were ranked second to seventh, respectively. Also, in order to achieve the appropriate composition patterns of green infrastructure, the functions of different types of green infrastructure were divided into categories including infiltration, storage, conveyance, irrigation, and rainwater collection, and the combined scenarios of this Infrastructures were examined. The results of this study proposed a suitable scenario of 30 green infrastructure combinations with different hydrological performance for development with different purposes.

Considering the necessity of achieving sustainability in cities, this research aims at assessing the practicality of the CASBEE-City tool for prioritizing development measures and strategies in Tehran Megalopolis, Iran. CASBEE is a method of assessing and rating the environmental performance of a built environment according to the Built Environment Efficiency (BEE) as an assessment index, which is based on the idea of eco-efficiency. This tool provides a composite index (BEE) which is calculated based on the city quality (Q) indices, including environmental, social, and economic aspects and the environmental load (L) covering the annual CO2-eq. emission per capita. The results of applying this tool to Tehran City show that this capital is ranked fairly poor (B-) in 2019, representing low quality and high load. According to the findings, recycling resources, social services, and public transportation, along with the decrease in carbon emissions are to be the priorities in the future city development plans. Presenting the results separated by each index, planners and decision-makers can accurately determine which aspect of the city’s quality should be given precedence for realizing sustainability in the mid and long term. A Comprehensive city assessment from the perspective of environmental efficiency is important because it provides guidelines for deciding upon a preferable course of action. This type of assessment should benefit not only citizens and local governments but also national governments. This kind of assessment helps national governments to determine which area should be the focus of further efforts toward improvement.