Evaluation of MARS for the spatial distribution modeling of carbon monoxide in an urban area

Spatial distribution modeling of CO in Tehran can lead to better air pollution management and control, and it is also suitable for exposure assessment and epidemiological studies. In this study MARS (Multi–variate Adaptive Regression Splines) is compared with typical interpolation techniques for spatial distribution modeling of hourly and daily CO concentrations in Tehran, Iran. The measured CO data in 2008 by 16 monitoring stations were used in this study. The Generalized Cross Validation (GCV) and Cross Validation techniques were utilized for the parameter optimization in the MARS and other techniques, respectively. Then the optimized techniques were compared based on the mean absolute of percentage error (MAPE). Although the Cokriging technique presented less MAPE than the Inverse Distance Weighting, Thin Plate Smooth Splines and Kriging techniques, MARS exhibited the least MAPE. In addition, the MARS modeling procedure is easy. Therefore, MARS has merit to be introduced as an appropriate method for spatial distribution modeling. The number of air pollution monitoring stations is very low (16 stations for 22 zones) and the distribution of stations is not suitable for spatial estimation, hence the level of errors was relatively high (more than 60%). Consequently, hourly and daily mapping of CO provides a limited picture of spatial patterns of CO in Tehran, but it is suitable for estimation of relative CO levels in different zones of Tehran. Hence, the map of mean annual CO concentration was generated by averaging daily CO distributions in 2008. It showed that the most polluted regions in Tehran are the central, eastern and southeastern parts, and mean annual CO concentration in these parts (zones 6, 12, 13, 14 and 15) is between 4.2 and 4.6 ppm

Influence of planting designs on winter thermal comfort in an urban park

Various planting designs behave in different ways on microclimate and thermal comfort due to mainly distinct features of vegetation type and ratio. The papers simulated the microclimate behavior and thermal comfort of different planting design scenarios of an urban park using ENVI-met model. We measured temperature, relative humidity and wind velocity during the coldest period of 2016. Seven scenarios of planting design with different types and ratios of vegetation were simulated. In scenario of evergreen trees, humidity was relatively high while temperature and wind velocity were decreased. Simulated grass covered park and deciduous trees showed higher temperature and wind velocity. Scenario of grasses and the scenarios with high ratio of deciduous trees in comparison with other scenarios indicated lower wind speeds. The findings can be seen as a possibility of improvement of winter thermal comfort, considering a proper planting design as an important step in order to achieve Citizen Satisfaction

Effect of climatic factors affecting saffron using analytic hierarchy process(AHP); (Case Study Roshtkhar Region, Iran)

The present paper aimed to determine the criteria for understanding climate and ranking factors influencing saffron and assess its impact on Roshtkhoar city of Khorasan Razavi province. The city of Roshtkhar has potential for increasing saffron cultivation; therefore, the main hypothesis during the research was, which climatic factors had the most influence on the cultivation of saffron in the city Roshtkhar. The research methodology was based on a period of ten years cross-sectional data collected from meteorological stations in the studied area. In this study, with taking into account of climatic factors affecting the cultivation of saffron, Analytical Hierarchy Process (AHP) method was used to prioritize rural and regional municipalities Roshtkhar cultivated land. Research process included data collection, analysis, statistical analysis, data entry software Expert choice, clustering and selection criteria, and integrating information. The results showed that, among environmental factors, precipitation index (0.281) and temperature coefficient (0.137) had the greatest impact in saffron cultivation. Water resources and evaporation of water had the lowest score in the survey accounted. In the municipalities of the city, Hossein-Abad districts had favorable conditions for growing saffron