Showing 4 results for Daneshvar
Msc. Graduated Student Najmeh Daneshvar-Marvast, Dr Somayeh Soltani-Gerdefaramarzi, Dr Samaneh Poormohammadi,
Volume 19, Issue 55 (12-2019)
Abstract
The phenomenon of evapotranspiration causes water and moisture losses from water, soil and vegetation levels. Due to the small amount of atmospheric precipitation and water resource constraints in Iran, it is important to calculate it through a suitable method. The present research attempts to evaluate the evapotranspiration reference crop (ETo) and present it in the form of zoning map as a basic tool for water management. In this study, the long-term average of seven meteorological stations and evaporation pan data were used to determine the appropriate ETo estimation method. Evapotranspiration of reference crop was calculated to 14 methods the based on climatic information in each station. Computational methods including combinational methods Penman-based, radiation-temperature method, temperature method and radiation method. The most appropriate computational method was selected based on the R2 and Nash -Sutcliffe statistics. The zoning of evapotranspiration of reference crop was carried out based on the geographic information of the meteorological stations and the GIS software. The results of the research indicate that the best method for this region as the cold and moderate climate are FAO radiation and Blaney-Criddle. Also, the zoning result shows that west of the catchment has less evapotranspiration rather than its east. Sunshine hours, maximum temperature and wind speed were the most effective factors for evapotranspiration in this area by sensitivity analysis.
Atefeh Moradi, Mariam Daneshvar, Seyed Abdol-Hadi Daneshpour, Hooman Bahmanpour,
Volume 23, Issue 68 (4-2023)
Abstract
Today, sustainable placement is one of the main approaches of urban planners and regional planners. The purpose of this study was to design and fit a consolidated model of localization of densely populated areas with emphasis on environmental balance. The purpose of this research is practical and it is a survey-analysis type. At first, according to the theoretical foundations, the research background and interviewing the experts designed the integrated model (basic conceptual model). Then the model was fitted by referring to experts (86 simple). The initial model of the research was investigated and tested using SEM using Smart PLS 2 software. The results showed that the factor loadings of all questionnaire questions were more than 0.4 and were therefore acceptable. The t-values for all questions are greater than 1.96 and are therefore significant at 95% confidence level. On the other hand, environmental equilibrium in locating subtropical regions is affected by 7 criteria and 22 sub criteria, among which environmental quality had the highest impact (path coefficient= 0.5227) and semantic structure (path coefficient = 0.0353) the least. Also, the mean of the common index index was 1.147 and the coefficient of determination (R2) was 0.9184. The overall fit of the model (GOF) was calculated to be 0.55235. In the final study, it was found that all paths have significant coefficients and thus the conceptual model of research was confirmed.
Parvin Daneshvar, Dr Taghiloo Ali Akbar, Dr Hassan Heydari,
Volume 23, Issue 69 (6-2023)
Abstract
Increasing urbanization today and the lack of integrated urban management have led to inadequate planning in cities. In this regard, the local councils, as the most prominent local institutions and the most important decentralization manifestations, symbolize the serious presence of the people to determine their own fate, if they are institutionalized in the governance structure as coordinators of the executive agencies. In these cities, they can play a valuable role in the social security of cities. The present study was conducted using descriptive-analytical approach and field method. In this study 354 people were selected using Cochran model. Next, based on the results of the questionnaire, the results were analyzed using SPSS software. Conclusions: Based on the Friedman test, among the research items, the second item is "Social Security Development", and the first item is "Economic Security Development". Among the items, the second item (Social Security) with 2.90 points out that the role of local councils in social security development is higher than other dimensions and the first item with 1.98 points of economic security development comes in last. has taken. Also, the one-sample t-test showed that the significance level of the test is less than (0.05) and at 95% confidence level there is a positive significant difference between the dimensions of council functions and the dimensions of sustainable urban security development.
Mina Daneshvar, Dr Hassan Lashkari, Reza Borna,
Volume 25, Issue 0 (Special Issue 2026)
Abstract
Thunderstorms are considered compound atmospheric hazards, as they simultaneously involve several hazardous phenomena such as lightning, strong and gusty winds, intense convective rainfall, and torrential precipitation. Consequently, these storms are often associated with damage to urban infrastructure and environmental impacts. The objective of this study is to analyze the spatiotemporal distribution of thunderstorms across Tehran Province over a 33‑year period corresponding to the last three solar cycles. Owing to its distinctive topographic conditions and geographical location, Tehran Province is regarded as one of the regions prone to the occurrence of this phenomenon. The data used in this research include lightning reports recorded at nine synoptic stations in Tehran Province during the period 1986–2019. To improve the accuracy of thunderstorm system identification, only events that were simultaneously recorded at a minimum of two stations and during at least two six‑hour observation intervals were selected. The analyses were conducted at monthly, seasonal, and annual scales using statistical and spatiotemporal approaches within the framework of three 11‑year solar cycles. Zoning maps of thunderstorm occurrence frequency were also produced for solar cycle 24 using a larger number of stations with an appropriate spatial distribution. The results indicate that the highest frequency of thunderstorms occurs during the spring season, particularly in May. Despite the passage of most precipitation systems during autumn and winter, the lowest thunderstorm activity was observed in winter. Approximately 70% of the systems had a one‑day duration, and more than half of the events were reported only twice per day. Spatially, Imam Khomeini station and, at a regional scale, the southwestern part of the province in most seasons and the northeastern part during summer exhibited the highest frequencies. Considering the economic and infrastructural impacts as well as aviation‑related hazards, the development of thunderstorm warning systems in Tehran Province appears to be essential.
