Showing 5 results for parvin
Nader Parvin,
Volume 15, Issue 39 (12-2015)
Abstract
Nader Parvin,
Volume 17, Issue 46 (9-2017)
Abstract
studying and identifying the middle levels change affecting the formation of a circular pattern creation is inevitable. In this study, the annual rainfall data for selected stations Zab River Basin during the period 2015-1986 were the standard time. After indexing and spatial-temporal threshold, 184 days without rainfall were selected in the wet period of three severe drought in the region. Level 500 HP height data located in the range of 0 to 80 degrees northern latitude and eastern longitude on dry days as a matrix S_Mode were used and these data using principal component analysis were processed using modern statistical methods. Based on the correlation matrix, the main focus of the 500 HP topography of the basin dry days were identified and analyzed. The results show that, in the happening time of dry days, twelve atmospheric middle levels of height change focus have been effective. In this regard, the following two centers having the highest anomalies (R≥0.7) are detected according to the high levels of the atmosphere: 1) the center of Eurasia-Africa, 2) the center of West Africa, respectively, 48% and 10% of the total area of the study. Such changes in middle atmospheric levels cause to strengthen and deepen the traffic axis and on the ridges. In the meantime, the change of first center has the highest impact on creation of stability and domination of dryness in days of Zab River Basin.
Dr Mahmoud Hooshyar, Dr Behrouz Sobhani, Nader Parvin,
Volume 19, Issue 54 (9-2019)
Abstract
Early heat waves are extreme events that cause heavy losses in plant and animal life and cause many social and economic problems for communities. The purpose of this study was to identify synoptic patterns and statistical analysis of preterm heat waves in northwestern Iran. To do this, the maximum daily temperature data of March 14th was used for fourteen synoptic stations in the northwest of the country during the statistical period (1333-1393) Hijri Shamsi. Then, on the basis of the threshold, the Baldy index was selected for 61 days of heat wave. All statistical characteristics of the data were processed in SPSS software. They were The elevation data of the middle atmosphere of the atmosphere was extracted from a NCEP / NCAR database on a network with an arc 2/5 × 2/5 degree on the 0 to 70 degree eastern longitude and 0 to 60 degrees north latitude. The matrix was made up of 864 columns in 40 rows, with rows of days with thermal waves and elevation data on the columns on the middle of the atmosphere. The analysis of the basic components was performed on the algebraic data matrix matrix And 12 components that account for about 93 of the variations in pressure levels above 500 hp, were identified. To identify the coherent patterns, cluster analysis was performed on the scores of the components by the WARD integration method. Five types of pre-heat generation waveform patterns were identified. The results of this study showed that the premature heat waves in the northwest of Iran are due to high altitude formation in southern Arabia, the Aden valley and the center of Sudan at a level of 500 hpa and the formation of Sudan's low pressure in the sea level and the discharge of its tabs to the north and northeast of the region The case study (Northwest of Iran) also includes events occurring.
Mansor Parvin,
Volume 22, Issue 64 (3-2022)
Abstract
Semi-arid watersheds are sensitive to soil erosion process and suffer considerable losses each year. Morphometric studies are an important method for identifying susceptible erosion zones and are a prerequisite for assessing erosion patterns in watersheds.The semi-arid Kamyaran basin is at risk of soil erosion due to lithological diversity, varied geomorphology, rugged topography and the nature-based livelihoods of its inhabitants and determination of soil erosion potential of this basin is essential for scientific management and sustainable development. The purpose of this study is to prioritize soil erosion potential in the Kamyaran basin. Methodologically, this research is based on WSA and averaging methods based on the calculation and ranking of morphometric parameters. The results showed that according to WSA methods and averaging 53.63% and 75.91% of Kamyaran catchment area, respectively, are located in areas with high soil erosion potential and require protection plans. The WSA method has better performance for prioritizing soil erosion studies due to different morphometric parameters and how to calculate it accurately. Sub-basins located in the northern areas of the Kamyaran Basin have high potential for soil erosion and sub-basins in the southern areas have low soil erosion potential. In general, the amount of soil erosion potential in Kamyaran basins is affected by the lithological and geomorphological conditions of the basins and the parameters related to infiltration have the most influence on the extent of soil erosion potential in the basins.
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.
