Khadijeh Javan,
Volume 16, Issue 43 (16 2016)
Abstract
In this study, the Frequency and the spell of rainy days was analyzed in Lake Uremia Basin using Markov chain model. For this purpose, the daily precipitation data of 7 synoptic stations in Lake Uremia basin were used for the period 1995- 2014. The daily precipitation data at each station were classified into the wet and dry state and the fitness of first order Markov chain on data series was examined using Chi-square test at a significance level of 0.01 and was approved. After computing transition probability matrix, the persistent probability, average spell of dry days and rainy days and weather cycle was calculated. By calculating the frequency of 1-10 rainy, the spell of this periods and 2-5-days return period were calculated. The results show that in this study period the average of rainy days is 25% and the probability of Pdd is more than other states (Pww ، Pdw و Pwd). The average spell of rainy days in the study area was estimated at about two days. Generally, in all stations the persistent probability of wet state is more than rainy state. Estimation of frequency and spell of rainy days and 2-5-days return period show that with increasing duration, the frequency of rainy days decreases. Also with increasing duration of rainy days, their spell is reduces and return period increases.
Hassan Afrakhteh, Mohammad Hajipur, Farhad Javan,
Volume 18, Issue 50 (3-2018)
Abstract
The oil has gradually obtained a predominant place in national economy since 1950 and nowadays, is the main important resource securing country financial needs. Two questions are the base of this research regarding contradiction of oil rent and traditional economic sectors including agriculture and livestock rearing which always have been intensified. These two questions are as follows: what are the impacts of oil wealth distribution among different regions on Iran's rural economic structure? What has been the locational-spatial consequences of this oil wealth distribution on agricultural sector as a main element of Iran's rural economic structure? Research required data have collected based on document study on the country during 2006- 2011. Collected data are analyzed based on Shift-Share Analysis and Gibbs- Martin methods. Result show that there have not been any incentive in the local, regional and national management for strengthening rural economic structure using oil wealth. In addition, absence of industrial sector in rural economic structure with emphasis on agricultural sector both from policy making view and credit securing show that there have not been any logical sight on the political economic system facing rural space economy for development.
Mrs Sahar Mehrran, Mr Ali Akbar Taghilou, Mrs Khadijeh Javan,
Volume 23, Issue 70 (9-2023)
Abstract
Analysis of land use change in Nazlou district of Urmia in the 2005-2018 time series
Abstract Population growth, increased prosperity, the spread of technology, and the improper use of land have in recent decades imposed many changes on land. Nazlou district in Urmia city has been exposed to many changes due to its favorable natural conditions, location in the development paths of Urmia-Cir and Urmia-Bazargan, establishment of numerous industrial estates and so on. So planning to manage these changes requires studying land use changes. The purpose of this study was to detect land use changes in Nazlou district in Urmia city using Landsat TM and OLI satellite images by Object Oriented Classification. Also, two methods of change detection and change intensity index in land use change monitoring were used to investigate the severity and trend of land use changes. This study was descriptive and analytical and data collection was done by documentary method. The survey showed that during the study period (2005-2018) of the total area of 77498.37 hectares, the total area under study was approximately 25981.56 ha (33.52%). The highest level of change in 2005 relates to the level of the horticulture, with its downward trend in 2018. In contrast, changes in rangeland and dryland land use have an increasing trend, respectively.
