نشریه جغرافیا و برنامه ریزی محیطی
سال بیستم شماره 4 (پیاپی 36، زمستان 1388)

For studying thermal requirements of developmental stages of sunflower based on number of days and accumulated growing degree days (GDD) and relationship of these stages with vegetative growth and seed and oil yield, fourteen hybrids and one open pollinate sunflower genotypes were chosen and evaluated by using a randomized complete block design in four replications in 2005 at the kabotarabad Agricultural Research station of Isfahan. The Number of days and cumulative growing degree days (GDD) from planting to staring, blooming, flowering, 75 percent flowering, 100 percent flowering and physiological maturity were highly and significantly affected by genotypes. Genotypes clustering, based on 14 developmental stage trait showed the sunflower genotypes grouping in early, mid and late maturity groups. Open pollinate cultivar was placed in mid ripening group. The correlation coefficients among vegetative and reproductive growth with number of days and growing degree days of developmental stages were generally positive and significant. According to the results, physiological maturity period and related cumulative growing degree days are the most effective period on seed yield. Oil percentage had not any significant correlation with developmental stages and accumulated growing degree days.

The road of Aralan village (38°23′21″ - 38°27′15″N and 45°33′08″- 45°34′24″E) is a 10.7km paved mountain road. Widening and repairing operations on this road have begun since 2007. Inattention to regional geomorphologic considerations at the time of these operations caused activity of some of geomorphologic processes in parts of the route. This paper is an effort to analyze the role of these kinds of operations on the landscape transformation and their geomorphic results and to investigate and analyze geomorphology of road route. The methodology of this paper is based on field studies and interpretation of geologic maps, topographic maps and aerial photos and study of literature review are used for complete field information. The results showed that, the road of Aralan crossed four geomorphological units with special processes: 1) alluvial fan (floods and debris flows), 2) red Miocene (gully erosion and landslide), 3) arcuate ridge (rockfalls, falls and landslide) and 4) high plateau (liquification and landslide). The presence of debris deposits and Quaternary alluvials on Miocene sediments (mainly marly) on three recent units has an inevitable role on slope stability. In spite of the importance of such debris deposits, removal of this debris cover and appearance of Miocene formations as the result of recent road widening and repairing operations have caused aggravation of geomorphic processes such as mass wasting and gully and rill erosion. This is a regrettable phenomenon that could be prevented by taking into consideration the assessment of geomorphologic activities; inattention to its next effects can capture us into a crisis similar to forest removal and inopportune activities in the domains of agricultural and animal husbandry.

Water crisis is one of the most important crises in the management of human societies and environment which almost affect all of the development bases in the international, regional and national levels. Drought assessment and its intensity are very different and includes statistical (Standardizatation, probabilities), meteorological (Synoptic, dynamic) and hydrological (water balance) methods. In this research we have used percale normal index to analyze the meteorological drought in Sistan and Baluchestan province which has suffered from severe drought during recent years. According to the results of the present work, the annual precipitation of between 36 to 52 percent of the studied years is higher than mean precipitation of the province. 10 to 23 percent is in the borderline of drought, 3 to 13 percent is exposed to weak drought, 6.7 to 23 percent to moderate drought, 6 to 20 percent to severe drought, and 6.7 to 23 to very severe drought.

Coasts are vulnerable to damaging effect of erosion in any area. Coastal management needs an integrated coastal zone management (ICZM) in such a way that a sustainable development can be established in these areas. In Chabahar coastal area the unregulated plans and activities of various parts aiming at accomplishing development programs, the unstable exploitation of marine sources, and other coastal activities have led to the sea and coast pollution. It has also led to disorders in ecosystem processes and balance in the shoreline. In other words, the increase of population and hunting activities in coastal area of Chabahar, unawareness of coastal organizations on relations and living processes existing in the sea and coast, as well as the failure of plans, which do not follow environmental standards, have imposed problems on the process of natural interaction. This has accelerated coastal erosion and the annihilation of different types of marines in coastline areas. Meanwhile, natural limitations and difficulties have also led to little attention to environmental problems with regard to human activities in this area. The findings of this research show that the compilation of strategies of environmental sustainable development needs an awareness of ecosystem process of sea and coast, distinction between the limitations and potentials of natural environment, and also the effective role of coastal management. Following the investigation of limitations and potentials of natural environment and coastal management activities, we have proceeded to propose the appropriate ways and to complete the environmental sustainable development of Chabahar coast in the future development horizons of this region.

This study is to identify these factors in order to design a plan for reducing hail damages in the vulnerable areas of the East Azarbaijan province. For this purpose, the daily hailing data from 6 stations in East Azarbaijan province between 1987- 2006 years were collected. The results revealed that the highest amount of hailing happened in the south west of the province (marageh district), while the lowest was in the north west (jolfa district)and Poisson distribution shows that it best fitted the hail data on the study area.

Iran has a lot of renewable and nonrenewable energy resources. Since Iran has a special geographic position, it has a lot of solar and wind energy resources. Both solar and wind energy are free, renewable and adaptable with environment. The study of 10-year-wind data in Iranian synoptic stations shows that the production of wind power electricity is possible in many regions of Iran such as the Coast of Oman Sea, Persian Gulf islands, coastal areas of Khozestan province, the Eastern area of Iran, and stations of Manjil, Rafsanjan, Ardebil and Bijar. Also the production of wind power electricity is possible in many other regions of Iran during limited time. According to the findings of this study, Synoptic stations are divided into four different groups in terms of wind speed. The first group has great wind power most of the year, the second group has great wind power in some parts of the day sometime in the year, the third has wind power in limited times during the year and the fourth group does not have any significant wind power throughout the year.

It is emphasized that control and reduction of effective factors of flood formation and intensification with the aim of flood discharge is one of the important principles of soil and water resources management in order to prevent destructive flood damages. In this regard, investigation and identification of the most important factors that influence flood formation and intensification in great watershed of Esfahan-Sirjan, located in Iran central district (with area 99300 square kilometers), was carried out, using revised records of 14 gauged flood discharge station by utilizing factor analysis statistical technique. In this study, effective factors in flood was determined and calculated; they include topography, climatology, soil, geology, plant cover and land use of studied sub-basins. Results of factor analysis application show that time of concentration, catchment slope and drainage density of 1 order streams with 37.9%, 29% and 24.6% weighed impact, respectively, are the most influential factors in flood formation and intensification in the study area. Thus, for optimum management of soil and water resources conservation in watersheds, it is necessary to investigate practical and scientific methods in order to reduce negative impacts of these factors on flood phenomenon in the studied sub-basins.