جستجوی مقالات مرتبط با کلیدواژه « بیابان اولیه و ثانویه » در نشریات گروه « آبخیزداری، بیابان، محیط زیست، مرتع »

Since geological formation is very important in the process of desert and desertification, in this article lithology, stratigraphy of the Boushehr province was studied with the help of 1:100000, 1:250000 scale maps of G.S.I and N.I.O.C using GIS methodology. Quaternary formations and most of the evaporatic formations in the province were recognized. Saline and evaporatic formations were introduce as “Primary deserts”. Then with the help through overlaying the drainage network on the basic map of Quaternary formations, the secondary deserts was then recognized this kind of desert possess the evaporative material such as gypsum and salt. Both of these processes (The primary and secondary deserts) have formed Boushehr province deserts. final Results showed that 47% of Boushehr province area is classified as desert including 592041 ha “Primary deserts” and 574579 ha as ‘secondary deserts”. It was concluded that most important geological formation effective in deserts formation in Boushehr province comes from Hormoz series, Gachsaran, Mishan and Aghajari formations.

The country of Iran is situated in an arid and semi-arid zone, with an average precipitation of about 250 mm per year. Hormozgan province in southern Iran, is one of the most arid parts of Iran with an average annual rainfall of only 170mm. The study area is located in the Zagros and Makran geological zones.. In the study area the oldest formations are of Palaeozoic age. Another characteristic of the Zagros zone are diapirs. Diapirs rise up from the deepest part of sedimentary rocks, and after cutting through the upper layers, they may appear at the surface, which seriously affect groundwater quality and land use. Desertification; in Iran has occurred from Neosene and Quaternary. Geological formation have important effect on salinisation and desertification. Thus, the geographical investigation of desert area is very important. This investigation is based on GIS method Applications, geological map (1:250000) and supported by, fieldwork. At the first, prepared and digitizing of geological maps by Ilwis program and was carefully checked and corrected where possible. The next step prepared evaporation formation and Quaternary maps and its overlying. Prepared cross map of Quaternary and Hydrographic network and determination of primary and secondary deserts area. The final step was prepared a cross map of primary and secondary desert area map and checked by fieldwork. To comparison between units of desert area map, can be result, more than 78 percent of study area is situated in the deserts area.