Nasrin Nikandish; Seyyed Farzad Hosseynizadeh Arani
Volume 22, Issue 87 , November 2013, , Pages 81-86
Abstract
Analyzing landslide and risk management are among the important responsibilities of managers. The present study explores different features of landslide using Google earth satellite images and Geographic Information system. Case study includes landslide zone in Chahar Takhte which is located in Ardal, ...
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Analyzing landslide and risk management are among the important responsibilities of managers. The present study explores different features of landslide using Google earth satellite images and Geographic Information system. Case study includes landslide zone in Chahar Takhte which is located in Ardal, Chahar Mahal va Bakhtiary province. Data was collected from Google earth and digital elevation model. Maps of landslide zone, land use, topographic and landslide development were produced based on the obtained images. Results indicate that the sliding mass is located near one of Karun tributaries, and undercutting by this tributary is one of the main reasons for the occurrence of landslide. The toe of this mass discharges sediments into the river. Rotational landslide happen in alluvium, colluvium and skirts with a less than 20 degree slope, while cliffs and toe have steep slope. Other reasons for the occurrence and development of landslide includes water drainage in Naqan city, roads and irrigated agriculture. 53 percent of flows are drained in south and south west directions. Main cliff in the landslide zone is located near grade IV and V water flows. Agricultural lands, roads and even Naqan face the threat of landslide zone development.
Nasrin Nikandish; Abbasali Arvin; Vajiheh Shahsavari; Farshad Soleymani
Volume 22, SEPEHR , July 2013, , Pages 23-29
Abstract
Drought is a global phenomenon which can happen nearly everywhere and result in major economic, social and environmental costs and losses. In this study, annual precipitation data of 7 synoptic stations and 8 pluviometric stations in a 20 year period (1986-2005) were applied to investigate climatic droughts ...
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Drought is a global phenomenon which can happen nearly everywhere and result in major economic, social and environmental costs and losses. In this study, annual precipitation data of 7 synoptic stations and 8 pluviometric stations in a 20 year period (1986-2005) were applied to investigate climatic droughts in Hormozgan province. After preparation of data, the intensity of drought was calculated using two statistical indices (percent index of normal precipitation and annual precipitation metric). Then, the results in each station were compared with its corresponding precipitation to select the best zoning method.
Finally, percent index of normal precipitation was selected as the best index for zoning drought. Results of the zoning indicated that in 1992, 1997, 1996, 1995 wet year was dominant in the area, while in 1993, 1994, 2000, 2004, 2005 average dry year covered a large part of the area and in 2001, 2003 very dry and extremely dry year was dominant. Drought does not show a specific trend considering its continuation, intensity and extent and lacks a homogeneous temporal and spatial distribution.
