Zakieh Safarpour; Jalil Farzadmehr; Ali Golkarian; Mahdi Bashiri
Abstract
Landslide is one of significant mass movement which causes normous annual human and sesmic region. Therefore, finding hazardous areas for planning and management of them is necessary. So, in this reasearch, occurred landslide in watershed region of bidvaz dam which has area of 161 square kilometers and ...
Read More
Landslide is one of significant mass movement which causes normous annual human and sesmic region. Therefore, finding hazardous areas for planning and management of them is necessary. So, in this reasearch, occurred landslide in watershed region of bidvaz dam which has area of 161 square kilometers and 125 landsliding points are surveyed in different hydrological conditions by index model of slope stability. For specified slopes, graiding test was done and geotechnical parameters were attained. Then, by using Arc view and Arc GIS packages and calibrating parameters in SINMAP and incorporating the geotechnical and hydrological parameters with digital elevation model, SINMAP was conducted. After that, validation was done in two common and high hydrological conditions including rainfalls with a return period of 2-10 years and 20-50 years Respectively. Results showed that the performance of model in simulation of landslides is not appropriate at common hydrological cases. However, increase in hudrological humidity condition, performance of model improves. In calibration and validation, prediction of model increase 21 % and 26 %, respectively. Therefore, utilizing SINMAP model in high hydrological humidity conditions can be useful for choosing dangerous ways according to the landslide map.
Fariba Alavizadeh; Kamalledin Naseri; Ali Golkarian; Ali Tavili
Abstract
Soil erosion is a main hazard in most area of the country specially in arid and semi-arid regions and itis very important because of sedimentation, pollution, increased flooding and its negative effects onsoil productivity. One of the features of arid and semi-arid areas is the presence of low cover ...
Read More
Soil erosion is a main hazard in most area of the country specially in arid and semi-arid regions and itis very important because of sedimentation, pollution, increased flooding and its negative effects onsoil productivity. One of the features of arid and semi-arid areas is the presence of low cover ofvascular plants. These empty spaces are usually good niches for biological soil crusts or cryptogamslike mosses. These crusts contribute to a variety of ecological functions and have different effects onsoil features and vascular plants. The present study was carried out in the rangelands of Torogh dambasin of Khorasan- Razavi province in order to find the effects of such kind of plants (mosses) onwater erosion. For this purpose, artificial runoff streams in plots with two intensity (low and high) for30 minutes. In order to study the effects of different amount of mosses on sedimentation and specificerosion, four different density of mosses in the same experimental situation were studied: high (60-75% of plot), medium (35-50% of plot), low (10-20% of plot) and control (0%). The results ofanalysis of variance and tukey method by the use of Minitab software showed a significant differencein 95% level between the four considered density of mosses and the two intensity of water. As mossesdensity decrease, sedimentation and specific erosion increased consequently. But there were nosignificant differences in infiltration between the different treatments.
