Abstract
Groundwater behavior has been considered as one of the main factors that have been causing many landslides in Iran. However, investigation and study for groundwater flow in landslide has not been enough. We investigated temperature of groundwater flow and underground temperature in every one-meter depth at some landslides in semi-arid area, northwestern Iran in 1997 and 1998. Ground water vein-streams have been especially tried to presume by the result of onemeter depth underground temperature survey at the Barikan landslide. In addition, water quality investigation (water temperature, electric conductivity, chemical analysis) has been carried out at springs, irrigation channel and river in and around this landslide to evaluate these vein-streams. The conclusions of this study have been made as follows : From the measured temperature of one-meter depth underground and ground water at some landslides around the Alborz mountains, it is understood that the one-meter depth underground temperature survey is applicable in northwestern Iran. However the determination about inappropriate period for this survey is necessary in future because this period is different from the case of Japan. There are five low temperature zones at the Barikan landslide, which is first serious case of this survey in Iran. From the results of water quality test and location of springs, it is estimated that groundwater veinstreams in the landslide mass form these low temperature zones. In addition, the groundwater that is supplied fromthe terrace behind the active landslide block has an effect on landslide movement at the Barikan.
