Geographical Research

The aim of this paper is to evaluate the effect of tectonic on the volume of alluvial fans around Danehkhoshk Anticline. To achieve the purpose of this study، at first، borders، sweep angle(S) and radius(R) of alluvial fans were obtained based on Quick bird Satellite image and then difference in the altitude between the apex and toe of alluvial fans (h) were calculated based on topographic map at a scale of 1/50000. The alluvial fan volumes were calculated based on mentioned parameters. The strata dips of anticline limbs (DAL) were measured at mountain front (at the upstream side of fan) by clinometer. Danehkhoshk anticline was subdivided into 7 tectonic zones based on dip of strata on limbs and subsequently، mean of mentioned parameters were calculated in each zone. Result of this study reveals that there is positive relation between strata dips of anticline limbs (DAL) and fan volumes، with a correlation coefficient of 33%. Data analysis reveals that correlation coefficient between DAL and V is higher (87%) in alluvial fans with larger basin areas (180 to 737 hectares). It means that tectonic has stronger effect on fan’s volume in fans with larger basin areas. Evaluating the relation between means of DAL and V in tectonic zones represents that there is positive relation between mentioned parameters with a correlation coefficient of 69%. There is no meaningful relationship between mean basin area (BA) and mean fan volume. The positive relationship with fairly low correlation coefficient exists between mean basin topographic slope (BS) and fan volume. This study also shows that the presence of fault in the upstream basins of alluvial fans has an important role in increasing fan volume (V) so that، in each zone، the highest rate of V belongs to a fan that has a faulted basin.