Modeling and Landslide Volume Estimation Based on Landslide Area in Chahardangheh Basin (Mazandran Province)

Given the importance of knowing the landslide volumes in watershed management, this research was conducted in order to determine the best model to estimate the landslide volumes based on the area, and to compare the empirical relationship derived from this research with other empirical relations obtained in the world. For this purpose, the area, volume and depth features of 18 landslides of Chahardangeh Basin was firstly prepared and then the location and area of 485 landslides were identified using Google Earth satellite images of this study area. Then, the relationship between the area and volume of landslides, measured by 10 models of curve estimation, were evaluated during field operations, and the models were compared and evaluated using the values of R2, F-statistic and S.SE. In the next step, the amount of volume and depth of landslides of the area were calculated using empirical correlations obtained in this study and other relations presented in the literature, and they were compared and evaluated with the observed data. The results showed that the power law with R2= 0.8 and Sig = 0.00 has lower S.SE than other models, and provides the best fit to the observed data. Also, the estimated volume values with this relationship fit rather well with observed values. The estimated depth using Whitehouse (1983) and Imaizumi (2007) with 7.89 m and 7.09 m, respectively, was close to mean of observed depth with 7.60 m. The average depth of 18 Landslides used in the model with a depth of 5.76 meters is very close to 485 landslides which have been detected in the area with an average depth of 5.64 meters.