Effect of Precipitation Characteristics on Spatial and Temporal Variations of Landslide in Kermanshah Province in Iran

Landslide can be defined as the mass movement of sloping slopes under the influence of mass gravity and its stimuli such as earthquakes,floods and flood plains.This phenomenon is one of the natural hazards that every year causes a lot of financial and financial losses in mountainous,rain-fed and seismic areas.Detection of time and the magnitude of landslides are necessary to understand the causes of landslide and to warn potential hazards.In this research,the amount of landslide displacement in Kermanshah province was evaluated by the characteristics of rainfall.To this end,a network of fixed points in and out of the slipping mass of 20 points was created to monitor the amount of displacement on different slip load users and the amount of displacement of each point in 5 time intervals using the Global Positioning System for two-dimensional GPS measurement.The results of the 511-day follow-up showed that the total horizontal displacement of the moving points in the 5 intervals measured at 1658 mm has a monthly displacement rate of 112 mm.Also,the total vertical displacement of moving points at the same time is 899 mm,with a monthly movement rate of 71 mm.Then,precipitation variances such as rainfall,rainfall,precipitation duration,maximum rainfall intensity in the intervals of 10,20,30 and 60 minutes and the average rainfall intensity were calculated and extracted for each of the 5 time periods.The drawing of the vectors of points on the topographic map of the area indicated that the direction of mass movement is in the direction of elevation gradient of the region.The results showed that only the precipitation severity with the landslide had a good correlation.The landslide movement had the highest correlation with average rainfall intensity(R=0.85)and with maximum 30 minutes rainfall(R=0.67),respectively,and other rainfall characteristics like amount,duration,and type of rainfall had not significantly correlated with movement of landslides.

Cross-sectional rainfall observation on the central-western Tibetan Plateau in the warm season:System design and preliminary results

The central and western Tibetan Plateau(CWTP)is characterized by harsh environment and strong interactions among the spheres of earth as well as significant changes in climate and water cycles over the past four decades.The lack of precipitation observations is a bottleneck for the study of land surface processes in this region.Over the past six years,we have designed and established two observation transects across the south-north and the west-east in this region to obtain hourly rainfall data during the warm season(May-September).The south-north transect extends from Yadong Valley on the southern slope of the Himalayas to Shuanghu County in the hinterland of the plateau,with a total of 31stations;the west-east transect extends from Shiquanhe in the west to Naqu in the central TP,with a total of 22 stations.The observation dataset has been applied to clarify the spatiotemporal characteristics of precipitation in the CWTP,to evaluate the quality of typical gridded precipitation products,to support the development of regional climate models,and to reveal the processes of summertime lake-air interactions.The observation dataset has been released in the National Tibetan Plateau Data Center.