N NARASIMHA RAO
Articles written in Journal of Earth System Science
Volume 129 All articles Published: 1 January 2020 Article ID 0030 Research Article
In recent past, rainfall-induced debris flow events in Ladakh–Nubra region have caused loss of lives and damages to civil infrastructures and army locations. Therefore, there is a need of high spatial and temporal monitoring of precipitation, and further to assess susceptible rainfall-induced debris flow zones in the area. We assessed the rainfall data collected at two gauge stations and observed a significant increase in the rainfall amount over the study region during summer-monsoonal period 1997–2017. Increasing trend was also observed from CRU gridded precipitation dataset. A GIS-based multi-criteria evaluation (MCE) method was performed by combining topographical, environmental and hydrological parameters for mapping of rainfall-induced susceptible zones. Suitability analysis of precipitation forecasts from WRF model at higher resolution (3 km) was also performed. A good agreement (r = 0.76) was observed between 4-day model forecast and field observed rainfall. Further, the simulated precipitation from WRF was incorporated into GIS model for assessment of debris flow susceptible zones for two cases of heavy precipitation events. The modelled high, medium, low and very low risk susceptible zones identified for the year 2015 events are validated with field survey and pre-post satellite imageries, and found in good agreement (ROC = 76.6%). The model was able to identify affected areas during the Leh cloud burst event in year 2010. In addition, a threshold value of rainfall for initiation of debris flow in the region was also reported.
Volume 129 All articles Published: 10 January 2020 Article ID 0040 Research Article
A localized extreme precipitation event occurred over Munsiyari (Uttarakhand, India) on 2nd July 2018 causing Cash floods, landslides and damage to the hydropower project. A preliminary study has been carried out by using Weather Research and Forecasting (WRF) model with three-dimensional variation data assimilation technique (3DVAR) to examine the feasibility of the model to predict the localized phenomena. Sensitivity experiments were carried out with two different microphysics in the model. Results show that P3 1-category plus double moment cloud water microphysics scheme with 3DVAR in WRF simulates the quantity of precipitation closer to the observed precipitation over Munsiyari. The vertical velocity and relative humidity were also simulated well during 3DVAR data assimilation as compared to without data assimilation over study region.
Volume 129, 2020
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