A Study on the Heavy Rainfall Event Around Kedarnath Area (Uttarakhand) on 16 June 2013
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A study on the heavy rainfall event around Kedarnath area (Uttarakhand) on 16 June 2013 M S Shekhar1,∗, S Pattanayak2, U C Mohanty2, SPaul3 and M Sravana Kumar1 1Snow & Avalanche Study Establishment, Research & Development Centre, Him Parisar, Sector 37A, Chandigarh 160 036, India. 2School of Earth, Ocean and Climate Sciences, Indian Institute of Technology, Bhubaneswar, Toshali Bhavan, Satya Nagar, Bhubaneswar 751 007, India. 3Meteorological Office, Sector-39, Chandigarh 160 022, India. ∗Corresponding author. e-mail: [email protected] The heavy rainfall event during 14–17 June 2013 in Uttarakhand and more specifically, its occurrence around the Kedarnath region on 16 June 2013 with devastating floods and massive landslides ruined thousands of lives and properties. Increasing levels of water in two main rivers of the State, namely Alaknanda and Mandakini, resulted in the collapse of bridges, damaging and washing away of property worth many crores. In the present study, the advanced research version of the Weather Research and Forecasting (WRF) system (hereafter used as WRF model) is used to simulate this heavy rainfall event. The synoptic analysis at different locations such as Rudraprayag, Uttarkashi, Chamoli, Pauri, Tehri, Dehradun and adjoining districts suggested that the rainfall is about 200% more than normal. The rainfall associated with this event is well captured with the model simulation. The rainfall simulated by WRF model is in the range of 320–400 mm over Kedarnath during the actual occurrence of the event, which is in reasonably good agreement with the observed value of rainfall (325 mm) collected by Wadia Institute of Himalayan Geology. 1. Introduction During 14–17 June 2013, Uttarakhand and its adjoining areas received heavy rainfall associated The complex orography in the foothills of the with landslides that caused a huge damage and Himalayas and more specifically in the northern ceased many lives. Also, the occurrence of such states of India significantly influences the extreme high impact events in Uttarakhand during mon- events like heavy to very heavy rainfall/snowfall, soon season are not uncommon. Uttarakhand has avalanches, cloudbursts, flash floods, landslides, experienced many such heavy rainfall events in etc. The low level convergence of south-easterlies the past, mainly during the months of July and and north-westerlies along with the complex ter- August. In September 1970, heavy rainfall and rain of foothills coupled with vertical shear of wind landslides claimed lives of 223 people in Uttara- and orographic uplifting lead to short-lived intense khand. Similarly, on 16 July 2001, 14 villages were convective precipitation. The mountainous regions affected, 27 people lost their lives in this event, of Uttarakhand are frequented by many weather- along with damage to 154 houses. More than 43 and terrain-related hazards due to its intricate geo- hectares of agricultural land was also washed away spatial location, leading to significant loss of lives and 11 km stretch of Rudraprayag–Kedarnath road and damage to the property. got severely damaged. On 6 August 2010, Leh was Keywords. Uttarakhand; heavy rainfall; floods; mesoscale model. J. Earth Syst. Sci. 124, No. 7, October 2015, pp. 1531–1544 c Indian Academy of Sciences 1531 1532 M S Shekhar et al. down-poured with a cloudburst event and a detailed the districts of Rudraprayag, Uttarkashi, Chamoli, study was carried out by Ashrit (2010), Sravan et al. Pauri and Tehri. The holy shrine of Kedarnath was (2012) and Thayyen et al. (2013). However, the June the scene of maximum destruction. As a first step 2013 heavy rainfall event that occured in the holy towards the synoptic analysis of the event along pilgrim area Kedarnath ceased thousands of lives with the prediction of such extreme events numer- and caused catastrophic damage due to landslides, ically, this paper makes an effort to simulate the debris flow and extensive flooding. Also, this ex- event on 16 June 2013, so as to capture the quan- treme rainfall event occurred for the first time titative precipitation associated with this event. in the month of June and extended the entire The methodology and data used is provided in Uttarakhand. Because of the lack of vegetation and section 2. The results and discussion describing the higher friction over terrain slopes, the rainwater synoptic features as well as the model simulated along with the rocks and mud gushed through the results are presented in section 3, followed by populated areas and caused heavy loss of human conclusions in section 4. life and property. Joseph et al. (2014) studied the basis of heavy rainfall events of Uttarakhand in the perspective of large scale monsoon and suggested 2. Data and methodology that the monsoonal low pressure system enhances the low-level convergence with excessive moisture There is no adequate technique to predict the heavy interacting with strong upper-level divergence pro- rainfall event in the complex mountainous region duced through mid-latitude westerly trough that due to coarse resolution of the meteorological data augmented the monsoonal heavy rainfall in the network. Numerical weather prediction models often orographic region. The study also examines the fail to simulate and predict these types of events extended range prediction of the event through due to the limitations of the upper atmospheric coupled general circulation model CFSv2 and sug- profile data as well as a high resolution data net- gested that CFS model could predict the event 10– work over the region. Remote sensing data over the 12 days in advance, though the mid-latitude influ- regions also need to be of very high temporal and ence is not captured. Singh et al. (2014) examined spatial resolution to capture the characteristics of the dynamics of the June 2013 heavy rainfall event the event. As a first step towards the prediction of in the context of historical and pre-industrial cli- such extreme events, this study makes an effort to mate and suggested that the early arrival of mon- simulate the event on 16 June 2013 by using the soon brought heavy rainfall in the mountain region Weather Research and Forecasting (WRF) model, where snow cover typically melts prior to the onset so as to capture the precipitation associated with of monsoon. The study also claims that the impact this localized mesoscale phenomenon. Snow and of anthropogenic forcing increased the likelihood of Avalanche Study Establishment (SASE), Chandi- such an event. Srinivasan (2013) hypothesized that garh, gives mountain weather forecast 6 days in a landslide caused by the heavy rainfall event might advance by using WRF model covering the snow- have blocked the Mandakini River which origi- bound mountainous areas of western and central nated from the Chorabari Glacier of the Himalayas Himalaya with a grid resolution of 9×9km.The and the dammed water behind the landslide might SASE has established an Automatic Weather Sta- have flushed in the early morning of 17 June. tion (AWS) just near to the Kedarnath temple so Dobhal et al. (2013) concluded that the heavy rain- as to monitor various atmospheric phenomena and fall during 15–17 June 2013, along with the melting give weather and avalanche forecast to the users, snow in the surrounding Chorabari Lake, washed mainly Army and Indo-Tibetan Border Police off the banks of Mandakini River, causing massive (ITBP) deployed in those areas. However, due to devastation. The floods triggered landslides as a heavy rainfall, the AWS was badly affected and catalyst to damage structures, killing the trapped stopped disseminating data after 2000 hrs IST on people and caused vulnerability to properties. The 16 June 2013. There was no observational record present study on the simulation of a heavy rain- of precipitation over the study region, i.e., over fall event in Uttarakhand and more precisely sur- Kedarnath except that of Wadia Institute of Hima- rounding Kedarnath is a more concise numerical layan Geology. The AWS of Snow & Avalanche approach to predict the unprecedented heavy rain- Study Establishment which had been installed fall with a few presentations of synoptic features, just at the back side of the Kedarnath temple though a few synoptic studies have already been stopped dissemination of data after 2000 hrs IST carried out by Dobhal et al. (2013) and Dube et al. on 16 June 2013. Due to nonavailability of pre- (2013). cipitation sensor at the station, the data with Uttarakhand witnessed an intense heavy rainfall regard to observed precipitation in the area during event in the afternoon/wee hours of 16 June 2013, that period could not be recorded. However, the which resulted in heavy loss of lives and property in precipitation observation from the Meteorological A study on the heavy rainfall event around Kedarnath on 16 June 2013 1533 Department of Chandigarh gives a district-wise runat NCMRWF and their respective skills in pre- rainfall distribution. dicting high rainfall event associated with this event In this study, the high resolution non-hydrostatic is presented. Advanced Research WRF (ARW) mesoscale model (version 3.2.1) developed at National Centre for Atmospheric Research (NCAR) is used to simulate 3. Results and discussion the heavy rainfall on 16 June 2013. It is a fully The synoptic features as well as numerical simula- compressible primitive equation model and versa- tion results of the Kedarnath heavy rainfall event tile for both research and operational purposes. In are presented in this section. the present study, a single domain with resolution of 3 km, keeping Kedarnath and its adjoining areas as the center is used. The configuration used to run 3.1 Synoptic features of the event the model is depicted in table 1. The performance The heavy rainfall event in mid-June 2013, cen- of mesoscale models depends on the quality, consis- tered on the north Indian state of Uttarakhand tency and representativeness of initial and lateral caused devastating flood and landslides which is boundary conditions.