Trend Analysis of Rainfall, Temperature and Runoff Data: A Case Study of Rangoon Watershed in Nepal
Purpose: The study has been carried out to investigate and assess the significance of the potential trend of three variables viz. rainfall, temperature and runoff over the Rangoon watershed in Dadeldhura district of Nepal.
Methodology: In this study, trend analysis has been carried out on monthly, seasonal and annual basis using the data period between 1979 to 2010 for rainfall and temperature and 1967 to 1996 for runoff. Mann-Kendall test and Sen’s slope estimate test were applied to identify the existing trend direction and Sen’s slope estimator test were used to detect the trend direction and magnitude of change over time.
Main findings: The most important findings are, i) There is warming trends over the Rangoon watershed as Mann-Kendall statistic (Z-value) for most of the maximum temperature values are positive, ii) Rainfall and runoff affected by fluctuations every year though the annual rainfall showing a rising trend whereas runoff showing a falling trend. The rainfall seasonal trend analysis indicates that monsoon and post-monsoon period showed a positive rainfall trend with z statistics of +1.93, and +1.12 respectively, whereas pre-monsoon and winter seasons showed a negative trend with z statistics of -1.02, and -0.54 respectively. However, the annual rainfall in the Rangoon watershed showed a positive trend with a z value of +1.70.
Importance of this study: This case study has been undertaken to investigate the trends of important climatic variables viz. rainfall, temperature which have a direct impact on the agriculture of the region.
S Kundu, D Khare, A Mondal, PK Mishra, March 2014, Long term raingall trend analysis (1871-2011) for whole India, Climate Change and Bio-diversity, 45-60.
PK Meena, D Khare, S Kundu, PK Mishra, February 2015, Long term trend analysis of mega cities in Northern India using rainfall data, Indian Journal of Science and Technology 8(3), 247-253
S Kundu, D Khare, A Mondal, PK Mishra, January 2015, Analysis of spatial and temporal variation in rainfall trend of Madhya Pradesh India (1901-2011), Environmental Earth Sciences 73(12), 8197-8216
Duhan D, Pandey A., 2013, Statistical analysis of long term spatial and temporal trends of precipitation during 1901-2002 at Madhya Pradesh, India, Atmospheric Research, Elsevier, 122:136-149.
Deasy Nalley, November 2012, Analyzing trends in temperature, precipitation and streamflow data over Southern Ontario and Quebec using the discrete wavelet transform, Department of Bioresource Engineering, McGill University, Montreal
Arijit Ganguly, Ranjana Ray Chaudhuri, Prateek Sharma, September 2015, Analysis of trend of the precipitation data: A case study of Kangra district, Himanchal Pradesh, Internation research of Granthalaya.
Mondal A, Kundu S, Mukhopadhyay A, 2012, Rainfall trend analysis by Mann-Kendall test: A case study of North-Eastern part of Cuttack district, Orissa. International Journal of Geology, Earth and Environmental Sciences, ISSN:227-2081, 2(1):70-78.
Hamed K H, Rao A R, 1998, A modified Mann-Kendall trend test for auto correlated data. Journal of Hydrology, 204: 182-196.
Agnieszka Rutkowska, 2013, Statistical Methods for trend investigation in Hydrological non-seasonal series, University of Agriculture in Krakow, Octa, Sci. Pol., Formatio Circumiectus 12(4), 85-94
A. Serrano, V. L. Mateos and J. A. Garcia, July 1998, Trend Analysis of Monthly Precipitation Over the Iberian Peninsula, Departamento de Fisica, Universidad de Extremadura, Badajoz, Spain
for the Period 1921-1995, Vol 24, No. 1-2, PP. 85-90
Jain S K, Kumar V. 2012, Trend analysis of rainfall and temperature data for India. Current Science, 102(1): 37-39.
Basistha A, Arya D.S., Goel N.K., 2008, Analysis of historical changes in rainfall in the Indian Himalayas. International Journal of Climatology, 29:555-572.
Joshi M.K., Pandey A.C., 2011, Trend and spectral analysis of precipitation over India during 1901-2000. Journal of Geophysics Research.
Mann HB (1945). Non-parametric test against trend. Econometrica 13, 245–259.
Kothawale DR and Rupa Kumar K (2005). On the recent changes in surface temperature
trends over India. Geophysical Research Letters 32
Kumar, V and Jain SK, 2010. Trends in seasonal and annual rainfall and rainy days in Kashmir valley in the last century, Quaty Intl., 212, 64-69
Prathasarathy, B and Dhar, O.N., 1974. Secular variations of regional rainfall over India. Q.J.R. Meteorol. Soc., 100, 245-257.
Kharmeshu N. 2012, Trend detection in annual temperature and precipitation using Mann-Kendall test-a case study to assess climate change on select states in North-eastern United States. Department of Earth and Environmental Sciences, University of Pennsylvania: 1-24.
Rao, P.G., 1993. Climate changes and trends over a major river basin in India. Climate Res., 2, 215-233.
Longobardi A, Villani P., 2010. Trend analysis of annual and seasonal rainfall time series in the Mediterranean area. International Journal of Climatology, 30: 1538-46
- There are currently no refbacks.
Copyright (c) 2017 Amar Bahadur Pal, Deepak Khare, Prabhash Kumar Mishra, Lakhwinder Singh
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.