Chapter 7
Comparison of Classical Mann–Kendal Test
and Graphical Innovative Trend Analysis
for Analyzing Rainfall Changes in India
Tapash Mandal , Apurba Sarkar, Jayanta Das ,
A. T. M. Sakiur Rahman , and Pradip Chouhan
Abstract The analysis of rainfall trends is of the utmost importance for sustainable
management and planning of agriculture and water resources under changing climate. Therefore, this study aims to detect the long-term rainfall trends of 36 meteorological subdivisions of India for the period 1901–2015. The graphical innovative
trend analysis (ITA) technique and the classical statistical Mann–Kendall (MK) or
modified Mann–Kendall (mMK) tests are used to detect historical rainfall changes.
The nonparametric Sen’s slope (Q) estimator is also applied to measure the magnitude of change. The ITA results show about 61.11% of the subdivisions exhibited
decreasing trends in annual rainfall. On the seasonal scale, about 58.33%, 50%,
69.44%, and 88.88% of the subdivisions are experiencing decreasing trends in
pre-monsoon (Mar–May), monsoon (Jun–Sep), post-monsoon (Oct–Nov), and winter (Dec–Feb) seasons, respectively. The results of the Z statistic show a good match
(about 90%) with the graphical ITA method. However, the ITA method is able to
detect subtrends while, MK/mMK shows only the monotonic trend. Such a trend
analysis of rainfall can provide significant information that will be useful to build up
adaptive capacity and community resilience against climate change. This study can
be helpful for regional-scale planning about pre and post-disaster floods, drought
mitigation, and agricultural development.
T. Mandal
Department of Geography and Applied Geography, University of North Bengal, Darjeeling,
West Bengal, India
A. Sarkar (*) · P. Chouhan
Department of Geography, University of Gour Banga, Malda, West Bengal, India
J. Das
Department of Geography, Rampurhat College, Birbhum, West Bengal, India
A. T. M. S. Rahman
Department of Earth and Environmental Science, Kumamoto University, Chuo-ku, Kumamoto,
Japan
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
M. N. Islam, A. van Amstel (eds.), India: Climate Change Impacts, Mitigation
and Adaptation in Developing Countries, Springer Climate,
https://doi.org/10.1007/978-3-030-67865-4_7
155
Comparison of Classical Mann–Kendal Test
and Graphical Innovative Trend Analysis
for Analyzing Rainfall Changes in India
Tapash Mandal , Apurba Sarkar, Jayanta Das ,
A. T. M. Sakiur Rahman , and Pradip Chouhan
Abstract The analysis of rainfall trends is of the utmost importance for sustainable
management and planning of agriculture and water resources under changing climate. Therefore, this study aims to detect the long-term rainfall trends of 36 meteorological subdivisions of India for the period 1901–2015. The graphical innovative
trend analysis (ITA) technique and the classical statistical Mann–Kendall (MK) or
modified Mann–Kendall (mMK) tests are used to detect historical rainfall changes.
The nonparametric Sen’s slope (Q) estimator is also applied to measure the magnitude of change. The ITA results show about 61.11% of the subdivisions exhibited
decreasing trends in annual rainfall. On the seasonal scale, about 58.33%, 50%,
69.44%, and 88.88% of the subdivisions are experiencing decreasing trends in
pre-monsoon (Mar–May), monsoon (Jun–Sep), post-monsoon (Oct–Nov), and winter (Dec–Feb) seasons, respectively. The results of the Z statistic show a good match
(about 90%) with the graphical ITA method. However, the ITA method is able to
detect subtrends while, MK/mMK shows only the monotonic trend. Such a trend
analysis of rainfall can provide significant information that will be useful to build up
adaptive capacity and community resilience against climate change. This study can
be helpful for regional-scale planning about pre and post-disaster floods, drought
mitigation, and agricultural development.
T. Mandal
Department of Geography and Applied Geography, University of North Bengal, Darjeeling,
West Bengal, India
A. Sarkar (*) · P. Chouhan
Department of Geography, University of Gour Banga, Malda, West Bengal, India
J. Das
Department of Geography, Rampurhat College, Birbhum, West Bengal, India
A. T. M. S. Rahman
Department of Earth and Environmental Science, Kumamoto University, Chuo-ku, Kumamoto,
Japan
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
M. N. Islam, A. van Amstel (eds.), India: Climate Change Impacts, Mitigation
and Adaptation in Developing Countries, Springer Climate,
https://doi.org/10.1007/978-3-030-67865-4_7
155