Skip to main content

Advertisement

Log in

Assessing the state of homogeneity, variability and trends in the rainfall time series from 1969 to 2017 and its significance for groundwater in north-east India

  • Original Paper
  • Published:
Natural Hazards Aims and scope Submit manuscript

Abstract

Rainfall is the key climatic variable, on which water availability, food security and livelihood depend, especially in an agrarian society like the northeast region of India. It is an ecologically sensitive zone, harbouring world’s three biodiversity hotspots and the world’s highest rainfall zone. Therefore, the assessment of variability and trend in the rainfall regime in this region is imperative. The present study focuses on testing the homogeneity status and prevalent trends in the long-term rainfall data at five different locations in North-East India, namely Cherrapunji, Dibrugarh, Guwahati, Kailashahar and Tulihal. The impact of rainfall variability on groundwater level was further investigated. The estimation of precipitation concentration index and standard precipitation anomaly was also carried out to investigate the intra-annual variability and drought conditions in this region. The results indicate the homogeneous nature of rainfall time series at 99% significance level at all the sites with low coefficient of variance (CV, %) at Dibrugarh in monsoon and annual rainfall series. The precipitation concentration index values show high intra-annual variability in the rainfall data. Decadal and annual standard precipitation anomaly values indicate the presence of extreme and severe drought conditions in the last two decades. The trend analysis results display the presence of significant negative trends in monsoonal and annual rainfall at Dibrugarh. During pre-monsoon season, all the sites exhibiting positive drift with only Guwahati and Tulihal have significant trends (at 90% significance level). Monthly rainfall trend analysis results revealed strong and significant (95%) negative trends during peak monsoon months of July at Dibrugarh and Guwahati and with 85% significance level at Cherrapunji (which was the world’s highest rainfall zone in recent past). The impact assessment results indicate a direct association between rainfall and groundwater at lag2, i.e., the impact of any change in the rainfall amount on groundwater in a given area may be evident after two seasons. The results revealed an enhancement of 1.0 ± 0.1, 1.1 ± 0.2, 0.9 ± 0.2 mm in the groundwater level for each mm increase in the rainfall at DBR, GHY and KSH, respectively. At CHR, the relation was evident only after 10 seasons because of excessive rainfall and runoff. The results had significant bearing for the policy makers and farming community in the region for better planning of crop cultivation in order to adapt to the changing climate in this region.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8

Similar content being viewed by others

Data availability

The data used in this study were procured from India Meteorological Department (IMD), Pune, and Water Resources Information System (https://indiawris.gov.in/wris/#/groundWater). These are the public repositories maintained by the government of India.

References

Download references

Acknowledgements

The authors would like to acknowledge the India Meteorological Department (IMD), Pune for providing the necessary data for this study. We also like to thank Tezpur University, Assam, India, for providing institutional support and fellowship during this study.

Funding

Two of the authors have received institutional support and fellowship from Tezpur University, Assam, India, during the course of this study.

Author information

Authors and Affiliations

Authors

Contributions

All authors contributed to the study's conception and design. Data collection and analyses were performed by Ms. Parashmoni Borah and Dr. Suhasini Hazarika. The first draft of the manuscript was prepared by Ms. Parashmoni Borah. Review, editing and supervision were done by Dr. Amit Prakash. All authors subsequently commented on previous versions of the manuscript. All authors have read and approved the final manuscript.

Corresponding author

Correspondence to Amit Prakash.

Ethics declarations

Conflict of interest

The authors have no conflicts of interest to declare that are relevant to the content of this article.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Below is the link to the electronic supplementary material.

Supplementary figure 1: Extracted seasonal components of groundwater and rainfall time series at CHR (PNG 3787 kb)

Supplementary figure 2: Extracted seasonal components of groundwater and rainfall time series at GHY (PNG 3911 kb)

Supplementary figure 3: Extracted seasonal components of groundwater and rainfall time series at KSH (PNG 3881 kb)

11069_2021_5068_MOESM4_ESM.jpg

Supplementary figure 4: Daily rainfall time series at CHR showing available and unavailable data (1969-2017); -99 is assigned to unavailable data values (JPG 554 kb)

11069_2021_5068_MOESM5_ESM.jpg

Supplementary figure 5: Daily rainfall time series at DBR showing available and unavailable data (1969-2017); -99 is assigned to unavailable data values (JPG 584 kb)

11069_2021_5068_MOESM6_ESM.jpg

Supplementary figure 6: Daily rainfall time series at GHY showing available and unavailable data (1969-2017); -99 is assigned to unavailable data values (JPG 597 kb)

11069_2021_5068_MOESM7_ESM.jpg

Supplementary figure 7: Daily rainfall time series at KSH showing available and unavailable data (1969-2017); -99 is assigned to unavailable data values (JPG 478 kb)

11069_2021_5068_MOESM8_ESM.jpg

Supplementary figure 8: Daily rainfall time series at TUL showing available and unavailable data (1969-2017); -99 is assigned to unavailable data values (JPG 466 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Borah, P., Hazarika, S. & Prakash, A. Assessing the state of homogeneity, variability and trends in the rainfall time series from 1969 to 2017 and its significance for groundwater in north-east India. Nat Hazards 111, 585–617 (2022). https://doi.org/10.1007/s11069-021-05068-y

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11069-021-05068-y

Keywords

Navigation