Country:
India
Location:
Gujarat
Time period :
2001 - 2010
Implementing Institution/ Organization:
Department of Geography, Haringhata Mahavidyalaya, University of Kalyani, Nadia District, West Bengal, India
Goals
To assess the groundwater trends in pre- and post monsoon scenario to observe the response to climate change-induced rainfall patterns before and after the monsoon.
Objectives
Assess aquifer recharge by analyzing pre- to post-monsoon groundwater storage change in various districts of Gujarat from 1981 to 2010
• Assess the impact of meteorological drought on the groundwater regime
• Examine the spatiotemporal variations in groundwater quality in the state
Methodology (approach)
1- Data collection;
- Rainfall data
• The CGIAR-CSI CRU TS 2.1 Climate Database (1981–2010) • India Meteorological Department (IMD), Pune (1981–2010)
- Groundwater Data
• District-wise data of average groundwater level and total dissolved salts (TDS) from Gujarat Water Resources Development Corp. Ltd (GWRDC) and Central Ground Water Board, Government of India (1981–2010).
• Data of groundwater levels were collected twice a year, i.e. pre-monsoon (May) and post-monsoon (October) periods, and are available with 5-year intervals (1981–2010).
2- calculating the deviation of mean groundwater level in observation wells in respect of previous year data. The previous year is taken as the base year for calculation.
3- the change in rainfall is calculated by measuring the rainfall deviation of the present year in respect to last year data of the particular station.
4- The data for TDS to measure groundwater quality was also analysed on a time scale from 1981 to 2010.
For statistical analysis, SPSS and EasyFit professional software have been used.
Study Results
1.Correlation Between Rainfall and Groundwater Levels:
- There is a strong positive correlation between rainfall extremes and the decline in groundwater levels. This indicates that reduced rainfall leads to significant drops in groundwater levels.
- The correlation coefficient (R) is highest for Kutch (R = 0.96), followed by Bhavnagar and Junagadh (R = 0.95), Porbandar (R = 0.93), and Surat (R = 0.91). This shows that these districts are highly dependent on rainfall for groundwater recharge and are thus more vulnerable to drought and water scarcity.
- In urban areas like Ahmedabad, the correlation is lower due to less scope for infiltration and recharge because of the land cover.
2. Temporal Changes in Groundwater:
- The change in groundwater levels due to changes in rainfall has increased significantly since 2005, with a rise of over 50% compared to previous years (1990, 1995, and 2000).
- Northern Gujarat has seen a steady decline in the water table, dropping by 70 meters below ground level over the last 30 years. In many areas, groundwater levels have reached depths of 200 meters below ground level, posing a severe risk of aquifer salinization.
3. Impact of Drought on Groundwater Quality:
- Drought conditions lead to a gross loss of surface and groundwater, particularly in drought-prone and desert areas where evapotranspiration exceeds precipitation. This exacerbates water scarcity and increases groundwater pollution.
- The quality of groundwater during droughts is affected by an increase in Total Dissolved Solids (TDS), making it unsuitable for drinking. TDS levels beyond 500 ppm can cause gastrointestinal irritation, and water quality compromise levels up to 2000 ppm are considered tolerable.
4. Population Growth and Groundwater Depletion:
- There is a direct adverse impact of rising population on groundwater resources. From 2001 to 2011, despite a smaller increase in population compared to previous decades, the decrease in groundwater levels was more severe. This is attributed to intensified groundwater pumping using deeper wells and more powerful pumps.
In summary, the findings emphasize the critical interplay between rainfall, population growth, and groundwater levels, highlighting the need for sustainable management practices to address the severe water crisis in Gujarat.
lessons learned
1. Climate Change Impact: Recurrent droughts and altered rainfall patterns due to climate change significantly deplete groundwater levels and deteriorate water quality.
2. Overextraction: Excessive demand for groundwater, especially in northern Gujarat, has led to severe depletion beyond the annual recharge capacity, exacerbated by intensive pumping and deeper well drilling.
3. Population and Urbanization: The increasing population and rapid urbanization have intensified the pressure on groundwater resources, with more severe impacts observed in the 2001-2011 decade.
4. Water Quality Deterioration: Overextraction and droughts have compromised groundwater quality, raising Total Dissolved Solids (TDS) levels and making the water unsuitable for drinking.
5. Policy and Management: The study advocates for incentive-based water conservation, zero wastage, water treatment, and reuse. Effective policy management integrating sustainable development, climate change adaptation, and water market regulation is essential.
6. Data and Research Needs: Integrating GIS with ground-level data can improve drought preparedness and water management. Continuous research and real-time data collection are crucial for understanding and mitigating groundwater depletion impacts.
These lessons emphasize the necessity for sustainable groundwater management strategies in response to climate change and growing human demands.
Conclusions
The study has revealed that water tables in Northern Gujarat are falling steadily and have declined by 70% BGL over the last 30 years. A significant increase in TDS during droughts has made groundwater unsuitable for drinking. Rising pressure of population on an already dwindling water table will eventually multiply the impact from extreme weather events like heatwaves and meteorological drought which will affect the vegetation and ultimately lead to hydrological drought.
Recommendations
The future studies on this can explore how the agricultural sector is also under pressure with the growing demand for water coupled with population explosion. Integrating GIS data with ground-level data can be a way forward in drought preparedness and managing water scarcity.
References (resources) Found is the case study
Nairwita Bandyopadhyay, Department of Geography, Haringhata Mahavidyalaya, University of Kalyani, Nadia District, West Bengal, India January 2023 Ecological Footprints of Climate Change, Springer Climate, https://doi.org/10.1007/978-3-031-15501-7_8
