Modelling groundwater futures under climatic uncertainty for local policy and planning: A case of quantification of groundwater resources at sub-regional level in the Ganges basin

Study region: Nalanda district, Bihar, India, a sub-tropical region, and part of middle Ganga River basin. Study focus: Assessing the impacts of climate change on aquifers' seasonal replenishment is thus crucial for planning for future local food and water security. This study looks at how futu...

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Main Authors: Syed Adil Mizan, Alok Sikka, Shreya Chakraborty, Alison Laing, Anton Urfels, Timothy J. Krupnik
Format: Article
Language:English
Published: Elsevier 2025-06-01
Series:Journal of Hydrology: Regional Studies
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Online Access:http://www.sciencedirect.com/science/article/pii/S2214581825001399
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author Syed Adil Mizan
Alok Sikka
Shreya Chakraborty
Alison Laing
Anton Urfels
Timothy J. Krupnik
author_facet Syed Adil Mizan
Alok Sikka
Shreya Chakraborty
Alison Laing
Anton Urfels
Timothy J. Krupnik
author_sort Syed Adil Mizan
collection DOAJ
description Study region: Nalanda district, Bihar, India, a sub-tropical region, and part of middle Ganga River basin. Study focus: Assessing the impacts of climate change on aquifers' seasonal replenishment is thus crucial for planning for future local food and water security. This study looks at how future groundwater levels will be affected by climate change in relation to important functioning thresholds that are typical for aquifers that replenish periodically. New hydrological insights for the region: The result shows the projected groundwater levels from 2018 to 2060 using the CMIP6 global climate model, using rainfall data from three GCMs selected based on their different projected scenarios of levels of high intensity rainfall. Given the key role of low intensity rainfall in groundwater recharge, we find that incorporating rainfall intensity in groundwater models can be crucial for more robust projections. Our findings also show that higher total rainfall does not necessarily equate to higher groundwater recharge or lesser groundwater declines. Instead, the least groundwater declines were found in projections, where relatively higher total rainfall was also associated with lower high intensity rainfall periods, highlighting the need for combining and comparing varied SSPs and climate models for accurate future trends. At the sub-regional level, we find that climate change could lead to maximum groundwater loss of ∼ 0.8 km3 in 42 years in Nalanda district. Current trend analysis (2000–2018) already shows a negative annual groundwater balance. Even assuming no changes to current groundwater extraction rates, climate change will result in decreased groundwater levels and storage. The projection trends also reveal distinct short-term, medium-term, and long-term shifts which offer different policy windows for managing and governing the groundwater resources.
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spelling doaj-art-43f122ec5ed443f8a5cd46be41e739262025-08-20T03:13:07ZengElsevierJournal of Hydrology: Regional Studies2214-58182025-06-015910231510.1016/j.ejrh.2025.102315Modelling groundwater futures under climatic uncertainty for local policy and planning: A case of quantification of groundwater resources at sub-regional level in the Ganges basinSyed Adil Mizan0Alok Sikka1Shreya Chakraborty2Alison Laing3Anton Urfels4Timothy J. Krupnik5International Water Management Institute (IWMI), New Delhi, India; Corresponding author.International Water Management Institute (IWMI), New Delhi, IndiaInternational Water Management Institute (IWMI), Dhaka, BangladeshInternational Maize and Wheat Improvement Center (CIMMYT), New Delhi, IndiaInternational Rice Research Institute (IRRI), Los Banos, Laguna, PhilippinesInternational Maize and Wheat Improvement Center (CIMMYT), Dhaka, BangladeshStudy region: Nalanda district, Bihar, India, a sub-tropical region, and part of middle Ganga River basin. Study focus: Assessing the impacts of climate change on aquifers' seasonal replenishment is thus crucial for planning for future local food and water security. This study looks at how future groundwater levels will be affected by climate change in relation to important functioning thresholds that are typical for aquifers that replenish periodically. New hydrological insights for the region: The result shows the projected groundwater levels from 2018 to 2060 using the CMIP6 global climate model, using rainfall data from three GCMs selected based on their different projected scenarios of levels of high intensity rainfall. Given the key role of low intensity rainfall in groundwater recharge, we find that incorporating rainfall intensity in groundwater models can be crucial for more robust projections. Our findings also show that higher total rainfall does not necessarily equate to higher groundwater recharge or lesser groundwater declines. Instead, the least groundwater declines were found in projections, where relatively higher total rainfall was also associated with lower high intensity rainfall periods, highlighting the need for combining and comparing varied SSPs and climate models for accurate future trends. At the sub-regional level, we find that climate change could lead to maximum groundwater loss of ∼ 0.8 km3 in 42 years in Nalanda district. Current trend analysis (2000–2018) already shows a negative annual groundwater balance. Even assuming no changes to current groundwater extraction rates, climate change will result in decreased groundwater levels and storage. The projection trends also reveal distinct short-term, medium-term, and long-term shifts which offer different policy windows for managing and governing the groundwater resources.http://www.sciencedirect.com/science/article/pii/S2214581825001399Groundwater modellingMODFLOWClimate scenarioRainfall intensityGangetic basinIndia
spellingShingle Syed Adil Mizan
Alok Sikka
Shreya Chakraborty
Alison Laing
Anton Urfels
Timothy J. Krupnik
Modelling groundwater futures under climatic uncertainty for local policy and planning: A case of quantification of groundwater resources at sub-regional level in the Ganges basin
Journal of Hydrology: Regional Studies
Groundwater modelling
MODFLOW
Climate scenario
Rainfall intensity
Gangetic basin
India
title Modelling groundwater futures under climatic uncertainty for local policy and planning: A case of quantification of groundwater resources at sub-regional level in the Ganges basin
title_full Modelling groundwater futures under climatic uncertainty for local policy and planning: A case of quantification of groundwater resources at sub-regional level in the Ganges basin
title_fullStr Modelling groundwater futures under climatic uncertainty for local policy and planning: A case of quantification of groundwater resources at sub-regional level in the Ganges basin
title_full_unstemmed Modelling groundwater futures under climatic uncertainty for local policy and planning: A case of quantification of groundwater resources at sub-regional level in the Ganges basin
title_short Modelling groundwater futures under climatic uncertainty for local policy and planning: A case of quantification of groundwater resources at sub-regional level in the Ganges basin
title_sort modelling groundwater futures under climatic uncertainty for local policy and planning a case of quantification of groundwater resources at sub regional level in the ganges basin
topic Groundwater modelling
MODFLOW
Climate scenario
Rainfall intensity
Gangetic basin
India
url http://www.sciencedirect.com/science/article/pii/S2214581825001399
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