Exploring the Dynamics of Groundwater Level using Innovative Trend Analysis (ITA) Technique over Three Districts of North-West Region of Bangladesh
Abstract
n northwest Bangladesh, groundwater depletion presents serious obstacles to agricultural sustainability and water security. In order to evaluate groundwater level dynamics (2013–2022) in three drought-prone districts—Rajshahi, Chapainawabganj, and Naogaon—this study used the Innovative Trend Analysis (ITA) technique. Significant spatial heterogeneity is revealed by the results: Chapainawabganj exhibits a statistically significant declining trend in groundwater levels over the study period. In contrast, Naogaon exhibits a strong increasing trend, with most data points falling within the Increasing Triangle, indicating a significant recovery or improvement in groundwater levels. For Rajshahi, the trend appears relatively stable with slight fluctuations, as reflected in the minimal positive slope (0.009) and weak positive cross-correlation (0.15). In 56.67% of monitoring wells, ITA found hidden trends, especially during pre-monsoon periods that connected depletion to decreased rainfall (6.4% decline since 1985) and intensive irrigation using deep tubewell for Boro rice. Implementing localized policies, improving aquifer recharge, and implementing water-efficient irrigation are among the recommendations. In water-stressed areas, this study emphasizes the importance of striking a balance between agricultural demands and aquifer sustainability in groundwater management.
Conclusion
Critical new understanding of regional aquifer sustainability comes from a thorough study of groundwater dynamics in northwest Bangladesh. Key results show notable spatial variability; Naogaon showed a 0.2 m increase that remained statistically significant, while Chapainawabganj district showed groundwater level declines of 0.019 m and Rajshahi showed relatively stable GWL with slight fluctuations of 0.009 m over the 2013–2022 period [23]. The Innovative Trend Analysis (ITA) approach revealed intricate seasonal patterns where 56.67% of tracked wells showed declining water tables compared to 18.33% with increasing levels [23], so effectively capturing non-monotonic trends undetectable by conventional means. These findings complement more general regional studies showing 20-foot groundwater declines in Barind Tract areas since 1988 and aquifer depletion rates in important zones approaching 250 mm/year [2]. While climate drivers show declining rainfall (6.4% reduction since 1985) and rising temperatures (0.8°C rise), the identified trends strongly correlate with anthropogenic factors - irrigation demands for Boro rice farming account for 494 million m¹ annual groundwater extraction in Rajshahi alone, so aggravating recharge deficits [2], [24]. With the low-permeability clay layers (1.5–4.5 m thick) of the Barind Tract restricting vertical recharge despite monsoon precipitation [1], hydrogeological heterogeneity emerges as a major control. Particularly useful was the ability of the ITA to differentiate low/moderate/high value trends in pre-monsoon periods when irrigation demand peaks and recharge is low [23]. This helped to identify critical depletion phases. By capturing both monotonic and hidden trends across Rajshahi, Chapainawabganj, and Naogaon, the research reveals seasonal and spatial variations often overlooked by conventional methods. These insights are vital for shaping groundwater policies, promoting efficient irrigation, and supporting localized solutions like managed aquifer recharge and crop diversification. Moreover, the approach presents a scalable framework for groundwater monitoring in other drought-prone or data-limited areas, contributing to sustainable water resource management under increasing climate and human pressures. To address the challenges revealed by this study, several targeted recommendations are proposed for sustainable groundwater management in the region. Scale acceptance of alternate wetting-drying (AWD) technology, proven to reduce irrigation water use by 30% while maintaining rice yields [24] Establish crop diversification initiatives in important depletion areas (such as Godagari, Tanore) favoring drought-resistant varieties like wheat and maize. Create surface water storage systems along rejuvenated river channels (such as Padma, Mahananda) to offset 42% of groundwater demand during dry seasons [2] Using monsoon floodwaters, build managed aquifer recharge (MAR) systems based on successful models in India's Telangana State (15% recharge enhancement). Hossain et al. (2024) add volumetric groundwater pricing to overused blocks (such as Chapainawabganj Sadar) combined with smart metering technologies [6]. Implement wetland preservation programs to protect 18% of natural sources of recharging threatened by development [23], [24]. Extend real-time groundwater monitoring systems from present 60 wells to more than 200+ IoT-enabled stations. Apply machine learning models for predictive resource management, combining ITA outputs with climate projections. Promote inclusive stakeholder participation in groundwater management planning so that farmers, local authorities, and underprivileged areas are actively engaged. Initiatives for capacity-building should provide local managers with the tools and knowledge required for efficient use of resources [23], [25]. The implications of these findings are significant for both policy and practice in groundwater management. Sustained depletion risks irreversible aquifer compaction (subsidence rates >5mm/year observed in analogy basins) and ecological degradation of 12 protected wetlands in the research area [23], [25]The observed non-monotonic trends imply that climate change could cause more hydrological variability, so aggravating groundwater stress during droughts caused by El Niño [1] Current extraction trends compromise the rice output capacity of northwest Bangladesh 38% of which is Model projections show, without intervention, 22–40% yield declines for Boro rice in critical zones resulting from water quality degradation and increasing pumping costs [2], [24] Socio-economically, 2.1 million smallholder households are vulnerable depending on groundwater. The noted 1.4 m drop in Chapainawabganj directly relates to 17% higher irrigation energy costs, so compromising farm profitability [24]. This work validates ITA's superiority over conventional methods in complex aquifer systems, especially its capacity to identify latent trends in medium groundwater values (ρxy = -0.14 to 0.45) that conventional methods overlook [23]. Under anthropogenic pressure, the technique provides a repeatable framework for examining non-stationary hydrological systems. These results highlight how urgently integrated water governance solutions balancing aquifer sustainability with agricultural output are needed. The shown spatial heterogeneity in groundwater responses (56.67% declining vs 18.33% increasing wells) calls for localized management strategies instead of consistent policy approaches [23]. Future studies should give coupling ITA top priority in order to estimate depletion thresholds and maximize intervention timing by means of machine learning approaches