Spatial variation of groundwater response to multiple drivers in a depleting alluvial aquifer system, northwestern India

Abstract

Unsustainable exploitation of groundwater in northwestern India has led to extreme but spatially variable depletion of the alluvial aquifer system in the region. Mitigation and management of groundwater resources require an understanding of the drivers behind the pattern and magnitude of groundwater depletion, but a regional perspective on these drivers has been lacking. The objectives of this study are to (1) understand the extent to which the observed pattern of groundwater level change can be explained by the drivers of precipitation, potential evapotranspiration, abstraction, and canal irrigation, and (2) understand how the impacts of these drivers may vary depending on the underlying geological heterogeneity of the system. We used a transfer function-noise (TFN) time series approach to quantify the effect of the various driver components in the period 1974–2010, based on predefined impulse response functions ( θ). The dynamic response to abstraction, summarized by the zeroth moment of the response M0, is spatially variable but is generally large across the proximal and middle parts of the study area, particularly where abstraction is high but alluvial aquifer bodies are less abundant. In contrast, the precipitation response is rapid and fairly uniform across the study area. At larger distances from the Himalayan front, observed groundwater level rise can be explained predominantly by canal irrigation. We conclude that the geological heterogeneity of the aquifer system, which is imposed by the geomorphic setting, affects the response of the aquifer system to the imposed drivers. This heterogeneity thus provides a useful framework that can guide mitigation efforts; for example, efforts to decrease abstraction rates should be focused on areas with thinner and less abundant aquifer bodies.

Clustering Groundwater Level Time Series of the Exploited Almonte-Marismas Aquifer in Southwest Spain

“…On a global scale, GWL time series clustering can contribute to the identification and separation of spatiotemporal processes associated with both climate and human disturbances. This separation is often tackled through complex transfer function-noise models [50,51]. Similar aquifer exploitation regimes in different countries or regions could then be clustered together and provide the basis to build time series classification models based on labeled time series resulting from the clustering analysis.…”

Characterising groundwater-surface water connectivity in the lower Gandak catchment, a barrage regulated biodiversity hotspot in the mid-Gangetic basin

“…It is likely that this, combined with adequate recharge from canal and river water, is hydraulically restricting the downward movement of shallow recharge to greater depths within the Pleistocene aquifer, and maintaining groundwater levels. This contrasts with observations in many other parts of the IGB (Mukherjee et al 2015;Lapworth et al, 2015;MacDonald et al, 2016, Bhanja et al 2017van Dijk et al, 2019). In addition, the availability of canal flows for irrigation for much of the year in the upper and mid Gandak catchment zones may continue to reduce the need for shallow groundwater abstraction for irrigation in these zones.…”

“…These studies have tended to focus on areas of the IGB that have experienced the largest depletion in groundwater levels (e.g. Lapworth et al, 2015;Joshi et al, 2018;van Dijk et al, 2019). However, there are many parts of the basin where long-term groundwater levels are shown to be stable over the last few decades (MacDonald et al, 2016), as a result of limited groundwater exploitation in relation to the role of surface water sources in maintaining groundwater levels.…”

Groundwater Variability Across India, Under Contrasting Human and Natural Conditions

“…Comparing the two is complicated by the different hydrogeological conditions, spatiotemporal patterns of depletion, and human interventions . Chronologically, north India's groundwater irrigation began earlier; it started in the mid-1960s at a large-scale particularly in the northwestern states of Punjab, Haryana, and Rajasthan through the massive crop intensification program, known as the Green Revolution, which triggered land-use changes and unsustainable groundwater usage (Joshi et al, 2021;Panda et al, 2021;Rodell et al, 2009;Tiwari et al, 2009;van Dijk et al, 2020). Still, to evaluate our hypothesis, we compared the most vulnerable representative states, Punjab (north) and AP (south).…”