Quality controlled, reliable groundwater level data with corresponding specific yield over India

Abstract

Groundwater is a vital resource for domestic, agricultural, and industrial use, with its demand growing due to population growth and climate change. Several studies have identified groundwater depleting in India at unsustainable rate over North-west part, but a contrasting trend is observed in the southern India. To better study groundwater dynamics quality-controlled and reliable well data is essential, which is missing. Here we process seasonal groundwater levels from 32,299 wells across India to obtain reliable well data and provide respective specific yields. Initially, wells with no data and negative values are removed. Later three-sigma method is imposed on each well to eliminate outliers. Finally, wells with at least two values per year, with no value repeating more than twice consecutively, are retained, resulting in 2,759 reliable wells. We used vectorization-based method to classify aquifer types and estimated specific yields based on hydrogeological map. We also provide open access to data and scripts so that researchers can study groundwater variations, compare GRACE and model-based groundwater estimates against in-situ well data.

Fig. 1

Hydrogeological map of India (Source: Bhanja et al.).

Fig. 2

Well type distribution over India.

Fig. 3

GWL variations for unfiltered wells.

Fig. 4

Filtered wells with GWL variations at four random well locations.

Fig. 5

Seasonal GWL variations for filtered wells.

Fig. 6

Map of Mann-Kendall trend test (significant at p ≤ 0.05) of filtered GWLs for January, May, August and November months over India for the period between 2000 to 2022.

Fig. 7

Specific yield map for filtered well locations over India.

Fig. 8

Spatial plot of r and RMSE between GWSC_insitu and GWSC_GRACE over India. Boxes in the figure shows mascon boundaries and numbers indicate mascon number.