Statistical Analysis of Groundwater Level Variation in Semi-arid Upper Godavari Basin
Groundwater supports the economy of semi-arid parts of India during the non-monsoon season. However, in the era of climate change and increased water demand, the groundwater supply is at risk. In the current study, the variation in the groundwater levels in the semi-arid upper Godavari basin is examined for pre- and post-monsoon seasons using the Mann-Kendall trend test. The trend in the difference between the groundwater levels during these seasons is also analyzed. Breaks in the groundwater level time series in both seasons are identified using the Pettitt test. The study revealed that, the groundwater levels are mostly increasing in the post-monsoon season. However, more than 60% of wells depict the declining trend of groundwater level in the pre-monsoon season. The gap between the groundwater levels measured during the pre- and post-monsoon seasons is widening throughout the upper Godavari basin. Though the breaks in the pre- and post-monsoon groundwater levels coincide with the major drought year, the negative change in the mean value after the break year cannot be attributed only to climatic variation. Hence, the current study highlights the immediate need for water conservation and water demand management, in the upper Godavari basin.
KeywordsGroundwater level Mann-Kendall trend test Pettitt test Semi-arid upper Godavari basin
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