Assessment of groundwater level trends and decline rates in Phu Loi ward, Can Tho city for the period 2000-2024

Abstract

This study aims to assess groundwater-level variations across all seven aquifers in Phu Loi ward, Can Tho city, based on a series of monitoring data from 2000 to 2024. The non-parametric Mann-Kendall test and Sen’s slope estimator were applied to determine the trend and the decline rate of each aquifer. The results showed that except for the qh aquifer, which exhibited no significant trend, the remaining six aquifers showed a downward trend, with decline rates ranging from 0.38 to 0.6 m/year (p<0.001). During the study period, the qp2-3 and qp1 aquifers recorded the earliest rapid declines in groundwater level. The n₁³ aquifer showed an increasingly rapid rate of groundwater-level decline. The results provide a scientific basis for evaluating groundwater-resource conditions and identifying aquifers at risk of severe depletion.