Along with rapid population growth in Vietnam, there is an increasing dependence on groundwater for various activities. An Giang province is known to be one of the agricultural intensification areas of The Vietnamese Mekong Delta (VMD). This study aimed to evaluate the spatiotemporal variation of groundwater quality for a period of ten years from 2009 to 2018 in An Giang. The weighted groundwater quality index (GWQI) was developed based on the fuzzy analytic hierarchy process (Fuzzy-AHP) for assigning weighted parameters. The results show that that shallow wells in the Northeast and Southeast regions of An Giang were mostly categorized under “bad water” quality with high arsenic (As) concentration over the years partly due to huge amounts of sediment deposition in monsoon season. Overall, the reason for the poor groundwater quality in An Giang was the combined effect of both natural and human activities. On the other hand, we detected high values of GWQI links with high As concentration in areas where people extract more groundwater for irrigation. Temporal variation of GWQI suggested that groundwater quality at eight wells has improved from 2009 to 2018 in the wet season as compared to the dry season. The reason behind the improvement of groundwater quality during wet season was the decrease in river discharge, which causes less deposition of suspended solids near the flood plains. Moreover, the filling of unused wells can reduce the movement of pollutants from unused wells to groundwater aquifers. Although there was not sufficient evidence to show the relationship between As and sediment concentration, the temporal reduction trend in river discharge and suspended solids was detected in An Giang. The understanding of groundwater quality can help policymakers protect and manage limited water resources in the long-term.

The Vietnamese Mekong Delta (VMD) is one of the largest rice-growing areas in Vietnam, and exports a huge amount of rice products to destinations around the world. Multi-dike protection systems have been built to prevent flooding, and have supported agricultural intensification since the early 1990s. Semi-dike and full-dike systems have been used to grow double and triple rice, respectively. Only a small number of studies have been conducted to evaluate the water quality in the VMD. This study aimed to analyze the spatiotemporal variation of water quality inside the dike-protected area. Surface water samples were collected in the dry and wet seasons at 35 locations. We used multivariate statistical analyses to examine various water quality parameters. The mean concentrations of COD, NH₄⁺, NO₃⁻, PO₄³⁻, EC, and turbidity were significantly higher in water samples inside the full-dike system than in water samples from outside the full-dike systems and inside the semi-dike systems in both seasons. High concentrations of PO₄³⁻ were detected in most of the primary canals along which residential, tourist areas and local markets were settled. However, NO₃⁻ was mainly found to be higher in secondary canals, where chemical fertilizers were used for rice intensification inside the dike system. Water control infrastructures are useful for preventing flood hazards. However, this has an adverse effect on maintaining water quality in the study area.

The COVID-19 pandemic has changed how we define “home”, which is recast as the new coffee shop, restaurant, entertainment center, and office during the pandemic. The shift toward working from home led to substantial changes in how consumers behave, affecting the consumption of resources in some cases for years to come. Using data from six water utilities in various states in the U.S., we investigated how water consumption has changed attributable to the implementation of stay-at-home (SAH) orders. The results indicated an overall increase of between 3.08% and 13.65% in daily water consumption during the SAH orders compared to the same period in 2018 and 2019, with the gaps closing as lockdown restrictions eased. The findings also revealed that the changes in water consumption across sectors and user groups were heterogeneous. Specifically, the results showed that total daily residential water demand during SAH orders in 2020 increased significantly, between 11.80% and 13.65%, relative to the same period in 2018 and 2019, but the changes in water consumption for non-residential properties headed in opposite directions with reductions between −22.53% and −45.08%. In addition, we found that the low-income groups did not change their water consumption even with the lockdown.