Urban aquifers are facing increasing pressure from climate change, land-use change and abstraction, altering groundwater levels and threatening sustainable water consumption availability and utilisation. Therefore, this study projects future changes of climate, land use and abstraction, while analyzing the vulnerability of groundwater levels to such changes and formulating adaptation options to reduce the vulnerability of groundwater resources in Lahore. The objectives are achieved using the modelling and qualitative approaches.
The results show an increase in mean and extreme climate under climate change scenarios. The warm and wet extremes are projected to increase (significant at P=5%) under medium (RCP4.5) and high end (RCP8.5) scenarios. Annual changes in all climate indices will be significant except for the warm spell duration index. Land use projections show increased built-up in land use type from 965 to 3716 km2 and 3329 km2 under R1S1 and R2S2 scenarios (significant at P=5%). The built-up land use will dominate agriculture land use in the future. The future population will increase (significant at P=5%) from 6.4 M to 24.6, 27.5 and 28.7 M under SSP1, SSP2 and SSP3 scenarios, respectively.
The vulnerability of urban areas will increase in the future due to the high negative impact and low adaptive capacity under combined scenarios. Agriculture and surrounding areas will remain less vulnerable in the future under combined scenarios due to the low negative impact and medium adaptive capacity. The results of this study may help groundwater experts and related institutions to understand the potential situation of groundwater resources in Lahore and formulate adaptation strategies to counteract diminishing groundwater resources in the area.