The interaction between groundwater and urban environments is a growing concern for many rapidly urbanizing cities around the world, affecting both recharge and flow, since impervious surfaces reduce infiltration by increasing runoff, whereas over-abstraction leads to groundwater depletion and land subsidence. Additionally, industrial pollution and wastewater disposal contribute to contamination, impacting groundwater quality. The effective governance of groundwater within such urban locales necessitates a profound understanding of the hydrogeological context, coupled with robust tools for projecting fluctuations in groundwater levels and changes in water quality over time. We quantified urban groundwater recharge in Guwahati city, Assam, India, using the rainfall infiltration method and a numerical approach. Precipitation, evapotranspiration, runoff, and recharge from surface water bodies were considered the components of natural recharge, while leakages from water supply, domestic wastewater, and industrial wastewater were considered the components of urban recharge. The cumulative total of natural and urban components determines the actual groundwater recharge. The estimated natural groundwater recharge is 11.1 MCM/yr, whereas the urban groundwater recharge is 44.74 MCM/yr. Leakages from urban infrastructure resulted in significantly higher groundwater recharge than from natural inputs. Steady declines in groundwater recharge were observed from estimates taken at various time points over the past two decades, suggesting the need for prompt action to improve groundwater sustainability.

Remote sensing (RS) and geographical information system (GIS) have been extensively used for their ability to provide better scope for decision making in terms of monitoring and managing various natural resources: water, land, forest, agriculture, natural hazards, climate change, etc. In this chapter, the authors precisely discuss in detail about the various applications of remote sensing and GIS in numerous fields such as monitoring water quality, crop modelling, monitoring wildlife habitat and forest management, application in agriculture and soil science, water resource, as well as natural disaster management. This chapter will also incorporate several case studies where GIS and remote sensing were used as a powerful tool to delineate and monitor environmental changes and take the necessary steps to manage the same. This chapter will thus focus on the importance of remote sensing and GIS and its impact in sound decision-making, which in turn will secure the sustainable utilization of natural resources to reach the requirements of present as well as future generations.

Groundwater is a natural renewable resource vital for any life on Earth. Groundwater management is of emerging concern for the conservation and protection of this resource. With the advent of innovative technologies, managing such resources become easier to some extent. This chapter illustrates some of the advanced technologies, their contribution, challenges and future prospects for the conservation and sustainable management of groundwater. AI methods have become widespread in decision-making in recent years and are accepted globally due to their cost-effectiveness, time-saving, and efficient nature. AI-driven models provide precise analytical modelling, real-time monitoring, and data integration in groundwater management. Innovative AI models can detect the vulnerable regions that are prone to pollution and depletion of groundwater level and can draw the attention of scientists, local people and policymakers for prompt intervention.

Groundwater quality assessment is essential for ensuring safe drinking water, given that groundwater serves as a primary water source. The quality of groundwater is deteriorating due to population growth and urbanization. This study evaluates groundwater quality in Guwahati City, Assam, India, by analyzing basic hydrochemical parameters and trace element concentrations. The findings indicate that fluoride (F-) originates mainly from geogenic processes. Elevated arsenic (As) concentrations in one well are likely linked to local anthropogenic sources, while widespread manganese (Mn) and lead (Pb) contamination across the city may result from industrial wastewater and landfill leachate. The dominant hydrochemical facies was Ca-Mg-HCO3 during the dry, pre-monsoon, and monsoon seasons, shifting to Na-K-HCO3 in the post-monsoon season, potentially influenced by ion-exchange processes. Cluster analysis identified poor water quality in the northeastern part of the city, and principal component analysis demonstrated that both geological and anthropogenic factors affect water quality. Human health risk assessment further revealed that children are more susceptible to non-carcinogenic health risks, whereas adults are more vulnerable to carcinogenic health risks. These findings highlight the need for targeted groundwater monitoring and pollution control to protect public health, particularly among vulnerable populations.