An Overview of Groundwater Monitoring through Point-to Satellite-Based Techniques

Abstract

Groundwater supplies approximately half of the total global domestic water demand. It also complements the seasonal and annual variabilities of surface water. Monitoring of groundwater fluctuations is mandatory to envisage the composition of terrestrial water storage. This research provides an overview of traditional techniques and detailed discussion on the modern tools and methods to monitor groundwater fluctuations along with advanced applications. The groundwater monitoring can broadly be classified into three groups. The first one is characterized by the point measurement to measure the groundwater levels using classical instruments and electronic and physical investigation techniques. The second category involves the extensive use of satellite data to ensure robust and cost-effective real-time monitoring to assess the groundwater storage variations. Many satellite data are in use to find groundwater indirectly. However, GRACE satellite data supported with other satellite products, computational tools, GIS techniques, and hydro-climate models have proven the most effective for groundwater resources management. The third category is groundwater numerical modeling, which is a very useful tool to evaluate and project groundwater resources in future. Groundwater numerical modeling also depends upon the point-based groundwater monitoring, so more research to improve point-based detection methods using latest technologies is required, as these still play the baseline role. GRACE and numerical groundwater modeling are suggested to be used conjunctively to assess the groundwater resources more efficiently.

Shortfalls and Challenges in Groundwater Regime Monitoring

“…The nonparametric Mann-Kendall trend analysis and standardized precipitation index (SPI) have been applied to detect the trend of groundwater level and rainfall variability, respectively. Masood et al concluded -that GRACE and numerical groundwater modelling are suggested to be used conjunctively to assess the groundwater resources more efficiently [31]. Sreekanth et al used remote sensing data, field observations, and numerical groundwater modelling to investigate long-term groundwater storage losses in the regional aquifer of the Ganga Basin in India [32].…”

“…suggested -'These methods and instruments include steel tape, electronic measuring tapes, pressure transducers, sounding devices, test drilling, geophysical investigation techniques, piezometers, digital water level recorders, exploratory well drilling, and isotopes, etc.' [31].…”

Reconstructing Groundwater Storage Changes in the North China Plain Using a Numerical Model and GRACE Data

“…As the main source of fresh water in many regions of the world, groundwater supplies approximately 50% of the demand for drinking water, 40% of the demand for self-sufficient industries, and 20% of the demand for irrigation water [1]. Furthermore, groundwater can not only store a large amount of precipitation but can also effectively maintain the flow of rivers in dry periods [2]. However, globally, the increases in extreme climate and the frequency of human activities such as groundwater overexploitation have led to aquifer depletion [3].…”

“…Point-based measurement, satellite-based monitoring, and regional groundwater estimation through numerical modeling are the most original methods and tools for detecting groundwater level fluctuations [2]. Point-based measurements take time and manpower and require a great number of monitoring points to ensure their representativeness.…”

Groundwater mapping and locally engaged water governance in a small island terrain: Case study of Karainagar island, Northern Sri Lanka

“…Aquifer monitoring with community engagement is a key element to ensure sustainable use of the groundwater resources in an island terrain (Masood et al, 2022). Aquifer monitoring implies the process of measuring, monitoring, and analyzing the physical, chemical, and biological characteristics of an aquifer.…”