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.

In this study, hydraulic design of the aerators of steep slope orifice spillways (26°–32°) was evaluated using physical and numerical modeling techniques. The Bunji Dam spillway, which is proposed to be constructed on the Indus River in Pakistan, was selected for physical and numerical modeling of the aerators. Extensive experimentation was carried out on a physical model of the Bunji Dam spillway by changing the air vent size and ramp angle of the aerator. Three air vent sizes and five ramp angles were constructed to assess the hydraulic performance of the aerator. The numerical model was formulated using Computational Fluid Dynamics (CFD)—FLOW 3D. The air vent size showed a significant impact on the dimensionless performance indicators of the aerators. Empirical equations were developed based on the outputs of physical and numerical models of the aerator. It is believed that the proposed equations will be useful for the estimation of nondimensional cavity length and air entrainment coefficient of the orifice spillway aerators having a short horizontal stretch leading to a convex curvature with slope varied from 26° to 32°.

Trash racks are usually composed of an array of bars installed in a hydropower scheme to safeguard the turbines by collecting water-borne detritus. However, current design approaches for the design of trash racks focus on structural criteria. A little attention renders the proper evaluation of hydraulic criteria, which causes a significant hydraulic head loss in low head hydropower schemes with an integral intake. This study investigates the head loss through trash racks by employing computational fluid dynamics (CFD) for several design combinations. A three-dimensional model of trash racks using fractional area/volume obstacle representation (FAVOR) method in FLOW-3D is set up to define the effects of the meshing on the geometry and several simulations are carried out considering various approach velocities and different bar spacings, inclination angles, and blockage ratios. The results indicate that head loss increases with an increase in approach velocity, the inclination angle of the rack with channel bed, and blockage ratio. It is noticed that a clear spacing between vertical bars greater than or equal to 0.075 m has a minimum head loss before it becomes significantly high for lower spacing. In addition, the head loss coefficient increases for screen angles greater than 60°, which can be considered as an optimal parameter for design purpose.

Portable hydropower turbines are turbines with a scale below 5 kW and which can be carried from one place to another easily by hand due to their light weight. This study was carried out to evaluate the potential of Archimedes Screw Turbine (AST) as an improved portable hydro-power turbine (PHPT) to address shortcomings in available portable turbines. The design of Archimedes screw hydro-power turbine is mainly concerned with screw geometry, which is determined by a variety of internal and external characteristics, including its length, external and internal diameter, Pitch of blades, and Number of the blades, which were 80 cm, 18 cm, 9.53 cm, 18 cm and two number of blades respectively. The turbine was manufactured from stainless steel material according to design parameters and installed in the laboratory. Experimental testing was performed at different discharges (Q) of 0.3, 0.4, 0.5, 0.6, and 0.7 ft³/s and at the angle of inclination of 22, 30, 45, and 55° of screw shaft to measure power outputs and overall efficiencies. The maximum overall efficiency obtained was 70% at a flow rate of 0.5 ft³/s and at an angle of inclination of 30°. The power output at maximum overall efficiency was 42 watts and hydraulic efficiency was 75.5%. At the flow rate of 0.3 ft³/s and an angle of inclination of 55°, the turbine produced a minimum power output of 22.8 watts and an overall efficiency of 39.4%.Experimentation revealed that the flow rate (Q) and inclination of the turbine shaft affect the turbine Power output (P_o) and overall efficiency (η_o). This study helps to manufacture small AST on a large scale, to utilize small flows of water, and to evaluate the possibilities of AST as an appropriate portable hydro-power generation turbine. Further research and experimentation are needed to assess whether 3D printing can be effectively scaled for broader implementation in low-resource areas.

This study, under the context of a global perspective, focuses on the Indus Basin Irrigation System (IBIS) of Pakistan specifically the Jhelum and Chenab rivers inflows. The IBIS operation relies on seasonal planning strategies, informed by forecasts of river inflows at key stations by the Indus River System Authority (IRSA). In this study, Artificial Intelligence (AI) models including Generalized Regression Neural Network (GRNN), and Multi-Layer Feedforward Neural Network (MLFN) along with the statistical model Autoregressive Integrated Moving Average (ARIMA) were used to forecast the inflows of both rivers for 5 years (2020–2024) with a lead time of 1 year. Historic flow data of 59 years (10 daily from 1966 to 2024) were collected from IRSA. The collected data from 1966 to 2014 are used for calibration/training and from 2015 to 2020 are used for validation/testing of selected models for both study locations. The results of correlation and error estimation depicted that Artificial Neural Network (ANN) models predicted better inflows than the ARIMA model. The average RMSE and R² of ANN models is 9.68 and 0.92 and the average RMSE and R2 of ARIMA Model is 10.17 and 0.88, this results in improvement of average RMSE and R2 by 4.82% and 4.35% in case of ANN Models when compared with ARIMA Model. Qualitative analysis shows that ANN techniques better predicted the high and low flows when compared with statistical methods. Specifically, the application of the ANN models has enhanced the precision of forecasted inflows assessment compared to the probabilistic inflow forecasting methods used by IRSA. The average RMSE and R2 in case of IRSA forecast is 11.47 and 0.88 and the average RMSE and R2 in case of ANN Models is 10.30 and 0.92, this results in improvement of average RMSE and R2 by 10.20% and 4.35% in case of ANN Models when compared with IRSA forecast. This study highlights the need for utilization of ANN models in place of probabilistic inflow forecasting methods to improve the accuracy of time series inflow forecasts.

Shock waves are generated downstream of spillways during flood operations, which have adverse effects on spillway operations. This paper presents the physical model study of shock waves at the Mohmand Dam Spillway project, Pakistan. In this study, hydraulic analysis of shock waves was carried out to investigate its generation mechanism. Different experiments were performed to analyze the rooster tail on a flat spillway chute and to examine the factors affecting the characteristics of the rooster tail. The study results show that shock wave height is influenced by spillway chute slope, pier shape, and flow depth. Moreover, the height of the shock wave can be minimized by installing a semi-elliptical pier on the tail part of the main pier. Further modifications in the geometry of the extended tail part of the pier are recommended for the elimination of the shock wave. Based on observed data collected from the model study, an empirical equation was developed to estimate the shock wave height generated on the flat slope spillway chutes (5° to 10°).