Water Conservation and Management (WCM)

The impact of downstream face inclination on the discharge coefficient of chute spillways is thoroughly examined in this work using experimental investigation. Physical models were used in a series of controlled discharge laboratory tests where downstream face angles (0 = 30°, 45°, 60°, and 70 °) were systematically varied in parallel. Twenty foam models with five different lengths of the crest (Lcr) values 10, 11, 12, 13, and 14 cm were created in the lab. Additionally, each model was attached to a plain stilling basin that measured 1 m in length (Lb) and 3 cm in depth. Every test was carried out in a lab flume that was 15 m long, 0.3 m wide, and 0.45 m high. The discharge values are 21.3, 20.9, 19.7, 19.3, 18, 15.6, and 14.8 l/s. A non-dimensional technique, according to Buckingham’s theorem, linking the value of Ca as a dependent variable and other independent non-dimensional variables of 0, Fr1, and was determined by dimensional analysis. SPSS v26 was used to process experimental data to determine a non-dimensional relationship between the coefficient of discharge and the other geometric and hydraulic non-dimensional parameters. The results also demonstrate how submergence conditions and downstream geometry interact on the value of Cd. A predictive association for Ca with a coefficient of determination of 0.955 is suggested based on the combined dataset,providing increased accuracy.

Understanding how local bacterial communities interact with different plastic types in freshwater ecocystems remains limited, despite the continuous accumulation of synthetic polymers. The objective of this study was to use a raw microbial community from the Tigris River as a natural inoculum to evaluate its biodegradation potential. As the sole carbon sources, High-density polyethylene (HDPE) and polyethene terephthalate (PET) were subjected to 90 days of controlled laboratory conditions. Analysis of colony-forming units (CFU/ml) revealed significant differences in colonization dynamics (p <= 0.001) . HDPE showed irregular semistable growth, while PET supported continuous bacterial increase. 16S rRNA sequencing showed a consortium dominated by Pseudomonas aeruginosa (GJ-TIG1), Bacillus subtilis (GJ-TIG2), and Bacillus subtilis (GJ-TIG3), suggesting functional cooperation. The GJ-TIG1 strain likely acts as the first colonizer by oxidizing the plastic surface, which enables GJ-TIG2 and GJ-TIG3 to use enzymatic hydrolysis of ester bonds. These biological findings were confirmed by physical and chemical analyses. Field-emission scanning electron microscopy (FESEM) showed distinct damage in PET compared with limited surface changes in HDPE. Fourier transform infrared (FTIR) and gas chromatography-mass spectrometry (GC-MS) analyses supported this difference by detecting breaking of the ester bonds and the formation of by-products such as phthalates and hydrocarbons. These results indicate partial biodegradation by a natural consortium, with its effectiveness deppending on the type of polymer. This study therefore provides basic insights into bioremediation of microplastic contamination in the Tigris River, which often suffer from a scarcity of such studies.

Labyrinth weirs are widely used in hydraulic civil engineering due to their ability to increase discharge and flow velocity, thereby dispersing energy within specific channel widths. This study experimentally investigated the hydraulic performance and energy dispersion characteristics of triangular labyrinth weirs under the influence of weir height and number of water cycles. A single-, two-, and three-cycle labyrinth weir was tested at three different heights: 10 cm, 20 cm, and 30 cm, under various flow conditions. were tested under various flow conditions and crest heights. Upstream and downstream flow depths and velocities were measured to evaluate the specific energy, energy loss (AE), and energy dissipation efficiency (%η). The experimental results indicate that energy dissipation increases significantly with both the number of cycles and crest height. The three-cycle triangular labyrinth weir exhibited the highest performance, achieving energy dissipation efficiencies exceeding 50% at higher flow rates and crest heights. The results confirm that triangular labyrinth weirs provide effective downstream energy reduction and improved hydraulic control. The findings of this study can support the optimal design of labyrinth weirs in spillways, irrigation channels, and energy dissipation structures.

This paper presents the development and substantiation of an intelligent control approach for a corona discharge – based water disinfection system powered by renewable energy sources. The aim of the study is to improve disinfection efficiency and energy performance of the system under conditions of unstable power supply by optimizing the operating regimes of the corona discharge. The research combines theoretical analysis, mathematical modeling, machine learning and reinforcement learning methods, and laboratory-scale experiments. The results show that stable corona discharge operation in the voltage range of 5 – 30 kV ensures the generation of ozone at concentrations of 10-40 mg/L and hydroxyl radicals in the range of 10-9 10-6 mol/L, providing microorganism inactivation efficiencies of 90 99.99%. The application of the intelligent control algorithm enables discharge instability to be maintained within ±10-15% under solar and wind energy fluctuations of ±20-50%, while reducing overall energy consumption by 15-35%. The obtained results demonstrate that the proposed approach has significant scientific and practical potential for enhancing the stability and energy efficiency of renewable energy-powered water disinfection systems.

The Wanagama Forest represents a notable success in the rehabilitation of degraded karst landscapes. This restoration effort has not only enhanced vegetation cover but also contributed to the development of a favorable microclimate that supports ecological functions and human well-being. Over time, the forest has played an important role in improving water availability, which is essential for meeting the needs of nearby communities. Karst regions, including Wanagama, are typically characterized by limited water retention capacity and are highly vulnerable to seasonal drought, particularly during prolonged dry periods. Despite its recognized success in land restoration, studies focusing on the hydrological dynamics of the Wanagama Forest remain relatively scarce. Therefore, this study aims to (1) assess the water balance, (2) evaluate the drought index, and (3) determine the runoff coefficient within the rehabilitated forest area. The analysis applies the Thornthwaite-Mather approach to estimate water balance components, alongside calculations of the dryness index (la) and runoff coefficient (C). The results indicate an increasing trend in annual water surplus, reaching approximately 15.654 mm/year, accompanied by a rise in water deficit of about 9.014 mm/year. The calculated drought index of 1.15% suggests that the area experiences low drought stress and can be classified as having a non-critical water condition. In addition, the runoff coefficient ranges between 0.3 and 0.5, indicating a moderate proportion of rainfall contributing to surface runoff while a substantial amount infiltrates into the soil.

Malaysia has abundant water resources. However, overpopulation, urbanisation, inadequate water management, and climate change contributed to water stress in several states. Water insecurity particularly in household consumption arose from an imbalance between water demand and supply. In this study, household water security was assessed across five key dimensions: pipe bursts, water amount, water pressure, water reliability or resilience, and price. The study aimed to examine the status of these water security dimensions and to estimate households’ willingness to pay (WTP) for improvements to strengthen the overall water security framework. A choice experiment approach was employed to estimate WTP for enhancements in each water security parameter. The questionnaire comprised sections on household experiences with water operators, water consumption patterns, choice experiment scenarios with three attribute levels per parameter, and socioeconomic characteristics. The sample consisted of 500 residential consumers. The findings provided valuable insights for developing a comprehensive household water security framework to support the Energy Transition and Water Transformation Ministry’s goal of achieving an estimated 180 litres per person per day by 2025, as well as the United Nations Sustainable Development Goal (SDG) 2030 target of ensuring access to clean water and sanitation for all and promoting long-term water security.

The application of the zero residues level in the removal of tin (II) cations from wastewater using tangerine peels via adsorption technique was the main objective of the current study. A batch-type adsorption unit was used to detect the optimal operating conditions that conducted the maximum percentage removal of target cations. The effect of six major design parameters on the recovery efficiency of tin (II) cations from contaminated aqueous solutions was investigated. Experimental results showed that more than 90% was the maximum tin (II) cation removal efficiency achieved at 150 minutes, 4.5 ppm, 400 rpm, 50°C, and 5.5 and 6 g for contact time, initial concentration of tin (II) cations, agitation speed, temperature, pH, and tangerine peels dosage, respectively. The study also indicated that the treatment efficiency is directly proportional to the agitation speed, the adsorbent dosage, the temperature and the contact time, while the proportional with the initial concentration of tin (II) cations was inversely. The effect of acidity was consistent, being directly proportional within the acidic ranges, and inversely proportional within the basic range.

The phenomenon of erosion in river basins that have water infrastructure is a major problem in river basin management. Global climate change and high levels of change in watershed utilization that exceed their carrying capacity accelerate erosion and increase sedimentation. Modeling the effectiveness of bench terrace conservation by combining real-time rainfall data from satellites with erosion analysis using the MUSLE (Modified Universal Soil Loss Equation) method is expected to yield an appropriate model to reduce erosion rates. This research is novelty in developing an integrated land conservation model utilizing Global Precipitation Measurement (GPM) satellite rainfall data as the primary source of hydrological input for reservoir catchments. Unlike other studies, which generally rely on spatially limited station-based rainfall data, this study integrates GPM-based MUSLE results with a bench terrace conservation scenario to evaluate the effectiveness of conservation measures under spatially and temporally variable rainfall conditions. The results of the analysis show that the erosion rate reached 403.930 tons/year in a catchment area of 3325 hectares, indicating a fairly high level of erosion. The application of the open bench terrace conservation method can reduce erosion by 4.02% of the total area of the watershed, with the mechanism of reducing surface flow velocity, increasing infiltration capacity, and retaining soil particles. Modeling conservation practices using the terrace bench method can control erosion and is a crucial step in sustainable watershed management. Therefore, integrating erosion modeling and soil conservation practices is necessary to maintain environmental stability and extend the lifespan of water resource infrastructure within the watershed.

Southern Iraq, especially Wasit and Maysan governorates, is experiencing flash flooding and water shortages. Limited hydrological research and streamflow data limit runoff estimates, flood risk assessment, disaster preparation, and floodwater harvesting. Simulating the hydrological and hydraulic response of a 2,945.33 km² watershed during a March-May 2019 flood and modelling rainfall-runoff processes with 2019 daily rainfall data in ArcGIS, HEC-HMS, and 2D HEC-RAS highlights the potential for floodwater harvesting to address seasonal shortages. In the HEC-HMS software, the SCS-CN method for losses, the SCS Unit Hydrograph for transformation, and the Muskingum routing method were used to compute run-off in each watershed reach. The extracted discharge outputs were input as upstream boundary conditions to a 2D HEC-RAS model to estimate flood extent. Simulations revealed about 144.4 million m³ of runoff volume, with initial abstraction (la) having the greatest impact on volume. Qualitative comparison with Sentinel-2 satellite imagery from a similar flood occurrence indicated good spatial consistency for model validation. Because of their concentration on flood forecast accuracy, quantitative measures like CSI were evaluated but not employed as validation evidence. Although data is rare in ungauged arid basins, integrated modelling can improve water planning and flood risk management if monitored and regulated.

The current investigation aimed to study the suitability of buckthorn leaves – without any further treatment as a readily available and inexpensive adsorbent for recovering cobalt cations from contaminated aqueous solutions using a batch-type adsorption unit under various operating agents. The source of buckthorn leaves used was from perennial trees in the city of Baghdad, and the fresh leaves were carefully collected before being washed, dried, ground, and prepared to be an adsorption medium. The results obtained indicated that buckthorn leaves were remarkably efficient in removing cobalt cations from contaminated aqueous media, reaching 72.45% of 45 ppm at 6, 400 rpm, 150 minutes, and 7 g for each of pH, agitation speed, contact time, temperature, and adsorbent dosage, respectively. Thus, agricultural waste has proven its ability to be an important source of useful materials instead of being disposed of as waste that requires effort and cost to remove.