International Journal of Water (4 papers in press)

Regular Issues

• Monitoring the Processing and Supply of Clean Drinking Water using the Hybrid Gateway Method based on the Internet of Things (IoT)  
  by Rindra Yusianto, Rabei Ali, Herwin Suprijono, Marimin Marimin 
  Abstract: This research aims to implement IoT-based monitoring in water treatment systems. A Gateway device will be designed to support the integration of a new IoT-based monitoring system based on conditions at the Petanglong, Indonesia. A Raspberry Pi and Node-Red software were used as programming tools to carry out the Gateway function and create a monitoring dashboard display with the MQTT protocol as a communication path that connects the Gateway device with the cloud server. The results show that the Gateway device can work well in the new IoT-based monitoring system. The accuracy level of data reading between the value in the field and the dashboard display results is 99%, which works ideally at a reading time interval of every 5 seconds, with the difference in data display time and the dashboard display being in the time range of 2
  Keywords: Internet of Things; Hybrid Gateway Method; Monitoring System; Raspberry Pi; Water Treatment System.
  
  
• A transformative social policy approach to implementing IWRM in Zimbabwe and South Africa  
  by Newman Tekwa, Beatrice Dube 
  Abstract: The article examines water policy reforms in Zimbabwe and South Africa, focusing on challenges arising from the adoption of integrated water resource management (IWRM) and neoliberal philosophies. Through the transformative social policy perspective and qualitative research, the paper provides a comparative analysis of both countries’ experiences. Findings highlight divergent approaches, with Zimbabwe's reforms enabling democratic social transformation, while South Africa's emphasis on IWRM principles of economic efficiency and environmental sustainability has marginalized social equity. Considering their shared colonial history, our analysis underscores incorporating historical and contextual factors into water sector reforms for equitable change and protection of vulnerable groups, including women. By examining the intersection of water policy reforms, transformative social policy, and local realities, this study contributes to the discourse on equitable and sustainable water management.
  Keywords: integrated water resource management; irrigation; South Africa; transformative social policy; water reforms; Zimbabwe.
  DOI: 10.1504/IJW.2024.10066741
   
  
• Impact of alteration in soil hydraulic variables on collective infiltration using HYDRUS-1D  
  by Ali Javadi, Kaveh Ostad-Ali-Askari 
  Abstract: The analysis of sensitivity is a crucial component of modeling. The sensitivity index of the van Genuchten-Mualem parameters on cumulative infiltration under various irrigation managements was calculated in this study using the HYDRUS-1D model. Treatments included two irrigation managements, two irrigation periods (short and long periods) and three irrigation water qualities (ECi= 0.6, 3 and 6 dS/m). The two irrigation managements were intermittent irrigation at the 30% depletion of field capacity (M1) and daily irrigation with 0.15 leaching fraction (M2). The soil columns underwent infiltration tests at 16 and 114 day intervals. Following HYDRUS-1D model calibration of the infiltration process, the impact of a 20% change in soil hydraulic parameters (0.8 to 1.2 parameter values) on cumulative infiltration was examined. Infiltration is most sensitive during the short irrigation period under intermittent irrigation when the soil was dried and wetted successively, whereas it is the most sensitive during the long irrigation period under daily irrigation when the soil was wetted continuously. In fact, as soil permeability increases, infiltration becomes more sensitive to parameter changes.
  Keywords: soil permeability; Genuchten-Mualem parameters; water quality; hydraulic parameters; irrigation management; HYDRUS-1D model; inverse modelling; sensitivity analysis; sensitivity index; intermittent irrigations.
  DOI: 10.1504/IJW.2024.10067210
   
  
• Detecting changes in surface water extent of the Weija dam, Accra, Ghana using MNDWI indices from Landsat satellite imagery  
  by Barbara Baidoo, George Yao Kafu, Kenneth Kobina Yedo Aidoo, Joseph Mihaye, Alex Barima Owusu 
  Abstract: This study is the case of the Weija dam, located in Accra, Ghana. It provides potable water to about 80% of the city’s 5 million residents. The study’s objective is to evaluate the changes in the spatial extent of the Weija Dam from 2011 to 2021. The study used Landsat 7 ETM+ and Landsat 8-OLI images to analyze the changes in the dam's surface area. The Modified Normalized Difference Water Index (MNDWI) algorithm was used in generating open water features for the analysis. Additionally, we conducted in-depth interviews to assess primary knowledge of the causes and effects of the dam's changes. Results show the dam had priorly retreated to approximately 19.668 sq km in 2011, the study's base year, representing 48% reduction from its initial construction size of 38 sq km in 1978. The study discloses that the Weija dam's surface area increased by 1.7% in 2013 compared to 2011. However, in 2017 the dam receded by 1.5 sq km and a further 0.4 sq km in 2021.
  Keywords: lake surface water; Weija Dam; spatial extent; floods; change detection.
  DOI: 10.1504/IJW.2024.10067822