Domestic Water Supply Research Articles

Exploring future global change-induced water imbalances in the Central Rift Valley Basin, Ethiopia

Lake Ziway, the only freshwater lake in Ethiopia’s Central Rift Valley basin, has been the source for irrigation, floriculture, fish farming and domestic water supply in the region for the last few decades. This study examined the impacts of the planned future agricultural developments and climate change on the lake water balance by an integrated application of the Soil Water Assessment Tool and Water Evaluation and Planning models. The future projections of precipitation and temperature from the Coordinated Regional Downscaling Experiment, CORDEX-AFRICA, under the Representative Concentration Pathways 4.5 and 8.5 were used for the climate change impact assessment. Nine irrigation development and climate change scenarios were developed and simulated to examine the separate and combined impacts on the lake water balance and supply coverages. The study showed that the planned future agricultural developments could result in a mean annual lake water level decline by about 0.15 m, with a considerable reduction (27% to 32%) in the outflow to the downstream Bulbula River. Climate change could increase evaporation losses from the shallow lake resulting in a drastic decrease in the lake water level, especially during the dry season. It could also significantly reduce (by about 74%) the amount of water flowing out of the lake. The combined impacts of future development and climate change are likely to reduce the supply coverages of most of the competing demands. Approaches need to be studied to minimize the lake water evaporation losses and explore water demand/supply management options.

Assessing glyphosate concentrations in six reservoirs of Paraíba do Sul and Guandu River Basins in southeast Brazil

Glyphosate is a popular herbicide used worldwide, and several studies consider it to be an environmental hazard affecting human health. The present study aimed to detect glyphosate in six different reservoirs of Paraíba do Sul and Guandu River Basins in Southeast Brazil, used for multiple purposes, including fishery activities and domestic water supply. Ion chromatography was used to analyze the water samples, as it is a fast and environmentally friendly technique to detect glyphosate. Our results revealed that, despite differences related to trophic state, season of the year or distance to urban areas, glyphosate was detected in all reservoirs and in three of them with concentrations above the limit imposed by Brazilian legislation. Among the environmental variables studied, turbidity presented the highest correlation with glyphosate concentrations. The effect of rainfall increasing turbidity in the rivers reinforces the importance of draining waters from surrounding areas that transport glyphosate into the aquatic ecosystems. The detection of the herbicide in the various systems confirms the wide use of this compound in the drainage basins of the studied reservoirs and highlights the importance of water monitoring. Further, the results reveal how urgent and important it is to explore through laboratory experiments the pathways of degradation of this herbicide in tropical and subtropical aquatic environments together with its effects on flora and fauna.

COVID-19 Pandemic/Lockdown and its Impact on Sustainable Access to Safe Water in the Developing World: A Case Study

COVID-19 pandemic has impacted on the global socio-economic spectrum, including water accessibility especially in developing countries. The global achievement in water access subsector at the end of MDGS could be jeopardized with the unabated prevalence of a novel and contagious disease which knows no bound. With the pandemic and its spreading mode through close contact which brought about the total lockdown of the global community, accessibility to improved water could have been restricted. To assess the impact of the disease/lockdown on water access, a survey was conducted during the lockdown-free days across randomly selected inhabitants of Iwo, Osun State, Nigeria. Data analysis was descriptive. The results revealed that the disease/lockdown restricted the movement of the respondents to search for potable water. Respondents adopted various strategies to ensure water availability in their homes including night fetching (12.2%), rotation (16.2%), purchase (1.4%), surface sources (8.8%) among others. About 78.3% either agreed or strongly agreed that the pandemic had pronounced impacts on domestic water supply and subjected them to untold hardship searching for water while trying to avoid physical contact. This work, therefore recommends review of global target on water access to ensure each house is connected to safe and sustainable water sources.

Impact of Nitrate Vulnerable Zones and Catchment Sensitive Farming on Water Quality in UK: Case Study of Ingbirchworth and Scout Dyke Reservoirs

The rivers and water streams are considered as a source of fresh drinking water for the human being on earth. The main source of water entering to these reservoirs is surface run off, snow melting and underground water. The water at the river’s mouth is generally in the form of small streams which are considered clean but as they flow down the catchment, pollutants and nutrients start to enter in larger amounts due to anthropogenic activities and advanced land use by human beings. As per inspection of chief inspector “Drinking Water Inspectorate (DWI)” in 2016, out of more than 4600 water bodies and 3700 rivers in England, only one sixth could get “good” status and two third could get “moderate” status as per European union standards. This is though a good achievement in Europe but alarming also, as all rivers are required to have achieved specified “good” standards by 2021 (extended to 2027 for some categories). This phenomenon is pronouncing more complications in drinking water reservoirs or compensatory reservoirs from where water is taken out to utility companies and treated for domestic water supply incurring an enormous cost on its treatment before human consumption. The clean water standards can be achieved only if a strict control is implemented on entry of pollutants/ nutrients from surface run off using thorough catchment scale sensitive strategies. UK has been implementing strict measures under Environment Agency (EA), Department for Environment, Food and Rural Affairs (DEFRA) and other organizations like “Natural England”, “River Trust” and water utility/ supply companies to achieve desired standards of water quality in rivers by managing the whole catchment as per European union water framework directive (EU WFD) 2000.The catchment sensitive farming and nitrate vulnerable zones policies were started in 1992 and has been in full practice by implementing different stewardship schemes and fertilizers control measures in farmlands and arable lands. Ingbirchworth reservoir and Scout Dyke compensatory reservoir have been under catchment sensitive stewardship schemes to control quantities of nutrients especially nitrates and other pollutants since 2006 to maintain good quality water reservoirs for drinking and compensation to Don river. A partial success has been achieved in controlling the values of nitrates, phosphates, and suspended solids to enter from catchment farmlands by controlling the use of slurry/ fertilizers and implementation of good farming techniques. However, temporal and special variations show a variable result of presence of nitrates, phosphates and suspended solids at different streams in different times, more than specified limits of 11.3mg/L, 0.1mg/L and 25mg/L respectively. This requires more holistic efforts to control the bad practices in farming in adjacent farm/arable lands and improvements in stewardship schemes for catchment sensitive farming in Ingbirchworth areas.

Impact of Land Management on Water Resources, a South African Context

Globally, the changes exerted on the land cover have shown greater impacts on the quality and quantity of water resources and thus affecting catchment’s hydrological response (i.e., runoff, evapotranspiration, infiltration, amongst others). South Africa is a water-scarce country faced with domestic water supply challenges. A systematic review was conducted on the overview impacts of land use/land cover changes on water resources. Despite the country’s best efforts in ensuring the protection and sustainable use of water resources, the review indicated that water quality has been compromised in most parts of the country thus affecting water availability. The increase in water demand with development presents the need for better integrated strategic approaches and a change in behaviour towards water resource and land management. Thus, the review suggested a few possible solutions that will promote sustainable development, while protecting and preserving the integrity of South African water resources.

Does the Household Save Water? Evidence from Behavioral Analysis

Management of water supply in urban areas is a challenge that must be faced by water supply companies to ensure the continuity of domestic water supply to the residents in the area. Hence, this study aims to identify local people’s behavior and daily activities that led to domestic water wastage. Furthermore, the relationship between the demographic factors of the population trends in reducing water use through water savings in their daily activities or installing a home-saving water system is also undertaken. The data were analyzed and interpreted using IBM SPSS software such as descriptive analysis, covering frequencies, mean and standard deviation, correlation with bivariate correlation, cross-tabulation, and multivariate analysis (MANOVA). Availability and demand in water management will only be managed if water resources and water supply engineers address all the balance sides. It will ensure a more comprehensive and interconnected water sector, ensuring the security and sustainability of water.

Assessing community-based water management and governance systems in North-West Cameroon using a Cultural Theory and Systems Approach

Abstract The drive to ensure regular and reliable access to domestic water supplies is a major challenge for governments across sub-Saharan Africa. This study investigated the rural water systems in North-West Cameroon across rural districts using the lenses of Cultural Theory and Systems Thinking Analysis (STA). Different social groups were classified using Cultural Theory to assist in appreciating and presenting solutions to preventing water resources becoming degraded and ensure water supplies are maintained. STA focuses on causal feedback principles and therefore, was used to evaluate relationships between the stakeholders and systems. Thereby allowing the development of a suggested policy intervention mechanism for sustainable community-based Water Management (CBWM) in the region under study. Findings revealed that in Cameroon, the provisioning of domestic water to rural residents faces significant hurdles. This is due, in part, to the centralisation of governance, where the national government determines how water resources are managed throughout the country. This is despite the promulgation of laws that support the decentralisation of decision-making. It was found that CBWM systems prevailed due to the enormous contributions of local inhabitants, extended community networks and the diaspora. However, CBWM serve to reinforce the status and situational power of local elites, government officials and, to a lesser degree, men. Therefore, a concerted effort to implement a more democratic and transparent politico-cultural mechanism to manage water resources could serve both to resolve water management conflicts and develop suitable policy intervention mechanisms for sustainable CBWM.

Assessment of health risks and individuals' willingness to participate in drinking water management at flood-prone Pahang River Basin, Malaysia.

Rivers, the main source of the domestic water supply in Malaysia, have been threatened by frequent flooding in recent years. This study aims to assess human health risks associated with exposure to concentrated heavy metals in a flood-prone region of Malaysia and investigate the affected individuals' willingness to participate in managing water resources. Hazard indices and cancer risks associated with water contamination by heavy metals have been assessed following the method prescribed by the US Environmental Protection Agency. Yearly data of heavy metal contamination (Cd, Cr, Pb, Zn, Fe), water quality parameters (DO, BOD, COD, pH), and climatic information (annual rainfall, annual temperature) have been collected from the Department of Environment and Meteorological Department of Malaysia, respectively. The inductively coupled plasma mass spectrometry technique has been used by the department of environment for analyzing heavy metal concentration in river water samples. In this study, data from a stratified random sample of households in the affected region were analyzed, using partial least squares structural equation modeling, to predict the link between individuals' perceptions and attitudes about water resources and their willingness to engage in water management program. The health risk estimation indicated that the hazard index values were below the acceptable limit, representing no non-carcinogenic risk to adults and children residing in the study area via oral intake and dermal adsorption of water. However, the calculated value for cancer risk signified possible carcinogenic risks associated with Pb and Cd. In general, contamination due to pollution and flooding tends to increase in the basin region, and appropriate management is needed. The results identified perceived water quality as a significant factor influencing people's attitudes toward involvement in water management programs. As in many developing countries, there is no legal provision guaranteeing public representation in water management in Malaysia. The conclusion discusses the importance of these for the literature and for informing future policy actions.

Selection and Evaluation of influencing Parameters for Heat Load Forecasting Model

This paper analyses the factors affecting the heating consumption of a heating substation. The input parameters of neural network prediction model are analysed and selected. The average absolute error, average absolute percentage error, and mean square error are used to evaluate the effect of the prediction model. The results show that when the model input parameters are the maximum outdoor temperature, the average outdoor temperature, the average temperature difference between the primary supply and return of domestic hot water, the heating load in the previous three days, the heating load in the previous two days, the heating load in the previous day and when the model input parameters are the maximum outdoor temperature, the minimum outdoor temperature, the average outdoor temperature, the average temperature difference between the primary supply and return of domestic hot water, the heating load of the previous three days, the heating load of the previous two days, the heating load of the previous day, the effects are better.

Multivariate Streamflow Simulation Using Hybrid Deep Learning Models.

Reliable and accurate streamflow simulation has a vital role in water resource development, mainly in agriculture, environment, domestic water supply, hydropower generation, flood control, and early warning systems. In this context, these days, deep learning algorithms have got enormous attention due to their high-performance simulation capacity. In this study, we compared multilayer perceptron (MLP), long short-term memory (LSTM), and gated recurrent unit (GRU) with the proposed new hybrid models, including CNN-LSTM and CNN-GRU. Hence, we can simulate one-step daily streamflow in different agroclimatic conditions, rolling time windows, and a range of variable input combinations. The analysis used daily multivariate and multisite time series data collected from Awash River Basin (Borkena watershed: Ethiopia) and Tiber River Basin (Upper Tiber River Basin: Italy) stations. The datasets were subjected to rigorous quality control processes. Consequently, it rolled to a different time lag to remove noise in the time series and further split into training and testing datasets using a ratio of 80 : 20, respectively. Finally, the results showed that integrating the GRU layer with the convolutional layer and using monthly rolled average daily input time series could substantially improve the simulation of streamflow time series.

Evaluating critical success factors in public – private partnership water supply infrastructure projects

Research background: Public-private partnership (PPP) has been implemented in Vietnam since 1995 in the field of water supply. It is worth noting that not all governments are successful in implementing the PPP policy. According to studies in many countries in the region on the factors affecting the success of a PPP project, there are many similarities. However, differences in politics and administrative systems of each country can lead to changes in the influencing factors, changes in the degree of influence of the above factors on the success of the PPP project. Purpose of the article: This article aims to identify critical success factors (CSFs) that enable successful project execution, contributing to knowledge for practitioners in assessing the likelihood of success in executing a public-private partnerships PPP water supply project. Methods: In-depth interviews with PPP specialists in the water supply sector have confirmed the list of CSFs, after which the attributes are weighted to evaluate among different types of PPP by applying the AHP approach. The influences of CSFs were evaluated by data collected using a sample survey of 20 experts involved in the water supply sector and PPP projects in Vietnam. In Vietnam, the study finds seven CSFs affecting the success of PPP projects in the domestic water supply sector, including political environment, commitment of partners, strong consortium, asset quality/social support, national PPP unit, good governance, and project feasibility. Findings & Value added: The results reveal that the political environment is CSF that has the strongest impact on the success of the projects. As suggested by AHP, the BOO contract type of a PPP project in Vietnam water supply industry is chosen above the BOT contract.

The Disappearing Colorado River: Historic and Modern Attempts to Manage the Lifeline of the United States Southwest

Historic Native American and modern civilizations have been forcing the unstable use of the Colorado River and adjacent land resources for centuries. Much can be learned from past Native American cultures that created irrigation systems to offset low rainfall. These lessons learned can be applied to our modern civilization. We can learn a lot from their previous behavior and experiences and could apply the lessons learned to our current disappearing Colorado River situation. Little of the Colorado River water flow reaches the international border with Mexico near Yuma, Arizona. Intensive consumption, mostly in the United States, has dried up the lower 160 km of the river. Since the 1960s, the Colorado River has rarely flowed into the Gulf of California and when it does it becomes is a major international news event. The Colorado River Delta is drought prone and its headwater tributaries are a vital source of water for 40 million people. The Colorado River has whitewater rapids, canyons, and many United States National Parks. The tributary and river flow is managed by an extensive system of dams, aqueducts, and reservoirs. Most years the entire Colorado River flow is used for United States agricultural irrigation and domestic water supply purposes. The agricultural and urban needs in the United States are continuing to grow and it appears the days of Colorado River flowing into Mexico and the Gulf of California are numbered and declining every decade. The Colorado River is disappearing and restoration efforts appear to be too little too late. If the Colorado River valley is ever going to recover management lessons and failures learned from the Native Americans, including the Hohokam, must be applied. A balanced approach to water management is needed and must include aggressive conservation and efficiency measures.

The Effectiveness of Rain Water Harvesting for Sustainable Practices in West Hararghe Zone, Oromia Regional State, Ethiopia

This study was conducted in West Hararghe Zone, Oromia regional state to evaluate rain water harvesting Effectiveness for sustainable practices. The data were collected from a total 336 household selected randomly. The data’s obtained were analyzed qualitatively. The study reviled that Rain water harvesting is one of the most important means to increase agricultural productivity and source of a domestic water supply for drought prone of Western Hararghe Zones. Specifically, in selected kebeles of Miesso district there is no access of perennial spring and river. Ground water also found at very deeper and can’t be extracted by their current economic and educational status. In line with this about 83.6% of the farmers were implemented rain water harvesting practices on their farm land and communal land to minimize the risks associated with scarcity of rainfall. From these value 97.3% were in Miesso district. In agreement with this, 54.8% of the house holders have been using roof top water harvesting system in this study area. Specifically, about 25% of the respondents use roof top water harvesting system in Miesso district. Additionally, about 30.1% of the farmers were constructed family pond on their farm land for vegetable/horticultural crop production, cash crops (chat) and also for livestock. Contour ridges were implemented by 89.3% and 92.4% of the farmers in Miesso and Habro districts, respectively. Similarly, 73.8% of the respondents in the study area were implemented flood water diversion to their farm land. Accordingly, 30.8% and 20.5% of the respondents from Habro and Miesso district state preferred flooding WH system than others techniques.

Determining the location of River Dam Group based on set cover Model: A case study of Zambezi River Basin

Taking the Zambezi River Basin as a typical case, this paper studied the location problem of dam group. Based on the topographical and elevation maps of the Zambezi River Basin, we evaluated each region by five indicators (Water head difference elevation, Geological environment, Climatic environment, Population distribution and Biodiversity), and selected the 22 candidate dam sites. Meanwhile, the relative feasibility index of dam construction is calculated by the entropy weight-grey correlation analysis. On this basis, combined with the water management capacity of the dam, a set coverage model of dam selection is established, and the neighborhood adaptive particle swarm optimization algorithm (NAPSO) is used to solve the 12 most suitable dam sites. Comparing with the water management capacity of the original Kariba Dam, the new dams’ water storage and flood control capacity, hydroelectric power generation capacity, domestic water supply capacity and other water supply capacity have been increased by 235.92%, 250.62%, 189.66% and 223.61% respectively. Our study can provide some guidance for the site selection project of river dam group.

소규모 열네트워크기반 분산형 열 프로슈머 구현을 위한 직팽식 태양열 히트펌프 적용 가능성 분석

In this study, the feasibility of a direct-expansion solar heat pump for a distributed thermal prosumer in a small-scale thermal network was investigated. In this analysis, a small-scale thermal network for cooling, heating, and hot water established in Jincheon eco-friendly energy town was selected as the test site, and a daycare center in town was also selected as a target building for heat prosumer. The direct-expansion solar heat pump was selected to serve and generate excess heat, and control logic was developed to facilitate the production and delivery of excess heat. In order to simulate the operation of the direct-expansion solar heat pump, an operation model was developed via ANOVA based on the operation data derived from the literature. Simulations were based on the derived model and the operation parameters of the Jincheon eco-friendly energy town. As a result, the direct-expansion solar heat pump showed a COP of 3.5 annually. The amount of heat supplied for domestic hot water from the central management center in the town was 105 ㎿h/y, and the amount of electric energy consumed by the electric heater located in each building for domestic hot water supply was 37.4 ㎿h/y. It was predicted that 51.6% of the electric energy consumption for serving domestic hot water could be reduced using the direct-expansion solar heat pump in the daycare center as the thermal prosumer.

НОРМИРОВАНИЕ ЭМИССИЙ ПРИ СБРОСАХ В ГЛУБОКИЕ ВОДОНОСНЫЕ ГОРИЗОНТЫ

Deep underground reservoirs are characterized by a stable structure with unique properties to contain and retain various production waste for a long time in a safe condition. In this context, deep underground aquifers are considered as localized underground targets designed for industrial waste disposal to prevent or reduce a maninduced load on surface water bodies, resources of which are sought-for the drinking and domestic water supply. 
 In the environmental legislation of the Republic of Kazakhstan, the limits for the environmental emissions are established within the maximum permissible discharges (MPD) of industrial wastewater exclusively for surface water bodies. At the same time, no define procedural conditions were determined in the legal norms for MPD limitation when injecting industrial wastewater to the underground aquifers that are also referred to the water bodies as defined. 
 A methodological approach to the limitation of harmful and (or) hazardous substances in industrial wastewater injected to the deep underground localized horizons is considered in the proposed review based on the existing developments of the leading oil companies in the Republic of Kazakhstan taking into account the requirements of the national environmental legislation.

Synthesis of past isotope hydrology investigations in the area of Ljubljana, Slovenia

Water isotope investigations are a powerful tool in water resources research as well as in understanding the impact that humans have on the water cycle. This paper reviews past hydrological investigations of the Ljubljansko polje and Ljubljansko barje aquifers that supply drinking water to the City of Ljubljana, with an emphasis on hydrogen, oxygen and carbon stable isotope ratios. Information about the methods used and results obtained are summarised, and the knowledge gaps identified. Overall, we identified 102 records published between 1976 and 2019. Among them, 41 reported stable isotope data of groundwater, surface water and precipitation and were further analysed. Isotope investigations of the Ljubljansko barje began in 1976, while groundwater and surface water investigations of the Ljubljansko polje and along the Sava River began as late as 1997. Isotope investigations of carbon started even later in 2003 in the Ljubljansko polje and in 2010 in the Ljubljansko barje. These investigations were performed predominantly in the frame of short-term groundwater research projects at five main wellfields and sites along the Sava River. Almost no large-scale, long-term stable isotope studies have been conducted. The exceptions include groundwater monitoring by the Union Brewery in Ljubljana (2003- 2014) and precipitation in Ljubljana since 1981. Since 2011, more detailed surveys of the Ljubljansko barje were performed, and in 2018, the first extensive investigation started at wellfields and objects that form part of the domestic water supply system. Given the number of available studies, we felt that publishing all the numerical data and appropriate metadata would allow for a better understanding of the short and long-term dynamics of water circulation in the urban environment. In the future, systematic long-term approaches, including the appropriate use of isotopic techniques, are needed.

Domestic Water Supply Vulnerability to Climate Change and the Role of Alternative Water Sources in Kingston, Jamaica

Globally, freshwater resources are threatened, resulting in challenges for urban water supply and management. Climate change, population growth, and urbanization have only exacerbated this crisis. For the Caribbean, climate change through the impact of increasing temperatures and rainfall variability has resulted in more frequent and intense episodes of disasters including droughts and floods which have impaired the quantity and quality of freshwater supplies. Using Caribbean-specific climate forecasting, it is shown that rainfall totals in Kingston, Jamaica, are expected to reduce by 2030 and 2050 under two RCPs. In addition, the timing of the primary rainy season is expected to shift, potentially impacting water supply security. Analysis of the potential of rainwater harvesting (RWH) to augment supply and enhance water supply resilience shows that in two communities studied in Kingston, it can contribute up to 7% of total water supply. Household storage requirements are about 1 m3 per household, which is feasible. RWH offers the potential to contribute to climate change adaptation and mitigation measures at a household level. Policy, incentives, and increased awareness about the potential of RWH to meet non-potable household demand in Kingston must be improved, as well as efforts to reduce the currently unreasonably high levels of non-revenue water in order to move towards an integrated, sustainable, and climate-resilient urban water supply strategy for the city.

Evolution of Traditional Water Collection Techniques in the Algerian Sahara

This article discusses many of the inherited techniques for collecting and managing spring water used in the gardens of Boussaada, Ain Madhi, Small Mechria, and Stitten located in the Saharan atlas’ ranges over a period of nine centuries. Based on the missions carried out since 2017 in the four regions, we conducted site investigations and surveys of the local population. The results showed that domestic water supply and irrigation were carried out using traditional water collecting techniques such as well and foggara and small dams. The water harvesting technology characterizes a specific region according to its topography and hydrology. Currently, this hydraulic heritage meets technical and social problems, especially with the advent of modern technologies that give more water with less human effort but hurt the environment. The objective of this study is to conduct a comprehensive inventory of all water sources in the study areas while evaluating the negative impact on them due to the emergence of modern technologies. Keywords: Algeria; Dam; Foggara, Oasis; Source; Valley. DOI 10.35180/gse-2020-0045

About standards for hot water heating

This article examines the existing legislative features of hot water supply, sanitary-epidemiological and hygienic requirements, as well as temperature standards for the quality of hot water. Practice shows that the standard for heating cold water, in contrast to the standard for heating, is universally underestimated. A feature of domestic hot water supply systems that significantly affects the efficiency of their operation is the high value of the circulation flow in the heat balance. At constant circulation and hot water temperature in the range from 60°C to 70°C, the value of the actual specific heat consumption for TPP can be more than 0.1 Gcal Gcal/m3. In sparsely populated homes, neighborhoods, and where some of the residents have switched to independent gas or electric water heating, this value is even higher. In order to determine the actual coefficients for heating cold water to provide utilities for hot water and comparison with the approved standard for heating, affect the distribution of losses in heat supply and hot water, conducted a study of the modes of operation of intrahouse systems of a number of apartment houses in the heating system of the city of Ulyanovsk. Based on the results of technical measures, the values of the actual coefficients for cold water heating were determined, ways to reduce excess heat consumption for cold water heating were proposed, and the technical feasibility of their implementation was determined.