Water Conservation Systems Research Articles

Research and application of the method of measuring the effective utilization coefficient of irrigation water on farmland

Abstract Under the guidance of the new water management idea of “water conservation priority, spatial balance, system management, and two-handed effort,” the National Water Conservation Action Plan released in 2019 puts forward the key task requirements of “double control of total intensity,” in which the effective utilization coefficient of irrigation water in farmland is one of the indicators of water intensity control. The effective utilization coefficient of irrigation water is one of the water intensity control indicators. At present, there are practical difficulties in measuring the effective utilization coefficient of irrigation water in farmland, such as the low measurement rate of water consumption in the current irrigation area, the high input equipment and manpower requirements, and the difficulty in accurately measuring the net irrigation water absorbed by crops. Therefore, this paper proposed the method of “field monitoring - remote sensing inversion - a comprehensive analysis of data.” The method of “field monitoring - remote sensing inversion - econometric model construction - comprehensive analysis” was proposed in this paper, which can obtain gross irrigation water utilizing field monitoring, overcome the difficulty of accurate monitoring of net irrigation water using remote sensing, and carried out a comprehensive analysis, to realize the scientific, effective and rapid calculation of effective utilization coefficient of irrigation water. This method was applied to the Meixian District, Guangdong Province, and the research results show that it not only generates reliable measurement data but also alleviates workload. Furthermore, it offers scientific measurement techniques for water use efficiency indicators, facilitating the achievement of “dual control over total volume and intensity.” This paper provides an important technical basis for the rational allocation of water consumption and scientific approval of water use plans and supports the assessment of the effectiveness of water-saving irrigation development and the reasonable evaluation of the water-saving potential of farmland irrigation, thus providing a basis for local government departments at all levels to make planning, scientific decision-making, and macro-management.

Assessing the effectiveness of integrated watershed management practices and suggesting innovative strategies in southern Ethiopia

Integrated watershed management plays a vital role in promoting sustainable water resource management and addressing environmental challenges. This study aims to analyze and assess the effectiveness of existing IWM practices and develop new strategies to improve watershed management. The data collection process encompassed comprehensive field observations, surveys, and consultations with the stakeholders. According to a hydrometer test, loam soil was the average dominant soil type in Elgo and Kola shell kebele. The assessment of existing soil water conservation initiatives adhered to the rigorous standards set by the Ministry of Agriculture. From 2016 to 2022, Elgo Kebele saw significant land use changes: agriculture expanded by 11.24 %, bare land by 2.05 %, water bodies by 1.79 %, and settlements by 0.54 %, while forests declined by 15.34 %. In Kola Shele, agriculture, water bodies, and settlements slightly increased by 0.5 %, 1.03 %, and 0.033 %, respectively, with decreases in bare land (1.82 %) and forest (0.05 %). Only 25 % of sampled plots met the criteria for effective soil water conservation systems, indicating challenges in current practices. For cultivated land with less than a 15 % slope and vertisol, recommended conservation practices include broad bed and furrow, conservation tillage, grass strips, grassland improvement, and mulching. For slopes greater than 50 %, hillside terracing, graded bunds, and trenches are advised. Additional measures, such as water harvesting, grass waterways, revegetation, and actions against illegal farming, were proposed. In summary, this study highlights the urgent need for improved IWM practices, and used to enhance watershed management, address environmental and socio-economic issues, and promote sustainable land use in the study.

Analysis of stress field in the head area of the Three Gorges Reservoir based on coupled fluid-solid theory

The Three Gorges Reservoir, one of the largest water conservation system in the world, has been of keen interest to scientists globally since its impoundment. After construction of the dam, there has been a significant increase in seismic activity in the head area of the reservoir. It is generally accepted that earthquakes in this region are predominantly caused by the Jiuwanxi and Xiannvshan faults. This study focused on the stress changes occurring in the research area. A three-dimensional finite element model of the reservoir area was constructed using the geological structure and digital ground elevation data of the reservoir area. The fluid-solid coupling theory was applied to calculate the dynamic spatial changes in pore pressure and Coulomb stress in the faults and surrounding rocks during reservoir impoundment. The findings indicated that the added head pore water pressure at the bottom of the reservoir had a maximum impact range of approximately −2800 m on the surrounding rock, whereas the Xiannvshan and Jiuwanxi faults had a maximum diffusion range of approximately −4300 m. Rock permeability also played a significant role in the water storage process. During the 1 56 m water impoundment stage, owing to rapid water storage activity, stress could not be transmitted to both sides in a timely manner, resulting in the formation of an extreme stress change zone at −4000 m inside the fault. This may have been the reason for the frequent earthquakes during this stage. The 17 5 m cycle water storage stage also exhibited a significant degree of seismicity, potentially attributable to the long-term infiltration of reservoir water and accumulation of stress in the previous stage. The stress in the study area at the four stages are in a process of accumulation-release-accumulation-release.

IMPACT ASSESSMENT OF MACHINE LEARNING ALGORITHMS ON RESOURCE EFFICIENCY AND MANAGEMENT IN URBAN DEVELOPMENTS

Urban centers face the mounting challenge of balancing resource demands with sustainable practices in the face of population growth and environmental concerns. Machine learning (ML) has emerged as a transformative technology with the potential to optimize resource efficiency and management within urban environments. This article investigates the multifaceted impact of ML algorithms on enhancing resource management and the associated challenges and considerations. It delves into successful ML applications in vital urban sectors, including smart grids, water conservation, and intelligent transportation systems. Through the analysis of case studies, the article quantifies improvements in resource efficiency and highlights the contributions of ML to data-driven decision-making. Crucially, it emphasizes the need for a holistic approach, addressing computational costs, data bias, privacy concerns, and ethical considerations to ensure the responsible and equitable deployment of ML. The article concludes by underscoring the ongoing evolution of ML and its pivotal role in shaping sustainable and resilient urban futures.

Research on the density of underwater sand and gravel fillings based on geotechnical centrifugal tests

The density of underwater dumping materials plays a major role in cofferdam engineering designs. However, it is difficult to accurately measure the density of underwater dumping materials. This study investigated the influence of particle size distribution of granular materials on the density of underwater filling materials. Considering the underwater dumping project of a hydropower station dam in the Han River as the prototype condition, several underwater dumping density centrifugal tests were conducted on sand gravel and sand mixtures. Based on the CKY200 large-scale geotechnical centrifuge, a single-embankment vertical-blockage underwater filling test device in a centrifuge field was developed. The results demonstrated the relationship between the compactness of the dumping body and the grading of loose particles, depth of dumping, and height of the upper loading. This indicates that the underwater filling material has a higher compactness and can reach a dense state. When the grading is poor, the compactness decreases. The greater the depth of filling, the greater the compactness. When vertical compression was applied to the upper part of the backfill, the compactness of the backfill, particularly in shallow areas, was significantly improved. These results provide insights for the design and construction of underwater dumping water conservation systems.

Cover crop management systems improves soil quality and mitigate water erosion in tropical olive orchards

The production of olive trees in shallow soils in hillslopes requires adequate soil and water conservation systems. In this context, soil use and management besides vegetation cover contributes to better soil quality and the sustainability of the olive cultivation system. Thus, the objective was to determine the physical and chemical properties that are indicative of soil quality in areas of Dystrudepts, under different soil cover management systems in olive cultivation in tropical region. Olive tree culture field experiment was established in 2015, where soil was sampled over three years (2016, 2017 and 2021). The effect of five cover management systems were compared for each agricultural year, namely BS: bare soil in 2015/2016, 2016/2017 and 2017/2021; OBS: olive trees on bare soil in 2015/2016, 2016/2017 and 2017/2021; OSV: olive trees intercropped with mowed spontaneous vegetation in 2015/2016, 2016/2017 and 2017/2021; OJB: olive trees intercropped with jack beans (Canavalia ensiformis L.) in 2015/2016 and 2016/2017, and olive trees crowned intercropped with mowed spontaneous vegetation in 2017/2021; OMI: olive trees intercropped with millet (Pennisetum glaucum L.) in 2015/2016, olive trees intercropped with sunn hemp (Crotalaria juncea L.) in 2015/2017 and olive trees with spontaneous vegetations treated with herbicide (Roundup) in 2017/2021. The soil quality indices (SQI) proved to be sensitive to variations in different types of soil management from the second year of assessment, regarding water erosion. OSV and OJB showed the highest SQI, while OBS showed the lowest values. The SQI demonstrated an inverse correlation with soil and water losses starting from the second year of assessment. This highlights its efficacy in assessment the effects of adopted management on soil quality in the context of water erosion. Moreover, it reinforces the importance of vegetation cover in maintaining soil fertility, resulting in increase of soil organic matter and improving the structuring of Dystrudepts. The attributes that most correlated with the SQI were soil organic matter, effective cation exchange capacity, sum of bases, geometric mean diameter of aggregates, pH and unsaturated soil hydraulic conductivity. These attributes collectively provide valuable insights into soil health and water erosion susceptibility within the olive tree production system.

Uplifting Local Wisdom in Soil and Water Conservation System

The environmental conditions significantly influence the quality of life for humans and other living beings, thus requiring attention to robust and consistent environmental protection and management conditions by all stakeholders. Various principles are utilized in environmental protection and management, and one of these principles is culture and local wisdom. Local wisdom comprises noble values applied in the community's way of life, including, among other things, sustainable protection and management of the environment. Protection and management of the environment must also consider the noble values prevailing in the community's way of life. The occurrence of a water crisis resulting from the reduction of water sources and the weakened conditions of living organisms is due to the insufficient attention to the rules of local wisdom. Various efforts have been made for soil and water conservation, both by the government and environmentalists. The management of water and soil resources is not only the responsibility of the government outlined in various written policies but also the responsibility of the local community evident in the knowledge and experience of the community in carrying out various water and soil management activities.

Water management and irrigation for bulb onion (Allium cepa L.) growth and development in the Papua New Guinea Highlands

Water is crucial for nutrient intake, transportation, temperature regulation, and photosynthesis in bulb onion (Allium cepa L.) growth and development. Water scarcity, caused by climate variability and particularly during prolonged dry periods, has proved to be an obstacle to cultivating bulb onions in the Papua New Guinea (PNG) Highlands. Farmers have a limited grasp of the interdependence of soil, water, and plants. They have traditionally depended on precipitation, and water from streams and rivers, to irrigate their bulb onion crops. The main method for providing irrigation support is manual irrigation, with agricultural organisations assisting with basic irrigation technologies. Despite farmers and organisations efforts to improve irrigation practices, the prolonged dry season still raises labour demands for bulb onion farms. Farmers’ lack of knowledge about irrigation technology and soil water conservation contributes to this issue. Moreover, the lack of irrigation suppliers worsens the issue of limited soil water in onion farms. This paper gives an overview of onion production in PNG, focusing on irrigation practices and constraints in the Highlands region. It aims to stress irrigation’s importance in crop growth and explore PNG’s irrigation methods and soil moisture conservation practices. There is a need for a sustainable irrigation and soil water conservation system that is easy to use and incorporates crop water requirements. This system is vital for watering onions and conserving soil moisture, promoting their growth and yield. In this context, the use of mulch and irrigation systems can preserve and enhance soil moisture during prolonged dry phases.

TOP7: Dialy-ssist: A Complementary Dialysate Recycling System for Dialysate and Water conservation

Background: Hemodialysis (HD) is the dominant form of blood purification employed for patients with end-stage renal disease. Operationally, present HD systems utilize a hollow fiber kidney system in which blood is perfused thru while dialysate is cross-perfused over and surrounding the fiber bundle allowing for fluid, electrolyte and waste exchange, with equilibration based on the tonicity and ion concentration of the dialysate. Unfortunately, present systems require access to a large source of water and dialysate, are hospital or clinic-based, and non-portable. Here we examined the possibility of creating a system – “Dialy-ssist” to recapture dialysate and water, to allow for its reuse. Our long-term goal is to develop a system which has applicability to both hospital/clinic systems as well as for evolving home portable systems, freeing up the dependence and use of significant water supplies. As a first step here, we modeled the exchange efficiency needed for a dialysate recycling and water conservation system. Methods: A system was designed that utilizes activated charcoal, urease, zirconium oxide, and zirconium phosphate (Dialy-ssist). In silico modeling was performed to determine the optimal amount of activated charcoal, urease, hydroxyl zirconium oxide, and zirconium phosphate needed for removal of urea and ions such as Na+, Ca2+, Mg2+, K+, and Cl-. Wet in vitro confirmatory experiments were also defined. For these, effluent dialysate collected from a hospital hemodialysis system is run through the Dialy-ssist system for 4 hours, with samples taken hourly for analyte analysis and water purity assessment. Serial recycled dialysate will be compared to fresh utilized control. Results:In silico modeling revealed that for activated charcoal one ounce of activated charcoal will remove 90% or more of chloride, sodium, and potassium ions in the dialysate via perfusion through the system at 100 to 200 mL/min. Based on peer reviewed reaction kinetics for urea decomposition via urease, five grams of urease with excess zirconium oxide and zirconium phosphate is modeled to remove at least 30.4 mmol/L of urea, ~95%. Conclusion: Modeling of dialysate recycling via the Dialy-ssist system demonstrates its ability to adequately remove contaminants and achieve a purity level acceptable for clinical reuse. Salts and urea can be removed from the fluid with up to 90% efficiency allowing up to 3 cycles of recuse. Modeling also reveals that the system can conserve 36 – 108 liters of water. In vitro wet studies are ongoing to confirm and refine the efficacy of this system to advance it towards the clinic. Experiments will reveal solute actual removal rate compared to theoretical predictions. Samples collected over time will define the real lifespan of filters and sorbents of this system.

PS-BPB05-6: TOLVAPTAN INDUCES BODY FLUID LOSS AND ACTIVATION OF RENAL UREA-DRIVEN WATER CONSERVATION IN NORMAL RATS

Objective: We recently reported that body fluid loss models such as high salt-induced natriuresis, impaired urine concentration ability via kidney injury, and enhanced transepidermal water loss due to skin barrier dysfunction exhibit initial water loss and subsequent activation of the water conservation system in multiple organs. This activation of the water conservation system restores or even increases water content at the tissue level, which may be involved in abnormal body fluid distribution in various disease models. The water conservation system consists of renal urea recycling, the energy-intensive nature of hepato-muscular ureagenesis, and suppression of cardiovascular energy expenditure to save energy for ureagenesis. However, it is not clarified whether pharmacological fluid loss by diuretics activates the water conservation system. In this study, we examined the effects of water diuresis by tolvaptan, a selective vasopressin V2 receptor antagonist, on the water conservation system in normal rats. Design and method: 10-week-old male Sprague Dawley rats were fed with a control diet or a diet containing 0.1% tolvaptan. We measured water intake and urine volume for two weeks and also evaluated time-dependent changes in renal urea recycling and hepato-muscular ureagenesis in these rats. In addition, we also evaluated the effects of tolvaptan on blood pressure, heart rate, and renal sympathetic nerve activity by a radiotelemetry system in separate animals. Results: Tolvaptan markedly increased urine volume up to 126.7 ± 25.9 ml on day-1, which gradually decreased as much as one-third (48.1 ± 18.0 ml) on day-7. Tolvaptan significantly decreased body water content and increased plasma albumin concentration, an indicator of oncotic pressure, on day-1, suggesting that tolvaptan decreased body fluid and plasma volume on day-1. These changes in total body water content and plasma albumin concentration were restored on day-7. The restoration of body fluid on day-7 was associated with an increase in urea transporter A1-associated renal urea recycling. On the other hand, tolvaptan did not alter hepato-muscular ureagenesis or cardiovascular energy expenditure throughout the treatment. Conclusions: Tolvaptan induces initial body fluid loss by water diuresis and subsequent activation of renal urea recycling to restore the water loss. Activation of the water conservation system in addition to a rise in urine volume may be involved in the unknown distinct effect of the diuretics.

Analysis and Prediction of Water Balance Using Dynamic Modelling to Solve Water Scarcity in Cimahi

Cimahi is one of the most populated, fast-growing cities in Indonesia. Consequently, various environmental problems appear, primarily related to the sustainability of water resources. Exploitation and pollution of water, especially groundwater, are not accompanied by a good water conservation system that ensures proper water infiltration into the soil, causing several locations in the city to experience water deficits. The city may suffer a severe water shortage if this problem is unsolved. This study aims to predict and analyze the need and availability of water in Cimahi in the next few years to determine the right solution to deal with this problem. Analysis and prediction of water availability/needs were carried out by building a dynamic model using STELLA software for simulating the conditions in the next ten years. The results of the model were combined with the applicable spatial policies to formulate possible solutions. Results showed that Cimahi will experience a water crisis starting from 2029 with a total water deficit of 8.22 million M³. The model also predicted South Cimahi District is the area with the worst conditions where the water crisis has occurred since 2022 and peaked in 2029 with water sufficiency of only 59.83%. Based on local spatial planning laws and policies, the city's government is advised to improve its catchment area to protect its water resources. The vegetation cover area surrounding the catchment area can be improved, and water absorption capacity can be increased through civil technical actions such as building absorption wells. The model results showed that a proper solution could be done by expanding 142.8 Ha of green/vegetation cover, building 1576 units of absorption wells, and increasing the PDAM supply by 100 l/second.

Efficiency and its influencing factors of urban water sector in China and major OECD countries

Improving the efficiency and productivity of the water supply sector is related to the mitigation of a country's water resources crisis and the governance of the water ecological environment. This paper employs a sequential data envelopment analysis (DEA) approach to examine the comparative efficiency of China's urban water industry by using the country-level data from 1998 to 2017, and then attempts to make a cross-country comparison of the technology gap in the urban water industry between China and major OECD countries. The results show that China's urban water sector performance is improving despite falling short of urban water development in the major OECD. The gap between the performance of China's urban water sector and that of major OECD countries is narrowing. Efficiency improvement has become the main driver of productivity growth of urban water sector in both China and the major OECD countries. Besides, the reduction of capital deepening in the water industry and the easing of water stress could improve the water industry's performance in efficiency. While increased foreign direct investment instead reduces the water industry's efficiency, increased R&D expenditure can improve efficiency, but both are not statistically significant. These findings indicate that compared to major OECD countries, China's urban water industry should strengthen the reform change as soon as possible from asset-heavy to asset-light operation and service, and then improve the water conservation system.

Traditional medicine practices of Guji Semi-Pastoralist People to treat livestock ailments in Suro Barguda District, West Guji Zone, Ethiopia

The objectives of this research were to collect, identify, document, and analyze ethnoveterinary medicinal plants and their associated indigenous knowledge including their preparation and application by traditional healers, and the status of their conservation by Guji Semi-Pastoralist People of Suro Barguda District, West Guji Zone, Oromia Regional State, Ethiopia. Forty-six ethnoveterinary medicinal plant species representing 43 genera and 29 families were identified in the district (Additional file 1). About 26.1% of the families were represented by more than one species. The highest number of species was recorded for Asteraceae (5 species), followed by Euphorbiaceae (4 species) and most ethnoveterinary medicines were prepared from herbs and shrubs than other growth forms. Chopping the remedial parts and homogenizing them with cold water was found to be the major mode of remedy preparation. All documented ethnoveterinary plant species were harvested from the wild and observed as exposed to depletion. About 4.4% of the ethnoveterinary medicinal plants of Suro Barguda District were endemic to Ethiopia. This study indicated that the study area encompasses different species of ethnoveterinary medicinal plants which should be given conservation priority and the local community depends largely on these plants for the treatment of different livestock ailments although the healers had a very high intention to keep their traditional knowledge secrete. The indigenous knowledge of pastoralists about plants and breeding different species of livestock, as well as their environmental management systems (traditional forest, soil, and water conservation systems), should be incorporated in the planning and implementation of developmental interventions.

Assessment of the Effectiveness of Biophysical Soil and Water Conservation Structures: A Case Study of Offa Woreda, Wolaita Zone, Ethiopia

Soil erosion is a serious environmental and natural resource issue in Ethiopia, posing a significant threat to agricultural productivity and being one of the principal drivers of land degradation and soil fertility reduction. Evaluating the biophysical soil and water conservation structures’ effectiveness in Offa Woreda, Wolaita Zone, was the focus of the study. Purposive sampling was used to select the three kebeles that make up this watershed. W/Dekeya, Wareza, and Yakima are the three watersheds chosen for the selected study area. To meet the objective of this study, 504, 325, and 442 family heads were sampled. They comprised the overall 17% (227) of the study participants that were selected. Those who knew how to conserve soil and water, causes of degradation, and sensitive areas of their own plots of land in the study area received preference. The lack of capital, a short stretch of land, and various socioeconomic and physical conditions impeded the use of soil and water conservation systems. As a result, farmers have a reasonable position of the current biophysical soil and water conservation systems. Farmers in the study communities are aware of some traditional soil and water conservation practices as a measure to protect and restore the fertility and productivity of their farmlands. Community participation in encouraging farmers to participate in soil and water conservation practices is critical to resolving the issue of cutting-edge poverty, food insecurity, and environmental deterioration. From the study, we recommend that the government implements specific coverage and techniques as well as corrective intervention from nongovernmental organizations.

Tolvaptan induces body fluid loss and subsequent water conservation in normal rats

We have recently reported that the urea osmolyte-associated water conservation system is activated in fluid loss models such as high salt-induced natriuresis, renal injury-induced impaired renal concentrating ability, or skin barrier dysfunction-induced transepidermal water loss. The system consists of the interaction of multiple organs including renal urea recycling, hepato-muscular ureagenesis, and suppression of cardiovascular energy expenditure. Here, we determined the effect of pharmacological fluid loss induced by tolvaptan, a selective vasopressin V2 receptor antagonist, on water conservation. We evaluated the water conservation system in rats that consumed a control diet or a diet containing 0.1% tolvaptan. Tolvaptan increased urine volume on day 1, but this renal water loss then gradually decreased. Body water and osmolyte content were decreased by tolvaptan on day 1 but had normalized by day 7. Tolvaptan induced fluid loss on day 1, and the following restoration of body fluid on day 7 was associated with an increase in urea transporter A1-associated renal urea recycling. Tolvaptan did not affect hepato-muscular ureagenesis on day 1 and day 7, or cardiovascular energy expenditure during treatment. Thus, tolvaptan-induced fluid loss leads to activation of the water conservation system via renal urea recycling.

Modern world trends in the study of problems of irrigated viticulture: a brief overview

An overview of the latest scientific developments in the field of irrigated viticulture is presented. The emphasis is placed on innovative developments that study the phenological features of the development of the vine under water stress, the issues of the use of alternative sources for irrigation are highlighted, the main trends in the development of digital technologies for the manage-ment of water conservation systems are considered.

Assessment of the effectiveness biophysical soil and water conservation structures: A case study of Kiramuworeda, East Wollega Zone, Ethiopia

Soil erosion is one of the most serious global environmental issues affecting agriculture and soil fertility. On a global scale, water erosion is the most common type of soil erosion in agricultural areas, reducing the soil's ability to support productive agriculture. The efficiency of biophysical soil and water conservation systems must be evaluated before solutions for limiting soil losses may be considered. To promote sustainable land use in the study area, it is critical to understand farmers' knowledge of soil and water conservation structures, as well as the factors that influence their land management practices. Farmers in the study region are well-informed about soil and water conservation structures in general, as well as their causes, indications, and the amount of their plot of land that is susceptible to soil erosion in particular. Furthermore, they feature both traditional and modern soil conservation structures that are successful. However, several impediments to implementing the Soil and Water Conservation structures were found, including a lack of finance, the small area of their land, and other socio-economic and physical aspects. Furthermore, farmers had a highly positive attitude regarding the importance of contemporary Soil and Water Conservation structures. Their awareness, on the other hand, appears to be incorrect. Because they believe that the present SWC Structure is a government-led initiative to rehabilitate highly degraded areas rather than a mechanism of soil and water conservation on agricultural land. They believe that the structures take up a huge portion of a relatively small plot of land, preventing them from properly utilizing it. As a result, it is suggested that the government's policies and strategies, as well as corrective intervention from non-governmental organizations aimed at this issue and community participation in encouraging farmers to participate in soil and water conservation practices, are critical to resolving current poverty, food insecurity, and environmental degradation in the study area.

Hepatocellular carcinoma induces body mass loss in parallel with osmolyte and water retention in rats

AimsThe number of cancer survivors with cardiovascular disease is increasing. However, the effect of cancer on body fluid regulation remains to be clarified. In this study, we evaluated body osmolyte and water imbalance in rats with hepatocellular carcinoma. Main methodsWistar rats were administered diethylnitrosamine, a carcinogenic drug, to establish liver cancer. We analyzed tissue osmolyte and water content, and their associations with aldosterone secretion. Key findingsHepatocellular carcinoma rats had significantly reduced body mass and the amount of total body sodium, potassium, and water. However, these rats had significantly increased relative tissue sodium, potassium, and water content per tissue dry weight. Furthermore, these changes in sodium and water balance in hepatocellular carcinoma rats were significantly associated with increased 24-h urinary aldosterone excretion. Supplementation with 0.25% salt in drinking water improved body weight reduction associated with sodium and water retention in hepatocellular carcinoma rats, which was suppressed by treatment with spironolactone, a mineralocorticoid receptor antagonist. Additionally, the urea-driven water conservation system was activated in hepatocellular carcinoma rats. SignificanceThese findings suggest that hepatocellular carcinoma induces body mass loss in parallel with activation of the water conservation system including aldosterone secretion and urea accumulation to retain osmolyte and water. The osmolyte and water retention at the tissue level may be a causative factor for ascites and edema formation in liver failure rats.

Cost–benefit analysis of water conservation systems installed in household buildings in Nairobi County

ABSTRACT Cost–benefit analysis of installed water conservation systems (piped water storage, water recycling, and rainwater harvesting) is important in management of water resources in urban areas. This study analysed water conservation systems installed in households in Nairobi County using 200 households’ questionnaires. Benefit–cost ratio analysis indicated that the piped water storage system and rainwater harvesting system were viable with benefits at 2.80 and 2.03, respectively, while the water recycling system was not viable at 0.80. This study recommends installation of piped water storage and rainwater harvesting systems for quality, quantity, and reliable water to be availed in households within viable economic costs.

Assessment of Groundwater Quality and Pollution in the Songnen Plain of Jilin Province, Northeast China

Clean groundwater resources are vital to human health. To evaluate groundwater quality in the Songnen Plain (Jilin), a field investigation sampling test, multivariate statistical analysis, and spatial analysis were conducted based on a geographic information system. The main substances exceeding the standard were screened out, and the main controlling factors affecting groundwater quality were discussed. The research result showed that nine components exceeded groundwater standards by approximately 10%: Al, total hardness (TH), total dissolved solids (TDS), Mn, As, NO3−, Fe, F−, and BaP. The over-standard of TDS and TH in groundwater are mainly distributed in the geological environment conditions and unreasonable exploitation and utilization of groundwater in this area. The results of the multi-index evaluation showed that the most important factors affecting groundwater quality were general chemical indices, followed by inorganic toxicology and heavy metals. Controlling the overexploitation of water resources, controlling agricultural activities and sewage discharge, and implementing water conservation systems are the main pathways to improve water quality in the study area. The research results can provide a reference for groundwater pollution control and water resource protection in the Songnen Plain (Jilin).