Annual Water Consumption Research Articles

Forecast of annual water consumption in 31 regions of China considering GDP and population

Abstract At present, water resources shortage has become one of the important factors restricting China's economic development, and water consumption prediction is the core task of water resources management. In this paper, a grey multivariate convolution model with adjacent accumulation (AGMC(1,N)) was proposed to predict the annual water consumption of 31 regions (provinces, municipalities and autonomous regions) in China under different growth rates of regional GDP and population. The results show that AGMC(1,N) model has a higher prediction accuracy. In addition, water consumption in more than 50% of the regions shows a downward trend due to the growth of regional GDP. Because of the influence of population, water consumption is also on the decline in more than 50% of areas. The predictive results can provide a basis for water resources management in China.

Comparative study on annual yield, water consumption, irrigation water use efficiency and economic benefits of different rice-oilseed rape rotation systems in Central China

Direct seeded planting pattern is considered as a practicable substitute to transplanting planting pattern because it has the advantages of saving labor, low input cost, high water use efficiency, and easy to manage. However, the comparison between different direct seeded rice-oilseed rape rotation systems and traditional transplanting rice-transplanting oilseed rape rotation system (TTR-TPO) has rarely been studied. In this study, the annual yield, water consumption, water use efficiency and economic benefits of different rice-oilseed rotation systems were compared during the rice and oilseed rape growing seasons from 2018 to 2020. Our results show that the average annual yield and water consumption of wet direct seeded rice-direct seeded oilseed rape rotation system (WDSR-DSO) and wet direct seeded rice-transplanting oilseed rape rotation system (WDSR-TPO) were significant higher than that of TTR-TPO and TTR-DSO. Annual yield of dry direct seeded rice-direct seeded oilseed rape rotation system (DDSR-DSO) and TTR-TPO was similar, but the water consumption of DDSR-DSO was reduced by 22.6% on an average than that of TTR-TPO. Irrigation water use efficiency (WUEi) and net economic return of DDSR-DSO were the highest, which were 72.3% and 15.2% higher than TTR-TPO, respectively. On the contrary, WUEi and net economic return was similar between WDSR-DSO, WDSR-TPO and TTR-TPO, traditional transplanting rice-direct seeded oilseed rape rotation system (TTR-DSO). Here, we show that DDSR-DSO is an alternative to TTR-TPO in central China due to higher WUEi and net economic return, less water consumption and similar annual yield. In addition, WDSR-DSO and WDSR-TPO may be suitable for regions where water levels are high for soil puddling during land preparation and rainfall is sufficient in the rice growth season.

Annual Water Consumption Forecast of Hefei Based on ARIMA Model

The ARIMA entity model was used in Hefei's current water demand coding sequence from 1990 to 2018. According to the ADF (Unit Root Test), it is clear that the number of differences d in the entity model is 2, and the main parameters in the entity model p, q are basic identification based on time series analysis related graphs, and based on the Akaike Information Content Rule (AIC) and other methods It is clear that the optimal entity model is ARIMA (1,2,1). ARIMA (1,2,1) is used to predict and analyze Hefei's water demand in the next two years. The results show that the reason for the deviation between the estimated value and the specific value is relatively small, indicating that the actual effect of the actual model predictive analysis is excellent.

Water-energy nexus approach for optimal design of hybrid cooling system in direct reduction of iron plant

Direct reduction of iron process in steel industry has special production conditions. Low quality cooling water, low cold and high hot cooling water temperature, space limitation for new equipment installation, high value-added of product and severe effect of cooling water temperature on production rate are of these conditions. Considering technical and economic constraints and limitations, this situation makes this process an attractive case study for converting the existing wet cooling tower to hybrid cooling system. In this paper, based on integration of process, dry and wet cooling system and ambient conditions profiles, a new method for designing hybrid cooling system has been proposed. The calculation program has been developed as a MATLAB code and resulted: 1) Calculation of annual water saving and energy consumption with reasonable accuracy, 2) Control system of dry and wet cooling blocks to maximize water saving under various ambient conditions, 3) Closed loop simulation of cooling system considering thermal feedback of process to cooling system and 4) Obtaining optimum values for 16 design parameters of dry block cooling (consisting air cooled heat exchanger and plate heat exchanger). The optimization has been done via genetic algorithm, considering annual response of each design under various ambient temperature and relative humidity. Considering design standards for new equipment and operational and technical constraints, made the optimization model reliable as well as checking the design parameters with process equipment constructors. In optimum point, converting existing wet cooling tower to hybrid cooling system in direct reduction of iron plant of Mobarakeh Steel Complex located in Isfahan province in Iran, will decrease the annual water consumption by 70.15% and production loss by 98% with payback period of 1 years and 10 months.

Problems and Countermeasures in Protection of Drinking Water Sources in Hubei Province

This paper introduces the current situation of drinking water sources in Hubei Province, and points out that in the new period of harnessing the Yangtze River, the drinking water sources are faced with prominent contradictions such as low annual water consumption and prominent non-point source pollution. At the same time, the emergency standby water source is insufficient, and the water production technology of water supply enterprises needs to be improved. In order to ensure the optimal allocation and rational utilization of water resources, some suggestions are put forward, such as controlling the non-point source pollution system, actively promoting the construction of standby water source, and timely upgrading the water supply treatment process of water plants.

Influence of the water discharge of the Kuibyshev reservoir on the dynamics of the ecosystem of the Seredysh and Bakhilovsky islands, the Volga River, Russia

The state of the ecosystem of the protected islands Seredysh and Bakhilovsky (former Shalyga) is significantly affected by the water consumption in the power site of the Zhigulevskaya Dam. The 62-year dataset was analyzed to study the patterns of temporal variability of water discharge from the filling of the Kuibyshev Reservoir to the present. Long-term variability of the water discharge is due to climatic conditions in the Volga River basin, it follows to some extent the 22-year cycle of solar activity. Natural seasonal variability of the water discharge is altered by regulation at the Zhigulevskaya Dam, especially under unfavorable conditions for the formation of the water flow. The periods of low-water, high-water and medium water content were defined in regard to the annual water consumption. The low-water period lasted 19 years from 1958 to 1976, the high water period, 20 years from 1977 to 1998, and the period of medium water availability, 23 years from 1999 through 2019. Extreme high-water and low-water years, which had an adverse effect on the functioning of the islands’ ecosystem, were calculated using the empirical data on the water flow rate. During the spring flood of extremely high-water years, the water level in the reservoir increased sharply, so a part of the island was flooded. In the summer dry season of extremely dry years, the water level decreased, so the island area increased due to the shore retreat and appearing of sandbanks around the island. The negative impact of the water discharge on the ecological state of the islands may increase if the rules for regulating the water flow at the Zhigulevskaya Dam are violated.

Investigation on geothermal water reservoir development and utilization with variable temperature regulation: A case study of China

Geothermal heating technology is an important technique for alleviation of energy crisis and environmental pollution. A numerical simulation and multi-objective optimisation for geothermal heating systems are conducted considering factors such as the heating load, heating modes, and region characteristics. Heating modes play a vital role in the utilization of geothermal reservoirs. It is found that regulated geothermal heating system can postpone the formation of thermal breakthroughs and shrink radius of the cold front. It’s also indicated that well spacing and production rate are the two main factors affecting the production performance and emission reduction of geothermal heating systems. Construction investment of geothermal wells and the annual water consumption of regulated geothermal heating system decreases by up to 30% and 60%, comparing with unregulated geothermal heating system, although electricity costs increase by 5% to 25%. Multi-objective optimized heating system parameters for Qingfeng project in China are achieved. The best regulated geothermal heating system with well spacing of 295 m and production rate of 100 m3/h generates the highest efficiencies in terms of heat production, emission reduction, and economic performance. The mathematical model and multi-objective optimization model can provide references for utilization of geothermal heating technology in other places with similar conditions.

Irrigation water consumption of irrigated cropland and its dominant factor in China from 1982 to 2015

Quantifying and mapping regional and global irrigation water consumption have attracted considerable attention from researchers. The existing models cannot accurately estimate the long-term sequence of irrigation water consumption at the regional scale. Despite being among the countries with the largest irrigated areas, China has not been specifically evaluated in terms of high-resolution long-term irrigation water consumption. In this paper, an irrigated cropland water model incorporating irrigated cropland mapping, the soil water balance equation, irrigated crop phenology, and partitioning evapotranspiration products was developed to fill the knowledge gap. We found that (1) the mean annual total irrigation water consumption of irrigated cropland in China during 1982–2015 was approximately 179.43 ± 24.60 km3. (2) The continued expansion of irrigated farmland dominated (67.2% ± 5.6%) the significant increase in annual total irrigation water consumption (slope=2.03 km3 yr−1, p<0.01), followed by changes in crop management practices (16.7% ± 6.1%), and the impacts of interannual climatic variability (represented by precipitation and potential evapotranspiration in this research) were weak. (3) The annual total irrigation water consumption in the arid zone increased quicker than that in wet regions.

Development and utilization of water resources and assessment of water security in Central Asia

The utilization of water resources and water security in Central Asia are critical to the stability of the region. This paper assesses the water security of the five Central Asian countries (Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan) by using the projection pursuit model based on particle swarm optimization (PSO-PEE). The results show that the average annual water consumption in Central Asia is about 1255.57 × 108 m3, and the proportion of agricultural water consumption decreased due in large part to the changes of crop planting structure. For the ecological security, Kazakhstan, Tajikistan and Kyrgyzstan have improved their status, but Turkmenistan is getting worse. For the quantity security of water resources, Tajikistan and Kyrgyzstan are relatively safe, whereas Uzbekistan is at risk. For the socio-economic conditions, Kazakhstan scored the highest, while Tajikistan and Uzbekistan scored the lowest, water consumption per 10,000 dollars of GDP across all five countries is relatively high but shows a significant decreasing trend. For the water supply and demand security, the status of Kazakhstan, Kyrgyzstan and Tajikistan are better than that of Turkmenistan and Uzbekistan. Kazakhstan has achieved a relatively safe level (level Ⅱ) and the degree of water security is high. Kyrgyzstan, Tajikistan and Turkmenistan are only in the basically safe level (level III). Uzbekistan is under significant pressure with regard to water security (level IV), which indicates that the country needs to strictly control population growth and strengthen the comprehensive management of water resources.

The height of a damless water intake structure threshold

More than 80% of the annual water consumption in Uzbekistan comes from large transboundary rivers such as the Amu Darya and Syr Darya. The rest of the water is formed on the territory of the Republic. Almost all year round, the turbidity of the Amu Darya and Zaravshan rivers is 3÷5 g/l, reaching 15÷18 g/l during flood periods.in most cases, water from the rivers is taken into irrigation channels using damless water intake structures. In order to prevent the ingress of bottom sediments from rivers into channels, thresholds have been constructed at water intake structures, the height of which is set constructively. As a result, bottom sediments pass through thresholds and move along the bottom of channels, reducing their cross-sections, as well as filling the chambers of pumping stations and pressure basins of hydroelectric power plants with sediments. After getting into the flow parts of pipelines and hydraulic machines (pumps and hydraulic turbines), they lead to abrasive wear, as well as other negative consequences. A lot of work has been done to prevent sediment from entering through water intake structures, but so far none of these proposals has provided an effective solution. In the laboratory of the Tashkent Institute of irrigation and agricultural mechanization engineers, a series of experiments were conducted on a glass hydraulic tray to determine the height of bottom sediments, taking into account their heterogeneity. Based on experiments, the dependence on determining the height of the ridge is derived. Based on the obtained dependence, a method for determining the height of the threshold of a damless water intake structure is proposed. This technique was experimentally tested on a laboratory tray. Specifying the threshold height will lead to optimization of capital costs for the construction of the threshold of the water intake structure, as well as reduction of operating costs for cleaning channels from sediment and repair work of hydraulic machines from hydroabrasive wear.

Transient simultaneous heat and mass transfer model to estimate drying time in a wetted fur of a cow

To reduce heat stress that contributes to complications in milk production and breeding, dairy cows are typically cooled by intermittent water sprays coupled with fan-induced air flow. Industry currently utilises fixed duration on and off-cycles; however, water efficiency may be improved by matching the sprinkler off-time to the cow drying time that corresponds to current outdoor environmental conditions. Electricity use can also be reduced by varying fan speeds to achieve the required heat rejection rate for a given set of conditions. To achieve savings in water and electricity, a transient, one-dimensional simultaneous heat and mass transfer model of evaporation within the wetted fur layer of a dairy cows was developed to estimate drying time and heat rejection rate based on ambient conditions. Water vapour concentration, liquid water content, and temperature within the fur layer were used to estimate a global drying time for fur. Model results was compared against a steady-state model in literature and the predicted net heat load is within 15% with a mean average error of 6.0%. Parametric analyses were performed to estimate drying time as a function of outdoor air temperature, air speed, humidity, and mean radiant temperature. Simulation results were used to develop a correlation for use in a control algorithm to predict the fan speed and sprinkler operation frequency needed to meet specified cooling load thresholds given outdoor conditions. Estimated savings demonstrated that the model-based controller could reduce annual electricity and water consumption by 20% and 40%, respectively. • Transient one-dimensional model for prediction of drying time from wetted cow fur. • Drying variation with outdoor temperature, humidity, air speed and roof temperature. • Predictive controller correlation based on regression of model simulation runs. • Controller shown to lower annual electricity by 20% and water consumption by 40%.

Benchmarking of water consumption and waste management in multi-unit residential buildings (MURBs) in Toronto

Water and solid waste benchmarking and developing meaningful performance indicators can help government and building owners to make effective decisions on improving their buildings’ efficiency and sustainability. For this study, information on 120 multi-unit residential buildings (MURBs) has been collected and analyzed. The study entails the following steps: performing water and solid waste benchmarking for the 120 MURBs, developing meaningful performance indicators; determining performance ranking; and estimating different levels of savings (water, solid waste, cost, and GHG emissions). The most appropriate performance indicator and the benchmarking range for water and solid waste are as follows: water consumption normalized by square metre, 1.06–4.19 m3/m2; solid waste benchmarking normalized by number of units, 1.58–17.4 yd3/unit. Also, the MURBs domestic hot water system efficiencies are found to be very low (with overall system efficiency in the range of 35% to 45%). A relatively strong correlation is found between annual natural gas consumption and annual water consumption.

3E (Energy-Exergy-Economic) comparative study of integrating wet and dry cooling systems in solar tower power plants

Unlike conventional power plants based on fossil fuels, which are generally erected in the coastal regions, where water resource availability is not a critical limitation, concentrating solar power (CSP) plants are usually installed in desert zones where there is a lack of water resources. In this regard, the main aim of the present study is to investigate the effects of deploying dry cooling option on the techno-economic performances of a solar tower power plant (STPP), in terms of energetic and exergetic yields, as well as total investment cost, net present value, and levelized cost of electricity.The obtained results show considerable drops in energy and exergy yields of the simulated plant with integrated dry cooling system compared to the one with the classic wet cooling mode. Furthermore, there are clear increases in the investment cost, as well as the levelized cost of electricity in the first plant. However, the main advantage of integrating dry system to solar tower power plants is to reduce its annual water consumption by almost 94.40%. The importance of this study is to define the main additions and shortcomings of using dry cooling system in solar thermal power plants, and which stage of the process needs to be improved.

A SAFSA- and Metabolism-Based Nonlinear Grey Bernoulli Model for Annual Water Consumption Prediction

A SAFSA- and Metabolism-Based Nonlinear Grey Bernoulli Model for Annual Water Consumption Prediction

Impacts of climate change and agricultural activities on water quality in the Lower Kaidu River Basin, China

In the context of climate change and over-exploitation of water resources, water shortage and water pollution in arid regions have become major constraints to local sustainable development. In this study, we established a Soil and Water Assessment Tool (SWAT) model for simulating non-point source (NPS) pollution in the irrigation area of the lower reaches of the Kaidu River Basin, based on spatial and attribute data (2010–2014). Four climate change scenarios (2040–2044) and two agricultural management scenarios were input into the SWAT model to quantify the effects of climate change and agricultural management on solvents and solutes of pollutants in the study area. The simulation results show that compared to the reference period (2010–2014), with a decline in streamflow from the Kaidu River, the average annual irrigation water consumption is expected to decrease by 3.84x108 m3 or 8.87% during the period of 2040–2044. Meanwhile, the average annual total nitrogen (TN) and total phosphorus (TP) in agricultural drainage canals will also increase by 10.50% and 30.06%, respectively. Through the implementation of agricultural management measures, the TN and TP in farmland drainage can be reduced by 14.49% and 16.03%, respectively, reaching 661.56 t and 12.99 t, accordingly, and the increasing water efficiency can save irrigation water consumption by 4.41 x108 m3 or 4.77%. The results indicate that although the water environment in the irrigation area in the lower reaches of the Kaidu River Basin is deteriorating, the situation can be improved by implementing appropriate agricultural production methods. The quantitative analysis results of NPS pollutants in the irrigation area under different scenarios provide a scientific basis for water environmental management in the Kaidu River Basin.

Energy and Exergy Analysis of Steam Source Optimization for Boiler Soot Blowing System

In order to improve the economy of boiler soot blowing system, the steam source position of boiler soot blowing system should be optimized. For a 1000MW ultra-supercritical coal-fired unit, the thermodynamic process of soot blowing steam in temperature and pressure reducing station was studied through energy analysis and exergy analysis in this paper, and it was revealed that the annual water and energy consumption of boiler soot blowing system was independent of the steam source position, the change of steam source position only affected the annual exergy loss of soot blowing system. The comparion results indicated that the annual exergy loss of soot blowing system with cryogenic reheater outlet as steam source was minimal. After adopting cryogenic reheater outlet as the steam source position of soot blowing system, it would be more economical than the original soot blowing system with platen superheater outlet as steam source. The annual exergy loss would be reduced by about 2.183×1010kJ, and it was equivalent to an annual increase of power generation revenue by about 2486000CNY.

РОЗРАХУНКОВІ ХАРАКТЕРИСТИКИ СЕРЕДНЬОГО РІЧНОГО СТОКУ ВОДИ ПРАВОБЕРЕЖНОЇ ТА ЛІВОБЕРЕЖНОЇ ЧАСТИН БАСЕЙНУ Р. ДНІСТЕР ДО М. ЗАЛІЩИКИ

The Dniester River is the second longest and most watery river in Ukraine, which is characterized by heterogeneity and diversity of conditions for the formation of water flow, both in terms of its length and numerous tributaries. The right-bank and left-bank parts of the Dniester River basin are quite different in terms of physical and geographical conditions, drainage network density, water regime and river water content. The object of the study is the average annual water flow of the rivers of the Dniester River basin, the subject is its calculated characteristics of different probabilities of exceeding. The purpose of the study is to analyze, systematize, generalize and compare the calculated characteristics of the average annual water flow of rivers of the right-bank and left-bank parts of the Dniester basin. Input data is based on the average annual river water discharge from 50 stream flow measuring stations in the Dniester River basin (to Zalishchyky). The data bank was formed from the beginning of observations until 2016. 89% of 28 right-bank stream flow measuring stations have a continuous series of more than 50 years, and 86% of 22 left-bank stream flow measuring stations have a continuous series of observations of more than 50 years. As for the catchment areas of rivers in the closing areas, the right bank is dominated by small ones – 64% of 28 stations have an area of less than 500 km2 and 25% – from 500 to 1,000 km2. 37% of 22 stations on the left bank have a catchment area of less than 500 km2 and 41% – from 500 to 1,000 km2. According to statistical criteria, the series of observations of the average annual river water discharge in both parts were mainly homogeneous and representative. Analytical distribution curves were calculated by the method of moments, as the coefficients of variation do not exceed 0.50. Generalization and comparison of the calculated characteristics of the average annual water flow of different probabilities of exceeding the rivers of the right-bank and left-bank parts of the Dniester basin have shown that the smallest scatter of certain analytical ordinates is observed for the probability of exceeding 50%, the transition coefficients from the norm are close to 1. The greatest spread of variation of ordinates is observed at extreme probabilities of excess of distributions, that is 0,01 % and 99 %. Analysis of the ranges of variability of transition coefficients from the norm of average annual water consumption has shown that the intensity of their change in the region of rare probabilities (0.01, 0.1, 1 %%) on the left bank is more significant than on the right bank of the Dniester basin. As for low-water supplies (95, 97, 99 %%), their ranges of variability coincide in both studied parts.

Изменение водности реки Волги в районе заповедного острова Бахиловский

The ecological state of the protected Islands Seredysh and Shalyga (now Bakhilovsky island) depends on the water content and flow of the Volga River. We have analyzed the long-term changes in the water flow of the Volga River for the period 1958-2017 in the alignment Zhiguli dam, located 12 km upstream from the island. According to the average annual water consumption, there are three periods that differ from each other in water content: low-water period (1958–1976), high-water period (1977–1997) and the period of average water content (1998–2017), with extremely low-water (1967, 1973, 1975, 1976, 1977, 1996) and extremely high-water (1966, 1979, 1981, 1990, 1991, 1994) years. In highwater years, during the passage of the spring flood, the island is almost completely flooded, and in low-water years, during the summer low water, the area of the island increases and changes its configuration.

ПОРІВНЯЛЬНЕ ОЦІНЮВАННЯ ВНУТРІШНЬОРІЧНОГО РОЗПОДІЛУ СТОКУ ВОДИ РІЧОК РОСІ ТА УБОРТІ

The article examines the intra-annual distribution of water runoff of the Ros and Ubort rivers, as well as its comparative assessment. The rivers Ros and Ubort were chosen for further research, because according to geographical conditions, river basins belong to natural and regulated water bodies. The rivers Ros and Ubort are characterized by summer-autumn and winter lows, which are disturbed by separate rises in water levels during rains or melting snow. The formation of the main part of river runoff is due to spring flooding. The initial data for studying the intra-annual distribution of runoff were the data of average annual water flow in the confluence of the rivers Ros and Ubort, namely: the river Ros – Korsun-Shevchenkivsky and the river Ubort – Perga for the entire period of hydrological observations. The initial data are the average annual water consumption of the closing sections of the Ros and Ubort rivers for the entire observation period. To confirm (or refute) the changes in the water content of the studied rivers, the homogeneity of some of their runoff characteristics was analyzed by different methods. Statistical methods for estimating the homogeneity of hydrological series are used for quantities that are random and internally independent. The homogeneity of the series of average annual water consumption over a multi-year period is estimated according to the current hydrological posts of the basins of the rivers Ros and Ubort. The analysis of previous publications on the intra-annual distribution of river water runoff for the territory of the studied river basins, the influence of climatic factors on the change of river runoff, as well as summarizes the results of these studies. The intra-annual distribution of river water runoff for years of different water content and separate phases for the basins of both studied rivers is calculated by the season composition method. The comparative characteristics of the obtained results are carried out and the common hydrological characteristics and significant differences in the studied river basins are revealed.

Lessons Learned from the First Passivhaus Building in Qatar

Energy efficient models have become the path to reduce energy consumption and Greenhouse gas emissions in the built environment in many developed countries. According to the Energy Performance of Buildings Directive (EPBD), new buildings constructed within the European Union (EU) countries are expected to be nearly zero energy buildings (nZEBs) by 2020, while new public buildings are expected to adhere to this target by 2018. The Passivhaus approach has been identified by several researchers as a possible roadmap to achieve nZEBs. The meticulous engineering and high standards of the Passivhaus building fabric, in addition to the high comfort levels, are the main reasons behind the success and widespread of the standard. Recently, in 2013 the Passivhaus principles have been applied to an experimental residential project in the hot and arid climate of Qatar. The project is composed of two identical buildings, one built according to the Passivhaus standard and the other according to normal practices in the country. The thermal performance and comfort levels of both buildings were assessed through dynamic simulation and on-site measurements. Results indicated that at least 50% reduction in annual operational energy, water consumption, and CO2 emissions were achieved in the Passivhaus model in comparison to the standard model. This paper aims to highlight the lessons learned through the Passivhaus project; first by exhibiting the Passivhaus criteria that have been met, second by showcasing the outcomes of the project, and third by displaying the barriers and difficulties that have been associated with building according to the standard in Qatar. Finally, recommendations and general guidelines are suggested towards a possible adoption of the Passivhaus standard in Qatar and the Gulf Cooperation Council (GCC) countries