Water-saving Technologies Research Articles

Co-development of East African regional water scenarios for 2050

Summary The development of and access to freshwater resources in East Africa is fundamental to the region's sustainable development goals. Following vision documents for regional development and working with local stakeholders, we developed water scenarios up to 2050 that inform the hydro-economic modeling analysis of the extended Lake Victoria Basin, the headwaters of the Nile River. Water scenarios that take an integrated approach to assessing the combined effects of climate change, land use, and increasing human water use suggest that the flow regime of the Nile may remain relatively stable. However, if this stability is to be achieved, while at the same time sufficient water is preserved for healthy freshwater ecosystems, a large fraction of water infrastructure must rely on advanced, often costly technologies and management. Interconnected analyses of both upstream and downstream water resources over time, guided by co-developed scenarios, are indispensable for planning sustainable water-development pathways.

Did water-saving irrigation protect water resources over the past 40 years? A global analysis based on water accounting framework

Water-saving technologies have long been seen as an effective method to reduce irrigation water use and alleviate regional water shortage. However, growing reports of more severe water shortage and increasing application of water-saving technologies across the world have necessitated reassessment of agricultural water-saving. This study develops a simple method based on satellite-based ET partitions to estimate water withdrawal, water consumption and return flow from the 1980s to 2010s, and quantifies water-savings across globe and four hot-spot irrigated areas at both field and regional scales based on water accounting framework. The results show that global irrigation water flows keep increasing from the 1980s to 2010s, with over 50% increase from the expansion in irrigated lands. While water-saving technologies are found mainly applied in originally old irrigated lands, traditional flooding irrigation is still dominant in newly-developed irrigated lands. Non-beneficial water consumption (soil evaporation) is effectively reduced by water-saving technologies, but return flow has increased at the same time. At field scale, water-saving technologies fail to save water because the accumulated increased return flow is more than the accumulated decreased non-beneficial water consumption. At regional scale, however, water is saved because the return flow percolated to fresh aquifers is seen as beneficial rather than loss. At the same time, the accumulated increase of beneficial water consumption (crop transpiration) exceeds regional water savings, which explains the paradox between wide application of water-saving technologies and more severe regional water shortage. This study provides key new evidence for the paradox of irrigation efficiency and helps reconsidering water-saving technologies and their impacts on regional water resources.

Predicting the Water Rebound Effect in China under the Shared Socioeconomic Pathways.

The rebound effect exists widely in the fields of energy, irrigation, and other resource utilizations. Previous studies have predicted the evolution of different resource utilizations under the shared socioeconomic pathways (SSPs), but it is still unclear whether total water use has a rebound effect. This study uses the SSPs as the basic prediction framework and evaluates the water resources and economic status of the provinces in China using the hydro-economic (HE) classification method. Then, combined with the SSPs scenario setting parameters, the conditional convergence model and the method recommended by the Food and Agriculture Organization of the United Nations (FAO) are used to simulate the changes in water use efficiency of the different provinces in China under different scenarios. Based on the future GDP forecast data of China’s provinces, combined with the forecast of water use efficiency changes, the total water use changes in China’s 31 provinces under different pathways from 2016 to 2030 are calculated. Among them, the future GDP data is predicted based on the Cobb–Douglas production function and SSPs scenario settings. Using a comprehensive evaluation of the evolution of the efficiency and the total amount, this study reveals whether there is a rebound effect. The results showed that with the continuous growth in the water use efficiency, the total water use had a “U” type trend, which indicated that there was a rebound effect in the total water use of China under the different SSPs. Based on this information, this study proposes some suggestions for irrigation water-saving technologies and policies.

The impact of urbanization and aging on food security in developing countries: The view from Northwest China

Different from the urbanization and aging population challenges experienced by developed countries, developing countries face huge impacts of these challenges on food security. Previous studies on the effects of urbanization and an aging population in developing countries on food security were mostly qualitative discussions and focused on individual aspects of grain production or consumption. In this paper, we combine rural household survey data with statistical data to comprehensively assess and reveal the impact of these two factors on food security in developing countries. Their impact on food security has both negative and positive aspects. Taking Northwest China as an example, the grain yield of every family will increase by 26.0 and −9.4 kg (P < 0.05) for every 1% increase of these two factors. For every 1% increase in urban and elderly population, regional grain consumption will increase by 0.07% and −0.09%, respectively. The negative impact of urbanization on the agricultural labor force and farmers’ enthusiasm for growing grain is gradually increasing. Along with urbanization, food consumption of urban and elderly populations increased by 1.3 and 0.5 times, respectively, from 2000 to 2016. Coupled with the preference of urban residents for animal-based food products (the average annual consumption growth rate is 2.7%), the per capita food demand continues to increase, which brings about food security challenges. However, the improvement of these two factors promotes the development of agricultural mechanization and water-saving technology. This not only addresses the negative impact of labor shortage in grain production, but also reduces the grain water footprint and promotes its sustainable development. Based on the above research results, this paper proposes to use the economic benefits of urbanization to feedback to rural areas: strengthen technical guidance, train farmers and invest in machinery and equipment to promote the development of smart agriculture, and increase and refine agricultural subsidy policies to ensure the sustainable development of food production. The study can serve as a reference for other developing countries and ultimately contribute to ensuring global food security.

The potential for expansion of irrigated rice under alternate wetting and drying in Burkina Faso

Achieving rice self-sufficiency in West Africa will require an expansion of the irrigated rice area under water-scarce conditions. However, little is known about how much area can be irrigated and where and when water-saving practices could be used. The objective of this study was to assess potentially irrigable lands for irrigated rice cultivation under water-saving technology in Burkina Faso. A two-step, spatially explicit approach was developed and implemented. Firstly, machine learning models, namely Random Forest (RF) and Maximum Entropy (MaxEnt) were deployed in ecological niche modeling (ENM) approach to assess the land suitability for irrigated rice cultivation. Spatial datasets on topography, soil characteristics, climate parameters, land use, and water were used along with the current distribution of irrigated rice locations in Burkina Faso to drive ENMs. Secondly, the climatic suitability for alternate wetting and drying (AWD), an irrigation management method for saving water in rice cultivation in irrigated systems, was assessed by using a simple water balance model for the two main growing seasons (February to June and July to November) on a dekadal time scale. The evaluation metrics of the ENMs such as the area under the curve and percentage correctly classified showed values higher than 80% for both RF and MaxEnt. The top four predictors of land suitability for irrigated rice cultivation were exchangeable sodium percentage, exchangeable potassium, depth to the groundwater table, and distance to stream networks and rivers. Potentially suitable lands for rice cultivation in Burkina Faso were estimated at 21.1 × 105 ha. The whole dry season was found suitable for AWD implementation against 25–100% of the wet season. Soil percolation was the main driver of the variation in irrigated land suitability for AWD in the wet season. The integrated modeling and water balance assessment approach used in this study can be applied to other West African countries to guide investment in irrigated rice area expansion while adapting to climate change.

Strategic decision-support modeling for robust management of the food–energy–water nexus under uncertainty

Food, energy, and water (FEW) are interconnected pillars that underpin the security of people’s livelihoods. In this paper, we propose a decision-support model to better understand and aid management of regional FEW nexus systems under uncertainty. We apply the model to a case study focusing on fluctuations in water supply, which significantly affect production in the agriculture and energy sectors in Shanxi Province, China. We use a two-stage, stochastic, chance-constrained programming approach to the proposed spatially detailed cost-minimizing FEW nexus model under demand and natural resource (land and water) constraints. This approach translates the target reliability level (i.e., the probability that the devised solution can satisfy all constraints) into a penalty that has to be paid in the case of their non-fulfillment. On this basis, robust decisions (i.e., production options suitable for a broad variation in certainty of water supply) are derived. Using this approach, we estimate the penalties required to achieve given levels of reliability by incentivizing the deployment of water-saving technologies. For example, our model predicts that water storage would become cost-effective if the penalty for exceeding the available water supply were 2.5 times higher than the current price for industrial water; this would enable at least 40% reliability compared to 18% if the penalty were at the current water price level. Taking advantage of the differences in water intensity of crops in different sites, our model optimizes the reservoir location, which allows water withdrawal by agriculture to be reduced by 1.23%. We also evaluate the benefits of incorporating uncertainty and missed opportunity due to a lack of perfect information. In the case study, we show that the benefits of including uncertainty in the form of the two-stage stochastic programming approach appear to be quite significant, reaching 4% of the total solution costs. Water-importing costs, taxes, and subsidies are instruments that translate into the penalty in this model; the modeling approach presented here can thus be used to inform cost-effective and robust management of the FEW nexus in Shanxi Province, China, and other water-scarce regions around the world.

Decoupling economic growth from water consumption in the Yangtze River Economic Belt, China

Decoupling economic growth (EG) from water consumption (WC) is crucial to regional sustainable development. Therefore, it is necessary to analyze the spatial and temporal decoupling of WC and EG, and then to identify the feasible paths for achieving the desired level of decoupling. Firstly, this paper measures the WC of the provincial areas in the Yangtze River Economic Belt (YREB) from 2004 to 2017 by using the water footprint (WF) method; Secondly, the decoupling analysis of WF and EG is carried out based on the Tapio decoupling model, furthermore, the spatial autocorrelations of decoupling results are examined by the Moran’s I index with three different spatial weight matrices; Finally, the paths of achieving strong decoupling (SD) of WC and EG are explored by using the static fixed effect regression model. Three main conclusions can be drawn: (1) The WFs of most provincial areas in the YREB show an overall increasing trend and there are huge disparities among the provinces in terms of their WFs; (2) The WF and EG in the YREB are decoupled either strongly or weakly. More SD has been achieved since 2015 in general. No spatial autocorrelations are observed; (3) Reducing the WF as the economy grows is a necessary condition for achieving SD. Moreover, developing water-saving technologies is a key path of achieving SD since it has huge positive impact on WF reduction. In a nutshell, this study provides a novel framework and results that can be used as an evaluation index and policy insights for decoupling EG from WC.

Analysis on energy saving and environmental protection in building design

The goal of the concept of environmental protection and energy conservation is to promote the development of resource economy. In the process of my country's economic development, the ecological environment has been destroyed and the resource situation is not optimistic. Implementing the concept of environmental protection and energy conservation in the design of building water supply and drainage can increase resource utilization, weaken the damage to the environment by project construction, reduce project costs, and alleviate the current situation of resource shortage in my country. Combining this situation, this article focuses on analyzing the importance of the application of energy-saving and water-saving technologies in the construction of building water supply and drainage and the specific application of energy-saving and water-saving technologies.

Study on water saving strategy of students' dormitory in Chifeng University

In order to solve the problem of waste of living water in Chifeng College Students' dormitory, the actual situation of water consumption in student dormitory was investigated. This paper analyzes the potential of water-saving and water-saving technology and strategy of Chifeng College, and finds out the water-saving mode suitable for the dormitory of Chifeng College. On this basis, the research on the application of reclaimed water treatment technology and the construction of reclaimed water treatment station in Chifeng university is carried out. This study provides theoretical and experimental support for solving the problem of water-saving in Chifeng College.

The technique development of non-washing of mineral fertilizers in the soil through the screen formed on the interpolymer complex basis

The problem of global climate change is on the agenda of mankind, not only because of the average annual temperature rise on the planet but also because of changes in the entire geosystem, rising global oceans, melting ice and permanent glaciers, increasing uneven rainfall, changing river flow patterns and climate instability, other changes involved. The world pays special attention to research work to develop technologies for the management and efficient use of water resources. In particular, it is important to conduct research to develop new water-saving irrigation technologies using cheap and chemical, and technical means.

Climatic adaptation as priority of sustainable development of the agrifood system in the southern regions of Russia

The article presents current and prospective estimates of the climatic changes parameters and their contradictory impact on the productivity of the agrifood system in the country’s southern regions. In the period up to 2030-2050, against the background of an increase in heat supply and duration of crop season, a mixed arid-humid type of moistening will have been predicted with an increase in aridization towards an increase in the frequency of droughts, including soil ones, as well as increased harmfulness of certain types of agricultural pests and pathogens. A new climate-adapted paradigm of sustainable development of the agrifood system in the South of Russia, based on Climate-Smart Agriculture, is proposed. The priority measures of climatic adaptation of the agrifood system in the South of Russia are grounded in connection with the growth of the spacing of winter crops, heat-loving, fruit and berry crops, vineyards; water-saving and moisture-retaining technologies; phytosanitary measures for the prevention and control of climate-dependent pests; agrotechnical methods of increasing the adaptive potential of crops to climate change; climate-adaptive schemes for the use of pastures; engineering of highly productive and climate-resistant agrophytocenoses and agroecosystems. Measures to stimulate climatic adaptation of the agrifood system in the South of the Russian Federation should involve the development and inclusion in the sectoral State Program of the Russian Federation of the Adaptation of Agriculture of the Constituent Entities of the South of the Russian Federation to Climate Change pilot section with an annual competition of regional agro-climatic projects based on budget COFUND; financing farms for the implementation of climate-adapted and related agricultural activities, climate insurance.

Effective and rational use of irrigation water in the conditions of the republic of Karakalpakstan

The lack of water that has been repeated in recent years dictates the requirements of a strict regime of water conservation and economical use of water. Understanding the need for strict water conservation and the fight against unproductive water losses must be started with the producers of agricultural products, i.e., from farms, as rational water use and water conservation at the field level could save a significant amount of irrigation water. The article reflects the current state of water use in irrigated agriculture in the Republic of Karakalpakstan. The main, inter-farm, and intra-farm canals have been studied in detail, and the mode and efficiency of their work have been assessed. The obtained results of the conducted field research works on irrigation technologies are presented. Suggestions on the choice of water-saving irrigation technologies are given, as well as recommendations on the effective use of irrigation water in the non-growing season.

Review on research of water saving for natural ventilation cooling tower

Thermal power plant is one of the eight high water consumption industries in China, and circulating cooling water is the largest water consumption project. Under the increasingly severe situation of water resources in China, measures must be taken to reduce the evaporation loss, wind blowing loss and pollution discharge loss of natural ventilation cooling tower. Based on the comprehensive summary of water-saving technology of natural ventilation cooling tower, we compared the advantages and disadvantages of various technologies to provide a basis for water-saving transformation of cooling tower.

Characterization and Classification of Soils of Zamra Irrigation Scheme, Northeastern Ethiopia

Understanding soil types of a given area is an important prerequisite to design optimum management strategies such as irrigation water management. The study was thus conducted on characterization and classification of Zamra irrigation scheme in Abergelle district of Amhara Region, which has an area of 196.16 ha. For this study, 53 auger observations, four profile pits, extensive visual observations, reconnaissance survey, and descriptions of soil profiles and laboratory analysis were used to study the morphological and physicochemical properties of the soils of the scheme. Twelve disturbed and undisturbed soil samples were collected from all profiles of each genetic horizon for laboratory analysis. The soils of the study area were identified based on Food and Agricultural Organization of the United Nations/World Reference Base for Soil Resources (FAO/WRB) 2015. The results revealed that the textural classes of all profiles of the study site ranged from sandy clay loam to sandy loam. The chemical properties of the soil in terms of total nitrogen, organic matter, and available phosphorus were in the very low and low categories as per the criteria developed by Tekalign and Olsen, respectively, whereas exchangeable bases (Ca, Mg, K, and Na), cation exchange capacity, and extractable micronutrients (Fe, Mn, Zn, and Cu) were medium to high. Based on morphological, physical, and chemical analyses, the soils were classified as Leptic Regosols (Eutric, Loamic; 21.99% of the area), Vertic Cambisols (Hypereutric; 17.87%), Haplic Regosols (Eutric; 36.69%), and Rhodic Nitisols (Eutric; 23.44%). Therefore, management techniques that enhance soil fertility (including crop rotations, manuring, fallow periods, proper management of crop residues, and leguminous cover crops) and water-saving technologies suitable to the terrain of the area are the best options to enhance land productivity in the area.

Issues of assessment of the surface area effect on irrigated water consumption

This article focuses on improving water-saving technologies for efficient use of water resources, the development and recommendation of modern irrigation methods, and assessing the impact of surface area on irrigation water consumption.

Study of irrigation characteristics and improvement of irrigation techniques using interpolymer complex-based anti-filtration screen

In the world, special attention is paid to targeted research on water resources management and efficient use of irrigation water resources. In this regard, one of the main tasks is to improve the technique of irrigation of fields using cheap chemical and technical means, the development of new methods of water-saving irrigation, the development of the theory of water-saving technologies in irrigation of fields. In this regard, the use of inexpensive interpolymers to reduce soil composition and irrigation water infiltration is of particular importance.

Hydraulic calculation of reliability and safety parameters of the irrigation network and its hydraulic facilities

Nowadays, more than 155.7 thousand km of irrigation networks are operated by WUA, farms and clusters. 95% of irrigation networks were built and commissioned in the 80s of the last centuries.The parameters of the irrigation canals, built in the 70-80s of the XX century, are set for irrigation of cotton and alfalfa irrigated agriculture during the growing season 170-210 days. Irrigation networks have been designed for this crop rotation scheme.Since 1993, the rotation scheme has changed to cotton-wheat. Irrigation networks began to operate continuously throughout the year after the transition of agricultural production to the cultivation of autumn cereals, which require irrigation from October to May. As a result, it has become difficult to carry out repair work on irrigation networks.In addition, irrigation networks have been designed, built and operated by adapting crops to traditional irrigation systems. In recent years, large-scale work has been carried out on the widespread implementation of water-saving technologies in agriculture.

Up-scaling Water Saving Technologies in Rice Cultivation under Corporate Social Responsibility

Rice crop being the major consumer of water, the water use efficiency of growing rice crop is low compared to other field crops. The promising technologies on water saving in rice were advocated to the farmers on corporate social responsibility basis by upscale and popularization of these techniques among poor land holding farmers in rice growing locations of Villupuram district of Tamil Nadu State in India. The main objective of the study was to bring awareness among farmers on water saving technologies in rice production, thereby increasing water usage efficiency and enhanced grain yield. Field demonstrations were carried out in 25 locations each separately in Villupuram district for up scaling water saving technology in rice cultivation like System of Rice Intensification (SRI) and Alternate Wetting and Drying Irrigation (AWDI). SRI compared with conventional transplanted rice (CTR) and AWDI with flood irrigation as farmers' practice. The bio-metric observation data was recorded in the demonstration field plots. The average mean data was computed and used for analysis. SRI has showed higher yield attributes viz., Productive tillers (19) and 174 number of grains/panicle over CTR, besides enhanced water productivity of 0.63 kg/m by minimizing the no. of irrigation to 19 and quantum of 3 water requirement (9800 m /ha). Increase in the grain yields up to 19.44 percent over 3 CTR obtained with water saving made the farmers confident on the water saving technologies. Among the irrigation methods <em>viz., </em>flood irrigation and AWDI, 9.4 percent yield increase with 30.4 percent water saving as recorded under AWDI method of irrigation management in lowland rice cultivation. Popularization of water saving technologies in rice cultivation has created greater awareness on water quantification and need based water management among the farmers in the project area.

Влияние способов водоснабжения на водно-физические свойства почвы в аридных условиях юго-востока Казахстана

This article provides data on soil moisture and density, depending on the test options for water-saving technologies. The effectiveness of the «Aqusorb» hydrogel in regulating the water holding capacity of soils and improving its structure, which directly affects the growth and development of plants, has been shown. The best supply of soil moisture was noted in the options when the preparation was applied, 1.5 kg/m3 and 2.0 kg/m3. When using the preparation favorable water-air regime of soils appears, especially in critical periods for the development of plants. The purpose of the research was the scientific justification for the use of the «Aquasorb» hydrogel to improve the water-physical properties of the soil, which will directly contribute to the development of consumer and decorative gardening in the arid regions of southeast Kazakhstan. Experiments on the study of the water-physical properties of soils were performed according to generally accepted methods.

Virtual water output intensifies the water scarcity in Northwest China: Current situation, problem analysis and countermeasures

With 80% water resources in the south and 65% arable land in the north, China is facing a rigorous challenge due to the spatial mismatch between water distribution and food & energy production to make a balanced development of economy and ecosystem. In the past decades, the northwest has played a prominent role in maintaining national food and energy security. However, the lack of water resources in this region poses a great threat to sustainable development. Based on this, this study quantitatively analyzed the evolution trend of water footprint (WF) of major crops and energy products in Northwest China from 2000 to 2015 and revealed the virtual water (VW) transfer pattern with commodity trade and its water resource stress caused by the virtual water output. The results show that, although the improvement of technology has greatly reduced the WF per unit production, the northwest region is still a net VW output area, whose net VW output associated with food and energy trade is increasing sharply from 287.2 × 108 m3 (2000) to 328.5 × 108 m3 (2015) with a growth rate of 14.4%, seriously aggravating the local water resource pressure. To ensure the water, food and energy safety of the northwest, we proposed countermeasures and suggestions on technological development and strategic planning, including water-saving technology promotion, industrial and agricultural structure optimization, and the coordinated management of physical and virtual water. The above findings provide a scientific reference to ensure the sustainable development of Northwest China.