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Abstract Optimization allocation of agricultural water and land is a very complex system involves multiple objectives. Moreover, weights of each objective were signed by subjective judgement of decision makers is unreasonable. Furthermore, uncertainties are inevitable in the optimization allocation of irrigation water and land. In order to solve the above problems, this paper developed an improved multi-objective stochastic fuzzy programming method. The developed model was then applied to a case study in Wuwei City, Gansu Province, China. Maximum net benefit, maximum agricultural water productivity, and minimum irrigation area were regarded as planning objectives. A series of optimal irrigation and planting structure schemes were obtained under multiple uncertainties. From the results, water resources shortage in Wuwei city is very severely and it could not satisfy Wuwei's water demand even if the risk probability P i reaches 0.25. Moreover, water and irrigation area would vary in different crops. Such changes would mainly take place in potato, vegetable and cucurbit, which have the same characteristics with higher yield, lower cost or lower irrigation quota than other crops. Furthermore, the decision makers could make reasonable decisions on the optimal use of irrigation water and land resources under multiple objective and uncertainties based on the obtained results. Highlights • This paper developed an improved multi-objective stochastic fuzzy programming method. • It simultaneously optimizes irrigation water amount and irrigation areas. • AHP method was introduced to assign weight of each objective. • Optimal irrigation schemes were obtained under multiple uncertainties. • It could be helpful to make decision under multiple uncertainty and multiple objectives. [ABSTRACT FROM AUTHOR]

Water price reform is an effective way of rationalizing and protecting water resources in areas where water is scarce. This paper first presents a method for measuring water footprint by sector based on the non-competitive input-output technique. Second, this research explores the relationship between water price adjustment and labor compensation, as well as regional water export. Accordingly, this paper constructs a mathematical planning model for differentiated water price adjustment by sector with the objectives of minimum water exports and maximum labor rewards, and conducts a simulation study in the water-scarce Henan Province. The study's findings suggest that: (1) In contrast to direct water use, water consumption in Henan Province is more balanced in terms of water footprint, with the food and tobacco processing industry replacing agriculture as the leading water consumption sector. (2) Sectoral differentiated pricing saves 6.9% more export water resources in Henan Province than uniform sector-wide pricing with the same export GDP loss. (3) At present, the industries in Henan Province that are in urgent need of increased water charges are agriculture, textile industry, Manufacture of leather, Processing of timber and furniture, Manufacture of paper and printing, and Manufacture of chemical products these totals 6 industries. An increase of $1.73, $4.87, $38.55, $51.20, $5.83 and $6.55 per cubic meter in the water price of these six industries can reduce the export water resources of Henan Province by 10.72%. As a result, our findings can be used to optimize water allocation and improve sustainable water use in water-scarce regions. • Sub-sectoral differentiated water price adjustment method is proposed. • Sectoral differentiated pricing approach is more conducive to water conservation. • The method can find the local sectors in urgent need of water price adjustment. • Adjust sectoral water price with minimize economic impact to achieve water saving. [ABSTRACT FROM AUTHOR]

From the perspective of sustainable development in irrigation areas, imperfect constraints, which have negatively impacted previous agricultural planting structure optimization models, tend to produce unreasonable optimization results. Thus, in this paper, attempts are made to incorporate the resilience of water resource systems into the constraint set and explore the optimal layout of agricultural planting structures in irrigation areas. We selected 12 sample irrigation areas in Heilongjiang Province, China, including Chahayang, Fuyu, and Tailai, as the research areas and considered their actual situations. Then, we established a multiobjective optimization model for an agricultural planting structure with rice, soybean, and corn planting areas as decision variables; socioeconomic benefits, agricultural production benefits, ecological benefits, and water resource benefits as objective functions; and water resource system resilience and net crop output value and other factors as constraints. Fifteen scenarios were assessed through the combination of objective functions, and the nondominated sorting genetic algorithm III (NSGA-III) was used to optimize and analyze the agricultural planting structure of typical irrigation areas in Heilongjiang Province and to determine the optimal planting plan. The research results found that the function values adjusted by planting area have significantly improved compared to those before optimization. The adjustment trend of agricultural planting area is to increase the planting area of rice and soybean and reduce the planting area of corn. The introduction of constraints on water resource system resilience ensures that other benefits remain basically unchanged; thus, the water resource objective function is significantly better with resilience constraints than without them. Therefore, water resource system resilience can act as an effective constraint; this finding enriches and expands the theoretical and methodological system for optimizing the management of agricultural planting structures in irrigation areas and thus provides important technological support for ensuring regional food security, ecological security, and water security, which has substantial practical significance. • Exploring the feasibility and implementation path of embedding the resilience of water resource systems. • Seeking the optimal adjustment plan for agricultural planting structure in irrigation areas based on the NSGA-III algorithm. • Analyzing the constraint effect of water resource system resilience on the optimization of agricultural planting structure. [ABSTRACT FROM AUTHOR]

The increasing pressures of global warming, population growth and epidemic occurrence are causing challenges in meeting the growing requirements for water, energy and food. In particular, the contradiction between the supply and demand for water, food, and energy is exacerbated by inefficient resource utilization and carbon emission increase. Incorporation of the interlinked aspects of water, energy, food and carbon emissions from agricultural systems into one water-food-energy-carbon nexus facilitates integrated resource management. Biochar application to farmland is a potential strategy for carbon management and agricultural productivity improvement. The integration of biochar systems and the water-food-energy-carbon nexus is an efficient and coordinated alternative method for sustainable agricultural management and a crucial strategy for addressing water, energy and food security issues. Accordingly, this paper proposes an approach for the synergistic regulation of water, land, energy, and carbon emissions in a circular agricultural system by balancing water supply and demand, land allocation, electricity consumption, and economic upgrading principles. A two-stage circular agriculture framework is constructed, with biochar and electricity generated from agricultural residues at the first stage and employed at the second stage. Economic-environmental-energy harmonization is considered in the methodology, and the agrotechnical potential of biochar is quantified via crop yield increase and greenhouse gas emission reduction functions. This approach can assist decision makers in providing the best policy options given certain agricultural resources to achieve the maximum economic performance of the system while minimizing environmental side effects. In this paper, the model framework is applied to the Sanjiang Plain in northeastern China to verify the feasibility of the approach. The results indicate that the external electricity demand is reduced by 87.8% due to the generation of biofuels. Cropland greenhouse gas emissions are reduced by 34.09%–67.06% via the application of biochar. This study proposes an optimization method with important implications for the improvement of regional cropland management techniques and development of sustainable circular agriculture. This methodology can be extended to other agriculture-centered regions with limited resources and environmental problems. • Carbon cycle is integrated in agricultural water-food-energy-carbon (AWFEC) nexus. • An AWFEC nexus based model is developed for agricultural resources recycling. • Biochar and electricity are optimized sustainably for circular agriculture. • Analysis of resources recycling on economic-environmental balance is performed. [ABSTRACT FROM AUTHOR]

A water price increase has been used as an effective method to guarantee national water security and maintain national food security in China. The reasonableness of the water price has a direct influence on people's attitude, behavioural decision regarding willingness to pay, and motivation for water conservation. A double-bounded dichotomous choice contingent valuation method was used to assess the impact of integrated agricultural water price reform on farmers' willingness to pay for irrigation water in northwest China. The estimated mean willingness to pay in the study area was 0.144 RMB/m3. A comparison showed that higher education and longer experience in farming were likely to result in a higher willingness to pay in the study area. Participants who had a higher awareness of water price reform showed a higher likelihood of agreeing to higher bidding. Those who thought the current water price was lower had a higher willingness to pay for irrigation water. Participants who considered agricultural water resources to be scarce in the area also had a higher willingness to pay. In contrast, the bidding variables were negative and significant at the 1% level, showing that participants were more inclined to reject a higher bid. Meanwhile, the older the participant, the less they were willing to pay. An unintended finding was that participants' willingness to pay decreased if they chose to use water-saving technology. One possible explanation was that the investment in the construction of the infrastructure (such as pipes and pumps) may have exacerbated farmers' burden and may not have resulted in any benefits to them. Based on the results of this paper, a related optimization policy was presented for water price reform. Image 1 • Water price reform influenced farmers' bearing capacity. • Willingness to pay was higher than the prices currently paid in northwest China. • Six variables were positively while three ones were negatively significant on WTP. • A reasonable grasp of the scale of the water price adjustment was essential. [ABSTRACT FROM AUTHOR]

Abstract Agricultural water and land, which are intricately related, are the two most critical resources for food production. However, the sustainability of agricultural water and land resources is faced with challenges due to intensive human activities and climate change. This paper builds crop water footprint model under uncertainty, and evaluates regional crop (rice, maize and soybean) blue and green waterfootprint under different probability. On this basis, the water footprint characteristics and differences of crops were analyzed. Then, an optimization model of crop planting structure with the objectives of minimum blue water footprint and the maximum agricultural net benefit was constructed and Monte Carlo simulation method was used to solve the model. The model can take into account the crop water footprint at different probabilities, enabling decision makers to combine years of information to make better decisions. Then, the model was applied to the Hulan River Irrigation District, and three scenarios were designed to analyze the optimal planting structure under different conditions. Under different scenarios, the optimization results have certain differences, but overall, increasing the area of crop cultivation, especially rice, has a good role in promoting regional agricultural development. Due to the optimization of the planting structure, the net benefit of the irrigation area increased by 7%, 15% and 5% in each of the three scenarios. Solutions are valuable for producing scientific alternatives that help decision makers determine the water and soil relationship management policies they need. [ABSTRACT FROM AUTHOR]

Agriculture, a strategic industry that secures the country and stabilizes society, has invariably been valued by China to feed its 1.4 billion people. However, the long-term extensive development of agriculture has led to a series of water problems such as groundwater overexploitation, water shortages, and water pollution in some areas of China, resulting in great pressure on the ecological environment and social economy. In this paper, we constructed a dynamic optimization simulation model based on the input–output (I–O) approach within the horizon of 2012–2025 to explore the synthetic optimal policies for achieving both socioeconomic development, and water resources and water environment protection in a node city on the middle route of the South-to-North Water Transfer Project, Handan. Six scenarios based on various synthetic policies were adopted. The simulation results show that during the simulation period, the maximum development of the social economy can be achieved under the premise of achieving the specific objectives of water resources and water environment protection in a comprehensive scenario. In addition, the water environment improved: the annual chemical oxygen demand (COD) emissions reduced by 7.5%, 10.3%, 5.0%, and 5.9% in pig farming, cattle farming, chicken farming, and households, respectively. Furthermore, the water supply–demand structure was optimized. The water demand of wheat planting and groundwater extraction decreased at an annual rate of 9.1% and 7.7%, respectively. The supply of reclaimed water increased at an annual rate of 9.2%. The model adapted in the paper can simulate and evaluate the impact of all the feasible synthetic policies on the economy, water resources, and water environment, and provide targeted, scientific recommendations for solving the agricultural water use problems in other regions. [ABSTRACT FROM AUTHOR]

This paper aims to assess the conditions under which hydraulic projects can be considered as an efficient option, from an environmental point of view, to secure water supply of agricultural areas using the Territorial Life Cycle Assessment (T-LCA) methodology. Firstly, the environmental performance of three theoretical agricultural land-use planning scenarios are defined: (1) a business-as-usual case without irrigation, (2) irrigation with an Inter-Basin Water Transfer (IBWT) and (3) with an Agricultural Reservoir (AR). These are all assessed by computing the territorial eco-efficiency (i.e. a ratio between the services provided by land planning scenarios and their related environmental impacts). Secondly, Territorial Life Cycle Assessment methodology was used to assess the water-energy-infrastructure nexus between the two hydraulic projects. Results indicate that the eco-efficiencies of the scenarios vary according to the service considered and to the type of land use. For land management or economic functions, the scenario without irrigation can perform better, while hydraulic projects are more eco-efficient for functions related to biomass production. The analysis of the water-energy-infrastructure nexus highlights the trade-offs between the two types of project. On one hand, IBWT allows for the use of a low-stress water resource and less energy, but may require high material consumption. On the other hand, AR uses less material while relying on a more scarce water resource. IBWT performs better than AR if the pipe length is less than 100 km, with a water allocation of 1% (proportion of the infrastructure allocated to the considered agriculture area). This study underlines the importance of considering the territorial context in the environmental assessment of land planning projects in order to support decision-making. [Display omitted] • Territorial LCA is used to assess various development scenarios for irrigated areas. • Comparison of scenarios is based on eco-efficiency ratios. • The water-energy-infrastructure nexus points out trade-offs between infrastructures. • Conditions under which the water-transfer scenario performs better are discussed. • The T-LCA framework successfully manages territorial multifunctionality. [ABSTRACT FROM AUTHOR]

Sustainability is the core concept of modern agricultural planning. Existing studies lack quantitative research on the dynamic effects of the optimal use of agricultural water and land resources (AWLR) on agricultural sustainability. This paper constructs a simulation-optimization-assessment-based modeling framework for the dynamic correlation between agricultural sustainability and the water-land nexus under uncertainty. The framework includes uncertainty simulation of the water supply and demand, development of an optimization model for synergistic regulation of AWLR, and construction of a two-layer dynamic response relationship function between integrated water and land resource use and agricultural sustainability. This framework provides the following advantages: (1) the synergistic allocation of AWLR can be optimized to achieve synergistic development of the five dimensions of resources, economy, society, ecology and environment; (2) the dynamic probability distribution of AWLR and the corresponding response to each dimensional objective and agricultural sustainability can be generated; and (3) the response of agricultural sustainability and AWLR use to changing environments can be obtained. The framework was quantified and analyzed via stochastic simulation, multi-objective nonlinear optimization and fuzzy C-means clustering and applied to the Heilongjiang area of the Songhua River Basin in China. The results indicate that when the irrigation water volume is reduced by 10% and the planted area is increased by 5% in the study area, the economic efficiency increases by 10.49%, the social and ecological effects increase by 10%, and the agricultural sustainability increases by 10.07%. The initial surface water and groundwater irrigation amounts should be regulated within the ranges of [600,800] 107 m3 and [400,600] 107 m3, respectively, and the total amount should not exceed 1150,107 m3. The proposed framework can help reveal the intrinsic linkages between agricultural sustainability and AWLR allocation considering different environmental change scenarios, which can provide authorities with AWLR management decisions in response to changing environments. [Display omitted] • A simulation-optimization-evaluation modeling framework for AWLR is developed. • Probability distributions of AWLR are optimized under changing environment. • Balance conflicts between resource, economy, society, ecology, and environment. • Bilayer dynamic correlations for sustainable use of AWLR are built. • The performance of the framework is evaluated. [ABSTRACT FROM AUTHOR]

This study presents an analysis of stakeholder influence on water-related disclosure in the most water-sensitive industry, namely, agriculture. The availability of clean water is currently under pressure, and stakeholders are starting to pay attention to a company's water responsibilities. The influence of stakeholders is analyzed using the lens of ethical or normative stakeholder theory. The sample includes 195 agriculture companies registered in the OSIRIS database from 2017-2019. The data were collected from the database, company reports, and other company official media on the internet. Following the Hausman test procedure, the data were analyzed using random effect model. Governments, foreign shareholders, and international operations were found to be significant drivers of water disclosure practices. However, the creditor power hypothesis was rejected, as it had an insignificant influence. This paper contributes to the literature by providing empirical evidence of stakeholder influence on water disclosure in the agriculture industry, which has not been previously investigated. • Water related disclosure of 195 companies are explored based on stakeholder theory. • Greater government, and foreign ownership associated with more water disclosure. • Creditor does not have significant influence on disclosure. • Company operates internationally related to higher level of water disclosure. [ABSTRACT FROM AUTHOR]

Abstract: Agriculture plays a key role in relation to global water stresses. Increasingly, water footprints (WF) are being used to indicate the impacts of the water use by production systems. International standards for WF are being developed and this paper contributes to these from a hydrological perspective. The impacts of water use through the life cycle of grape-wine production on water resources were assessed for two regions in New Zealand: Marlborough and Gisborne. The functional unit (FU) was a 750-mL bottle of wine at the winery gate. The WF was assessed using a full water-balance calculated by subtracting inflows from outflows. The net usage from groundwater and soil moisture storage was quantified as blue and green water footprints. We found a large variability of blue-WF even within a region. For the grape-growing stage, the average blue-WF was negative, at −81 L/FU and −415 L/FU for Marlborough and Gisborne indicating the water resources are being recharged on an annual timescale. The green-WF was negligible. The grey-WF, water required to dilute NO3-N leached in the vineyard phase, was 40 and 188 L/FU for Marlborough and Gisborne. However, the average concentration of NO3-N in the leachate was well within the drinking water standard of 11.3 mg/L (5.01 mg/L and 8.7 mg/L for Marlborough and Gisborne). The impacts of the winery phase were very small compared with that of the vineyard. The variability we have found indicates the importance of considering water issues at the local scale. Locale is the essence of terroir for wine. [Copyright &y& Elsevier]

To expand the field of harmony theory research, new paths for sustainable development of agricultural regions are explored. The uncertainty problem is selected to determine the optimal parameters of the random forest (RF) model. This paper uses the Dragonfly algorithm (DA) to calibrate the RF model parameters, proposes an improved model (DA-RF), and applies it to measure the agricultural water and soil resources composite system harmony (AWSRCSH) of the Jiansanjiang Branch of the Heilongjiang Great Northern Wilderness Agribusiness Group Corporation. The results show that the DA-RF model can effectively improve the simulation ability and stability with a running time that is longer than that of an empirical method. The annual variation in the AWSRCSH of the Jiansanjiang Branch presents an "N-type" trend. From 1997 to 2005, the branch had not yet entered a peak period of resource and agricultural development, while the AWSRCSH had steadily improved during this period. From 2005 to 2008, due to predatory operations, the AWSRCSH decreased, and the speed of this decrease increased. From 2008 to 2016, since local water and soil resource development was strictly controlled and agricultural modernization increased, the AWSRCSH gradually increased. Due to the advantages of water resources and topography, the AWSRCSH in the farms adjacent to the river was greater than that in inland farms. To address the slow growth rate of the AWSRCSH, some adaptive regulation strategies were proposed according to key driving factors, and the effect of harmonious regulation was predicted. • Construct AWSRCSH measurement model based on the DA-RF model. • Explore the characteristics and possible causes of the spatial and temporal evolution of AWSRCSH of Jiansanjiang Branch. • Evaluate the performance of the DA-RF model. • Explore the regulation strategy based on AWSRCSH. [ABSTRACT FROM AUTHOR]

The creation of an efficient and environmentally friendly irrigation canal schedule strongly depends on the accuracy of the prespecified water demand (PSWD) process in existing scheduling practices and modeling studies. Overestimating water demand would result in spillage losses from over-irrigation, while underestimating water demand would lead to crop yield losses due to deficit water supply. However, prespecifying an accurate water demand often poses various challenges for both farmers and canal administrators, as it involves the temporal variability in agrometeorological conditions, the spatial diversity of soil properties, and the sensitivity of crops to water stress at different growth stages. Therefore, to reduce the uncertainty of prespecifying water demand and avoid the adverse effects of an inaccurate water demand on canal water allocation, this paper proposes an alternative canal scheduling model that maximizes canal scheduling service quality by targeting the ultimate objectives of the irrigation system (UOIS) without considering the prespecified water demand as the model input. The UOIS canal scheduling (UOIS-CS) model aims to optimize the canal water delivery schedule via simulation of soil water and salt migration using the Simultaneous Heat and Water (SHAW) model, to provide the most suitable soil moisture content and soil salinity for crops. The UOIS-CS model is used for the Hetao Irrigation District, Inner Mongolia, a typical agricultural watershed in China, where supplementary irrigation is performed after the autumn harvest (i.e., autumn irrigation) to leach excessive soil salt and preserve a moderate amount of soil moisture for the beginning of the next spring sowing period. To evaluate the irrigation performance of the UOIS-CS model further, a comparative analysis between the UOIS-CS model and the widely used PSWD-based canal scheduling (PSWD-CS) model is conducted. Compared with the PSWD-CS model, the proposed UOIS-CS model exhibits a superior irrigation performance in terms of leaching soil salt and preserving soil water, and a lower risk of canal overload operation during a higher water demand period. The improved performance of the UOIS-CS model is attributed to its greater adaptability to the spatial diversity of soil properties and the temporal variability in agrometeorological conditions, which originates from the full use of the equifinality of model performance metrics and model inputs. The UOIS-CS model provides managers with an effective approach to formulate a canal water delivery schedule with improved irrigation efficiency and lower overload risk. The proposed framework is generic and can be applied to non-crop growing seasons. • The canal scheduling method based on the ultimate objectives of irrigation system is well adapted to the environment. • Scheduling canals with prespecified water demand processes has a higher risk of canal overload operation. • Adopting the SHAW model to simulate soil water and salt migration in canal water allocation optimization. [ABSTRACT FROM AUTHOR]

The eastern plain of China is one of the most important grain production areas in China. Meanwhile, the plain is also an important coal production area with a large number of "coal-grain composite regions". Coal mining causes land subsidence and waterlogging, which destroys a significant amount of cultivated land. However, there is no dataset for the spatio-temporal distribution of subsidence water to assist related decision-making on a regional scale. Accurate monitoring of subsidence water is still a challenge, especially distinguishing among subsidence water, natural water and artificially excavated water by only using remote sensing data. Here, A new method to generate a dynamic map for the subsidence ponding year and the restoration year using the Google Earth Engine platform with 33-year-old Landsat imagery was created. The time segmentation method was used to first extract the change water pixels corresponding to subsidence water and artificially excavated water with similar trajectory features. Then, the morphological characteristics of the two types of change water at the beginning year of water accumulation are used to construct 13 landscape indexes. This approach utilizes the Random Forest algorithm to distinguish between subsidence water and artificially excavated water. The Huang-Huai-Hai plain area in eastern China was selected as the study area and extracted the subsidence water areas from 1986 to 2018. The identification accuracies for subsidence ponding year and restoration year are 88% and 85%. 79% of the subsidence water areas are located in cultivated land, which shows significant impacts to agricultural activities. The method proposed could be applied to other similar areas, the results could provide reference and data for decision-making and related land reclamation planning. • A novel methodology was developed for mapping mining subsidence water. • Map of the subsidence ponding year and restoration year. • Random forest algorithm can effectively extract the patch of subsidence water. • Contribute to monitor annual subsidence water at a regional scale. • This paper belongs to change detection using Landsat time series. [ABSTRACT FROM AUTHOR]

Irrigation expansion driven by a growing global food demand is threatening the sustainability of scarce water resources. An exemplar is the Ica Valley in Peru which has experienced significant agricultural transformation over the last three decades with uncontrolled abstractions leading to over-exploitation of the Ica-Villacuri aquifer. This paper critically assesses the impacts of agricultural expansion on the long-term sustainability of groundwater resources in the Ica Valley. We apply a combination of spatial analysis and irrigation modelling by farming type (large and small-scale), followed by a multi-criteria assessment on irrigation water use. Historical trends in cropped area were analysed using Landsat satellite imagery to identify agricultural expansion and the changing composition between large and small-scale farms. The blue water footprint (WF blue) for croplands was calculated distinguishing between surface and groundwater abstractions for eight disaggregated geographical zones within the Ica Valley. The economic benefits of water consumption were assessed using the water productivity indicator, and the environmental sustainability of water resources spatially evaluated using a monthly blue water sustainability index and adapted version of the groundwater debt. The analyses showed that the groundwater footprint accounts for 87% of the total WF blue (483 Mm3) with 286 Mm3 groundwater consumed under unsustainable conditions (exceeding groundwater recharge). The highest water productivity (2.4–5.4 sol/ton) occurs in zones with intensive groundwater abstractions and where most large-farms are located, but it is also where the sustainability issue is most acute. Modelling showed that based on existing climate conditions and cropping patterns, irrigated agriculture is locally unsustainable throughout the valley, with the exception of small-scale farming in the peri-urban and middle valley areas. Around 10% of total aquifer recharge results from small-scale irrigated farming, whereas recharge from large scale farming is negligible. The greatest impacts occur in zones dominated by large-scale farms, where a period of 3.7–5.9 years is estimated to be needed to replenish water resources consumed by agricultural production. There is thus an urgent need to manage water resources more effectively and promote more sustainable use of water to protect both traditional and agro-export agricultural practices as well as allocations for urban water supply and the environment. Image 1 • Export-oriented agricultural expansion is exerting severe pressure on water resources. • Groundwater footprint accounts for nearly 90% of total irrigation demand (536 Mm3). • Large-scale farming comprises 83% of the groundwater footprint in the Ica Valley. • About 68% of the annual groundwater footprint exceeds groundwater renewability. • Around 18% of total aquifer recharge results from small-scale irrigated farming. [ABSTRACT FROM AUTHOR]

In this study, the water footprint (blue, green and grey WF) and virtual water theory were used to uniform measure the new challenges (population growth, population urbanization, dietary structure change, energy industry development, grain trade and climate change) of food security in Northwest China. Moreover, this study quantified the demand for new challenges to water resources from 2000 to 2016, and then evaluated their impact on water resources and food security in Northwest China. The results showed that in 2000–2016, population growth caused the food consumption WF to increase from 153.8 Gm3 to 159.6 Gm3, with an average annual growth rate of 0.4%. The ratio of per capita consumption of WF of urban residents to rural areas has increased from 80.3% to 120%. The per capita food consumption in the region increased by 1.3% annually due to changes in dietary structure. However, with the increase of water use efficiency, the WF decreased by 0.3% per year. Among them, the total consumption WF of food rations decreased by 51.9%, with an average annual decrease of 4.4%, and that of meat, dairy products and aquatic products increased by 2.4%, 10.8% and 3.0% per year, respectively. From the economic point of view, the development of the energy industry has increased the competition index of energy-grain to water resources from 0.22 to 0.49. Due to climate change, although the precipitation increased at a rate of 3.2 mm/yr, the increase in ET 0 was 3.3 mm/yr, and thus the demand for water resources in agricultural production increased. Based on the results, this paper suggests to carry out measures such as optimizes crop planting structure, adopts effective biological, agricultural technologies, guides healthy food consumption structure, strengthens international food trade and biofuel use and so on to reduce the WF of grain crops and energy industry. Ultimately, the goal of reducing regional water stress and ensuring food security is achieved. Image 1 • Analysis of its impact on food security from the perspective of six factors. • The water footprint (WF) and virtual water measure the above indexes uniformly. • The WF of energy and animal products increased by 400.0% and 47.9% in 2000–2016. • Virtual water output is increasing in the Northwest (2.2 G m3/yr). [ABSTRACT FROM AUTHOR]

Water is considered the most critical resource for sustainable agricultural development worldwide. Water scarcity has become an issue, especially in arid and semi-arid areas. There is the need to develop efficient management options to reduce water consumption and waste. In order to measure irrigated crop technical efficiency, a stochastic frontier production method – in which the inefficiency component is heteroscedastic – is used with the aim to assess what crop type and production technique revealed highest efficiency. The model is applied to a case study in southern Italy by using 2016 data from the EU Farm Accountancy Data Network. Our results show that the assumption of heteroscedasticity in the one-sided error term in the stochastic frontier is valid: individual farms' characteristics critically influence technical efficiency. Processing tomato is the most efficient crop production system; organic farms tend to have a lower level of technical efficiency compared to conventional farms; and fertigation system is found to increase the level of technical efficiency. • Efficient agriculture water management through improved water use is a critical response to growing water scarcity. • This paper aims at measuring technical efficiency of irrigated crop production in Italy giving emphasis on the water use input. • The adopted stochastic approach allows us to incorporate the one-sided component error which reflects farms inefficiency. • Model results indicate that comparable technical efficiency scores among farms does exist. [ABSTRACT FROM AUTHOR]