Agricultural Water Consumption Research Articles

A comprehensive analysis of blue water scarcity from the production, consumption, and water transfer perspectives

The issue of growing water scarcity has been increasingly perceived as a global systemic risk. To solve it, an integrated approach considering different perspectives of water scarcity is at a premise. In this study, we developed an approach to calculate the blue water scarcity (BWS) and integrated the production, consumption, and water transfer perspectives into a single framework. The results are as follows: The average BWS in the Hetao irrigation district was 0.491 during the 2001–2010 year period, which was much larger than the threshold of 0.30, indicating a high water stress level. From the production perspective, the agricultural sector was the largest contributor to regional water scarcity and the average BWS was as high as 0.479. From the consumption perspective, BWS related to virtual water export was much larger than that related to water consumption for making products to be consumed locally and the values were 0.422 and 0.069, respectively. Under the influence of physical and virtual water transfer, BWS changed from 0.242 (medium to high water stress level) to 0.491 (high water stress level). Strategies for reducing agricultural water consumption, such as increasing crop water productivity, improving irrigation efficiency, and promoting more reasonable irrigation water price, could be adopted in the Hetao irrigation district to alleviate regional BWS. Compared with physical and virtual water import, the virtual water export played a more important role in influencing the regional water scarcity, and the increase in crop water productivity, decrease in crop export volume, or adjustment of trade pattern from water-intensive crops to water-extensive ones could be feasible measures to decrease virtual water export for lower water stress, while the trade-offs in the product-consuming regions should be considered.

A New Temperature-Vegetation Triangle Algorithm with Variable Edges (TAVE) for Satellite-Based Actual Evapotranspiration Estimation

The estimation of spatially-variable actual evapotranspiration (AET) is a critical challenge to regional water resources management. We propose a new remote sensing method, the Triangle Algorithm with Variable Edges (TAVE), to generate daily AET estimates based on satellite-derived land surface temperature and the vegetation index NDVI. The TAVE captures heterogeneity in AET across elevation zones and permits variability in determining local values of wet and dry end-member classes (known as edges). Compared to traditional triangle methods, TAVE introduces three unique features: (i) the discretization of the domain as overlapping elevation zones; (ii) a variable wet edge that is a function of elevation zone; and (iii) variable values of a combined-effect parameter (that accounts for aerodynamic and surface resistance, vapor pressure gradient, and soil moisture availability) along both wet and dry edges. With these features, TAVE effectively addresses the combined influence of terrain and water stress on semi-arid environment AET estimates. We demonstrate the effectiveness of this method in one of the driest countries in the world—Jordan, and compare it to a traditional triangle method (TA) and a global AET product (MOD16) over different land use types. In irrigated agricultural lands, TAVE matched the results of the single crop coefficient model (−3%), in contrast to substantial overestimation by TA (+234%) and underestimation by MOD16 (−50%). In forested (non-irrigated, water consuming) regions, TA and MOD16 produced AET average deviations 15.5 times and −3.5 times of those based on TAVE. As TAVE has a simple structure and low data requirements, it provides an efficient means to satisfy the increasing need for evapotranspiration estimation in data-scarce semi-arid regions. This study constitutes a much needed step towards the satellite-based quantification of agricultural water consumption in Jordan.

Land suitability assessment for optimum management of water consumption in precise agriculture

Optimum irrigation management is an important factor in precise agriculture. The main objective of this research is to compare different irrigation methods based upon a parametric evaluation system in an area of 41,200 ha in the Rasht region, north Iran. Once the soil properties were analyzed and evaluated, suitability maps were generated for surface, sprinkler and drip irrigation methods using a geographic information system and remote sensing. Parametric methods including Storie and Khidir, were used for land suitability evaluation to propose suitable irrigation system. Khidir method was more accurate than Storie method. The obtained results of khidir method showed that for 40,487.3 ha (98.3 %) of the study area the drip irrigation method was suitable. Capability ratings were the highest in all soil series for drip irrigation. The results demonstrated that by applying drip irrigation method instead of sprinkler and surface irrigation methods, the arability of 40,487.3 ha in the Rasht region would improve. The comparison of the different types of irrigation revealed that drip irrigation system was more effective and efficient than the surface and sprinkler irrigation methods and improved land suitability for irrigation purposes. It is of note, however, that the main limiting factors in using surface, sprinkler and drip irrigation methods in this area were drainage and soil texture.

Effects of Water Management Strategies on Water Balance in a Water Scarce Region: A Case Study in Beijing by a Holistic Model

Irrigation is facing increasing pressure from other competitive water users to reduce water consumption in a water scarce region. Based on the Basin-wide Holistic Integrated Water Assessment (BHIWA) model, the effects of water management strategies on water balance in the dry regions of North China were analyzed. The results show that, with the decrease of irrigation water supply reliability (IWSR) and the increase of irrigation water use efficiency (WUE), irrigation water use decreased significantly, leading to reduced agriculture water consumption, and sustained ground water levels. Compared with the increase of WUE, the decrease of IWSR contributes more to reducing irrigation water consumption and protecting groundwater. Sensitivity tests show that among various water cycle components, irrigation water use is most sensitive to changes, followed by agriculture water consumption, and then groundwater level. Reducing IWSR is an effective strategy to reduce irrigation water consumption and promote sustainable water resources management, which could be the support of basic data and theory for regional water resources planning.

Changing Characteristics of the Water Consumption Structure in Nanjing City, Southern China

Understanding the changes in water consumption structure in order to take measures for demand control is very important for sustainable water resources management. In this study, using the Southern China area of Nanjing as an example, we employed the information entropy method to analyze the water consumption structure, as well as the grey incidence analysis to analyze synthetic incidence degree of the factors associated with agricultural, industrial, domestic, and ecological water consumption. The results show that the degree of balance among water consumption sectors has increased from 0.755 to 0.825 between 1993 and 2014. Gradual decrease of the relative proportion of a single water user structure in a water consumption system has made the utilization of water resources in Nanjing rational and diversified. The study identifies three stages of transformation of water structure in Nanjing, namely, a growth period from 1993 to 2002, an adjustment period from 2003 to 2010, and another growth period from 2011 to 2014. The synthetic incidence degree analysis indicates that adjustments of the agricultural and industrial water consumption as well as water saving measures are the main factors that affected water consumption structure in Nanjing. It is expected that the results obtained from this study will provide references to optimize the utilization of urban water resources.

Effects of temperature and growing seasons on crop water requirement: implications on water savings

Water savings can be improved through reducing agricultural water consumption. The crop water requirement (CWR) depends on several factors including temperature and growing seasons. This study investigated the effects of temperature and growing seasons on CWR in Saudi Arabia. Increase in temperature by 1°C increased the CWR by 1.9 - 2.9%, 1.9 – 3.0% and 2.2 – 3.8% for dates, alfalfa and wheat respectively. Total CWR was estimated to be 8713 million cubic meters in 2011, which showed an increase of 1.8 – 2.9% for 1°C increase in temperature. CWR for wheat was more sensitive to growing seasons than dates and alfalfa. Empirical relationship was developed to predict the effects of growing seasons on CWR for wheat while changes in CWR for dates and alfalfa were not significant. Through shifting growing seasons and minimizing the effects of temperature for the major crops, significant amount of groundwater may be saved, which can reduce the production of costly desalinated water. Keywords: Water resources; conservation; crop water requirement; temperature; growing seasons; policy

Comparing the Performance of FSL and Traditional Operation Methods for On-Request Water Delivery in the Aghili Network, Iran

AbstractThe management improvement of irrigation networks is inevitable because of limited water resources and competition in various sectors of industry, agriculture, environment, and urban water consumption. Application of appropriate water delivery scheduling is one of the methods to improve irrigation management. Several delivery methods are practiced in irrigation networks according to water availability, type of network control system, and exiting capacities. One promising delivery method is the on-request system, which could be applied manually in irrigation networks. High performance of delivery methods arise from the determination of appropriate operation instructions. In previous studies, the Fuzzy SARSA learning (FSL) method was applied to determine operation instruction for on-request delivery in a canal of the Aghili irrigation network located in southwest Iran (SARSA is the definition of state, action, reward, state, action). In this work, the conventional manual operation on the same canal ...

Consumptive water footprint and virtual water trade scenarios for China — With a focus on crop production, consumption and trade

The study assesses green and blue water footprints (WFs) and virtual water (VW) trade in China under alternative scenarios for 2030 and 2050, with a focus on crop production, consumption and trade. We consider five driving factors of change: climate, harvested crop area, technology, diet, and population. Four scenarios (S1–S4) are constructed by making use of three of IPCC's shared socio-economic pathways (SSP1–SSP3) and two of IPCC's representative concentration pathways (RCP 2.6 and RCP 8.5) and taking 2005 as the baseline year. Results show that, across the four scenarios and for most crops, the green and blue WFs per tonne will decrease compared to the baseline year, due to the projected crop yield increase, which is driven by the higher precipitation and CO2 concentration under the two RCPs and the foreseen uptake of better technology. The WF per capita related to food consumption decreases in all scenarios. Changing to the less-meat diet can generate a reduction in the WF of food consumption of 44% by 2050. In all scenarios, as a result of the projected increase in crop yields and thus overall growth in crop production, China will reverse its role from net VW importer to net VW exporter. However, China will remain a big net VW importer related to soybean, which accounts for 5% of the WF of Chinese food consumption (in S1) by 2050. All scenarios show that China could attain a high degree of food self-sufficiency while simultaneously reducing water consumption in agriculture. However, the premise of realizing the presented scenarios is smart water and cropland management, effective and coherent policies on water, agriculture and infrastructure, and, as in scenario S1, a shift to a diet containing less meat.

Effect of maize sowing area changes on agricultural water consumption from 2000 to 2010 in the West Liaohe Plain, China

The West Liaohe Plain is located in the eastern Inner Mongolia, known as the golden maize belt in China, where maize acreage has continued to rise in recent years. Water is the main limiting factor for maize production in the region, therefore, this study calculated the effect of maize sowing area changes on agricultural water consumption in the West Liaohe Plain in 2000, 2005 and 2010, based on remote sensing and meteorological data. Maize remote sensing classification was constructed based on moderate-resolution imaging spectroradiometer, normalized difference vegatation index (MODIS NDVI) data. Then the maize sown area and water requirement and irrigation water resources were investigated. Finally, the effect of the maize sowing area changes on agricultural water consumption in the West Liaohe Plain was systematically analyzed in 2000, 2005, and 2010. The results showed that maize sown areas rose from 2000 to 2010 and were concentrated in the center of the West Liaohe Plain. Average per unit maize water deficit amount also increased in an uneven distribution, increasing from the south, east and north to the center and west of the West Liaohe Plain. The per unit area maize water deficit increased from 2000 to 2010, and reached 266 mm in 2000, 272 mm in 2005 and 273 mm in 2010, respectively. And the study concluded that water deficit during the whole growth period of maize in the West Liaohe Plain was defined by a single peak curve. The maize water requirements increased with maize sowing area changes from 2000 to 2010, and the maize water requirements increased from 0.89 billion m3 in 2000 to 1.19 billion m3 in 2005, and 1.21 billion m3 in 2010.

Crop Planting Structure Optimization for Water Scarcity Alleviation in China

SummaryAlong with globalization, countries consume a large amount of goods and services from both domestic and international markets. As one of the world's largest agricultural countries, China is faced with serious water scarcity and has to reduce the water consumption from both domestic and global aspects, of which the crop planting structure optimization (CPSO) between regions based on the virtual water perspective could be a solution for efficient agricultural water consumption. In this article, three scenarios of Chinese agriculture, including agricultural water consumption restrictions relaxed scenario, agricultural water consumption limited scenario, and net utilization ratio of water resources limited scenario, were designed to minimize the national agricultural water consumption under various water, land, and crop planting constraints in individual provinces and analyze the impacts of the CPSO. The results showed that compared with the historical situation of crop planting in 2007, 53.3%, 51.4%, and 47.3% of the agricultural water consumption and more than 10% of the sown area of China was saved under the three scenarios, respectively. Because of the reduction of agricultural water consumption and land use, it brought about the expansion of crops production in China. CPSO is found to have notable effects on water saving and food security considering the dependence of the crops by international trade.

Investigating the Effects of Sustainability of Climate Change on the Agriculture Water Consumption in the Zayandeh-Rud River Basin

Investigating the Effects of Sustainability of Climate Change on the Agriculture Water Consumption in the Zayandeh-Rud River Basin

Study on Soil Water Resource Carrying Capacity Based on Multi-objective Model in Hebei

Based on analysis and summary of the present achievements concerned soil water resource, the conception and connotation of soil water resource were defined and its carrying capacity was given in this study. According to characteristics of soil water resource carrying capacity, the multi-objective model of soil water resource carrying capacity was established for Hebei province. In the model, objective functions consists of 4 parts, including agriculture output value, grain yield, proportion of agricultural water consumption and eco-environmental water consumption, each crop’s planting area is defined as decision variable. After changing the multiple objectives into a single objective by fuzzy binary contrast method, this multi-objective model was solved by using the method of single objective programming. The results show that the agriculture output value and grain yield could be increased steadily and agricultural water consumption is decreased contrarily by the soil water resource optimum scheme in comparison with present situation. The consumptions of soil water resource are 6.80 and 7.62 billion m3 respectively in 2020 and 2030 by developing agricultural technology of the water-saving irrigation, straw returning, film-covering planting and greenhouse cultivation. The amount of saving water for agriculture is 0.75 and 1.79 billion m3 respectively in 2020 and 2030 year.

Effects of shallow groundwater table and salinity on soil salt dynamics in the Keriya Oasis, Northwestern China

In this paper, the spatial and temporal variability of groundwater depth and groundwater salinity associated with agricultural activities and land cover and land use (LCLU) in the Keriya Oasis, Xinjiang Uyghur Autonomous Region of China, was investigated. A decision tree classification was developed for LCLU mapping by using Landsat 8 imagery. Radial basis function, Pearson’s correlation coefficient, Moran’s I statistics and geographically weighted regression were employed to identify the spatial and temporal relationship between topsoil salinity and LCLU types. The results showed that groundwater depth in about 75 % of the study area was less than 3.0 m. Groundwater salinity showed an increasing trend with decreasing groundwater depth. A relatively higher positive correlation (r = 0.87) was found between groundwater salinity and topsoil salinity. Topsoil salinity was exacerbated by agricultural activities at the upstream of seasonal rivers, causing severe soil salinization and soil degradation in the downstream. Both groundwater depth and soil salinity showed seasonal fluctuations with the shallowest groundwater level occurring in spring, while during summer and autumn, groundwater depth increased due to the extensive of agricultural water consumption and the regional evapotranspiration, which was followed by a winter recharge; non-saline groundwater region was 21 % of the research area in spring, which dropped to 1.1, 1.0 and 1.2 %, respectively, during the summer, autumn and winter. The results also demonstrated that shallow groundwater depth of 2.5 m is the critical depth value for soil salinization in the Keriya Oasis.

Changes in Grain Production and the Optimal Spatial Allocation of Water Resources in China

Abstract: Changes in grain production are decomposed and compared among nine major Chinese river basins for the sake of optimal water allocation. The results show that water-deficient northern China, especially the Songliao River Basin and Huai River Basin, contributed the greatest share of the total grain increment from 1995 to 2010. The Songliao River Basin achieved increased grain output largely by expanding multiple cropping, while the Huai River Basin achieved it mainly by improving the yield per unit area. With increased reliance on expanding irrigation and multi-cropping, most northern basins have high levels of agricultural water consumption, despite the rising share of corn, a lower water intensive crop. In contrast, over the same period the warm and humid south, traditionally a major rice-growing area, mostly experienced a sharp decline in rice cropping area and the Southeast Rivers Basin even reduced multiple cropping indexes, contributing to decreased agricultural water consumption. Implicatio...

EVALUATION OF HARGREAVES BASED ON REMOTE SENSING METHOD TO ESTIMATE POTENTIAL CROP EVAPOTRANSPIRATION

In arid and semi-arid regions, agricultural water consumption information is very important to managing and developing water resources. Potential crop evapotranspiration (ETc) is the major parameter in agricultural water resources management. Remote sensing techniques were involved in this work to evaluate Hargreaves method for estimating ETc depending on satellite data. The difference between air temperature (Tair) and Land Surface Temperature (LST) varies particularly by surface water status. Normalized Difference Vegetation Index (NDVI) was extracted from NOAA/AVHRR and landsat8 satellite data to calculate emissivity as an intermediate step for producing LST. Linear relation between Tair and LST was established and R 2 was 0.93. Reference evapotranspiration (ETo) was estimated using agro-meteorological data through FAO-Penman-Monteith (FPM) which used as standard method and Hargreaves (Har) method. To calibrate ETo-Har, the ETo-FPM was used under the same conditions. Landsat8 data acquired on 13 th of Aug. and 08 th of Aug. 2014 and were used to calculate Crop coefficient (Kc) based on satellite data (Kc-Sat). LST was used to predict Tair ( o C) in Aug. 2014. ETo estimated using Har method and was used with Kc-Sat to estimate ETc-Har. ETo-FPM combined with Kc-Sat to estimate ETc-FPM. ETc-FPM used to evaluate ETc-Har. The relation between ETc- FPM and ETc-Har was very strong where R 2 as high as 0.99.

Agricultural water consumption decreasing nutrient burden at Bohai Sea, China

In this study, we discussed the impacts of human water consumption to the nutrient burden in a river estuary, and used Huanghe River as a case study. The agricultural water consumption from the Huanghe River has significantly decreased the natural water flows, and the amount of water consumption could be almost twice as high as the water entering into the estuary. According to our calculation, agricultural water usage decreased TN outflows by 6.5 × 104 Mg/year and TP outflows by 2.0 × 103 Mg/year. These account for 74% and 77% of the total output loads. It has been widely reported that the majority of the rivers in northern China were severely polluted by nutrients. Its implication on the budget of nutrient in the estuary ecosystem is not well characterized. Our study showed that the discharge of nutrients in the coast waters from polluted rivers was over concerned. Nutrients in the polluted rivers were transported back to the terrestrial systems when water was drawn for human water consumption. The magnitudes of changes in riverine nutrient discharges even exceed the water-sediment regulation trails in the Huanghe River. It has non-negligible impact on estimating the nutrient burden in costal water ecosystem.

Optimal model-based deficit irrigation scheduling using AquaCrop: A simulation study with cotton, potato and tomato

Water shortage is the main limiting factor for agricultural productivity in many countries and improving water use efficiency in agriculture has been the focus of numerous studies. The usual approach to limit water consumption in agriculture is to apply water quotas and in such a situation farmers should use an irrigation schedule that maximizes the yield and abides to the quota constraints. In contrast to the widespread use of irrigation scheduling based on agronomy practices, irrigation scheduling may be considered as a constrained optimization problem. When drip irrigation is used, the decision variables are the irrigation amounts for each day of the season. The objective function is the expected yield calculated with the use of a model. In the present work we solved this optimization problem for three crops modeled by the model AquaCrop. This optimization problem is non-trivial due to the non-smooth behavior of the objective function and the fact that it involves multiple integer variables. We developed an optimization scheme for generating sub-optimal irrigation schedules that take implicitly into account the response of the crop to water stress, and used these as initial guesses for a full optimization of daily irrigation. Performing this optimization with various values of water quotas produced the function that expresses the relationship between water quota and yield.

Environmental policy and management of freshwater resources in the Haraz-Ghareh Su Basin in comparison to other Caspian sub basins

Haraz-Ghareh Su is one of the seven sub-basins of the Caspian basin, located on the southern shores of the Caspian Sea, and as such, is in danger of water crisis due to absence of proper systematic policy and strategy. In this study, the pressure factors on the Haraz-Ghareh Su water resources were identified using DPSIR model. Then, the pressure parameters on the freshwater resources in the Caspian Basin were scored and prioritized into two categories: human and non-human criteria and eight sub-criteria with the help of questionnaires (the opinion of 36 specialists in environmental planning and management, as well as the use of FANP). Thereafter, the data layers were processed with the help of IDRISI software, and eventually, the data were overlaid in the ArcGIS and the final plan was made. The findings of the study shows that, among 8 effective sub-criteria on the environmental planning and management of the freshwater resources in the Haraz-Ghareh Su Basin, agricultural water consumption with 0.243 score points and dam-making with 0.039 score points are considered most and least important sub-criteria, respectively. Consequently, after the compilation and scoring of sub-basins of the Caspian basin, it appears that the sub-basin of Haraz-ghare Su with 0.158627 points had the worst situation in terms of the planning and management of freshwater resources in the Caspian basin. In order to decrease the pressure on the freshwater resources in the Haraz-Ghareh Su Basin, the formulation of long-term policy and strategy in this basin seems to be essential.

Sensor Research and Detection Technology for Efficient Water Usage and Security in Agriculture

Agriculture is the world’s largest consumer of water. Currently, 70% of global freshwater consumption is for agriculture, corresponding to a volume of over 2,500 km3. Unfortunately, water usage in agriculture is often highly inefficient with only a fraction of the water effectively used in plant growth. The rest of the water is lost via soil drainage, evaporation or transpiration. By 2050, the world’s population is expected to exceed 7 billion. The United Nations estimates that total agricultural water consumption will increase by 19% to meet global food demand. Additionally, increasing demand to shift more of the water used in agriculture to higher-value urban and industrial purposes will place additional stress on water for agriculture. Irrigation is also energy intensive. For example, irrigation with groundwater can lead to energy costs in the range of $10 to 100/acre per year. In California alone, agricultural irrigation uses 10 billion kilowatt hours of electricity annually. Water use efficiency in agriculture has been researched extensively. Conversion from traditional furrow irrigation to micro-irrigation methods has been shown to reduce irrigation needs by about 50% while improving yields. Unfortunately, present practice is less than ideal and often fails to collect all information necessary for cost effective management decisions. The utilization of above-ground irrigation systems has been shown to be effective, but a lack of adequate sensors for monitoring and control has led to non-optimal irrigation practices. Improving the efficient use of water resources still demands the development of new technologies that cost less and save energy by accurately assessing crop status for a given location, climate and soil conditions. Recently, advances in sensing and detection technologies as well as new approaches and protocols demonstrated potential for efficient irrigation control. Examples of the sensors include measurement of water efficiency, crop and soil-water conditions and evaluate food safety. Wireless sensor networks to transmit the measured information is also one of important technologies. As efforts to address issues in agricultural monitoring, our research team has developed smart dipstick sensors to measure liquid conditions including surface tension, viscosity, temperature, water content and acidity. Smart trap to monitor invasive pests and environment has demonstrated the use of sensor systems for protecting crops. A remote, wireless magnetoelastic biosensor has also been focused on identifying the presence of various pathogens for enhancing food safety and security. Sensor system and detection technology will enable targeted applications of water, fertilizer and pesticides to greatly reduce costs, improve producer profitability, and lead to a more sustainable agriculture. Efficient irrigation will also reduce environmental degradation while lowering energy usage in agriculture.

Changes in irrigation water consumption in the Nile Delta of Egypt assessed by remote sensing

This paper quantified irrigation water consumption according to vegetation cover changes in the Nile Delta using remote sensing data. Soil in the Nile Delta is clay, so the common irrigation system is tradition surface irrigation with less than 60 % irrigation efficiency. Agricultural field consumes more than 80 % of water resources under surface irrigation. In the previous decades, vegetation cover decreased in old lands because of urbanization. Vegetation cover changing studied at years 2002, 2007 and 2013 using Landsat 7, Landsat 8 and SPOT 4 satellite data. Monthly MODIS evapotranspiration (ETa) data were used to estimate the quantity of water consumed by vegetation cover in the Nile Delta. MODIS products land surface temperature (LST) and Normalized Difference Vegetation Index (NDVI) were used to estimate water deficit index (WDI). The FAO-Penman-Monteith (FPM) model was used to calculate reference evapotranspiration (ETo). The crop coefficient (Kc) was estimated according to NDVI. WDI and potential crop evapotranspiration (ETc) were used to calculate actual crop evapotranspiration (ETa). A linear relation between ETa based on MODIS product and ETa based on estimated method was established with R 2 as high as 0.86. The Nile Delta agricultural water consumption changed as a result of vegetation cover changing. The vegetation cover changing were 691,870, 698,510 and 693,340 (ha), and it consumed 3.78*109, 4.21*109 and 3.78*109 (m3/year) at years 2002, 2007 and 2013 respectively according to MODIS ETa product. On the other hand, vegetation water consumption according to estimated ETa changed and the results were 4.7*109, 5.3*109 and 4.8*109 (m3/year) at years 2002, 2007 and 2013 respectively.