Agricultural Water Use Research Articles

An Analytical Economic Study for The Optimal Use of Irrigation Water in Egyptian Agriculture

An Analytical Economic Study for The Optimal Use of Irrigation Water in Egyptian Agriculture

Water use efficiency control for a maize field under mulched drip irrigation

Agricultural ecosystem water use efficiency (WUE) is an important indicator reflecting carbon-water coupling, but its control mechanisms in managed fields remain unclear. In order to reveal the influencing factors of WUE in the agricultural field under mulched drip irrigation (DM), we carried out the 8-year continuous observations in a maize field from Northwestern China. The structural equation model, relative importance analysis and principal component analysis were used to quantify the regulation effects of environmental and biological factors on WUE at different time scales, in different growth stages and under different hydrothermal conditions. The results showed that annual WUE varied between 2.18 g C Kg−1 H2O and 3.60 g C Kg−1 H2O, with a multi-year mean of 2.91 g C Kg−1 H2O. The total effects of air temperature on the daily WUE in the whole growth period, the vegetative growth stage, the warm and dry years, the cold and wet years, and the warm and wet years were the largest, with values of 0.61, 0.80, 0.70, 0.70 and 0.91 respectively. However, vapor pressure deficit and net radiation had the largest total effect in the cold and dry years (−0.63) and the reproductive growth stage (−0.49), respectively. Leaf biomass played a leading role in regulating the daily and interannual WUE, and the relative importance of leaf biomass to WUE in the vegetative growth stage was up to 75 %. In the warm and wet years, the relative importance of root biomass to WUE was 33 %, slightly higher than that of leaf biomass (31 %). At the same time, we found that Ta has the potential to increase WUE under future climate warming. Our results improve the understanding of carbon-water coupling mechanisms and provide important enlightenment on how crop ecosystems should adapt to future climate change.

Transformation of water and land use in irrigated agriculture in Siberian regions (1990–2020)

The transformation issue of water and land use in irrigated agriculture in Siberian regions remains insufficiently studied. The study of this issue, especially over a long period, is very relevant. From 1990 to 2020 the area of irrigated land in Siberia decreased from 526 thousand hectares to 334 thousand hectares. In some subjects of the federation, the irrigation area decreased by 2-2.5 times in the Republic of Khakassia, and in the Novosibirsk region, it decreased slightly. In 1990, 15.9 thousand hectares of irrigated land (i.e., 3% of all irrigated land) were not used in agricultural production largely due to soil salinization and waterlogging. In 2020, there were 6.8 thousand hectares of such land. It is necessary to increase the share of fodder crops in irrigated crop rotations to improve soil fertility as well as to increase the production of fodder and livestock products. Due to the write-off of the worst lands in some regions (Republic of Tyva, Tomsk region), there is an increase in the share of lands with a good reclamation condition and a decrease in the share of lands with an unsatisfactory condition. In general, the share of lands with the good ameliorative condition in the Siberian District has noticeably decreased, especially from 2010 to 2020. Lands equipped with a collector-drainage network are available only in the Altai Territory and the Omsk Region. The area requiring capital work to improve the technical level of irrigation systems has sharply increased (from 10–25% in 1990 to 80–90% in some regions in 2020). The authors found that the area of actually irrigated lands in Siberia progressively decreased from 461 000 hectares in 1990 to 64 000 hectares in 2020. The number of sprinkling machines and installations decreased by 17 times, and the volume of water consumption – by ten times. In recent years state support for entities engaged in mining on reclaimed lands has been strengthened.

Sustainability Assessment of Water Resources Use in 31 Provinces in China: A Combination Method of Entropy Weight and Cloud Model.

As a fundamental and strategic resource, water is a crucial controlling element of ecosystem and natural environment and it plays an irreplaceable role in maintaining and promoting the sustainable development of the economy and society. To achieve the sustainable development of society, the economy and ecology, it is necessary to assess and improve the sustainability of water resources use. Based on the Human–Resource–Nature approach, this paper constructed an indicator system for the sustainability assessment of water resources use (ISSAWRU) in China from three perspectives: water resources condition, socio-economy and ecological environment. A five-level hierarchy of assessment indicators was established. Based on the entropy weight method and the cloud model which took both fuzziness and randomness into account, this paper established an entropy-cloud-based assessment model for the sustainability assessment of water resources use in 31 provinces in China in 2019. The assessment results were compared with results obtained by the TOPSIS method to test their reliability. Finally, a comprehensive and in-depth analysis of the sustainability of water resources use in China was conducted. According to the results, water resources per capita had a weighting of 0.306 and the greatest impact on the sustainable use of water resources. In addition, water structure, agricultural water use efficiency, forest coverage, and so on, had a significant impact on the sustainable use of water resources in China. The overall level of sustainability of water resources use in 31 provinces in China was not high—42% of the regions have unsustainable water resources use and there was a clear spatial distribution trend. The sustainability level of water resources use was higher in the southeast and economically developed regions. Therefore, each region should develop measures to guarantee water security based on the local conditions. This research helps policy makers to figure out the contributing factors associated with sustainability of water resources use and to set relevant rules and regulations to promote the use of water resources in a sustainable way.

Regional water footprint assessment for a semi-arid basin in India.

Water footprint assessment enables us to pinpoint the impacts and limitations of the current systems. Identifying vulnerabilities across various regions and times helps us prepare for suitable actions for improving water productivity and promoting sustainable water use. This study aims to provide a comprehensive evaluation of the sector-wise water footprint in the Banas River Basin from 2008–2020. The water footprint of the Banas River Basin was estimated as 20.2 billion cubic meters (BCM)/year from all sectors. The water footprint has increased over the year with the increase in population, the number of industries, and crop production demand. The average annual water footprint of crop production varied from 11.4–23.1 BCM/year (mean 19.3 BCM/year) during the study period. Results indicate that the water footprint has nearly doubled in the past decade. Wheat, bajra, maize, and rapeseed & mustard make up 67.4% of crop production’s total average annual water footprint. Suitable measures should be implemented in the basin to improve water productivity and promote sustainable water use in agriculture, which accounts for nearly 95.5% of the total water footprint (WF) of the Banas basin. The outcomes of the study provide a reference point for further research and planning of appropriate actions to combat water scarcity challenges in the Banas basin.

Managing irrigation under increasing water scarcity

AbstractWith rising physical and economic scarcity of water, increasing or sustaining agricultural production while limiting or reducing consumptive water use is an urgent challenge. This article examines the case of four countries—India, China, western United States, and Israel—where there is a long history of irrigated agriculture with significant public and private investments, to identify key themes for managing irrigation under increasing physical and economic water scarcity. The focus of irrigation management has expanded from investing in irrigation infrastructure to reforming institutions; strengthening policies pertaining to irrigation prices and rights; using incentives to reward reductions in irrigation application; and improving irrigation efficiency. However, this may not be sufficient to reduce consumptive use of water in agriculture. Reducing freshwater use in agriculture will require cost‐effective harnessing of other water sources through processes such as desalination and wastewater reuse, which may be difficult to implement in most geographies. Changes to policies in other sectors will likely be needed, especially in food procurement and land‐use, which require balancing water security with food security, and supporting potential losses in livelihoods and incomes from such changes. Finally, reductions in agricultural water use in a country will likely have implications for water use in other countries, through imports.

A Hydro-Economic Model to Calculate the Resource Costs of Agricultural Water Use and the Economic and Environmental Impacts of Their Recovery

In this paper, we estimate the resource costs of agricultural water use and simulate the environmental and economic impacts of their recovery. To this end, we develop a socio-hydrology-inspired, dynamic, protocol-based modular approach that interconnects economic and hydrologic modeling via two-way feedback protocols. The hydrologic module is populated with the AQUATOOL model, the Decision Support System used in Spanish river basins; while the economic module is populated with an ensemble of four Mathematical Programming Models (MPMs) that capture human agency and responses. This allows us to sample uncertainty and provide a range for resource costs estimates and the environmental and economic impacts of their recovery, rather than a point estimate. Methods are illustrated with an application to the Órbigo Catchment, a sub-basin of the Douro River Basin in Spain. Our results suggest significant resource costs (a 34–62% increase in existing charges, depending on the model) with non-trivial impacts on income (2–27% reduction) and the environment (water savings range between 6% and 69%), while the impact on tax revenue is ambiguous yet potentially significant (between [Formula: see text]2.3 million EUR/year and 5 million EUR/year).

Rising agricultural water scarcity in China is driven by expansion of irrigated cropland in water scarce regions

Rising agricultural water scarcity in China is driven by expansion of irrigated cropland in water scarce regions

The Water–Energy–Food Nexus: An Analysis of Food Sustainability in Ecuador

In Latin America and the Caribbean, the interrelationships among water, energy, and food are complex, partly due to their development models, which are intensive in their use of these resources. This research aims to recognize and quantify the use of water and energy in food in Ecuador by identifying the main interrelationships, together with their causes and current impacts. Regarding methodology, this research uses sectoral data available at the national level and international databases to obtain cross indexes. The following indicators were sought: percentage of energy demanded by food in different stages, extraction of water for agricultural use, food energy productivity, virtual water, and embodied energy. As a result, it was estimated that food consumes 50% of imported energy and cocoa stands out with 7.6 km3 of water footprint; the products with the highest energy consumption are shrimp with 2090 KBOE and fish with 1459 KBOE. Fishing and aquaculture products present with a significantly high consumption level. Nearly all the virtual water and embodied energy are exported in banana, cocoa, and shrimp. Exporting groups make extensive use of the country’s water and energy resources.

Potential impacts of reduced inflows to the Salton Sea: Forecasting non‐market damages

AbstractTerminal lakes throughout the American West provide important amenity and environmental values, but many are shrinking due to reduced inflows and warming temperatures. In California's Imperial Valley, agricultural water use reductions diminish inflows supporting the Salton Sea, a terminal desert lake and important environmental amenity for both the region and the state as a whole. The costs of these reduced inflows are difficult to monetize yet complicate management decisions. We assess the costs of potential future drought‐induced transfers by linking novel hydrologic scenarios to an economic framework for quantifying local and regional damages based on existing estimates of non‐market environmental values from the literature. The costs of lost wetland ecosystems, increases in particulate matter from exposed playa, and other local disamenities are substantial. For the scenarios considered, they range between approximately $500 million and $1 billion in present value (2019 USD). Estimated damages per acre‐foot (or thousand m3) of reallocated water exceed several thousand dollars. The majority arise from loss of wetland habitat; incremental particulate matter damages are relatively modest in our modeling but exacerbate salient air quality issues in the region. Interest in reallocating water from Imperial Valley, the largest user of Colorado River water, to other applications will increase over time. Our work highlights the importance of evaluating the impacts of such efforts.

Irrigation and warming drive the decreases in surface albedo over High Mountain Asia

Human and climate induced land surface changes resulting from irrigation, snow cover decreases, and greening impact the surface albedo over High Mountain Asia (HMA). Here we use a partial information decomposition approach and remote sensing data to quantify the effects of the changes in leaf area index, soil moisture, and snow cover on the surface albedo in HMA, home to over a billion people, from 2003 to 2020. The study establishes strong evidence of anthropogenic agricultural water use over irrigated lands (e.g., Ganges–Brahmaputra) which causes the highest surface albedo decreases (≤ 1%/year). Greening and decreased snow cover from warming also drive changes in visible and near-infrared surface albedo in different areas of HMA. The significant role of irrigation and greening in influencing albedo suggests the potential of a positive feedback cycle where albedo decreases lead to increased evaporative demand and increased stress on water resources.

Hill Dam Design to Improve Water Use in Rural Areas—Case Study: Sacachún, Santa Elena

The Sacachún commune in Ecuador currently faces a lack of water for its agricultural development; this reduces its possibilities of socio-economic development and causes migration to urban areas. This research proposes a presa colinar (hill dam) design that uses ancestral knowledge and classic engineering techniques to promote water use during the dry season in semi-arid regions. The methodology consisted of: (i) a systematic compilation of the ancestral structures used for water planting and harvesting in Ibero-American; (ii) selecting an appropriate place to build the hill dam; (iii) the dam’s body design; (iv) and creating a proposal for agricultural water use. The results helped define a good location for the hill dam implementation. In addition, a 10 m high and 40 m wide earthen dam was designed, with a storage capacity of 114,341 m3, extending agriculture to 7.5 ha through a polyculture system of six different plants. The embankment has a cofferdam located downstream, which provides stability in static and pseudo-static conditions. In addition, the dam slopes have a 2:1 ratio, and a spillway channel and filter drain were dimensioned to protect the dam.

Ground-Penetrating Radar Detection of Hydrologic Connectivity in a Covered Karstic Setting

Increasing demand for water for agricultural use within the Dougherty Plain of the southeastern United States has depleted surface water bodies. In karstic landscapes, such as the Dougherty Plain in southwest Georgia where the linkages between surface and ground waters are close, there is a need to understand the physical characteristics of the subsurface that allow these close linkages. Having a better understanding of the subsurface characteristics will aid numerical modeling efforts that underpin policy decisions and economic analyses. Two common features on this karstic landscape are draws and geographically isolated wetlands. Using LiDAR, aerial imagery, and ground-penetrating radar, this study investigates the subsurface characteristics of a draw and a series of geographically isolated wetlands. GPR reflections indicative of karst features are laterally continuous and connect the landscape to the nearby Ichawaynochaway Creek. The identification of the size and scale of the laterally continuous karstic features will guide the implementation of groundwater models used to determine irrigation and forest restoration programs while minimizing the impacts of water use on surface streams and the ecosystems.

Assessment of water availability for agricultural activities in the savannah Plateau of Adamawa-Cameroon.

The availability of water for agricultural use in the savannah plateau of Adamawa, Cameroon, is addressed in this paper. Specific field tests coupled with climatic data analysis have helped to characterize the hydrological and hydrogeological conditions of water resources in a small catchment. An agricultural suitability map, based on the water availability during the dry season, is produced. Measured saturated hydraulic conductivities indicated an acceptable disposition of the soils for agriculture. The transmissivity values indicated moderate groundwater potential with mean annual recharge of 96mm. The agricultural suitability map shows that only 8.8% of the basin area is very favorable for agriculture and that 51% of the basin is not suitable for agriculture, due to water scarcity during the dry season. Due to the considerable depth to the water table, pumping for irrigation purposes is not affordable for the local low-income farmers. Therefore, there is a need to implement adapted solutions for irrigation to support farmers' endeavors, such as the development of water retention basins or the construction of boreholes equipped with electric pumps supplied by solar energy for irrigation.

Evaluating water resources carrying capacity: The empirical analysis of Hubei Province, China 2008–2020

Scientific evaluation of water resources carrying capacity (WRCC) is the basis for implementing water resources conservation measures. Hubei Province, with the longest runoff mileage of the Yangtze River, the reservoir area of the Three Gorges Project and the core water source area of the South-to-North Water Diversion Middle Line Project, bears great responsibility for ecology conservation in China. How to evaluate WRCC in Hubei Province has become significant. This study created a WRCC evaluation method based on information entropy method, principal component analysis and Spearman’s rank correlation coefficient to assess the WRCC in Hubei Province from 2008 to 2020. The available indicators were collected and summarized from the aspects of economy, population, resources and environment. By three-dimensionally displaying different indicators’ eigenvalues of principal component analysis, the major indicators can be screened. Subsequently, information entropy method was applied to estimate WRCC in Hubei Province and Spearman’s rank correlation was examined between WRCC and relevant factors. The results indicated that the WRCC in Hubei Province had been unstable in the range of 0.065 to 0.088 with the annual growth rate of 0.096%. It had a few peaks in year 2010, 2012, 2014, 2015 and 2016 while it decreased dramatically in year 2009, 2011, 2013, 2018 and 2020. Specifically, agricultural water use is more influential than industrial water use. The annual decline at 1.865% in agricultural water use is much smaller than the annual decline at 10.471% in industrial water use. Economically developed areas in the province have higher WRCC while economically backward areas have weaker WRCC.

Agricultural water use efficiency and spatial spillover effect considering undesired output in China

Abstract Solving the problem of agricultural water use efficiency is an effective means to understand the agricultural ecological civilization and food security. In order to balance the relationship between agricultural water efficiency and regional economic size, this study examines the agricultural water use efficiency in China based on the Super-SBM model of unexpected output. At the same time, the Spatial Durbin Model (SDM) was introduced to analyze the spatial spillover effect and try to find ways to improve agricultural water use efficiency from the perspective of influencing factors. The present study used the panel data of 30 provinces in China from 1998 to 2018 to obtain empirical results. The results show that (1) China's agricultural water resources’ utilization efficiency in 21 years has not remained high: the results showed that it was 0.496 in 1998, 0.572 in 2008, and 0.657 in 2018, but it is slowly rising which explains that the low efficiency is mainly caused by the low pure technical efficiency. (2) The overall agricultural water use efficiency in China is in a situation of spatial agglomeration but there has been a trend of shifting positive correlations to negative correlations among neighboring provinces. It found that in 1998, the sum of the number of `High-high agglomeration type' and `low-low agglomeration type' provinces was 20, and the sum of `low-high agglomeration type' and `high-low agglomeration type' provinces was 10. In 2018, the total number of `high-high agglomeration type' and `low-low agglomeration type' provinces decreased to 12, while the total number of `low-high agglomeration type' and `high-low agglomeration type' provinces increased to 18, which specifically manifested as a negative spillover effect. (3) During the research period, the province's agricultural fixed asset investment, fiscal expenditure on agriculture, forestry, and water affairs, the number of years of education of rural residents and the increase in crop sown area have positive impacts on the efficiency of agricultural water use in the province. Meanwhile the transfer of labor and increase in the disposable income of rural residents reduced the efficiency of agricultural water use in the province. Fixed agricultural investment, labor transfers, and financial expenditures for agriculture, forestry, and water affairs in neighboring provinces have negative impacts on the province's agricultural water use efficiency. The impact is specifically manifested as a negative spatial spillover effect. As a result, China's agriculture will move towards healthy and green development. Therefore, the efficiency of agricultural water use needs to be comprehensively improved.

Managing Agricultural Water Use in a Changing Climate in China

The United Nations predicts that over 40 % of the world's population (3.9 billion) would suffer from severe water deficiency by 2050, indicating that global water disequilibrium and deficiency will intensify, creating challenges for national and regional water supplies. With per capita water resources at a quarter of the world average level, China is one of the most water-scarce countries. Employing a single stage Stochastic Frontier Analysis, this paper studies the impact of climate change induced fluctuation in temperature and precipitation on agricultural water (AW) use efficiency in China and addresses its volatility and regional disparity over time and across region. We utilize fine-scale meteorological factors including temperature, precipitation, crop growing degree days and crop harmful degree days to proxy the changing climate condition. Our results reveal temperature-related climate change factors such as average annual temperature, crop growing degree days and crop harmful degree days demonstrate the negative impacts on AW use efficiency, and the decline in precipitation due to climate change lowers AW use efficiency. More importantly, we find that when the information on climate damage is provided to farmers, the negative effect of climate change on AW use efficiency can be alleviated. Furthermore, we conclude that the North China Plain, Southwest and Northeast regions with shortages of water endowment have the best AW use efficiency, followed by the Yangtze River Basin and the Northwest region. The South Coast region with ample water sources has the poorest performance. We therefore conclude that AW use efficiency in China is affected by climate change, with heterogeneous impacts across regions. Policy implications on risk management are drawn to enable better adaptation to climate change in agricultural water use.

Climate change and water security in the northern slope of the Tianshan Mountains

Water security is under threat worldwide from climate change. A warming climate would accelerate evaporation and cryosphere melting, leading to reduced water availability and unpredictable water supply. However, the water crisis in the Northern Slope of Tianshan Mountains (NSTM) faces dual challenges because water demands for fast-growing urban areas have put heavy pressure on water resources. The mountain-oasis-desert system features glacier-fed rivers that sustain intensive water use in the oasis and end in the desert as fragile terminal lakes. The complex balance between water conservation and economic development is subtle. This paper investigates changes in hydroclimatic variables and water security-related issues on the NSTM. The spatiotemporal variations in glaciers, climatic variables, rivers, lakes and reservoirs, groundwater, surface water, human water use, and streamflow were analyzed for the past four decades. The results show that temperature in the NSTM exhibited an apparent upward trend with a more significant warming rate in the higher altitude regions. Glacier mass loss and shrinkage was strong. The average annual streamflow increased from 1980-1989 to 2006–2011 at most hydrological stations. The monthly dynamics of surface water area showed notable variability at both inter-annual and seasonal scales, revealing the impacts of both natural and anthropogenic drivers on surface water availability in the region. The terrestrial water storage anomaly showed a decreasing trend, which might be related to groundwater pumping for irrigation. Human water use for agriculture and industry grew with the increase in cultivated land area and gross domestic product (GDP). The increased agricultural water use was strongly associated with the expansion of oases. It is unclear whether water availability would remain high under future climatic and hydrological uncertainties, posing challenges to water management. In the context of rapid urban growth and climate change, balancing water for humans and nature is vital in achieving the Sustainable Development Goals (SDGs) in NSTM. This study provides a baseline understanding of the interplay among water, climate change, and socio-economic development in NSTM. It would also shed light on wise water management under environmental changes for other rapidly developing mountain-oasis-desert systems worldwide.

Optimized empirical model based on whale optimization algorithm for simulate daily reference crop evapotranspiration in different climatic regions of China

The accurate estimation of reference crop evapotranspiration (ET0) is of great significance to improve agricultural water use efficiency and optimize regional water resources management. At present, the applicability evaluation system of ET0 models is still lacking in several climate regions in China, leading to the confusion in application of the ET0 model in some specific regions. In this study, the daily meteorological data of 84 representative stations in four climate regions of China during the past 30 years (1991–2019) were selected to evaluate the ET0 simulation results of twelve empirical models (four temperature models, five radiation models, and three hybrid models) on the daily scale, and the optimal models suitable for each climate region were screened. Whale optimization algorithm (WOA) was used to optimize the optimal model to improve the simulation accuracy, and the ET0 results were compared with those predicted by extreme learning machine (ELM). The results showed that the estimation accuracy of the hybrid model was the best throughout China, followed by the radiation model, and the temperature model was relatively poor, with R2 ranges of 0.77–0.88, 0.60–0.86, and 0.58–0.82, respectively. Among the temperature-based models, Hargreaves-Samani and Improve Baier-Robertson model had the highest accuracy, with R2 of 0.80 and 0.79. Among the radiation-based models, Priestley-Taylor and Jensen-Haise models had the best accuracy, with R2 of 0.82 and 0.79. Among the hybrid models, Penman model had the highest accuracy, with R2 of 0.84. The accuracy of Hargreaves-Samani and Improve Baier-Robertson model in SMZ climate region was higher than TCZ, TMZ, and MPZ, and the accuracy of Jensen-Haise model in TCZ was the highest. The estimation accuracy of Priestley-Taylor and Penman models was similar in SMZ, TCZ, TMZ and MPZ. Using WOA to optimize the optimal temperature, radiation, and hybrid models, the prediction accuracy was improved by 12.05 %, 11.06 %, and 10.46 %, which were higher than the result of ELM model, with R2 of 0.90, 0.91, 0.95 and 0.90, respectively. Therefore, it is recommended to adopt WOA to optimize the empirical model to estimate the ET0 all over China.

An Assessment of the Rational Range of Eco-Compensation Standards: A Case Study in the Nujiang Prefecture, Southwestern China

Eco-compensation is an effective means of coordinating ecological protection and economic development, and the assessment of its standards is core content in the study of eco-compensation projects. To improve the operability of eco-compensation standards, taking Nujiang Prefecture as the study area, we combine the equivalent factor method and water footprint method to evaluate the ecosystem-service-value (ESV) spillover and use the market comparison method to calculate the opportunity cost. The final eco-compensation upper and lower limits model is constructed on the basis of the ESV spillover and opportunity cost. The results show the following: (1) the ecological protection of Nujiang Prefecture has been effective, based on the stabilization of its ESV after an initial increase. The main types of ecosystem services provided are regulation and provision services. Gongshan County makes the most significant contribution to the total ESV. (2) The ratio of the ESV self-consumption in Nujiang Prefecture shows a trend of first rising and then falling. This is mainly explained through the reduction in the use of industrial and agricultural water. After deducting self-consumption through the water footprint method, it can be observed that there is ecological spillover in Nujiang Prefecture. (3) The opportunity cost in Nujiang Prefecture increases yearly from 2005 to 2020 owing to ecological protection policies. Combined with the ESV spillover, it is determined that the rational range of the eco-compensation standard is between CNY 6.17 × 102 million and 120.01 × 102 million in 2005, between CNY 10.02 × 102 million and 128.25 × 102 million in 2010, between CNY 30.34 × 102 million and 197.12 × 102 million in 2015, and between CNY 41.97 × 102 million and 227.52 × 102 million in 2020. The current study can offer decision makers a more flexible eco-compensation standard while coordinating the contradiction between regional ecological protection and economic development.