Simulating the Impacts of Irrigation Levels on Soybean Production in Texas High Plains to Manage Diminishing Groundwater Levels

There is an increasing need to strategize and plan irrigation systems under varied climatic conditions to support efficient irrigation practices while maintaining and improving the sustainability of groundwater systems. This study was undertaken to simulate the growth and production of soybean [Glycine max (L.)] under different irrigation scenarios. The objectives of this study were to calibrate and validate the CROPGRO‐Soybean model under Texas High Plains’ (THP) climatic conditions and to apply the calibrated model to simulate the impacts of different irrigation levels and triggers on soybean production. The methodology involved combining short‐term experimental data with long‐term historical weather data (1951–2012), and use of mechanistic crop growth simulation algorithms to determine optimum irrigation management strategies. Irrigation was scheduled based on five different plant extractable water levels (irrigation threshold [ITHR]) set at 20%, 35%, 50%, 65%, and 80%. The calibrated model was able to satisfactorily reproduce measured leaf area index, biomass, and evapotranspiration for soybean, indicating it can be used for investigating different strategies for irrigating soybean in the THP. Calculations of crop water productivity for biomass and yield along with irrigation water use efficiency indicated soybean can be irrigated at ITHR set at 50% or 65% with minimal yield loss as compared to 80% ITHR, thus conserving water and contributing toward lower groundwater withdrawals. Editor's note: This paper is part of the featured series on Optimizing Ogallala Aquifer Water Use to Sustain Food Systems. See the February 2019 issue for the introduction and background to the series.     

Seeking calm water: Exploring policy options for India's water future

This paper seeks to identify some promising policy options which could be part of a strategic and holistic effort to address India's future water challenges. Significant increases in agricultural water productivity would be a major factor in reducing the need for developing new water sources. Crop diversification, appropriately targeted to account for the present agricultural systems and available water resources, will increase productivity. Furthermore, much more emphasis needs to be placed on effective management of the groundwater resources through renewed efforts to enhance artificial recharge and conservation. Also, efforts should be revived to improve the existing surface irrigation systems. In particular, systems could be reconfigured to provide a more reliable water supply and allow effective community level management, where appropriate. Finally, while some of the increasing demands from domestic and industrial users will be met by the development of groundwater and reallocation of water from the agricultural sector, this will not be sufficient. Given that such conditions are emerging in states with high economic growth and relatively water scarce basins, this will require the further development of water resources. In some cases, these conditions along with the demand for reliable water for high value crops, will be part of the justification for inter‐basin transfers.     

Deficit Irrigation Management of Maize in the High Plains Aquifer Region: A Review

Irrigated agriculture is a major economic contributor of the High Plains Region and it primarily relies on the High Plains Aquifer as a source of water. Over time, areas of the High Plains Aquifer have experienced drawdowns limiting its ability to supply sufficient water to sustain fully irrigated crop production. This among other reasons, including variable climatic factors and differences in state water policy, has resulted in some areas adopting and practicing deficit irrigation management. Considerable research has been conducted across the High Plains Aquifer region to identify locally appropriate deficit irrigation strategies. This review summarizes and discusses research conducted in Nebraska, Colorado, Kansas, and Texas, as well as highlights areas for future research. Editor's note : This paper is part of the featured series on Optimizing Ogallala Aquifer Water Use to Sustain Food Systems. See the February 2019 issue for the introduction and background to the series.     

Domestic water conservation potential in Saudi Arabia

Domestic water conservation in arid climates can result in efficient utilization of existing water supplies. The impacts of conservation measures such as the installation of water-saving devices, water metering and pricing schemes, water rationing and public awareness programs, strict plumbing codes, penalties for wasting water, programs designed to reduce leakage from public water lines and within the home, water-efficient landscaping, economic and ethical incentives are addressed in detail. Cost savings in arid climates, with particular reference to Saudi Arabia, in relation to some conservation techniques, are presented. Water conservation technology and tentative demonstration and implementation of water conservation programs are discussed.     

Impact of groundwater markets in India on water use efficiency: a data envelopment analysis approach

In the hard rock areas of India, overdraft of groundwater has led to negative externalities. It increased costs of groundwater irrigation and caused welfare losses. At the same time informal groundwater markets are slowly emerging and are believed to improve water distribution and to increase water use efficiency in the irrigation sector. These claims are evaluated in this study. For this purpose data was collected from a sample containing three different groups of water users: water sellers, water buyers and a control group of non-traders. First the socio-economic characteristics of these groups are compared. Then the efficiency of water use of the three groups is studied using Data Envelopment Analysis. The results indicate that groundwater markets provide resource poor farmers access to irrigation water, giving them the opportunity to raise their productivity. Water buyers are furthermore shown to be most efficient in their water use, while water sellers are also shown to be more efficient than the control group. The differences in efficiency between the groups are statistically significant. The demonstrated potential of groundwater markets to improve the efficiency of water use and to increase equity in resource access should be taken into account by the Indian government when deciding on their attitude towards the emerging groundwater markets.     

Evaluating the impact of water conservation on fate of outdoor water use: a study in an arid region

In this research, the impact of several water conservation policies and return flow credits on the fate of water used outdoors in an arid region is evaluated using system dynamics modeling approach. Return flow credits is a strategy where flow credits are obtained for treated wastewater returned to a water body, allowing for the withdrawal of additional water equal to the amount returned as treated wastewater. In the return credit strategy, treated wastewater becomes a resource. This strategy creates a conundrum in which conservation may lead to an apparent decrease in water supply because less wastewater is generated and returned to water body. The water system of the arid Las Vegas Valley in Nevada, USA is used as basis for the dynamic model. The model explores various conservation scenarios to attain the daily per capita demand target of 752 l by 2035: (i) status quo situation where conservation is not implemented, (ii) conserving water only on the outdoor side, (iii) conserving water 67% outdoor and 33% indoor, (iv) conserving equal water both in the indoor and outdoor use (v) conserving water only on the indoor side. The model is validated on data from 1993 to 2008 and future simulations are carried out up to 2035. The results show that a substantial portion of the water used outdoor either evapo-transpires (ET) or infiltrates to shallow groundwater (SGW). Sensitivity analysis indicated that seepage to groundwater is more susceptible to ET compared to any other variable. The all outdoor conservation scenario resulted in the highest return flow credits and the least ET and SGW. A major contribution of this paper is in addressing the water management issues that arise when wastewater is considered as a resource and developing appropriate conservation policies in this backdrop. The results obtained can be a guide in developing outdoor water conservation policies in arid regions.     

Draining us dry: scarcity discourses in contention over bottled water extraction

Water scarcity is a highly contested concept. The dominant narratives of water scarcity in policy debates have been criticised for prioritising purely quantitative metrics and eliding questions of inequality and power. While much scholarship on water scarcity examines contexts in the global South where potable water infrastructures do not reach most residents, this article examines conflict over commercial water extraction in a Northern setting where access to potable tap water is nearly universal, yet local water supplies are increasingly constrained. It addresses three main questions: (1) How are narratives or discourses of water scarcity mobilised by a range of actors in local conflicts over groundwater extraction for water bottling?; (2) To what extent do these discourses invoke biophysical versus socially produced scarcity, current versus future scarcity, and local versus regional or global scales of scarcity?; and (3) What are the implications of the findings for efforts by environmental advocates and communities to protect local water supplies? We explore these questions by analysing a local case study of conflict over groundwater extraction by the leading bottled water firm, Nestlé Waters, in southwestern Ontario, Canada. We find that the scarcity narratives deployed by local residents, activists, public officials, and bottling industry representatives illustrate the use of several forms of figurative conflation involving geographic and temporal scales of water scarcity, and economic and volumetric forms of scarcity. We argue that this conflation illuminates deeper issues of economic and social justice at the heart of the conflict, which transcend reductionist hydrological assessments of scarcity or abundance.     

Analysis of the role of waste minimisation clubs in reducing industrial water demand in the UK

As a result of the UK Government's waste policy, which increasingly encourages sustainable development, and the realisation that water in the UK cannot be treated as an unlimited resource, there is growing interest in reducing the demand for water by industry. A series of industrial waste minimisation clubs have been set up within the country. This paper identifies the effectiveness of these clubs in reducing the demand for water. An overview of some of the clubs show how there is a major discrepancy between potential and implemented water savings, whilst a more detailed analysis of three specific examples show how water demand and cost to the company can be reduced, with the project paying for itself within around 1 year. It appears that companies are able to reduce water consumption by approximately 30%. If this level of saving was taken up by the entire industrial sector in England and Wales, water consumption could be reduced by approximately 1500 Ml/day. This reduction would be more significant in regions of lower rainfall, for example East Anglia and Southeast England.     

Characterizing Drought in Irrigated Agricultural Systems: The Surface Water Delivery Index (SWDI)

Quantifying surface water shortages in arid and semiarid agricultural regions is challenging because limited water supplies are distributed over long distances based on complex water management systems constrained by legal, economic, and social frameworks that evolve with time. In such regions, the water supply is often derived in a climate dramatically different from where the water is diverted to meet agricultural demand. The existing drought indices which rely on local climate do not portray the complexities of the economic and legal constraints on water delivery. Nor do these indices quantify the shortages that occur in drought. Therefore, this research proposes a methodological approach to define surface water shortages in irrigated agricultural systems using a newly developed index termed the Surface Water Delivery Index (SWDI). The SWDI can be used to uniformly quantify surface water deficits/shortages at the end of the irrigation season. Results from the SWDI clearly illustrate how water shortages in droughts identified by the existing indices (e.g., SPI and PDSI) vary strongly both within and between basins. Some surface water entities are much more prone to water shortages than other entities based both on their source of water supply and water right portfolios.     

Estimating the economic value of improvements in river ecology using choice experiments: an application to the water framework directive

The Water Framework Directive is a major regulatory reform of water resources management within the European Union. Integrated catchment management plans must be prepared for all river basins, in order to achieve 'good ecological status' in all EU waters. Ecological status is a broader measure of water quality than the chemical and biological measures that were previously dominant. The Directive calls for a consideration of the economic costs and benefits of improvements to ecological status. In this paper, we use the choice experiment method to estimate the value of improvements in three components of ecological status. Given the high resource cost of valuation studies, benefits transfer methods will be needed in implementing the Directive. We thus also test the ability of choice experiments for benefits transfer across two very similar rivers in the UK.     

Factors affecting the variability of household water use in Melbourne,Australia

This study investigates the variability of household water use in Melbourne with the aim of improving the current understanding of factors affecting residential water use. This understanding is critical to predicting household water demand, particularly at an appropriate spatial and temporal resolution to support Integrated Urban Water Management based planning and to improve the understanding on how different household water demands respond to demand management strategies. The study used two sets of data each collected from 837 households under significantly different water use conditions in the years 2003 and 2011. Data from each household consist of the household characteristics and quarterly metre readings. Ordinary Least Square regression analysis followed by detailed analysis of each factor was used to identify key factors affecting household water use. The variables studied are household size, typology of dwelling, appliance efficiency, presence of children under 12 years, presence of children aged between 12 and 18 years, tenancy, dwelling age, presence of swimming pool, evaporative cooler, and dishwasher. All of them except presence of children aged between 12 and 18 years, tenancy and dwelling age were identified as variables that contribute to the variability of household water use in Melbourne. The study also found that the explanatory capacity of these variables increases with decreasing water use. This paper also discusses the significance of the explanatory variables, their impact and how they vary over the seasons and years. The variables found in this study can be used to inform improved prediction and modelling of residential water demand. The paper also explores other possible drivers to explain residential water use in light of the moderate explanatory capacity of the variables selected for this study thus, provides useful insights into future research into water demand modelling.     

Governance of water supply systems in the Palestinian Territories: A data envelopment analysis approach to the management of water resources

This study demonstrates that data envelopment analysis (DEA) can be a useful tool to assess the relative efficiencies of water supply systems and to establish benchmarks with which to measure progress in the management of water resources. Frontier efficiency models measure the efficiency of water use in the Palestinian Territories (West Bank and the Gaza Strip). At the municipality level, sufficient data for the years 1999-2002 were available to estimate efficiency and stability scores. The Gaza Strip efficiency scores were considerably lower than those of the West Bank. Water losses were the major source of the inefficiency as indicated by the large slacks of this input. The relative sizes of the municipalities affect efficiency scores little. Palestinian policy makers should focus on rebuilding the infrastructure of the water networks, beginning with the most DEA inefficient municipalities in order to minimize water losses.     

Watershed protection: Capturing the benefits of nature's water supply services

Healthy watersheds provide valuable services to society, including the supply and purification of fresh water. Because these natural ecosystem services lie outside the traditional domain of commercial markets, they are undervalued and underprotected. With population and development pressures leading to the rapid modification of watershed lands, valuable hydrological services are being lost, which poses risks to the quality and cost of drinking water and the reliability of water supplies. Increasing the scale and scope of programmes to protect hydrological services requires policies that harmonize land uses in watersheds with the provision of these important natural services. This article summarizes key attributes of hydrological services and their economic benefits; presents a spectrum of institutional mechanisms for safeguarding those services; discusses programmes in Quito (Ecuador), Costa Rica and New York City; and offers some lessons learned and recommendations for achieving higher levels of watershed protection.     

Harvesting of rainwater and brooklets water to increase mountain agricultural productivity: A case study from a dry valley of southwestern China

In semi-arid valleys of southwestern China, seasonal shortage of water is the major contributing factor to low and unstable crop yield. Harvesting of both rainwater and brooklets water in the semi-arid valleys of Ningnan county of Sichuan Province has brought about considerable economic and environmental change. Brooklet water is collected throughout the year but mainly during the rainy season in a series of ponds while rainwater is harvested in underground tanks constructed on road side or land boundaries with only a small opening above ground to save limited cropland. Increased water availability has promoted cultivation of sugarcane, tobacco, and mulberry, and increased per unit area yield of food crops. Sericulture, sugarcane and tobacco have become three important sources of farmers' income. The water harvesting has contributed considerably to increased rural income, poverty reduction, reduced soil erosion and improvement in overall environment. Government has played a key role in planning and implementation of water harvesting programmes. Financial support of government and clear ownership of water harvesting facilities are critical for the success of the programme. Application of similar water harvesting techniques in other areas with similar biophysical conditions would contribute to enhancing the rural economy and alleviating poverty.     

Water injustices and potential remedies in indigenous rural contexts: A water justice analysis

This paper examines Indigenous water rights in rural and remote Australia and how water justice seems to be elusive in many of these spaces. The purpose of this literature review is to link water justice theory and practices to the way different water cultures are valued in Australia while simultaneously critiquing the water justice movement. This paper situates the notion of water justice as a specific kind of environmental justice to cater for the unique qualities that define this resource. In doing so, this paper draws on Schlosberg’s (2004) conception of environmental justice with its trivalent approach that describes the following three ‘circles of concern’: recognition of difference, plurality of participation, and finally equitable distribution of resources and costs and benefits. This framework provides that if the first two ‘circles of concern’ are not in existence in a natural resource management process, then inequitable distribution of that resource is a likely outcome. This paper presents two areas where water injustices exist in the context of Indigenous rural and remote Australia. The first relates to how Indigenous rights to water have been inadequately recognized and the second presents empirical data on water supply and sanitation in rural and remote Indigenous communities that demonstrates ongoing dilemmas around securing this basic human right. The undervaluing of cultural differences relating to water is argued to be antecedent to the injustice manifest in poor water supply and sanitation provision for Indigenous rural contexts. This paper does not attempt to survey the body of ethnographic work on society-water relations in rural and remote Indigenous Australian contexts but reviews the gaps in current mainstream acknowledgement of Indigenous water cultures. In exploring water justice in rural and remote Indigenous Australia, this paper offers a novel approach to a dilemma more frequently analysed solely as a health development issue.     

The future of water in Australia: The potential effects of climate change and ozone depletion on Australian water quality,quantity and treatability

Water is a resource that is essential for all life on Earth. An exponentially growing human population, in addition to unprecedented industrial and technological development, threaten the availability and quality of this resource. Climate change and ozone depletion are two major environmental problems facing mankind today. These problems have the potential to further strain currently available freshwater resources. Recent research has shown that climate change and ozone depletion are linked phenomena and their interaction exacerbates their impact. Changes in precipitation, surface runoff, solar UV radiation, temperatures, and evaporation are some of the predicted outcomes of climate change and ozone depletion. They influence the biogeochemical cycles and aquatic ecosystems in lakes and rivers, and alter the character of natural organic matter (NOM) and, consequently, they have the potential to affect the quality, quantity and treatability of our water resources. Given these uncertainties, and the need to mitigate the consequences of climate change and ozone depletion, the issues of changing water quality, quantity and treatability cannot be ignored by Australian governments and water utilities.     

Analysis of a rural water supply project in three communities in Mali: Participation and sustainability

This paper presents a qualitative assessment of the participatory water management strategies implemented at the community level in rural Mali through a water supply project — The West Africa Water Initiative (WAWI) — coordinated by World Vision International, a non‐governmental and humanitarian organization. Data for the study were generated through a combination of primary and secondary sources in three villages. Results of the study indicate that while community‐based rural water supply is a positive step in responding to the needs of rural Malians, the installation of boreholes with hand pumps informed merely by consultative participatory approaches and limited extension involvement will not necessarily proffer sustainable rural water supply in the region. A “platform” approach to rural water supply management that can mobilize the assets and insights of different social actors to influence decision making at all stages, including the design and choice‐of‐technology stages, in water supply interventions is instead advocated.     

Building resilience to drought in desertification-prone savannas in Sub-Saharan Africa: The water perspective

Securing sustainable livelihood conditions and reducing the risk of outmigration in savanna ecosystems hosted in the tropical semiarid regions is of fundamental importance for the future of humanity in general. Although precipitation in tropical drylands, or savannas, is generally more significant than one might expect, these regions are subject to considerable rainfall variability which causes frequent periods of water deficiency. This paper addresses the twin problems of “drought and desertification” from a water perspective, focusing on the soil moisture (green water) and plant water uptake deficiencies. It makes a clear distinction between long‐term climate change, meteorological drought, and agricultural droughts and dry spells caused by rainfall variability and land degradation. It then formulates recommendations to better cope with and to build resilience to droughts and dry spells. Coping with desertification requires a new conceptual framework based on green‐blue water resources to identify hydrological opportunities in a sea of constraints. This paper proposes an integrated land/water approach to desertification where ecosystem management supports agricultural development to build social‐ecological resilience to droughts and dry spells. This approach is based on the premise that to combat desertification, focus should shift from reducing trends of land degradation in agricultural systems to water resource management in savannas and to landscape‐wide ecosystem management.     

Collective action: an alternative institutional arrangement for reducing water pollution in an industrial estate in India

This study explores the possibility of collective action as an alternative option for reducing water pollution for a cluster of small-scale industries. A case study of the Nandesari Industrial Estate in Gujarat, India, demonstrates the roles played by different agents, such as affected parties, polluters, non-governmental organizations, regulators and the court. The study empirically estimates the 'benefits' and 'costs' of water pollution abatement for a cluster of 250 small-scale industries at Nandesari, and uses these estimates for a social cost-benefit analysis. Benefits are estimated using the contingent valuation method, with a 'willingness to accept' format for the rural areas, and a 'willingness to pay' format for the urban area of the nearby Vadodara city. The article considers costs of command and control, market-based solutions and the option of common effluent treatment as alternative scenarios. It discusses how collective action and joint abatement at a common effluent treatment plant (CETP) by the 250 industries efficiently comply with the State Pollution Control Board norms, which had not been possible for the factories acting individually over the last 20 years. Finally, a detailed social cost-benefit analysis has been undertaken to estimate the net present social benefits with and without CETP. The cost-benefit analysis shows the economic advantage and social desirability of 'collective action' (joint treatment with CETP institutional arrangement) for water pollution abatement with respect to all possible scenarios comprising shadow prices of investment, foreign exchange, unskilled labour and equity considerations.     

Efficiency evaluation for regional urban water use and wastewater decontamination systems in China: A DEA approach

Rapid economic growth and urbanization in China have resulted in great water consumption in recent years. China has been facing increasingly severe water shortage crisis, especially in urban areas. This paper focuses on performance analysis for regional urban water use and wastewater decontamination systems in China. To this end, a DEA-based approach is developed. In the proposed approach, the efficiency of the system is decomposed into water use efficiency and wastewater decontamination efficiency. In the wastewater decontamination sub-system, the purified wastewater (reusable water) is treated as a desirable output; while in the water use sub-system, it is incorporated as a fixed input, which cannot be decreased in the process of efficiency optimization. The efficiency of the system is defined as the average of the two sub-systems’ efficiencies. The proposed approach can find inefficiencies caused by the internal factors between sub-systems, which cannot be identified using the traditional DEA approaches. We finally apply the proposed approach to analyze the efficiencies of regional urban water use and wastewater decontamination systems in China. Based on the application results, some findings and implications for efficiency improvement of urban water management in China are achieved.