Use Of Groundwater For Irrigation Research Articles

Applying stochastic goal programming: A case study on water use planning

A decision support model to help public water agencies allocate surface water among farmers and authorize the use of groundwater for irrigation (especially in Mediterranean dry regions) is developed. This is a stochastic goal programming approach with two goals, the first concerning farm management while the other concerns environmental impact. Targets for both goals are established by the agency. This model yields three reduction factors to decide the different reductions in available surface water, standard groundwater and complementary groundwater that the agency should grant/authorize for irrigation, this depending on if it is a dry or wet year. In drought periods, the model recommends using more groundwater (in percentage) than in wet periods. A case study using year-to-year statistical information on available water over the period 1941–2005 is developed through numerical tables. A step-by-step computational process is presented in detail.

An assessment of the potential and impacts of winter water banking in the Sokh aquifer, Central Asia

The dynamics of artificial recharge of winter surface flows coupled with increased summer groundwater use for irrigation in the Sokh aquifer (Central Asia) have been investigated. Water release patterns from the giant Toktogul reservoir have changed, as priority is now given to hydropower generation in winter in Kyrgyzstan. Winter flows have increased and summer releases have declined, but the Syr Darya River cannot pass these larger winter flows and the excess is diverted to a natural depression, creating a 40 × 109m3 lake. A water balance study of all 18 aquifers feeding the Fergana Valley indicated the feasibility of winter groundwater recharge in storage created by summer abstraction. This modeling study examines the dynamics of the process in one aquifer over a 5-year period, with four scenarios: the current situation; increased groundwater abstraction of around 625 million (M) m3/year; groundwater abstraction with an artificial recharge of 144 Mm3/year, equivalent to the volume available in low flow years in the Sokh River; and with a larger artificial recharge of 268 Mm3/year, corresponding to high flow availability. Summer surface irrigation diversions can be reduced by up to 350 Mm3 and water table levels can be lowered.

Using multiple‐variable indicator kriging to assess groundwater quality for irrigation in the aquifers of the Choushui River alluvial fan

AbstractThis work attempted to locate clean and safe groundwater for irrigation use in the Choushui River alluvial fan. Multiple‐variable indicator kriging (MVIK) was adopted to evaluate numerous hydrochemical parameters for a standard of water quality for irrigation in Taiwan. Many hydrochemical parameters in groundwater were distinguished into three main categories—salinity/sodium hazard, nitrogen hazard and heavy metal hazard. Safe and potential hazardous regions of groundwater for irrigation were delineated according to different probabilities estimated by MVIK. The probabilistic results of the classifications gave an opportunity to explore the spatial uncertainty of the hazards and helped government administrators establish a sound policy associated with the development and management of groundwater resources. Analysis of the results indicate that the central distal‐fan and mid‐fan aquifers are the best places to extract clean and safe groundwater for irrigation, and the deep aquifer (exceeding 200 m depth) has wider regions with clean and safe groundwater for irrigation than shallow aquifers. The northern and southern aquifers, with multiple hazards, limit groundwater use for irrigation. Although the proximal‐fan aquifer is a zone of groundwater recharge, the high nitrogen content seriously affects the environment and is not suitable for irrigation use. Copyright © 2008 John Wiley & Sons, Ltd.

Using energy pricing as a tool for efficient, equitable and sustainable use of groundwater for irrigation: evidence from three locations of India

This paper analyzes the potential impacts of energy pricing on efficiency, equity and sustainability in groundwater use. The analysis uses empirical data on water productivity in agriculture for crops, dairying and farms for north Gujarat, east US and south Bihar. For north Gujarat, the analysis uses data from well owners who pay flat rate tariff, and well owners who pay pro-rata tariff. For eastern UP and south Bihar, the analysis uses data from well owners and water buyers from diesel and electric well commands. The analysis also compares data from diesel well owners and electric well owners in south Bihar. The findings are as follows: Introducing marginal cost for electricity motivates farmers to use water more efficiently at the farm level through careful use of irrigation water; use of better agronomic inputs; optimize costly inputs; optimize livestock composition and carefully select crops and cropping patterns, which give higher return from every unit of water and grow low water consuming crops. It also shows that higher cost of irrigation water (because of higher energy cost) will not lower net return from every unit of water used as the farmers will modify their farming system accordingly. Further, change in the structure of power tariff from flat rate to pro-rata will not have any adverse effects on access and equity in groundwater use. Nor will it increase the monopoly power of well owners. The number of potential water sellers and not the number of potential buyers of water govern the price of water. Pro-rata pricing reduces cost of groundwater pumping per unit of land. It also reduces aggregate pumping, which is disproportionately higher than the reduction in net returns per unit of land. This leads to more sustainable groundwater use. This means that in water scarce regions, it would be possible for farmers to maintain net farm surpluses at higher energy tariff by improving productivity of water use. The empirical evidence further reinforces that the arguments against pro-rata pricing are flawed. Raising power tariff in the farm sector to achieve efficiency, equity and sustainability in groundwater use is socially and economically viable.

Watershed development in India. 1. Biophysical and societal impacts

This paper recommends a revision of watershed development policy in India in relation to the planning of development interventions involving agricultural intensification and rainwater harvesting following biophysical and societal impact studies carried out on two watershed development projects in Karnataka. A need for changes in policy has arisen in response to progressive catchments closure at the basin level and declining volumes of water flowing into village level reservoirs (known locally as tanks). Flow reductions have occurred largely as a result of increased agricultural intensification over the past 10–15 years. Field levelling, field bund construction, soil water conservation measures, farm ponds, the increase in areas under horticulture and forestry and the increased abstraction and use of groundwater for irrigation are all contributing factors to reduced flows. Planning methodologies and approaches, which may have been appropriate 20 years ago for planning water harvesting within watershed development projects, are no longer appropriate today. New planning approaches are required which (1) take account of these changed flow conditions and (2) are also able to take account of externalities, which occur when actions of some affect the livelihoods of others who have no control or influence over such activities and which (3) contribute to the maintenance of agreed minimum downstream flows for environmental and other purposes.

Hydrologic sustainability of the Sultan Marshes in Turkey

: Hydrologic changes in the Sultan Marshes ecosystem, a closed‐basin wetland in the semi‐arid Develi Basin in south‐central Turkey, are analyzed and related to intensification of irrigated agriculture in the catchment. Relationships between water‐level changes in the marsh, and inflows and outflows of surface water and groundwater are examined. Since the 1980s, surface runoff from the surrounding mountains into the Develi Basin has been captured in three major reservoirs and used for flood irrigation. Substantial declines in seasonally‐fluctuating water levels were recorded in the Sultan Marshes from 1993 to 2003. Our analysis shows that these trends are related to decreases in inflows from groundwater and springs, not to climatic changes. Simulations with a deterministic hydrologic model for the Örtülüakar Marsh, a sub‐system of the Sultan Marshes, as well as statistical analyses, showed that it is necessary to reduce water use from groundwater and springs to maintain pre‐1995 marsh water levels. Alternative groundwater management scenarios to sustain both the wetland and irrigated agriculture in the Develi Basin were tested. A 50% reduction in groundwater and spring‐water use for irrigation showed promising results for the Sultan Marshes. Irrigation in the basin uses 66% surface water and 34 % groundwater. A 50% reduction in groundwater use for irrigation therefore represents less than 20 % of total irrigation water used. Reduction in groundwater use is, however, linked to social and economic conditions in the Develi Basin, and incentives that encourage farmers to adopt sustainable groundwater use practices need to be developed.

Intensive Groundwater Use: Silent Revolution and Potential Source of Social Conflicts

Many papers, including a recent editorial of this journal Stakhiv 2003 , have advocated the need for a paradigm shift toward adaptive, integrated water resources management as a means to attain a rationalization in water use. There is, however, one significant element of water policy that has received less attention by most experts and water decision-makers: intensive groundwater use for irrigation in arid and semiarid regions more significantly in developing countries . This editorial provides an overview of this phenomenon and its main pros and cons, aiming to contribute to the current debate over adaptive integrated water resources management. Assessing the implications might not only shed some new light upon some pervasive world water visions, but also help to avoid or mitigate potential social conflicts. Groundwater development has for a long time provided drinking water to urban and rural populations of developed and developing countries. Currently, groundwater is estimated to provide about 50% of the world’s drinking-water supplies United Nations 2003 p. 78 . Moreover, groundwater is arguably the cheapest and fastest way to achieve the United Nations Millennium Declaration goal of halving the number of people worldwide without affordable drinking water and/or malnourished by 2015 Llamas and Martinez Cortina 2002 . In addition, groundwater abstraction by simplified mechanisms, such as the treadle pump, together with cheap drip irrigation systems, also constitutes a plausible alternative for developing countries to overcome the poverty threshold one dollar/person and day per capita income Polak 2004 . While the human and political relevance of these figures is obvious, it cannot be overlooked that urban and rural domestic supply for human consumption amounts to less than 15% of global water use. Thus, this editorial is concerned solely with irrigation, which is generally acknowledged to be about 70% of the world’s freshwater withdrawal United Nations 2003 . Note that this percentage might increase to about 90% if consumptive uses were considered.

Groundwater depletion: A global problem

In the past half-century, ready access to pumped wells has ushered in a worldwide “explosion” of groundwater development for municipal, industrial, and agricultural supplies. Globally, groundwater withdrawals total 750–800 km/year (Shah et al. 2000). Economic gains from groundwater use have been dramatic. However, in many places, groundwater reserves have been depleted to the extent that well yields have decreased, pumping costs have risen, water quality has deteriorated, aquatic ecosystems have been damaged, and land has irreversibly subsided. Groundwater depletion is the inevitable and natural consequence of withdrawing water from an aquifer. Theis (1940) showed that pumpage is initially derived from removal of water in storage, but over time is increasingly derived from decreased discharge and/or increased recharge. When a new equilibrium is reached, no additional water is removed from storage. In cases of fossil or compacting aquifers, where recharge is either unavailable or unable to refill drained pore spaces, depletion effectively constitutes permanent groundwater mining. In renewable aquifers, depletion is indicated by persistent and substantial head declines. Excessive groundwater depletion affects major regions of North Africa, the Middle East, South and Central Asia, North China, North America, and Australia, and localized areas throughout the world. Although the scope of the problem has not been quantified globally, on-going analysis by the senior author indicates that about 700–800 km of groundwater has been depleted from aquifers in the US during the 20th century. One of the best documented cases is the 450,000 km High Plains aquifer system in the central US, where the net amount of water removed from storage during the 20th century was more than 240 km—a reduction of about 6% of the predevelopment volume of water in storage (McGuire et al. 2003). In some of the most depleted areas, use of groundwater for irrigation has become impossible or cost prohibitive (Dennehy et al. 2002). In some cases, removing the most easily recoverable fresh groundwater leaves a residual with inferior water quality. This is due, in part, to induced leakage from the land surface, confining layers, or adjacent aquifers that contain saline or contaminated water. In coastal areas, where many of the world’s largest cities are located, the available volume of fresh groundwater is reduced by seawater intrusion and upconing, which in turn are caused by head declines in the aquifer. As depletion continues worldwide, its impacts worsen, portending the need for objective analysis of the problem and its possible solutions. This essay examines future options for evaluating and managing groundwater depletion in a changing physical and social landscape.

Food Chain Aspects of Arsenic Contamination in Bangladesh: Effects on Quality and Productivity of Rice

The total arsenic content of 150 paddy rice samples collected from Barisal, Comilla, Dinajpur, Kaunia, and Rajshahi districts, and from the BRRI experimental station at Rajshahi city in the boro and aman seasons of 2000 was determined by hydride generation-inductively coupled plasma emission spectroscopy (ICP). Arsenic concentrations varied from 10 to 420 µg/kg at 14% moisture content. Rice yields and grain arsenic concentrations were 1.5 times higher in the boro (winter) than the summer (monsoon) season, consistent with the much greater use of groundwater for irrigation in the boro season. Mean values for the boro and aman season rices were 183 and 117 µg/kg, respectively. The variation in arsenic concentrations in rice was only partially consistent with the pattern of arsenic concentrations in drinking water tube wells. There was no evidence from yield or panicle sterility data of arsenic toxicity to rice. Processing of rice (parboiling and milling) reduced arsenic concentrations in rice by an average of 19% in 21 samples collected from households. Human exposure to arsenic through rice would be equivalent to half of that in water containing 50 µg/kg for 14% of the paddy rice samples at rice and water intake levels of 400 g and 4 L/cap/day, respectively.

Sustainable use of groundwater for irrigation: a numerical analysis of the subsoil water fluxes

AbstractThe food‐producing regions of the world increasingly rely on irrigation from groundwater resources. Further increases of groundwater use can adversely affect the sustainability of irrigated agriculture and put food security at risk. Sustainability of irrigation at field scale with groundwater is obtained if groundwater recharge is in equilibrium with tubewell extractions and capillary rise. Traditional information on phreatic surface behaviour does not explain the processes causing a phreatic surface to decline or incline. In this study, the physically based numerical model Soil–Water–Atmosphere–Plant (SWAP) was applied to compute soil moisture content and vertical soil water fluxes in the unsaturated zone for the cotton–wheat and rice–wheat cropping system of Punjab, Pakistan. SWAP has been calibrated and verified with in situ measurements of soil moisture content and evapotranspiration fluxes measured by means of the Bowen ratio surface energy balance technique. Accurate data of the soil hydraulic properties are critical for the calibration of the soil moisture distribution. With knowledge of the van Genuchten–Mualem parameters available, SWAP could be applied to assess recharge and capillary rise for most field conditions, including basin irrigation. The results under Pakistani conditions show that deep percolation cannot always be estimated from root zone water balances. An annual recharge of 23.3 cm was computed for the cotton–wheat area. Sustainability of irrigation with groundwater is obtained if a reduction in irrigation with groundwater by 36% is obtained. An annual recharge of 38.9 cm is estimated in rice–wheat systems, and a reduction of 62% in groundwater extraction is required to reach sustainability of groundwater use at field scale. Such information cannot be obtained from classical phreatic surface fluctuation data, and unsaturated zone modelling therefore provides additional insights for groundwater policy making. Copyright © 2002 John Wiley & Sons, Ltd.

The effect of introducing pipelines into irrigation water distribution systems on the farm economy: a case study in the Southern Governorates Rural Development Project, Republic of Yemen1

AbstractThe Southern Governorates Rural Development Project (SGRDP) is a comprehensive participatory rural development project covering three of the five southern Governorates of the Republic of Yemen, namely Hadramaut, Abyan and Lahij. Its objective is to alleviate poverty in rural areas of these three Governorates. A major component of the project is to develop virgin lands for agriculture and allocate each 5 feddan (FD) plot to those farmers who do not own land (1 FD=4200 m2). As the annual rainfall in the project area is less than 100 mm and since landlords and other farmers already own lands suitable for agriculture in the major wadis, the only source of irrigation water in the newly developed land is the groundwater (GW). The SGRDP is aware of the scarcity of water resources in the country, particularly in the project area; it therefore makes every possible effort to optimize the use of GW for irrigation by practical means. One way of reducing GW used for irrigation is by replacing major canals in the farms by buried pipelines. This method has been tried in small‐scale individual farms outside the project area and it proved that farmers could adapt to the system without difficulty. Sprinkler and drip irrigation systems have been tried in many previous agricultural development projects in the country but with no apparent success, as far as the farmers' adoption of the method is concerned. Thus, the project, as the first stage to reduce the use of GW for irrigation in the newly developed areas, planned to eliminate, initially, the conveyance losses by replacing the open canals by buried PVC pipes. In this paper, it is attempted to show that the use of buried pipes in small scale irrigation schemes is financially feasible, even if the indirect and non‐tangible environmental benefits are not considered.This paper deals only with special GW schemes recommended for the project area; however, the outcome could be generalized and applied elsewhere in the country. Copyright © 2001 John Wiley & Sons Ltd.

Limits to intensity of milk production in sandy areas in The Netherlands

Agricultural land in sandy areas is mainly in use by dairy farms. As a result of intensive fertilisation and irrigation, environmental quality is threatened by lost nutrients and lowered groundwater levels. Therefore, Dutch government put decreasing limits to losses of nutrients, with lowest values for well-drained sandy soils. Besides, use of groundwater for irrigation will be restricted. Reducing milk production per hectare can be effective to reduce nutrient losses but is costly, as is the increase of output of nutrients by exporting manure. Improved resource management, leading to reduced inputs per kg milk, might be a more attractive option to realise both environmental and economic goals. This paper describes a procedure to quantify the impact of management on the limits of milk production per hectare on well-drained sandy soils, at defined maximum levels of permitted nutrient losses. The procedure has been applied to a range of farming systems, in order of increasing complexity of nutrient management. It is concluded that current average milk production intensity (12,400 kg ha(-1) yr(-1)) has to be reduced drastically if farm management is not successful in increasing the conversion of dietary N (into milk and body weight) and the re-use of N in manure. On the other hand, results suggest that an intensity of almost 15,000 kg ha(-1) yr(-1) should be attainable by best farmers.

Use of groundwater for irrigation in the Nile valley

The arable area of Egypt is confined to the Nile Valley and Delta. In order to provide for the needs of the rapidly increasing population and future agricultural requirements, all water resources in the area must be efficiently used. In the Nile Valley this can be achieved by extracting groundwater for irrigation and drainage. 1500 million m3 of groundwater are planned to be withdrawn from the Nile Valley aquifer. An interdisciplinary study was carried out in a pilot area to determine the impact of groundwater extraction and use in irrigating old lands. Results indicate that involvement of the farmers is very important and that groundwater extractions, if properly designed, are technically feasible and economically attractive.

Groundwater use for irrigation in Bangladesh: The prospects and some emerging issues

Groundwater represents a vitally important resource for Bangladesh for its irrigation development. Great efforts are now underway to increase irrigated acreage by employing a mix of three major types of tubewell system—deep, shallow, and hand tubewells. This paper attempts to analyse the past trends of development of groundwater irrigation as well as a number of relevant policy issues, such as the gap between the potential and actual use of the capacity of the different tubewell systems, the rate of groundwater withdrawal that can be sustained on a long-term basis, the recently adopted ‘privatization’ policy of the government, and the choice of scale in the promotion of the different types of tubewell systems. Finally, a number of problem areas are identified, and some immediate actions required to deal with the problems are indicated.