Estimation Of Water Requirements Research Articles

REFRACTORY GUNITE AND REFRACTORY CONCRETES COMPACTED USING VARIOUS METHODS/KAITRAI ATSPARUS TORKRETBETONIS IR KITAIS BŪDAIS SUTANKINTI BETONAI

The aim of these investigations is to develop refractory gunite using local and waste materials available in Lithuania, to investigate its physical and mechanical properties and compare them with the same density and composition concrete compacted by vibration and ramming methods. In this work light (vermiculite, expanded fire clay, diatomite) and heavy (shamotte) aggregates with aluminium cement as binding material were used. The concrete samples (7×7×7 cm) were fired at various temperatures from 20°C to 1100°C. Five types of refractory gunites with different dry mixtures having a bulk density from 850 to 1500 kg/m3 have been developed. It was shown that concrete cold crushing strength depends on dry mixture bulk density and firing temperature: heavy concrete samples compacted by vibration and ramming methods are stronger, while light concrete samples made by gunning are better. The influence of temperature decreases the strength characteristics, which was confirmed by ultrasonic impulse velocity measurement results. An estimation of water requirements for concrete sample production various compacting methods is given. It was found that gunite water requirements are substantially lower than for rammed or vibrated concrete. Newly developed refractory gunite was used in furnaces as lining in an exhaust flue at Mažeikiai Oil Refinery.

A statistical approach for estimating irrigation water usage in western Saudi Arabia

This paper presents a statistical practical approach to the estimation of irrigation water requirement in the western region of Saudi Arabia. The approach describes the variation in water requirements as a function of regional climatic parameters, types of crop grown and irrigation techniques used. Irrigation water requirements are also calculated, for comparison purposes, by Modified Penman and Blaney-Criddle methods, taking leaching requirements and losses into consideration. It is found that irrigation water requirements for vegetables and perennial crops are close to the values estimated by Blaney-Criddle method, while for fodder and cereal they are close to the values estimated by Modified Penman Method.

CROSOWAT: A decision tool for irrigation schedule

A numerical model has been developed to predict the soil moisture content over the root zone depth as a function of time and to estimate the irrigation water requirements in humid basins under various management options. An implicit finite difference model for transient one dimensional flow, backed up by routines for computing various components of the field hydrological cycle such as evapotranspiration, effective rainfall, surface runoff, capillary rise, etc. is proposed. The paper describes the assumptions made, theoretical considerations of various submodules, system flowchart, hardware requirements and details of input-output. Comparison of the model predicted soil moisture profiles with the field observations is also given along with the results of numerical experiments carried out with the model in the form of sensitivity analysis for various model parameters. Statistical error analysis is also given to prove reliability of the model for estimation of irrigation water requirements.

Modelling oxygen consumption rates of post-smolt Atlantic salmon in commercial-scale, land-based farms

Oxygen consumption rates of post-smolt Atlantic salmon (Salmo salar L.) were recorded during various growth trials at four land-based salmon farms in south-west Norway, during the period 1988–1992. Principle component analysis indicated that fish size, water temperature and current speed had the greatest influence on oxygen consumption of fish in all the farms. A multiple regression analysis showed that 70% of the variation in the oxygen consumption could be explained by these three parameters. The predicted effect of fish size, water temperature and current speed on oxygen consumption are consistent with those reported in studies conducted on salmonids held in tunnel respirometers. The model described in this study may be a useful tool for the estimation of oxygen and water requirements needed for the design and operation of land-based farms.

SIMULATION AND MAPPING OF SOIL‐WATER CONDITIONS IN THE GREAT PLAINS1

ABSTRACT: Soil‐water conditions provide valuable insight into the hydrologic system in an area. A soil‐water balance quantitatively summarizes soil‐water conditions and is based on climatic, soil, and vegetation characteristics that vary spatially and temporally. Soil‐water balances in the Great Plains of the central United States were simulated for 1951–1980. Results of the simulations were mean annual estimates of infiltration, runoff, actual evapotranspiration, potential recharge, and consumptive water and irrigation requirements at 152 climatic data stations. A method was developed using a geographic information system to integrate and map the simulation results on the basis of spatially variable climatic, soil, and vegetation characteristics. As an example, simulated mean annual potential recharge was mapped. Mean annual potential‐recharge rates ranged from less than 0.5 inch in much of the north‐central and southwestern Great Plains to more than 10 inches in parts of eastern Texas and southwestern Arkansas.

Estimation of Daily Water Requirements for Potted Ornamental Crops

Methodology was developed to estimate water requirements for production of 20 different potted ornamental plant species with practical application for water conservation in commercial operations. Water requirement prediction equations were generated using pan evaporation to estimate evaporative demand along with plant canopy height and width and flower height as input variables. Coefficients of determination (R2) for the prediction equations among plant species ranged from 0.51 to 0.91, with the lower values mostly associated with plant species with an open or less-uniform growth habit. Variation in water use among different cultivars of marigold also was associated with differences in cultivar growth habit. Estimation of the daily water requirements of potted Reiger begonia and Ficus benjamina using their developed prediction equations was compared to actual water use under common growing conditions to demonstrate the implementation of the method for plant species differing in growth habit.

Poinsettia Irrigation Based on Evaporative Demand and Plant Growth Characteristics

Abstract An easy method to estimate water requirements for poinsettia (Euphorbia pulcherrima Willd. ex Kl.) production with practical applications to commercial operations was developed to promote water conservation. A water-requirement prediction equation (P ≥ 0.01, R2 = 0.78) that used pan evaporation along with plant-canopy height and width as input variables was generated. Equation verification was carried out by comparing plant quality of crops irrigated according to the generated water-requirement prediction equation to crops irrigated “on-demand” or with capillary-mat irrigation. Plants irrigated with the prediction equation were smaller than plants grown with capillary mat, but plant quality ratings for ‘Annette Hegg Diva’ and ‘Dark Red Annette Hegg’ were not significantly different. ‘Gutbier V-10 Amy’ plants grown with irrigation on-demand were of higher quality than plants grown using either the capillary mat or the prediction equation. Applied water was significantly lower for plants irrigated with the prediction equation than would normally be applied in a commercial operation using a conservative fixed daily irrigation rate.

Water consumption by dryland crops as related to pan evaporation

Lysimeter data, especially for sorghum and millet have been analysed to know the water consumption at various growth phases. Results are compared with the pan evaporation for ready reference to estimate water requirement of these crops. The study reveals that the ratio of actual evapotranspiration and pan evaporation at different growth phases varies from. 49 to 71 and from. 56 to. 72 for sorghum and millet respectively. These ratios in a few individual weeks, especially in the vegetative phase exceed one. Water used by sorghum and millet during the whole life span IS, on an average, 61 and 66 per cent of pan evaporation respectively.

Water and fire: Water needs of future coal development in the Soviet Union and the United States

This paper presents estimates of water requirements for future coal use in the USSR and the U.S. Future levels of coal use were based on scenarios presented by IIASA in Energy in a Finite World. As a first step in the analysis, IIASA's coal scenarios were broken down from the scale of ‘world region’ to the scale of coal-producing region. This exercise revealed that American and Soviet coal targets, which seem feasible when viewed on the ‘world-region’ scale, may be difficult to attain on the coal-region scale due to insufficient coal reserves in some regions. In the next stage of the analysis, an analytical model was developed, which describes on the coal-region scale the quantity of water required during different stages of coal development from mining to its final conversion to useful energy. Application of this model to each of ten principal coal-producing regions of the US and USSR suggested that roughly 1–2 tons of water will be consumed for every ton-equivalent (tce) of coal-fuel delivered. However, these estimates assume a high degree of water conservation; with less emphasis on conservation, perhaps 50% more water will be required. Water requirements for coal were then compared with competitive water uses in each U.S. coal region, as well as estimates of surface water supply in these regions. It was found that the amount of water needed for coal is small relative to other projected water uses such as agriculture and industry. However, after accounting for competitive water uses, there will probably be little or no water available for coal use during dry years in the Southwest and Northwest regions. Unless significant quantities of water can be stored for these years, coal development will have to displace other water uses in these regions. Intense water pressure will probably also occur in the Asian-USSR coal region of Ekibastuz, and possibly in Kuznetsk, Kansk-Achinsk, and Tungusska. It is concluded, therefore, that an overall four- or fivefold expansion of coal use in the U.S. and Soviet Union will probably be constrained to some degree by both limited coal reserves and lack of readily available water.

New Evapotranspiration Crop Coefficients

Improved crop coefficients for various Pacific Northwest irrigated crops were developed for estimating crop evapotranspiration (ET) from estimates or measurements of reference ET. Reference ET was based on that for well watered, actively growing alfalfa with sufficient growth for near maximum ET in arid, irrigated regions. ET for the alfalfa reference crop and other crops was measured with sensitive weighing lysimeters at the field site near Kimberly, Idaho. The new crop coefficients are basal or minimal coefficients for conditions when soil evaporation is minimal but root-zone soil moisture is adequate. When combined with improved estimates of evaporation from wet soils, they should permit more accurate estimates of daily crop ET, more accurate irrigation scheduling, and more reliable estimates of crop water requirements. Curves were developed for alfalfa, potatoes, snap beans, sugarbeets, peas, sweet and field corn and winter and spring cereals.

Statistical and Numerical Representation of Irrigation Water Requirements

ABSTRACT INFORMATION from the initial phases of the develop-ment of a revised atlas of irrigation water requirements for the state of Wyoming is presented. The techniques and results of using the 3-parameter Weibull distribution to define the variability of irrigation requirements are discussed. Alternate methods of preparing and presen-ting estimates of irrigation water requirements are reviewed.

Use of modified Blaney and Criddle formula for Estimating water requirements

Experimental values of crop growth stage coefficients (Kc) were determined for paddy and sugarcane using lysimetric data recorded at Canning. Nellore, Annamalainagar and Anakapalle. Kc varies with the type of the crop, location and season. The seasonal variation of Kc is similar to potential evapotranspiration (PET).

PEAK PERIOD DESIGN STANDARDS FOR SMALL WESTERN U.S. WATER SUPPLY SYSTEMS1

ABSTRACT: In order to determine design capacities for various components of municipal and rural domestic water supply systems, engineers must estimate water requirements for an entire year (water rights), for the peak season (reservoir storage), for the peak day (pump or treatment plant size), and for peak hour (pipeline sizes). Historically, per capita water use rates have varied greatly between systems, particularly in semiarid regions where outdoor demands are large. The resulting uncertainty in design capacity estimates can cause either inadequate capacities or premature investment. In order to minimize that uncertainty multiple regression and frequency analyses were made of the various water demand parameters mentioned above for 14 systems in Utah and Colorado. Specifically, demand functions are reported for average month, peak month, and peak day. Peak hour demands were also studied but are reported in a different paper. The independent variables which were significant for monthly and daily demands were price of water and an outdoor use index which includes the effect of variation in landscaped area and accounts for use of supplementary ditch or pressure irrigation systems. The demand functions were developed with data from systems varying in size from very small low density rural systems to Salt Lake City's water system. The correlation coefficients (R2) vary from 0.80 to 0.95.

The possible impact on the arctic ocean of the proposed transfer of water from the northern rivers of the USSR to the south

Abstract A critic of excessive interbasin diversion of water from the northern to the southern watershed of Eurasia questions some of the estimates of water requirements in the southern regions of the USSR, particularly the amount of water needed to maintain the level of the Caspian Sea. He expresses concern about the impact of reduced runoff into the Arctic Ocean, stressing the role of freshwater in the eaily appearance of young ice in autumn, the heat of river waters in speeding spring breakup and, the role of river waters in generating a well defined gradient current draining water out of the Arctic Ocean into the North Atlantic. (For other perspectives on the north‐south diversion problem, see Soviet Geography, December 1978.)

The development of water multiplier impacts from input‐output analysis: An empirical example from Boulder, Larimer, and Weld Counties, Colorado

The relationship between economic activity in a regional economy and water intake and consumptive use requirements is investigated by using the Leontief model. Estimates of direct and indirect water requirements for the regional economy are developed and are applied to three distinct planning questions: estimated aggregate water use in the regional economy, estimated sector by sector water requirements in response to total projected changes in final demands, and estimated changes in water requirements in the regional economy given a change in a single sector's deliveries to final demand.

Water Requirements for Drip-Irrigated Tomato Production in Southwest Florida

Water management in drip irrigated tomato production requires information about the water needs of the crop as well as the water holding characteristics of the soil. Excessive irrigation can leach crop nutrients from the root zone while soil moisture deficit can result in crop stress. This publication will briefly present estimates of tomato plant water requirements under drip irrigated conditions for crops produced in the southwest Florida region. This is document SL-213, a publication of the Soil and Water Science Department, Florida Cooperative Extension Service, IFAS, University of Florida. Published February 2004. 
 https://edis.ifas.ufl.edu/ss432

The Water Supply System Up to A.D. 2001

BY the end of the century the capacity of the present public water supply system will be between 2000 and 2500 million gallons per day (m.g.d.) short of conservatively estimated water requirements. A minimum investment of approximately /iooom. will be needed to provide sufficient capacity to meet the shortfall. In planning the increase, however, more than financial considerations are involved. If the deficit were to be met by conventional catchment schemes, between 50 and 70 new reservoirs would need to be constructed, a high proportion of which would inevitably have to be sited in national parks or similar high amenity areas.' The public resistance to the Ullswater and Windermere schemes of Manchester Corporation and to the Cow Green and Forndale schemes indicates that a programme ten to twelve times larger could only be achieved at the expense of a great deal of social and environmental upheaval. Even so it is obvious that water resources to support an improved standard of living for an expanding population must be forthcoming, even where this involves the imposition of some social costs on the community. At the same time it is equally necessary that social as well as financial costs should be reflected in the choice of investment made. This is particularly true at the present time when a number of schemes with widely differing specifications are available to meet given economic requirements. Whereas the social losses brought about by damming one valley rather than another are broadly similar, allowing a choice between them to be made on strictly financial grounds, the social costs and benefits of conventional conservation schemes, barrages schemes and nuclear desalination are so disparate that they must necessarily receive explicit attention in investment planning.

Studies on the Rational Estimation of Water Requirement for Field (II)

Studies on the Rational Estimation of Water Requirement for Field (II)

Studies on the Rational Estimation of Water Requirement for Field (I)

Studies on the Rational Estimation of Water Requirement for Field (I)

Water Requirement of Field Crops Estimated from Total Solar Radiation

The proportion of the incident solar energy used in the evapotranspiration process is a measure of the water requirement of plants. It has been found that in Hawaii approximately 60 per cent of the insolation is used in evapotranspiration during a 12-mo period of alfalfa production. Monthly water-requirement estimates were made from the empirical equationwhere W = water requirement in inches per month, and S = solar radiation in calories per square centimeter per month.