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Response of Stream Discharge to Storm Depth in Gidan Kwano Inland Valley 0f Minna Nigeria
Enokela.O.S, N. A Egarevba
International Journal of Engineering Trends and Technology , 2012,
Abstract: Stream discharge and soil characteristics were evaluated on an experimental field for ten months. Calibrated rectangular weir was used to monitor stream discharge and sieve analysis was used to characterize the soil. Findings indicated a sandy loam, clay loam, and clay soil types at 0-60cm, 60-90cm, 90-120cm profile depths respectively .A range of 6.29 - 27.75%, 1.04 –1.80g/cm3 , 15.19 – 49.42% and 8.38 – 34.74% were established for moisture content, bulk density, porosity and available moisture content respectively down the profile ( 1 – 120cm) .Infiltration decreased from 0.2 to 0.07 cm/min and 0.25 to 0.025 cm/min at lower and upper fringe of the valley respectively. Stream discharge is highest in October with peak value of 41.897l/s and monthly average of stream discharge was 12.641l/s with only 67.7% of the storm depth translating to stream discharge. The discharge hydrograph exhibits a close nested multi-peak. These finding therefore, are viable information system for irrigation anddrainage practices on land and also useful in land and water resources planning.
The Effect of Irrigation Water Temperature on Discharge For Some Iranian Emitters in Trickle Irrigation  [cached]
B. Mostafazadeh,M. Kahnouji
Journal of Science and Technology of Agriculture and Natural Resources , 2002,
Abstract: The emitter discharge is affected by parameters such as pressure, irrigation water temperature, manufacturer’s coefficient of variation, and emitter clogging. In order to study the effects of irrigation water temperature on emitter discharge and to determine the discharge-pressure variations and manufacturer’s coefficient of variations, an experimental trickle irrigation system was designed and studied in the greenhouse, College of Agriculture, Isfahan University of Technology. Since the sensitivity of different emitters to water temperature variations is variable, four different, widely used, types of Iranian emitters including in-line long-path emitter, gun emitter, pressure compensating emitter, and double-chamber tube were used. Each emitter was evaluated under 14 different irrigation water temperature treatments ranging from 11 to 43.5°C. The results showed that in general as water temperature increases, the emitter discharge increases linearly in all types, except for the pressure compensating emitter in which the discharge decreases linearly. The emitter uniformity, absolute emission uniformity and Christiansen uniformity coefficient parameters were affected by emitter discharge variations. For each type of emitter under study, the changes in manufacturer’s coefficient of variations due to irrigation water temperature were different. The manufacturer’s coefficients of variations at a water temperature of about 20°C for double-chamber tube, in-line long-path emitter, gun emitter and pressure compensating emitter were equal to 5, 7, 13 and 22 percent, respectively. Moving from gun emitter to the double-chamber tube and finally to the in-line long-path emitter, the sensitivity to irrigation water temperature decreased. Sensitivity to pressure variations decreased in the order of gun emitter, double-chamber tube, in-line long-path emitter, and finally pressure compensating emitter.
CHANGES OF THE MINIMUM MULTIANNUAL DISCHARGE ON THE CRASNA / KRASZNA STREAM  [PDF]
K. KONECSNY,Z. NAGY
Aerul ?i Apa : Componente ale Mediului , 2012,
Abstract: Changes of the minimum multiannual discharge on the Crasna / Kraszna Stream. 72% of the Crasna/Kraszna River catchment area of 3142 km2 is situated on Romanian area, while 28% of it is situated on Hungarian area. In the last decades, a significant change occurred in the characteristics of the many years’ water level fluctuation on the lower river section on Hungarian area, as the investigations carried out in the previous years have already indicated based on the annual characteristical discharge data. The change can be determined also considering the medium and maximum discharges, but especially it is significant in the low water periods. On account of revealing the reasons and main characteristics of the changes, we have carried out the detailed statistical study of the last six decades’ daily discharge data, their many years’ development, on the other hand we have carried out the comparing study of the low water characteristics of the stations situated on the middle and lower river section. The increasing trend of the daily minimal discharge values and the decreasing trend of the number of low water days is in opposite direction with the decreasing trend of the precipitation change.
Evaluation of Water from Bokro Stream for Irrigation and Its Effect on Soil
O Akoto, T Wi-Afedzi, G Aidoo, J Apau
Journal of Science and Technology (Ghana) , 2010,
Abstract: This study focused on evaluating the water quality of the Bokro stream for its suitability for irrigation purposes. Among the water quality parameters examined were pH, total dissolved solids, conductivity, dissolved oxygen, hardness, major ions and concentration of some trace metals. The results revealed that most of the parameters examined were below the FAO limits for irrigation water. The results also indicated that nutrient concentrations (Sulphate, Nitrate-Nitrogen and Phosphate-Phosphorus) from the stream were far below the usual ranges in irrigation water. Based on values calculated for Sodium Adsorption Ratio and electrical conductivity, the water source could be described as possessing low salinity hazard and therefore no permeability problems are expected for the soils. In addition, human activities along the banks of the stream and inflow of untreated domestic sewage from communities in the catchment area of the stream were found to have great impact on the quality of water from the stream. Water from the stream will have no adverse effect on the soil when it is use for irrigation.
Spatial variability of discharge and pressure in subunit of microsprinkler irrigation with used and new emitters  [cached]
Wagner Walker de Albuquerque Alves; José Dantas Neto; José de Arimatea de Matos; Carlos Alberto Vieira de Azevedo; Vera Lúcia Antunes de Lima
Ambiente e água : An Interdisciplinary Journal of Applied Science , 2008,
Abstract: This work studied in field the spatial distribution of discharge and pressure in subunit irrigated by microsprinkler, considering used and new emitters. The data were collected in 28 emission points spaced in 10 x 18 m. The mean values were submitted to normality test and also to a geostatistical analysis; the verification of the spatial dependence and of the interpolation was accomplished by the method of krigagem and the spatial continuities were studied by means of semivariograms for the discharges and pressures of the subunit with new and used microsprinklers. It is verified that the models varied if the emitter was new or used. The mathematical model that better adjusted to the discharge of the new and used emitters was, respectively, exponential and spherical; for the pressure, the model was the inverse of the discharge, that is, spherical for new emitters and exponential for used ones. The values for the used emitters of the nugget effect (Co), landing (Co+Cl) and reach (Ao) were of l.0 L h-1, 33 L h-1 and 218 m and of 0.43, 137 kPa and 58 m, for discharge and pressure, respectively. The coefficient of irrigation uniformity, the coefficient of uniformity of the system and the water application efficiency increased, respectively, in 11.9, 10.58 and 10.75%, when the used emitters were substituted by new ones. The maximum distance (reach) where the estimated data of discharge and pressure are spatially correlated extrapolated the length of the derivation line for the discharge with new and used microsprinklers and for the pressure only with new microsprinklers. The nugget effect for the pressure in the system was smaller when it was changed the used microasprinklers by new ones, the inverse was observed for the discharge. There was an increase in pressure as well as in discharge when the used microsprinklers were changed by new ones.
Fertility Status of Soils under Irrigation along the Jakara Stream in Metropolitan Kano
GK Adamu, MU Dawaki
Bayero Journal of Pure and Applied Sciences , 2008,
Abstract: This study was conducted on the irrigated lands along the banks of the Jakara Stream in metropolitan Kano, with the aim of assessing its fertility level. Two sites (Hajj Camp and Magami) were selected based on concentration of irrigation activity and irrigation water source. Grid sampling was employed in which 100m2 of land was selected in each area and divided into ten equally sized grid cells of 1m2. Five samples were collected from each cell to a depth of 20cm from the surface using an auger, and the five samples were mixed up to make a composite sample. Analytical methods were employed in determining the levels of various fertility related parameters. The fertility parameters determined were organic carbon, organic matter, CEC, exchangeable bases (K, Ca, Mg and Na), total nitrogen, pH and available phosphorus. Analysis of the data obtained shows that values fell between medium to low fertility level except for organic matter at Hajj Camp which was high. On the whole, results of the research revealed soils of marginal fertility when USDA/NRSC (2001) guideline for soil quality assessment was adopted and values were compared with those recommended by Landon (1991).
A Study on Planned and Applied Irrigation Modules in Irrigation Networks: A Case Study at Büyük Menderes Basin, Turkey  [PDF]
Cengiz Ko?
Computational Water, Energy, and Environmental Engineering (CWEEE) , 2016, DOI: 10.4236/cweee.2016.54011
Abstract: In this study, irrigation modules calculated in planning and actualized operational stage of the irrigation networks are examined. Irrigation module used irrigation networks is a constant discharge parameter, meeting the needs of irrigation water requirement smonthly of crops in one hectare of irrigation area and it is a constant discharge flowing continuously for a month. Extent of the overlapping between the irrigation planning module and the operation module actualized during the operational stage of the irrigation network depends on changes in the cropping patterns, differences in the effects of field irrigation methods used by farmers on the capacity of the constructed system, the increases or decreases in the water demands depending on the irrigation period, as well as the extent of sustainability according to the selected operation method. A2 irrigation area of Aydin plain irrigation network, locating in the Büyük Menderes basin, Turkey is selected as study area, with an area of 2500 ha. Irrigation planning module calculated for this network is q = 1.16 l/s/ha and it has been designed as per the supply demand operation method. For the study; actualized irrigation module in the operation stage has been compared with the planning irrigation module by using Excel software and taking parameters such as actual crop pattern and percentage distributions, actualized irrigated areas, irrigation networks and water distribution, water intake of irrigation networks which have been calculated without operation losses, as well as with 5%, 10%, and 15% operation losses. The July operation module calculated for the examined irrigation network generally conforms to the planning module, as it has received the values close to or below the value of irrigation planning modules.
Quantifying spatial and temporal discharge dynamics of an event in a first order stream, using distributed temperature sensing
M. C. Westhoff, T. A. Bogaard,H. H. G. Savenije
Hydrology and Earth System Sciences (HESS) & Discussions (HESSD) , 2011,
Abstract: Understanding the spatial distribution of discharge can be important for water quality and quantity modeling. Non-steady flood waves can, particularly as a result of short high intensity summer rainstorms, influence small headwater streams significantly. The aim of this paper is to quantify the spatial and temporal dynamics of stream flow in a headwater stream during a summer rainstorm. These dynamics include gains and losses of stream water, the effect of bypasses that become active and hyporheic exchange fluxes that may vary over time as a function of discharge. We use an advection-dispersion model coupled with an energy balance model to simulate in-stream water temperature, which we compare with high resolution temperature observations obtained with Distributed Temperature Sensing. This model was used as a learning tool to stepwise unravel the complex puzzle of in-stream processes subject to varying discharge. Hypotheses were tested and rejected, which led to more insight in the spatial and temporal dynamics in discharge and hyporheic exchange processes. We showed that, for the studied stream infiltration losses increase during a small rain event, while gains of water remained constant over time. We conclude that, eventually, part of the stream water bypassed the main channel during peak discharge. It also seems that hyporheic exchange varies with varying discharge in the first 250 m of the stream; while further downstream it remains constant. Because we relied on solar radiation as the main energy input, we were only able to apply this method during a small summer storm and low flow conditions. However, when additional (artificial) energy is available, the presented method is also applicable in larger streams, during higher flow conditions or longer storms.
Regulation of stream water dissolved organic carbon (DOC) concentrations during snowmelt; the role of discharge, winter climate and memory effects
A. gren, M. Haei, S. J. K hler, K. Bishop,H. Laudon
Biogeosciences (BG) & Discussions (BGD) , 2010,
Abstract: Using a 15 year stream record from a northern boreal catchment, we demonstrate that the inter-annual variation in dissolved organic carbon (DOC) concentrations during snowmelt was related to discharge, winter climate and previous DOC export. A short and intense snowmelt gave higher stream water DOC concentrations, as did long winters, while a high previous DOC export during the antecedent summer and autumn resulted in lower concentrations during the following spring. By removing the effect of discharge we could detect that the length of winter affected the modeled soil water DOC concentrations during the following snowmelt period, which in turn affected the concentrations in the stream. Winter climate explained more of the stream water DOC variations than previous DOC export during the antecedent summer and autumn.
Impact of climate change and anthropogenic activities on stream flow and sediment discharge in the Wei River basin, China
P. Gao, V. Geissen, C. J. Ritsema, X.-M. Mu,F. Wang
Hydrology and Earth System Sciences (HESS) & Discussions (HESSD) , 2013,
Abstract: Reduced stream flow and increased sediment discharge are a major concern in the Yellow River basin of China, which supplies water for agriculture, industry and the growing populations located along the river. Similar concerns exist in the Wei River basin, which is the largest tributary of the Yellow River basin and comprises the highly eroded Loess Plateau. Better understanding of the drivers of stream flow and sediment discharge dynamics in the Wei River basin is needed for development of effective management strategies for the region and entire Yellow River basin. In this regard we analysed long-term trends for water and sediment discharge during the flood season in the Wei River basin, China. Stream flow and sediment discharge data for 1932 to 2008 from existing hydrological stations located in two subcatchments and at two points in the Wei River were analysed. Precipitation and air temperature data were analysed from corresponding meteorological stations. We identified change-points or transition years for the trends by the Pettitt method and, using double mass curves, we diagnosed whether they were caused by precipitation changes, human intervention, or both. We found significant decreasing trends for stream flow and sediment discharge during the flood season in both subcatchments and in the Wei River itself. Change-point analyses further revealed that transition years existed and that rapid decline in stream flow began in 1968 (P < 0.01), and that sediment discharge began in 1981 (P < 0.01) in the main river. In the two subcatchments, the transition years were 1985 (P < 0.01) and 1994 (P < 0.05) for water discharge, and 1978 and 1979 for sediment discharge (P < 0.05), respectively. The impact of precipitation or human activity on the reduction amount after the transition years was estimated by double mass curves of precipitation vs. stream flow (sediment). For reductions in stream flow and sediment discharge, the contribution rate of human activity was found to be 82.80 and 95.56%, respectively, and was significantly stronger than the contribution rate of precipitation. This evidence clearly suggests that, in the absence of significant decreases in precipitation, strategies for managing the region need to focus on human activities to control erosion without restricting stream flow.
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