155 research outputs found

    Sea Level Variations and their Relations to the Meteorological Factors in the Arab Gulf Area with Stress on Monthly Means

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    The hydrographic and meteorological conditions affecting the sea level in the Arab Gulf region have been reviewed. The monthly mean sea level data along the Saudi Arabian coast, relative to Indian Spring Low Water (ISLW) and the atmospheric pressure of eight years from 1980 to 1987 have been analysed spectrally. This indicated that the annual cycle is the main oscillation in both the sea level and pressure records. The oscillations with frequency less than 0.2 cycle/month were coherent. The Fourier analysis of six years data of monthly means showed that the annual cycle has an amplitude of 10-11 cm. The monthly mean sea level in the last two years was calculated using the harmonic simulation and the statistical models relating to the sea level and atmospheric pressure. The comparison between the calculated values and the observed ones in 1986 and 1987 showed reasonable agreement; the harmonic simulation deviated from the observations by about + 5 cm. The influence of the factors other than the atmospheric pressure on the sea level of the study area was found to be positive from June to December and negative from January to April or May, with maximum absolute value of about 11 cm, while the statistical models predict only the pressure effect

    Storm Surge Generation by Winter Cyclones at Alexandria, Egypt

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    The storm surges generated by winter cyclones in the Eastern Mediterranean, at Alexandria coast, are classified according to the synoptic situations. The data used are the hourly sea level values in the western harbour of Alexandria, the atmospheric pressure and the wind velocity at a station nearby the tide gauge during storm periods, from 1971 to 1984. Five types of storm surges were identified. Type A represents the weak surge case with a maximum residual of the order of 12-18 cm. Type B has a maximum residual between 20 and 24 cm. Type C is a moderate surge with an average maximum residual (26-30 cm). Type D has a strong surge, between 35 and 38 cm. Finally, type E has the strongest surge, reaching 43 cm. The depression tracks associated with each type are presented and the observed surges are compared with calculated ones using an equation given by Hamed (1983). A reasonable agreement, with a standard deviation ± 5 cm, was found between observations and calculations

    Long-Term Variations of Monthly Mean Sea Level and its Relation to Atmospheric Presssure in the Mediterranean Sea

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    The monthly mean sea level at 19 stations and the monthly mean atmospheric pressure at 15 stations in the Mediterranean Sea are analysed to find the trend of the sea level and to identify the significant oscillations from the power spectral estimates. The results show that from the present data at Marseille, Trieste and Genova it is expected that the sea level tends to increase by 13 cm /100 years, which will affect the water budget of the area. The spectral analysis of the pressure could explain most of the oscillations in the sea level time series at 12, 6 and 4 months’ periods, except in the Adriatic Sea where the steric effect is expected to have an important contribution

    A DEVELOPED EXPERT SYSTEM FOR CENTER PIVOT IRRIGATION SYSTEM MANAGEMENT UNDER NEWLY RECLAIMED SOILS OF EGYPT

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    Accurately estimation of actual crop evapotranspiration (ETa) as a parameter of irrigation scheduling is very critical for efficient use of limited irrigation water resources. The objectives of this study were to (1) build, verify and validate an expert system for managing on-farm irrigation water of some soils under Egyptian conditions, (2) study the effect of coefficient of uniformity (CU) and distribution uniformity for center pivot irrigation system, (3) study the effect of the precise estimation of daily actual crop evapotranspiration (ETa) on maximizing yield and improved water use efficiency. A rule-based program named CPISM-ES (Center Pivot Irrigation System Management- Expert System) was codes and compiled using python3.7.2 language. The program was verified using ready-to-use software programs (cropwat-8 and climwat 2) for estimating the daily reference evapotranspiration and a spreadsheet named the (FAO56Ax8.xls) introduced by FAO-56 for estimating the irrigation water management parameters. It also was validated by carrying out a field experiment at site :-El Salhyia(11.2 m above sea level, 30,35°N,30,26°E), was obtained from several different sources. The irrigation expert system aims to provide the farmers by the irrigation expertise to determine the exact water needed at exact time according to the crop requirements and the environmental factors which effect factors. The experiment included the following factors: a) obtaining climatic data from a weather station b) estimation crop evapotranspiration) coefficient of uniformity (CU) and distribution uniformity for center pivot irrigation system.  1- The estimation of actual crop evapotranspiration (ETa) using crop coefficient. 2- The seasonal cumulative ETa estimated by single-kc approach of El Salhyia (1875 m3 f.1season-1). 3- Yield: the highest of crop potatoes for El Salhyia (16.2 t.fed-1). 4- Water use efficiency: the maximum value of water use efficiency for El Salhyia (0.75 kg m-3)

    SOLAR HEATING SYSTEM USING PARABOLIC COLLECTOR FOR THERMAL OPTIMUM CONDITIONS OF BIOGAS PRODUCTION IN WINTER

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    The aim of this study is to enhance the fermentation temperature inside the digester by supplying the required thermal energy to be within the desired optimum range (mesophilic range) for biogas production during winter “cold days”. Two 50 L digesters were used in the experiment that was conducted at Solar Energy Laboratory, Department of Agricultural Engineering, Faculty of Agriculture, Ain Shams University, Cairo. One is a treatment digester and the other is a control digester. The treatment digester is thermally enhanced by a parabolic trough collector, while the control digester operated at the ambient temperature. The experiment was conducted through December 2018 and January 2019. The results show that the average temperature in the control digester through the experiment was 21.5°C, while in the treatment digester it was 27.08°C. This means that the parabolic trough collector enhanced the fermentation temperature in the treatment digester by 20.6%. The total biogas yield of the control digester and the treatment digester was 9684.7 mL/kg. T.S. and 24649.69 mL/kg. T.S. respectively. By comparing both productivities, it was found that the productivity of the treatment digester was 2.5 times more than the productivity of the control digester

    Energy and water saving by using modified closed circuits of drip irrigation system

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    The aim of this research was determine the energy and water use efficiencies under the modification of closed circuit drip irrigation systems designs. Field experiments carried out on transgenic maize (GDH, LL3), (Zea Mays crop) under two types of closed circuits: a) One manifold for lateral lines or Closed circuits with One Manifold of Drip Irrigation System (CM1DIS); b) Closed circuits with Two Manifolds of Drip Irrigation System (CM2DIS), and c) Traditional Drip Irrigation System (TDIS) as a control. Three lengths of lateral lines were used, 40, 60, and 80 meters. PE tubes lateral lines: 16 mm diameter; 30 cm emitters distance, and GR built-in emitters 4 lph when operating pressure 1 bar under Two levels slope conditions 0% and 2%. Experiments were conducted at the Agric. Res. Fields., Soil and Plant & Agric. System Dept., Agric. Faculty, Southern Illinois University, Carbondale (SIUC), Illinois, USA. Under 0% level slope when using CM2DIS the increase percent of Energy Use Efficiency (EUE) were 32.27, 33.21, and 34.37% whereas with CM1DIS were 30.84, 28.96, and 27.45% On the other hand when level slope 2% were with CM2DIS 31.57, 33.14, and 34.25 while CM1DIS were 30.15, 28.98, and 27.53 under lateral lengths 40, 60 and 80 m respectively relative to TDIS. Water Use Efficiency (WUE) when level slope 0% under CM2DIS were 1.67, 1.18, and 0.87 kg/m3 compared to 1.65, 1.16, and 0.86 kg/m3 with CM1DIS and 1.35, 1.04, and 0.75 kg/m3 with TDIS whereas with level slope 2% when using CM2DIS were 1.76, 1.29, and 0.84 kg/m3 compared to 1.77, 1.30, and 0.87 kg/m3 with CM1DIS and 1.41, 1.12, and 0.76 kg/m3 (for lateral lengths 40, 60, and 80 meters respectively). Water saving percent varied widely within individual lateral lengths and between circuit types relative to TDIS. Under slope 0% level CM2DIS water saving percent values were 19.26, 12.48, and 14.03%; with CM1DIS they were 18.51, 10.50, and 12.78%; and under slope level 2% with CM2DIS they were 19.93, 13.26, and 10.38% and CM1DIS were 20.49, 13.96, and 13.23% (for lateral lengths 40, 60, 80 meters respectively). The energy use efficiency and water saving were observed under CM2DIS and CM1DIS when using the shortest lateral length 40 meters, then lateral length 60 meters, while the lowest value was observed when using lateral length 80 meters this result depends on the physical and hydraulic characteristics of the emitters, lateral line uniformity, and friction losses. CM2DIS was more energy use efficiency, EUE, water saving, and WUE than either CM1DIS or TDIS

    AUTOMATIC IRRIGATION BY USING SOIL MOISTURE SENSOR IN VERTICAL CLOSED SYSTEM FOR LETTUCE PRODUCTION

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    The experiment was held at the Arid land Agricultural graduate studies and Research Institute - Ain Shams University. A soil moisture sensor is designed and used for measuring and controlling soil moisture content in plant media.  The device has been programmed and connected to three water-lifting pumps to operate them according to each treatment.         A vertical system has been constructed using 18 columns of white square styrofoam pots filled with perlite (In-organic substrate). Three soil moisture content treatments were selected as T1 = 60 %, T2= 80%, and T3 = 100% which were controlled by the sensors.  Solution tank filled with dissolved nutrient elements was used for supplying required water.       Two types of lettuce (green and red) lettuce seedlings were planted in the perlite substrate and irrigated by drip irrigation system. The system was closed and was based on smart automatic drip irrigation system,        Results revealed that, 556.5 liters of water was consumed under condition of T1 = 60 %, while 697.5 liters and 908.5 were consumed under condition of T2= 80 %, and T3 = 100% respectively After 47 days the Red lettuce yield (weight, number of leaves, and also weight of dry lettuce) was higher than green lettuce for all treatments. Yields of lettuce per system unit (4.5 m2) 16 kg/m2 and water use efficiency 26kg /m3 (Barbosa et al 2015) conventional production yielded 3.9 ±  0.21 kg/m2/y of lettuce produce, with water. Hydroponics offered 11±1.7 times higher yields but required 82±11 times more energy compared to conventionally produced lettuce

    Modification of water application uniformity among closed circuit trickle irrigation systems

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    The aim of this research was determine the ma- ximum application uniformity of closed circuit trickle irrigation systems designs. Laboratory tests carried out for Two types of closed circuits: a) One manifold for lateral lines or Closed cir-cuits with One Manifold of Trikle Irrigation Sys-tem (COMTIS); b) Closed circuits with Two Manifolds of Trikle Irrigation System (CTMTIS), and c) Traditional Trikle Irrigation System (TTIS) as a control. Three lengths of lateral lines were used, 40, 60, and 80 meters. PE tubes lateral lines: 16 mm diameter; 30 cm emitters distance, and GR built-in emitters 4 lph when operating pressure 1 bar. Experiments were conducted at the Agric. Eng. Res. Inst., ARC, MALR, Egypt. With COMTIS the emitter flow rate was 4.07, 3.51, and 3.59 lph compared to 4.18, 3.72, and 3.71 lph with CTMTIS and 3.21, 2.6, and 2.16 lph with TTIS (lateral lengths 40, 60, and 80 meters respec-tively). Uniformity varied widely within individual lateral lengths and between circuit types. Under CTMTIS uniformity values were 97.74, 95.14, and 92.03 %; with COMTIS they were 95.73, 89.45, and 83.25 %; and with TTIS they were 88.27, 84.73, and 80.53 % (for lateral lengths 40, 60, 80 meters respectively). The greatest uniformity was observed under CTMTIS and COMTIS when using the shortest lateral length 40 meters, then lateral length 60 meters, while the lowest value was observed when using lateral length 80 me-ters this result depends on the physical and hy-draulic characteristics of the emitter and lateral line. CTMTIS was more uniform than either COMTIS or TTIS. Friction losses were decreased with CTMTIS in the emitter laterals at lengths 40 meters compared to TTIS and COMTIS. There-fore, differences may be related to increased friction losses when using TDIS and COMDIS

    TURF IRRIGATION MANAGEMENT BASED ON RECENT TECHNIQUES

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    Irrigation, water management under climate change conditions plays an important role in rationalizing water uses efficiency in the agricultural development processes specially under aridecosystems conditions. Therefore, the objective of this study was to estimate the irrigation water requirement of savings landscaping areas under different recent techniques. So, this study focused on comparison between fully automatic with central control system (C.C.S) based on weather station and Control unit based on operator experience and background. The experiments were conducted during two years (from January 2014 to December 2015), in the site that located in District 5, New Cairo, Cairo, Egypt.  The results indicated the irrigation scheduling based on weather station data using a central control system (C.C.S) optimized maximize the irrigation water use efficiency and increase the amount of irrigation water saving  by about  14%, 36%,18% and 33% in Autumn, Winter ,spring and summer  respectively  in year of  (2014) and 7%, 29.7%, 16%, 33% in Autumn, Winter, spring and summer,  respectively in year of  (2015) compared with the other irrigation scheduling when based on calculated according to traditional method. In addition,  the results revealed that scheduling practices based on weather station data by using central control system could reduce the average of power consumption (about 314 KW) in year of (2014) and (about 347 KW) in year of  (2015).  Moreover ,the results revealed that the cost of water consumption for the central control system based on the data of the meteorological station for the two years 2014 and 2015, the years of study  were 018601 L.E./ 2 years compared with the other irrigation schedule when calculated according to the operator's experience was 010101 L.E./ 2  years. Where the cost of 36172, 13603, 23393 and 33642  L.E./ 2 years in the winter ,spring, summer, autumn and respectively of the central control system and 39600, 17068, 28820 and 45522  L.E./ 2  years in the winter, spring, summer, autumn respectively of the other system
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