Effects Of Different Water Levels Research Articles

Seismic response analysis of double-trough aqueduct considering fluid-structure interaction effect.

At present, the crude fluid-structure interaction analysis model cannot accurately characterize the interaction mechanism between aqueduct and water under earthquake action. In order to solve this problem, this paper analyzes the seismic response of the double-tank aqueduct under the action of earthquake by using the shaker test and the VOF (Volume of Fluid) method considering the free liquid level from the perspective of fluid-solid bidirectional coupling, explores whether the liquid movement in the double tank is consistent and the shock absorption effect of different water levels on the aqueduct, and analyzes the amplitude of free liquid level sloshing and the change of horizontal dynamic pressure caused by water level change from the generation mechanism of TLD (Liquid tuning dampers). The results show that the liquid movement in the two tanks in the double-channel aqueduct is basically the same under the action of earthquake, and the TLD effect of the liquid gradually increases with the increase of the water level in the aqueduct, and the maximum peak shock absorption rate is 63.4% at the maximum peak and 50.4% in numerical simulation. The shaking amplitude of the liquid is positively correlated with the water level height, and the magnitude of the shaking amplitude also reflects the magnitude of the moving water pressure.

Yield and biomass under the different water levels on three Japonica rice cultivars

Water level management is one factor in producing a higher rice yield. The objective of this study was to compare the effects of different water levels on the yield and biomass of three Japonica rice cultivars, i.e., Nikomaru (NM), Himenorin (HR), and Hinohikari (HH). Rice was transplanted in totally nine plastic boxes with dimensions of 96.0 x 45.8 x 35.8 cm, and with a soil particle density of 1.46 g cm−3. Each box contained 10 hills of rice with 3 seedlings per hill. Water levels were controlled as 2, 5, and 10 cm for each cultivar from 70 days after transplanting. We measured yield and biomass from 3 selected plants on each box. The highest yield was obtained with 5 cm for NM, with 10 cm for HR, and with 10 cm for HH as 7.68, 7.73, and 6.90 t ha−1, respectively. For NM, yield with 10 cm was 4.4% lower than with 5 cm, however, the harvest index (HI) with 10 cm was higher compared with 5 cm due to the lower biomass, but not significantly. Both for HR and HH, HI with 10 cm was the highest. We suggested that keeping the water level at 10 cm could produce a higher grain yield compared with shallower water level ponding for all cultivars.

Effects of Different Irrigation Regimes and Nitrogen Fertilization on the Physicochemical and Bioactive Characteristics of onion (Allium cepa L.)

The availability of water and nitrogen in the soil affect the metabolism of onion bulbs. The synthesis of metabolites and bioactive compounds are the most affected, along with the quality of the onion bulbs However, it is necessary to know the effects of different water levels and nitrogen fertilization to optimize the quality of the onion. The objective of this research was to study the effects of the different conditions of hydric stress and nitrogen fertilization during the development of onion (Allium cepa L.) crop, regarding its physicochemical and bioactive properties. Onions were grown using four available irrigation regimes (25, 50, 75 and 100%) and four doses of nitrogen fertilization (100, 150, 200 and 250 kg N ha−1). Onion without any treatment was considered as a control. The treatments low in irrigation and nitrogen fertilization increased the pH level (5.7 to 5.9) and bulb coloration in bright white/yellowish tones. An increase was observed compared to control in titratable acidity (0.13%) just in the nitrogen content, ascorbic acid (46%) and antioxidant capacity with DPPH (12.3%) and ABTS (93.7%). A decrease was shown in soluble solids (14.6%), firmness (3.5 kg cm−2), dry matter (6.6%), total phenols (50%) and FRAP (33.2%) values. Pyruvic acid remained constant (1.5 µmol g−1 FW). The onion bulb extracts showed an erythroprotective effect with a hemolysis inhibition percentage higher than 95%. Finally, the onions had low pungency, and were soft and extra sweet. The treatments with 25% usable humidity and nitrogen fertilization of 150 and 250 kg ha−1, favored the physical, chemical and bioactive quality of the onion bulb.

Soil aggregate disintegration effects on soil erodibility in the water level fluctuation zone of the Three Gorges Reservoir, China

Spatial hydrological alterations can affect soil structural stability. Over time, forces induced by water weaken soil aggregates and this has a negative implication to soil health. The Three Gorges Reservoir (TGR) in particular, experienced a long-term hydrological condition and repetitive seasonal water level fluctuations that could affect soil health. The present study was conducted to investigate the effects of different water levels on soil aggregate disintegration rate over time and its relation to soil erosion susceptibility in water reservoirs. Samples from different elevations (155 m, 160 m, 163 m, 166 m, 172 m, and 180 m) in the water level fluctuation zone (WLFZ) were exposed to continuous wet-shaking for 3, 9, 27, 54, and 81 min resulted to different WLF intensity accordingly. The results showed a comparative difference between aggregates size before and after the experiment where micro-aggregates (<0.25 mm) increased with respect to elevations increase. The exponential prediction proved that aggregate stability decreased with the increase of WLF intensity, insisting the effects of continuous hydrological stress to aggregate break-down. A couple of factors definitely confirmed that soil erodibility (k) is primarily determined by disintegration of soil aggregates for the surface soil of the TGR. Despite the fact that Disintegration rate (Dr) and k showed a positive relationship, R2 = 0.73 (p < 0.05), the results showed that the soil properties decreasing Dr also decreases soil erodibility in the study area. Non-effective role of soil organic matter (SOM) for stabilizing soil aggregates was primarily related to water level fluctuations inhibiting decomposition. Relying on the present findings, environmental problems mostly soil erosion in the TGR could be therefore linked to excessive destabilization of soil aggregates. Therefore, the results of this study should play a major role in determining the factors primarily inducing soil erosion in river reservoirs.

The Role of Interactive Visualization in Developing Stakeholders’ Understanding of Natural Resource Decision-Making: A Case Study of Te Waihora/Lake Ellesmere, Canterbury, New Zealand

The purpose of this study was to investigate whether stakeholders’ understanding of natural resource decision-making was influenced by the form that visualization of environmental changes were presented, using Te Waihora/Lake Ellesmere, New Zealand as a case study. An interactive visualization (I-Vis) tool “ElleVis,” developed by (Otinpong 2013), shows the effects of different water levels on the flora and fauna living in and around the lake. An experimental design was used in which 40 stakeholders were randomly assigned to a presentation of this information using I-Vis or a non-interactive paper form of the visualization (NI-Vis). While stakeholders in both groups significantly improved their understanding of information, stakeholders presented with information using I-Vis made a statistically significant greater gain in understanding than those presented information using NI-Vis (t(38)=2.663, p<.05). Semi-structured discussions with participants confirmed the importance stakeholders placed on the interactive nature of the visualizations. The findings inform discussions about how I-Vis tools might contribute to an understanding of environmental management situations where contested resources and/or a multiplicity of interests are involved.

Changes in some bioactive compounds of red cabbage (Brassica oleracea L.var.Rubra) under water stress

A two-year study was performed on red cabbage (Brassica oleracea L.var.Rubra) to assess the effect of different irrigation levels on yield, sugar and organic acid contents. The study was conducted using drip irrigation system on a clay loam soil. The volume of irrigation water applied with 4-day intervals to each treatment was based on Class-A pan evaporation (Ep). In the full irrigation treatment (I1.0), a pan evaporation using screen covered Class-A pan was measured with 4-day intervals and all amount of evaporation was applied in the normal (1.00xEp) treatment, and deficit amounts were imposed on three irrigation treatments as I0.7 (0.7xEp), I0.3 (0.3xEp), and I0.0 (0.0xEp). The plant-available soil water at maturity and yield of red cabbage was significantly related to irrigation amounts. Imposition of deficit irrigation resulted in yield reduction, especially in the severe stress treatments I0.3 and I0.0. Therefore, yields were related linearly to irrigation. That’s why, if there is no water scarcity full water demand of red cabbage need to be compensated for the whole growing season. However, in the deficit treatment, total sugar and especially ascorbic, oxalic, tartaric and malic acid contents increased, and only lactic acid decreased, on the other hand there was no significant effect of different water levels on the content of citric acid.

Response of Leek (Allium porrum L.) to Different Irrigation Water Levels Under Rain Shelter

ABSTRACTA pot experiment was conducted to investigate the effects of different water levels on water-use efficiency, yield and growth parameters of leek (Allium porrum L.) and was carried out in the practical research field of Ondokuz Mayıs University in Turkey. Different irrigation water levels were based on the weight changes of each pot and included 5 irrigation treatments [25% (I25), 50% (I50), 75% (I75), 100% (I100) and 118% (I118) times of consumed water]. Decreases in irrigation water resulted in decreases in plant height, stem diameter, leaf and stem fresh weights, leaf and stem dry weights and leaf area, but did not significantly affect leaf number or chlorophyll content. A yield-response factor of 1.26 was obtained, implying that the leek crop was sensitive to water stress caused by deficit irrigation. Comprehensive analysis of yield, water use efficiency, and evapotranspiration, the I75 treatment can be suggested for leek production in water-scarce regions.

Effect of Different Water Levels on Growth Performance of Sesame(Sesamum indicum L.) in Paddy Field Soil

The present study aimed to investigate the change in the morphological and physiological characteristics within sesame plant when subjected by regulating water levels. The experiment was conducted at ground water level(GWL) 0, 20, and 40 cm in a paddy field soil. The results showed that sesame growth characteristics, such as shoot length, stem thickness, leaf length, and leaf width were significantly higher in sesame at GWL 0 cm at 10 days after treatment(DAT) and 20 DAT than in those grown at a GWL of 40 cm. The shoot length and stem thickness of sesame grown at a GWL of 20 cm was significantly higher than those grown at a GWL of 40 at 10 DAT. The chlorophyll content was significantly lower in plants grown at a GWL 40 cm at 10 and 20 DAT over sesame grown in GWL of 0 and 20 cm. The stomatal conductance remained consistent in all the GWL at overall time period. Moreover, the Ca content of sesame was reduced in both GWL 40 cm and 20 cm at 10 DAT and 20 DAT as compared to GWL 0 cm. The K content was increased at 10 DAT but was reduced at 20 DAT at both GWL 20 cm and GWL 40 cm over plant grown at GWL 0 cm. Likewise, the P content was decreased at 10 DAT in both GWL 20 and GWL 40 cm but was significantly increased at 20 DAT in GWL 20 cm as compared to plant at GWL 0 cm. Since the experimental soil is paddy field soil these results helps to understand the efficiency of sesame to tolerate the different stress levels of soil moisture. Therefore, these research may help to predict the appropriate level of irrigation to be provided at different time period for the sesame if it is grown in rice field as a commercial crops.

Dynamic response of generation III+ integral nuclear island structure considering fluid structure interaction effects

AP1000 has two key components of water storage tank and air intakes for cooling down the temperature of containment vessel when an accident happened. The fluid–structure effects of different water levels and locations of air intakes may affect the dynamical response and stress distribution of integral structure of nuclear island. In the present study, three elevations of air intake with height of 62.23, 57.23 and 52.23 m and four cases of water levels with 0%, 40%, 60% and 80% water are designed to investigate the effect of dynamic response and structural damage for integral structure of nuclear island. The numerical results indicate that the dynamical response and the stress at lower location of air intake are less than the upper location. The case of water level 3 with air intake C is the optimal scheme for AP1000 nuclear island. In addition, some consolidated measures should be taken for the corner of air intake, and the original design of air intake around the upper corner of shield building may not be the optimal arrangement.

Plant growth response of subirrigated salvia ‘Vista Red’ to increasing water heights at two substrates

Subirrigation applies water and nutrients to the bottom of pots without wetting leaves, improving water use and reducing disease spread compared to overhead irrigation systems. However, water levels applied within the benches are often higher than required to promote capillary action, applying more water than needed and wasting pumping energy. The objective was to evaluate the effect of different water levels in plant growth of subirrigated salvia ( Salvia splendens ) ‘Vista Red’ in two substrates. Five water levels (0.75, 1.5, 3.0, 4.5, and 6.0 cm) and two substrates (pine bark: sphagnum peat moss and peat: perlite [both 75%: 25% v/v] ) were tested, with four replications. Substrate moisture was monitored by capacitance-type sensors connected to a multiplexer and data logger. Volumetric water content (VWC) was higher in peat : perlite (0.34 to 0.75 m 3 m -3 ) than pine bark: sphagnum peat moss (0.21 to 0.60 m 3 m -3 ) at all water levels. Higher water levels increased VWC in both substrates. The leaf chlorophyll index was 4% lower at the 6.0 cm compared to the other treatments in peat: perlite ( p 0.05), an indicative that the different water levels does not affect the plant growth. However, shoot plant height increased 13% in pine bark: sphagnum peat moss ( p= 0.0096) and 17% in peat: perlite ( p= 0.0335) as water levels increased. Water levels from 1.5 cm can be recommended for pine bark: sphagnum peat moss or peat: perlite in subirrigation, applying water according to plant needs, optimizing plant growth and reducing the nutrient solution pumping costs compared to systems that apply higher water levels.

Plant growth response of subirrigated salvia 'Vista Red' to increasing water levels at two substrates

ABSTRACT: Subirrigation applies water and nutrients to the bottom of pots without wetting leaves, improving water use and reducing disease spread compared to overhead irrigation systems. However, water levels applied within the benches are often higher than required to promote capillary action, applying more water than needed and wasting pumping energy. The present study was conducted to evaluate the effect of different water levels on plant growth of subirrigated salvia (Salvia splendens) 'Vista Red' in two substrates. Five water levels (0.75, 1.5, 3.0, 4.5, and 6.0 cm) and two substrates {pine bark: sphagnum peat moss and peat: perlite (both 75%: 25% v/v)} were tested, with four replications. Substrate moisture was monitored by capacitance-type sensors connected to a multiplexer and data logger. Volumetric water content (VWC) was higher in peat: perlite (0.34 to 0.75 m3/m3) than pine bark: sphagnum peat moss (0.21 to 0.60 m3/m3) at all water levels. Higher water levels increased VWC in both substrates. The leaf chlorophyll index was 4% lower at the 6.0 cm compared to the other treatments in peat: perlite (p&lt;0.0001). Stomatal conductance decreased overtime; but increased with the increase in water levels in peat: perlite (p&lt;0.0001). Different water levels had no effect on leaf area, net photosynthesis, number of branches and leaves, and shoot dry weight (p&gt;0.05), an indication that the different water levels do not affect the plant growth. However, shoot plant height increased 13% in pine bark: sphagnum peat moss (p=0.0096) and 17% in peat: perlite (p=0.0335) as water levels increased. Water levels of 1.5 cm and higher can be recommended for pine bark: sphagnum peat moss or peat: perlite in subirrigation, applying water according to plant needs, optimizing plant growth and reducing the nutrient solution pumping costs compared to systems that apply higher water levels.

Response differences of Eichhornia crassipes to shallow submergence and drawdown with an experimental warming in winter

Eichhornia crassipes is a noxious weed and is cold sensitive. Water level treatments may affect its overwintering and regrowth capability during warming winter. To test this hypothesis, an experiment was conducted to analyze the effects of different water levels on the survival rates and regrowth of E. crassipes under experimental warm winter conditions. Three water levels were set up including drawdown with rooted, shallow submergence with rooted and floating. Regrowth characters including number of ramets, Fv/Fm, biomass and biomass allocation were surveyed. The results showed that warming significantly increased survival, ramet numbers and the biomass of plants. Warming also significantly increased Fv/Fm in drawdown plants. Water level only impacted plants under warming conditions. Compared to floating plants, drawdown significantly decreased survival but increased total biomass, while submergence led to 100 % survival, significantly higher ramet numbers and increased total biomass. In terms of biomass allocation, the effects of warming were similar for drawdown and submergence cases; it resulted in increased shoot biomass allocation and a lower root mass ratio. Warming only significantly increased the stem mass ratio of floating plants. Our findings suggested that warming help E. crassipes successfully overwinter and regrow during the next growing season. Drawdown or shallow submergence cannot effectively control this species but rather promotes its regrowth during warm winters. Thus, this species has the potential to spread with warm winters and frequent water level fluctuations caused by future climate change.

Effects of different water levels on cotton growth and water use through drip irrigation in an arid region with saline ground water of Northwest China

Due to the mismanagement of water and fertilizer application, cotton cultivation in Xinjiang Northwest China is faced with the problems of soil deterioration and groundwater table ascension. This study was conducted to evaluate the effects of different levels of water applied through drip irrigation on cotton yield and water use in an arid region of Northwest China. The experiment included five water treatments in which the soil matric potential (SMP) at a depth of 20cm was controlled higher than −10kPa (S1), −20kPa (S2), −30kPa (S3), −40kPa (S4), and −50kPa (S5) after cotton was established. The results revealed that the highest cotton evapotranspiration (ETc) was achieved under S1 (−10kPa) treatment and the ETc, deep percolation and the ratio of deep percolation with irrigation water all increased with increasing SMP threshold. After three years experiment, no salt accumulation in surface soil layer was found under our irrigation schedule. The highest seed cotton yield was obtained when the SMP threshold was controlled above −30kPa in 2008, and −20kPa in 2009 and 2010. Moreover, the highest yield obtained after 3 years was 42% higher than the average yield achieved by local farmers in the area. Additionally, the water use value (WUE and IWUE) tended to increase as the SMP threshold decreased in 2009 and 2010. Considering the cotton yield and the impact of irrigation on the underground water table, an SMP higher than −20kPa at 20cm can be used as an indicator for cotton drip irrigation scheduling and agronomic practices in this area to help alleviate the dangerous increase in the water table while increasing the cotton seed yield.

Water levels and soil mulches in relation to strawberry diseases an yield in a greenhouse

The occurrence of diseases and its influence on strawberry yield in a greenhouse as well as its association with water management are still not well known. So, the aim of this work was to evaluate the effect of different water levels and soil mulches on strawberry plant health and yield in a greenhouse. The experiment was carried out at Atibaia, State of São Paulo, Brazil, from April to December 1995. The experimental design was a 2 × 3 factorial, in randomized blocks, with five replications, and consisted of two soil mulches and three water levels. The soil mulches consisted of clear or black plastic. Trickle irrigation was applied whenever the soil water potential reached -10, -35 and -70 kPa at a depth of ten centimeters. Cultivar Campinas IAC 2712 was used. Plants grown at a soil water potential of -10 and -35 kPa, with clear plastic mulch provided the best yields. A linear function fitted well considering total yield data and irrigation depths. The equation was y = -233.54 + 1.56x (R² = 0.78). The irrigation level of -70 kPa and the use of black plastic favored a greater incidence of soil-borne diseases late in the harvest season.

Active vibration control of a thin rectangular plate in air or in contact with water in presence of tonal primary disturbance

A rectangular aluminium plate vibrating in air or in contact with water is investigated. The plate is bolted to a wall of a rectangular Plexiglas container. Some modal analyses are firstly realised in order to verify the effects of different water levels and of the control components on the modal parameters. A filtered-x least mean square (FXLMS) adaptive feedforward algorithm is then applied to the system, realising structural vibration control in linear field with a SISO approach on the first vibration modes of the plate in presence of tonal primary disturbance.

Effect of different water levels on the properties of HSR class G cement

Changes in water level corresponding to small changes in slurry density have a substantial effect upon the physical cementing properties of HSR Class G oilwell cement under comparable conditions. The implications of this for practical oilwell cement slurry formulations for downhole usage are discussed.

Efeitos da irrigação por gotejamento na produção de pimentão (Capsicum annuum L.) em casa-de-vegetação

O presente trabalho teve como objetivo verificar os efeitos de diferentes níveis de água, aplicada na forma de gotejamento, em cultura de pimentão (Capsicum annuum L.) em condições de casa-de-vegetação coberta com lençol de polietileno. O cultivar utilizado foi "Agronômico 10G". O delineamento empregado foi inteiramente ao acaso, com quatro tratamentos e oito repetições. As irrigações eram feitas quando consumidos 10; 30; 50 e 70% da água disponível no solo para os respectivos tratamentos. O controle das irrigações baseou-se na evaporação do tanque "Classe A". O tratamento que era irrigado, quando haviam sido consumidos 30% de água disponível, apresentou uma tendência de elevar a produção, qualidade dos frutos e desenvolvimento vegetativo do pimentão. As variações da umidade do solo, no intervalo de água disponível, comprovam a importância da irrigação.

Biomass, productivity and relative rate of photosynthesis of Sphagnum at different water levels on a South Swedish peat bog

The distribution pattern of Sphagnum species on bogs follows a hummock‐hollow gradient. S. Sect. Acutifolia (that is in this study S. fuscum and S. rubellum combined) dominates hummock tops, ca 20 cm above the maximum water level with a green biomass of 50 g m−2, S. magellancium dominates at a lower level, about 5 cm above the water level with a green biomass of 75 g m−2 and S. cuspidatum dominates in the wettest hollows with a green biomass of about 50 g m−2.In situ measurements of length growth of S. Sect. Acutifolia and S. magellanicum using a 14CO2‐labelling technique during three consecutive years, revealed an unexpectedly high between‐year variation in length growth of 7‐23 mm yr−1, and 16‐22 mm yr−1, respectively. Consequently the dominating producer in the transition between hummock and hollow changes from year to year, probably depending on climatic conditions.In vitro experiments on the effects of different water levels of 2, 5, 10 and 20 cm below the moss surface, on photosynthetic activity of S. Sect. Acutifolia and S. magellanicum, measured by a second 14CO2‐technique, indicate optimal conditions for S. magellanicum at 10 cm above water level, and for S. Sect, Acutifolia at 20 cm above water level.Differences in capillary water transport capability between the species are more important than the sensitivity of photosynthesis to water stress in explaining field patterns of productivity and distribution.

Effect of irrigation levels at different growth stages on growth parameters and yield of four selected chilli accessions

An experiment as conducted at Bangladesh Agricultural University. Mymensingh in poly bags under glasshouse condition during October 1997 to March 1998 to know the effects of different water levels at different growth stages of four selected chilli accessions viz., C-027l, C-0272, C-0275, and C-0277. Six water treatments viz., watering once everyday (W1), watering twice everyday (W2). watering at 4 days interval (W3), watering at 8 days interval (W4), watering at 16 days interval (W5), and no watering (W0) were tested at three growth stages viz., Vegetable stage (S1), Flowering stage (S2), and Fruiting stage (S3). The accessions of chilli were selected from the results of a previous experiment where ten accessions of chilli collected from Spices Research Centre (SRC) of Bangladesh Agricultural Research Institute, Joydebpur, Gazipur were used. The primary selection was made on the basis of their tolerance and susceptibility to water stages. The results revealed that all the studied parameters viz., plant height, canopy diameter, root length, root volume, no. of fruits per plant, fruit length, fruit diameter, individual fruit weight, no. of leaves per plant, leaf area per plant, fruit yield per plant, leaf dry weight, stem dry weight, root dry weight, fruit dry weight per plant, varied significantly among the accessions under different water treatments at different stages of growth. Out of four accessions, C-0271 and C-0277 were found as water stress tolerant and susceptible, respectively. Key Words: Water level; growth stage; chilli accessions DOI: 10.3329/bjar.v34i1.5764Bangladesh J. Agril. Res. 34(1) : 143-155, March 2009