scholarly journals Numerical model of the catchments of the oziąbel and wołczyński strumień rivers – Wołczyn municipality

2012 ◽  
Vol 34 (2) ◽  
pp. 73-89
Author(s):  
Tomasz Olichwer ◽  
Marek Wcisło ◽  
Stanisław Staśko ◽  
Sebastian Buczyński ◽  
Magdalena Modelska ◽  
...  
Keyword(s):  
Numerical Model ◽  
Water Balance ◽  
Water Table ◽  
Cross Sections ◽  
Visual Modflow ◽  
Step Size ◽  
Hydrogeological Mapping ◽  
One Year ◽  
Discretization Grid ◽  
Hydrogeological System

Abstract The article presents a numerical model designed for determining groundwater dynamics and water balance of the catchments of the Oziąbel (Czarna Woda) river and the Wołczyński Strumień river in Wołczyn region. Hydrogeological mapping and modelling research covered the area of 238.9 km2. As a result of measurements performed in 2008-2009, flows were determined in major rivers and water table positions were measured at 26 points. In the major part of the area described, the water table, lying at the depth of 1.5-18.7 m, has unconfined character, and the aquifer is built of Neogene (Quaternary) sands and gravels. In the area under study, groundwaters are drawn from 6 wells with total withdrawal of 6133 m3/d. The numerical modelling was performed with the use of Visual Modflow 3.1.0 software. The area was partitioned by a discretization grid with a step size l = 250 m. The conceptual model of the hydrogeological system is based on hydrological data gathered over a period of one year, data from HYDRO bank database, cross-sections and maps. The boundaries of the modelled hydrogeological system were established on the watersheds of the Wołczyński Strumień river and the Oziąbel river, apart from the areas where they run together. The modelled area was extended (271.5 km2) around the Wołczyński Strumień river catchment to achieve a more effective mapping of the anthropogenic impact on its balance and the hydrodynamic system of the catchment area. The structure is characterised by the occurrence of one or rarely two aquifers separated by a pack of Quaternary clays. The investigation produced a detailed water balance and its components.

scholarly journals Simulation and Assessment of Groundwater for Domestic and Irrigation Uses

2019 ◽  
Vol 5 (9) ◽  
pp. 1877-1892 ◽  
Author(s):  
Majed Rodhan Hussain ◽  
Basim Sh. Abed
Keyword(s):  
Cross Sections ◽  
Three Dimensional ◽  
Water Quality Assessment ◽  
Alluvial Fan ◽  
Water Levels ◽  
Specific Yield ◽  
Annual Rainfall ◽  
Steady State Condition ◽  
Groundwater Samples ◽  
One Year

The alluvial fan of Mandali located between latitude 30˚45’00” N longitude 45˚30’00” E in east of Diyala Governorate, Iraq. Thirty-five wells were identified in the study area with average depth of 84 m and estimated area of 21550 ha. A three-dimensional conceptual model was prepared by using GMS program. From wells cross sections, four geological layers have been identified. The hydraulic conductivity of these layers was calculated for steady state condition, where the water levels for nine wells distributed over the study area were observed at same time. Afterward, PEST facility in the GMS was used to estimate the aquifer hydraulic characteristics. Other characteristics such as storage coefficient and specific yield have been determined from one year field observations that were collected by General Authority of Groundwater, Diyala Governorate. Also, the observations were used for calibration of unsteady state model. Then wells were hypothetically redistributed and increased to 103 wells, assuming a distance of 1500 m between the wells, a well productivity rate of were 7 l/s, annual rainfall rate was used for recharging. Three different wells operating times were suggested and these 6, 12, and 18 hr/day with total discharge of 150, 300, 450 m3/day and maximum drawdown of 7, 11, and 20 m respectively. For water quality assessment, the collected groundwater samples were analysed at the laboratory.  Results showed that the TDS in all wells was ranged from 1000-3000 mg/l but TDS in well number 18 was exceeded 3000 mg/l which indicate that the groundwater in this well is not recommended to be used for irrigation. According to Iraqi standard for drink (IQS 2009), it can be used for drinking if saline treatment units were provided.

High Temperature Corrosion of Evaporator Tubes with Thermal Sprayed Coatings

2010 ◽  
Vol 165 ◽  
pp. 110-117
Author(s):  
Jerzy Łabanowski ◽  
J. Ćwiek
Keyword(s):  
Cross Sections ◽  
Molten Salts ◽  
Single Layer ◽  
Steam Boiler ◽  
Low Emission ◽  
Distribution Of Elements ◽  
One Year ◽  
Sprayed Coatings ◽  
Thermal Sprayed Coatings

Degradation examinations of outer surface of low-emission steam boiler evaporator tubes are presented in the paper. Metallographic evaluation of scale morphology as well as determination of chemical composition of micro sites and distribution of elements on cross-sections is reported. Water-wall tubes were exposed in steam boiler for up to two years period. Common tubes produced from 16Mo3 steel suffered sulphide and molten salts corrosions. Thermal sprayed tubes with the single layer of 70%Ni 30%Cr alloy demonstrate better corrosion resistance, but become susceptible to sulphide corrosion due to presence of internal voids and cracks. Double layer Al2O3/Ni-30Cr coatings withstood corrosion attack for more than one year of operation, and then failed due to internal heterogeneity and crack generation.

scholarly journals Is the Responsiveness to Light Related to the Differences in Stem Straightness among Populations of Pinus pinaster?

Plants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 383
Author(s):  
Rosario Sierra-de-Grado ◽  
Valentín Pando ◽  
Pablo Martínez-Zurimendi ◽  
Bruno Moulia
Keyword(s):  
Cross Sections ◽  
Pinus Pinaster ◽  
Radial Growth ◽  
Wood Quality ◽  
Secondary Growth ◽  
Natural Populations ◽  
Ecological Features ◽  
Stem Straightness ◽  
One Year ◽  
Stem Curvature

Stem straightness is related to wood quality and yield. Although important genetic differences in stem straightness among the natural populations of Pinus pinaster are well established, the main drivers of these differences are not well known. Since the responses of trees to light are key ecological features that induce stem curvature, we hypothesized that populations with better straightness should exhibit lower photomorphogenetic and phototropic sensitivity. We compared three populations to identify the main processes driven by primary and secondary growth that explain their differences in response to light. One-year-old seedlings were grown under two treatments—direct sunlight and lateral light plus shade—for a period of 5 months. The length and the leaning of the stems were measured weekly. The asymmetry of radial growth and compression wood (CW) formation were analyzed in cross-sections. We found differences among the populations in photomorphogenetic and phototropic reactions. However, the population with straighter stems was not characterized by reduced sensitivity to light. Photo(gravi)tropic responses driven by primary growth and gravitropic responses driven by secondary growth explained the kinetics of the stem leaning and CW pattern. Asymmetric radial growth and CW formation did not contribute to the phototropic reactions.

scholarly journals McGill wetland model: evaluation of a peatland carbon simulator developed for global assessments

2010 ◽  
Vol 7 (11) ◽  
pp. 3517-3530 ◽  
Author(s):  
F. St-Hilaire ◽  
J. Wu ◽  
N. T. Roulet ◽  
S. Frolking ◽  
P. M. Lafleur ◽  
...  
Keyword(s):  
Water Table ◽  
Ecosystem Respiration ◽  
Gross Primary Production ◽  
General Structure ◽  
Terrestrial Ecosystem ◽  
Ecosystem Model ◽  
Terrestrial Ecosystem Model ◽  
Use Efficiency ◽  
One Year ◽  
Anoxic Zones

Abstract. We developed the McGill Wetland Model (MWM) based on the general structure of the Peatland Carbon Simulator (PCARS) and the Canadian Terrestrial Ecosystem Model. Three major changes were made to PCARS: (1) the light use efficiency model of photosynthesis was replaced with a biogeochemical description of photosynthesis; (2) the description of autotrophic respiration was changed to be consistent with the formulation of photosynthesis; and (3) the cohort, multilayer soil respiration model was changed to a simple one box peat decomposition model divided into an oxic and anoxic zones by an effective water table, and a one-year residence time litter pool. MWM was then evaluated by comparing its output to the estimates of net ecosystem production (NEP), gross primary production (GPP) and ecosystem respiration (ER) from 8 years of continuous measurements at the Mer Bleue peatland, a raised ombrotrophic bog located in southern Ontario, Canada (index of agreement [dimensionless]: NEP = 0.80, GPP = 0.97, ER = 0.97; systematic RMSE [g C m−2 d−1]: NEP = 0.12, GPP = 0.07, ER = 0.14; unsystematic RMSE: NEP = 0.15, GPP = 0.27, ER = 0.23). Simulated moss NPP approximates what would be expected for a bog peatland, but shrub NPP appears to be underestimated. Sensitivity analysis revealed that the model output did not change greatly due to variations in water table because of offsetting responses in production and respiration, but that even a modest temperature increase could lead to converting the bog from a sink to a source of CO2. General weaknesses and further developments of MWM are discussed.

Small permanent gullies: modelling and application to a semiarid region

2020 ◽  
Author(s):  
Pedro Henrique Lima Alencar ◽  
José Carlos de Araújo ◽  
Adunias dos Santos Teixeira
Keyword(s):  
Water Table ◽  
Cross Sections ◽  
Land Degradation ◽  
Gully Erosion ◽  
Drainage Area ◽  
Semiarid Region ◽  
Country Road ◽  
Brazilian Semiarid ◽  
Key Drivers ◽  
Shallow Soils

<p>Gullies are key drivers of land degradation, are important sources of sediment and increase sediment and pollutant connectivity in the catchment. They also play an important role in desertification areas, changing the water-table height and in farmlands, reducing productive areas. In this study, we attempted to model small permanent gullies, common in the Brazilian Semiarid Region, where the shallow soils limit the size of gullies cross-sections to a depth of no more than one meter. To model this process, we coupled the models of Foster and Lane (1983) and Sidorchuk (1999), in order to consider the effect of permanent gullies not considered in the first. Both models need as input the discharge peak and its duration, however, these data are frequently not available. We tested four different rain intensities (average, 60-minute, 30-minute and 15-minute), finding that the most intense 30 minutes represent the best the effects of the storms over gully erosion. The coupling of the two models is defined by a threshold that indicates when the equations for sidewall erosion proposed by Sidorchuk should be applied. To validate the model, we measured three gullies in the Brazilian Semiarid Region. The gullies were initiated in 1958 after the construction of a country road and have drainage area below 1 ha. The model yielded a Nash-Sutcliffe coefficient of 0.85.</p>

THE EFFECT OF TREE SHELTER ON THE STEM ANATOMY OF CORK OAK (QUERCUS SUBER) PLANTS

IAWA Journal ◽  
2003 ◽  
Vol 24 (4) ◽  
pp. 385-395 ◽  
Author(s):  
T. Quilhó ◽  
F. Lopes ◽  
H. Pereira
Keyword(s):  
Cross Sections ◽  
Quercus Suber ◽  
Cork Oak ◽  
Lower Percentage ◽  
Annual Rings ◽  
Height Ratio ◽  
Stem Anatomy ◽  
Tree Shelter ◽  
Wood Fibres ◽  
One Year

The effect of tree shelter on the growth and anatomy of bark and wood of cork oak (Quercus suber L.) seedlings was evaluated one year after planting. Stem cross sections were examined and percentage of tissues (vessels, axial parenchyma, rays and fibres) and diameter of vessels analysed. The cork oaks responded to the effect of shelter tubes with a 22% increase in apical growth and a 35% decrease in radial enlargement resulting into highly significant differences in the diameter-to-height ratio (0.099 and 0.193 respectively for sheltered and unsheltered plants). The stem anatomy showed adaptations to the protected environment of the shelter: the sheltered plants had a significantly higher percentage of parenchyma (30% vs. 19%, P < 0.001) and lower percentage of wood fibres (40% vs. 47%) compared with unsheltered plants. Annual rings were less clearly visible in the sheltered plants. These observations suggest that trees grown in protective shelters are less able to withstand the environment than those directly subjected to it.

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