scholarly journals Modeling Subsurface Drainage in Compacted Cultivated Histosols

2021 ◽  
Vol 2 ◽  
Author(s):  
Cedrick Victoir Guedessou ◽  
Jean Caron ◽  
Jacques Gallichand ◽  
Moranne Béliveau ◽  
Jacynthe Dessureault-Rompré ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Meteorological Data ◽  
Subsurface Drainage ◽  
Efficiency Coefficient ◽  
Matric Potential ◽  
Compact Layer ◽  
Compaction Rate ◽  
Drain Spacing ◽  
Drainage Rate ◽  
Water Percolation

Reclaiming histosols in Montéregie region, Québec, Canada, increases peat decomposition and compaction rate and decreases the effectiveness of subsurface drainage. The objective of this paper was to use HYDRUS-2D to model the behavior of subsurface drainage systems, in order to evaluate the compaction effect on drain depth and spacing, and to determine the compact layer thickness and saturated hydraulic conductivities (Ksat) resulting in an improvement of subsurface drainage]. The drainage model was calibrated [Nash-Sutcliffe efficiency coefficient (NSE) = 0.958, percent bias (PBIAS) = −0.57%] using Ksat, meteorological data, and matric potential (h) data measured on the project site from June 10 to July 19, 2017. The calibrated and validated model was used to analyze the variation of h values (Δh in cm d−1) as a function of drain spacing (2–7 m) and drain depth (1 and 1.2 m) and to identify the response surface of Δh to various compact layer thickness and Ksat combinations. The results showed that Δh was on average 58% greater below the compact layer than above it and that reducing drain spacing or increasing drain depth does not improve the drainage rate. The analysis of the compact layer thickness and Ksat effect on Δh showed that for a Δh of 40 cm d−1, Ksat actual values in the two uppermost layers should be multiplied by 50 for compact layer thickness varying from 12 to 35 cm. Water percolation in the soil is reduced by the compact layer. Soil management methods for improving Ksat should therefore be better than deepening the drains or and reducing the spacing.

Coefficients for Quantifying Subsurface Drainage Rates

2017 ◽  
Vol 33 (6) ◽  
pp. 793-799 ◽  
Author(s):  
R. Wayne Skaggs
Keyword(s):  
Meta Analysis ◽  
Soil Surface ◽  
Subsurface Drainage ◽  
Rainfall Events ◽  
Drainage Systems ◽  
Hydraulic Roughness ◽  
Drainage Rate ◽  
Design Projects ◽  
Research And Design ◽  
Different Soils

Abstract. It is proposed that technical papers on drainage research studies and engineered design projects should report standard coefficients or parameters that characterize the hydraulics of the system. The following coefficients define key subsurface drainage rates that can be used to quantify and compare the hydraulics of drainage systems across sites, soils and geographic locations. (1) The steady subsurface drainage rate (cm/d) corresponding to a saturated profile with a ponded surface. This subsurface drainage rate defines the length of time that water remains ponded on the soil surface following large rainfall events. It is proposed that this rate be called the Kirkham Coefficient (KC) in honor of Professor Don Kirkham who derived analytical solutions for saturated drained profiles for most soil and boundary conditions of interest. (2) Drainage intensity (DI), which represents the drainage rate (cm/d) when the water table midway between parallel drains is coincident with the surface. The DI can be estimated by the Hooghoudt equation and is dependent on the effective saturated hydraulic conductivity of the profile, drain depth, spacing, and depth of the soil profile or restrictive layer. (3) The drainage coefficient (DC), which quantifies the hydraulic capacity of the system. This value is the rate (cm/d) that the outlet works can remove water from the site. It is dependent on the size, slope, and hydraulic roughness of the laterals, submains, mains, and, in cases where pumped outlets are used, the pumping capacity. Routine inclusion of these three coefficients in the documentation of research and design projects would facilitate comparison of results from different soils and drainage systems, and generally, the meta-analysis of data pertaining to drainage studies. Keywords: Drainage, Drainage intensity, Drainage coefficient, Drainage nomenclature, Kirkham Coefficient.

scholarly journals Calibration of DRAINMOD for prediction of water table depths and drain discharges under waterlogged Vertisols of Maharashtra, India

2019 ◽  
Vol 11 (3) ◽  
pp. 724-731
Author(s):  
Shrimant Rathod ◽  
Sudhir Dahiwalkar ◽  
Sunil Gorantiwar ◽  
Mukund Shinde
Keyword(s):  
Water Table ◽  
Agricultural Research ◽  
Drainage System ◽  
Subsurface Drainage ◽  
Design Parameters ◽  
Design System ◽  
Research Station ◽  
Drain Spacing ◽  
Drainage Design ◽  
Rainy Days

An estimation of optimal design parameters of subsurface drainage system through monitoring of water table depths and drain discharges are expensive in terms of time and money. The simulation modeling is an effective tool for estimation of drainage design parameters at less cost and short time. In view to this, calibration of DRAINMOD model for prediction of water table depths and drain discharges were conducted by installing subsurface drainage system with 40 m drain spacing and 1.0 m drain depth at Agricultural Research Station, Kasbe Digraj, Dist. Sangli (Maharashtra) during 2012-13 to 2013-14. The field data on water table depth and drain discharge were used for calibration of DRAINMOD model. The input data files on climatic, soil, crop and drainage design system parameters were attached to DRAINMOD model and calibrated successfully. It is found that both observed and simulated water table depths and drain discharges showed a fluctuating trend and predicted both water table depths and drain discharges closely with the observed values during frequent rainy days and following the rainy days. The DRAINMOD model reliably predicted water table depths with a goodness of fit (R2 = 0.97), MAE (12.23 cm), RMSE (15.49 cm) and CRM (0.05); drain discharges with R2 of  0.93, MAE of 0.095 mm day-1, RMSE of 0.1876 mm day-1and CRM of 0.04. Thus, the calibrated DRAINMOD model can be used to simulate the water table depths and drain discharges in semi-arid climatic conditions of Maharashtra and in turn to estimate and evaluate drain spacing and depth.

scholarly journals Rainfall-runoff simulation of Bagmati River Basin, Nepal

Jalawaayu ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 61-71
Author(s):  
Yam Prasad Dhital ◽  
Binod Dawadi ◽  
Dambaru Ballab Kattel ◽  
Krishna Chandra Devkota
Keyword(s):  
Meteorological Data ◽  
Rainfall Variability ◽  
Complex Problem ◽  
Poor Correlation ◽  
Efficiency Coefficient ◽  
Runoff Simulation ◽  
River Flooding ◽  
Rugged Topography ◽  
Relative Coefficient ◽  
Monthly Runoff

Runoff simulation is a complex problem in mountain catchments due to high rainfall variability and rugged topography. In the lower parts of Nepal, river flooding is a serious disaster problem in July and August; sometimes it also occurs in September. In this context, Hydro-Informatic Modeling System (HIMS) was used for daily and monthly runoff simulation from the set of daily hydro-meteorological data (Maximum and minimum temperature, rainfall, and discharge) in the time series 1980 to 1989, 1990 to 1999, and 2000 to 2009, respectively. The model performed well for the monthly runoff simulation, whereas the efficiency coefficient and relative coefficient both were found a very good correlation between observed and simulated hydrographs, which varied between 0.883 to 0.940 and 0.889 to 0.945, respectively. However, the efficiency coefficient and relative coefficient both were found a very poor correlation between observed and simulated hydrographs for the daily runoff simulation, which averaged 0.342 and 0.348, respectively. The daily simulation result also might have been improved, if more number of uniformly distributed meteorological station data is available.

scholarly journals Neuro-fuzzy systems to estimate reference evapotranspiration

Water SA ◽  
2019 ◽  
Vol 45 (2 April) ◽  
Author(s):  
Mousaab Zakhrouf ◽  
Hamid Bouchelkia ◽  
Madani Stamboul
Keyword(s):  
Meteorological Data ◽  
Regional Scale ◽  
Subtractive Clustering ◽  
Efficiency Coefficient ◽  
Climate Data ◽  
Neuro Fuzzy ◽  
Physically Based ◽  
Fuzzy C Means Clustering ◽  
Daily Evapotranspiration ◽  
Semi Empirical

Routine and rapid estimation of evapotranspiration (ET) at regional scale is of great significance for agricultural, hydrological and climatic studies. A large number of empirical or semi-empirical equations have been developed for assessing ET from meteorological data. The FAO-56 PM is one of the most important methods used to estimate evapotranspiration. The advantage of FAO-56 PM is a physically based method that requires a large number of climatic parameter data. In this paper, the potential of two types of neuro-fuzzy system, including ANFIS based on subtractive clustering (S_ANFIS), ANFIS based on the fuzzy C-means clustering method (F_ANFIS), and multiple linear regression (MLR), were used in modelling daily evapotranspiration (ET0). For this purpose various daily climate data – air temperature (T), relative humidity (RH), wind speed (U) and insolation duration (ID) – from Dar El Beidain Algiers, Algeria, were used as inputs for the ANFIS and MLR models to estimate the ET0 obtained by FAO-56 based on the Penman-Monteith equation. The obtained results show that the performances of S_ANFIS model yield superior to those of F_ANFIS and MLR models. It can be judged from results of the Nash-Sutcliffe efficiency coefficient (EC) where S_ANFIS (EC = 94.01%) model can improve the performances of F_ANFIS (EC = 93.00%) and MLR (EC = 92.12%) during the test period, respectively.

Applicability of Modified TOPMODEL in the Arid Zone and the Humid Zone

2013 ◽  
Vol 423-426 ◽  
pp. 1418-1421 ◽  
Author(s):  
Shuang Liu ◽  
Jing Wen Xu ◽  
Jun Fang Zhao ◽  
Peng Hou
Keyword(s):  
Arid Zone ◽  
Meteorological Data ◽  
Efficiency Coefficient ◽  
Climate Conditions ◽  
Humid Zone

This study aims at discussing the applicability of modified TOPMODEL in different areas with various climate conditions in China, choosing the Youshuijie catchment (the humid zone) and the Yingluoxia catchment (the arid zone) . Hydro-meteorological data and 90-m-resolution DEMs are used for driving the models. From the Nash-Sutcliffe efficiency coefficient (NE), we can see that TOPMODEL performed much better in the Youshujie catchment than in the Yingluoxia catchment, which suggests that modified TOPMODEL is much more suitable in the humid zone.

scholarly journals Grapevine Phenology in Four Portuguese Wine Regions: Modeling and Predictions

2021 ◽  
Author(s):  
Samuel Reis ◽  
Helder Fraga ◽  
Cristina Carlos ◽  
José Silvestre ◽  
José Eiras-Dias ◽  
...  
Keyword(s):  
High Performance ◽  
Mean Squared Error ◽  
Cultural Practices ◽  
Meteorological Data ◽  
Efficiency Coefficient ◽  
Short Term ◽  
Phenological Stages ◽  
Predictive Capacity ◽  
Phenological Model ◽  
Wine Region

<p>Phenological models applied to grapevines are valuable tools to assist in the decision of cultural practices related to winegrowers and winemakers. The two-parameter sigmoid phenological model was used to estimate the three main phenological stages of the grapevine development, i.e., budburst, flowering, and veraison. This model was calibrated and validated with phenology data for 51 grapevine varieties distributed in four wine regions in Portugal (Lisboa, Douro, Dão, and Vinhos Verdes). Meteorological data for the selected sites were also used. Hence, 153 model calibrations (51 varieties × 3 phenological stages) and corresponding parameter estimations were carried out based on an unprecedented comprehensive and systematized dataset of phenology in Portugal. For each phenological stage, the centroid of the estimated parameters was subsequently used, and three generalized sigmoid models were constructed (budburst: d =−0.6, e = 8.6; flowering: d = −0.6, e = 13.7; veraison: d = −0.5, e = 13.2). Centroid parameters show high performance for approximately 90% of the varieties and can thereby be used instead of variety-specific parameters. Overall, the RMSE (root-mean-squared-error) is < 7 days, while the EF (efficiency coefficient) is > 0.5. Additionally, according to other studies, the predictive capacity of the models for budburst remains lower than for flowering or veraison. Furthermore, the F-forcing parameter (thermal accumulation) was evaluated for the Lisboa wine region, where the sample size is larger, and for the varieties with model efficiency equal to or greater than 0.5. A ranking and categorization of the varieties in early, intermediate, and late varieties was subsequently undertaken on the basis of F values. In this way, these results of the present study will be incorporated on a web platform, where the sigmoid model must convey valuable information regarding the development/evolution of the vineyard with short-term predictions.</p><p><strong>Keywords: </strong>grapevine; phenology modeling; sigmoid model; wine regions; short-term predictions; Portugal</p>

The influence of various treatments on the drainage of continuously made curd

1970 ◽  
Vol 37 (3) ◽  
pp. 417-429 ◽  
Author(s):  
N. J. Berridge ◽  
P. G. Scurlock
Keyword(s):  
Heat Treatment ◽  
Layer Thickness ◽  
Narrow Range ◽  
Pronounced Effect ◽  
Ph Change ◽  
Drainage Rate ◽  
Effects Of Ph ◽  
Expected Increase ◽  
Horizontal Layers

SummaryThe effect of layer thickness and orientation, and of pressure, temperature, and disturbance on the drainage rates of continuously made curd were determined. The effects of heat treatment of the milk and adjustments of its pH were briefly examined. An increase in temperature of the curd caused the expected increase in drainage rate as did also the application of pressure. Vertical layers of curd drained more quickly than almost horizontal layers, and keeping curd in whey retarded its drainage. The effects of pH change over the narrow range of interest (6·1–6·5) were relatively small. Pasteurization of the milk had no effect. Disturbance of the curd had the most pronounced effect in increasing its rate of drainage.

scholarly journals Evaluation of Parallel Pipe Subsurface Drainage System in a Waterlogged Paddy Field

2021 ◽  
Vol 108 (March) ◽  
pp. 1-7
Author(s):  
Kathirvel L ◽  
◽  
Manikandan M ◽  
Raviraj A ◽  
Baskar M ◽  
...  
Keyword(s):  
Groundwater Level ◽  
Paddy Field ◽  
Tamil Nadu ◽  
Root Zone ◽  
Soil Depth ◽  
Water Discharge ◽  
Drainage System ◽  
Subsurface Drainage ◽  
Drain Pipe ◽  
Drain Spacing

Inadequate natural drainage facilities and flat lands causes, some of the Cauvery river basin command are suffering waterlogging and alkalinity problems during the canal water supply and period of excess rainfall. Subsurface drainage system is the method to lower the depth to groundwater level below the root zone and creates a favorable environment for crop growth. A study aimed to evaluate the performance of the parallel pipe subsurface system installed in farmers’ field at Sembari village, Lalgudi Taluk, Trichy District, Tamil Nadu in a waterlogged paddy field from October 2020 to February 2021. The field experiment was conducted with the combination of three lateral drain spacing (7.5, 10.0 and 12.5 m) and two drain depths (60 and 80 cm). 63 mm PVC perforated pipes wrapped with coir envelope were laid as lateral drains at a grade 0.3%. Inspection chambers connected with collector drains laid at a grade of 0.6% were used to measure the drain water discharge, observation wells installed midway between lateral pipes drains were used for measuring the depth to groundwater level. Hydraulic properties of soil, depth to water level, discharge collected in drain pipe were used as evaluation parameters. This study revealed that soil hydraulic conductivity had been increased to 30%, pH, EC and ESP has been reduced to 12, 54 and 20%, respectively. The system has performed well to alleviate the waterlogged condition in 7.5 m lateral drain spacing and 80 cm drain depth treatment by observing the higher rate of decrease in depth to water of 0.3 to 0.4 m and a drainage coefficient of 0.069 to 0.29 cm/day.

scholarly journals Simulating glacier mass balance in the cross-border Poiqu/Bhotekoshi Basin, China and Nepal

2020 ◽  
Author(s):  
Bo Kong ◽  
Huan Yu ◽  
Wei Deng ◽  
Qing Wang
Keyword(s):  
Global Warming ◽  
Mass Balance ◽  
Snow Water Equivalent ◽  
Meteorological Data ◽  
Scientific Data ◽  
Glacier Mass Balance ◽  
Efficiency Coefficient ◽  
Cross Border ◽  
Runoff Depth ◽  
Hbv Model

Abstract To assess the change of glacier mass balance (GMB) in the Poiqu/Bhotekoshi basin in the context of global warming, this study applied a conceptual Hydrologiska Bryans Vattenbalansavdelning (HBV) hydrological model to quantify the GMB in the area. The HBV model was trained and validated based on in-situ hydro meteorological data from 10 weather stations in the basin. The dataset, which consists of the daily observations for both rainfall and air temperature, was partitioned into two decades, 1988–1998 and 1999–2008 for calibration and validation, respectively. The calibrated model was adopted to restore the daily runoff depth and then estimate the annual changes of GMB in Poiqu/Bhotekoshi basin over the period of 1988–2008. Results show that the Nash–Sutcliffe efficiency coefficient (Reff) of the daily runoff depth simulation after the runoff calibration process was above 0.802. Therefore, the simulated values of the HBV model are reliable and can be used to estimate the GMB of Himalayan cross-border glacial mountain basins with huge elevation difference, and provide scientific data support for water resources management. Furthermore, the result demonstrated a slow year-by-year rise of snow water equivalent because of global warming, and it highly correlates with the soil moisture, the spring temperature and the summer precipitation.

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