Journal of Irrigation and Drainage Engineering

Quantification of evapotranspiration (ET) and infiltration from vegetated stormwater control measures (SCMs), such as rain gardens, is necessary to properly assess their volume reduction potential. Weighing lysimeters at Villanova University mimic three rain garden designs and measure water budget parameters to determine how design elements impact ET. The designs compare two soil media with the same unconstricted drainage systems: a sandy loam and sand and two drainage systems with the same media (sand): an unconstricted valve (UV) outflow and internal water storage (IWS) outflow. A custom system distributed water over the lysimeters to mimic the runoff typically delivered to a rain garden during natural storm events. Runoff simulation trials were performed in summer and fall and compared to direct rainfall to the lysimeters during those seasons. Evapotranspiration rates were unaffected in the sandy loam lysimeter and increased in the sand lysimeters by the simulated rainfall in each system. Average ET over the entire study period was 2.9, 2.7, and $4.3\mathrm{mm}/\mathrm{d}$ for the sandy loam, sand, and sand internal water storage, respectively. Evapotranspiration made up 47, 43, and 70% of the water budget for the sandy loam, sand, and sand IWS systems, respectively. The native soil (sandy loam) did not negatively affect the rate of ET. The IWS drainage system enhanced ET over the unconstricted valve drainage system. In an effort to promote inclusion of ET into rain garden design, seasonal and monthly ET rates are provided as baseline values. The ASCE Penman-Monteith ET and Hargreaves ET equations adequately represent the unconstricted valve lysimeter systems and underrepresent the IWS lysimeter system.

Sediments are known to be potential reservoirs of pathogenic microorganisms that can influence the microbial quality of the overlaying water. A set of laboratory experiments was conducted to investigate the resuspension of Escherichia coli and the MS2 virus from bed sediment to the overlaying water in irrigation canals. Consequently, their concentration in moving water is dependent on flow properties (e.g., velocity, shear stress) and the size of bed sediment. When bed material is sandy loam, their quantity in water increases with the shear stress on bed surface. However, for a sandy bed, their presence in water has no apparent correlation with flow properties. The amount of MS2 virus in water was greater at low flow velocity and shear stress than Escherichia coli because the size of the MS2 virus is much smaller. Finally, an empirical relation was formulated for calculating the maximum allowable Escherichia coli concentration in sandy loamy bed sediment.

Greater or more constant discharge can be achieved at lower upstream water depths over the weir crest by increasing the effective lengths of labyrinth side weirs. Labyrinth weirs have unevenly shaped crests, resulting in greater crest lengths at the weir opening. Labyrinth side weirs have significant advantages over conventional weirs. For example, the discharge capacities of labyrinth side weirs are 1.5–4.5 times that of conventional side weirs. In this study, the effects of using an antivortex structure in trapezoidal labyrinth side weirs on discharge capacity and scouring were investigated for varying values of Froude number (${\mathsf{F}}_1$), dimensionless crest height ($p/y_1$), dimensionless weir opening length ($L/B$), dimensionless effective crest length ($L/L_{ef}$), and side wall angle ($\alpha$). First, using data from 537 experimental runs, the antivortex structures that most increased the discharge capacity were determined. Next, the optimum location and dimension of the antivortex structure were investigated. Based on 242 test runs, it was found that as the dimensions of the antivortex structure increased and as the antivortex structure moved toward the center of the weir opening, the discharge coefficient ($C_d$) increased by approximately 48%. Lastly, clear-water scour experiments were conducted using three antivortex structures with different trapezoidal labyrinth side weir flow intensities. The findings demonstrate that antivortex structures decrease scour depth around the water intake region.

Real-world problems in the agricultural sector are usually multiobjective in nature. More than one objective needs to be fulfilled simultaneously to incorporate economic and social requirements in an acceptable and optimal cropping pattern. Fuzzy multiobjective goal programming (FMGP) techniques can be used to solve optimization formulations. The purpose of this paper is to present a fuzzy multiobjective-based goal programming (GP) model for optimal allocation of land under cultivation to optimize cropping patterns. In this work, goal programming is implemented in two parts. In the first part, only two objectives, maximization of benefit and production, are considered. In the second part, seven objectives are considered in goal programming: maximization of benefit, maximization of production, minimization of investment, minimization of fertilizer application [i.e., minimization of nitrogen (N) application, minimization of phosphorus (P) application, and minimization of potash (K) application], and minimization of water application. FMGP is used to solve multiobjective formulations. Multiobjective solutions provide the necessary aspiration and tolerance levels for goal programming. Performance evaluation of the methodology is demonstrated for a real canal command area.

This study assumes that the infiltrated depth of border irrigation follows a normal distribution, and the soil infiltration variability represented by the variability of infiltration coefficient ($k$) and final infiltration rate ($f_0$) are the Kostiakov-Lewis equation, which can be scaled in the same proportion. Then, a combination of variance method, validated from field-experiment data, is proposed to evaluate the closed-end border irrigation that accounts for soil infiltration variability. The results show that the normalization equation for estimating the infiltrated water depth is reliable. Accuracy of simulated advance and recession trajectories can be improved with soil infiltration variations being considered. The irrigation performance indications estimated using the proposed method are in agreement with the measured values and simulated values under the variable soil. Meanwhile, in terms of infiltration parameters variation, Christiansen’s uniformity ($CU$) is the most significant factor, followed by the application efficiency ($E_a$) and the storage efficiency ($E_s$), and resulting in 37.01, 15.22, and 15.24% decreases of $CU$, $E_a$, and $E_s$ when the variation coefficient of the normalization factor ($C{V}_F$) increased from 0.0 to 0.5. Therefore, the variability of soil infiltration must be considered when evaluating closed-end border irrigation.

Information about the spatial pattern of soil salinity is important for special site management. The authors determined the spatial variation of salinity in a gravel-sand mulched (using gravel and sand as mulch) jujube orchard by measuring salinity in 256 soil samples collected from 0–10, 10–20, 20–30, and 30–50 cm layers at four sampling scales: $32\times 32$, $28\times 28$, $24\times 24$, and $20\times 20\mathrm{m}$. Soil salinity tended to increase with depth in the 0–50 cm soil profile, with a soil salinity range of $0.46–1.30\mathrm{g}/\mathrm{kg}$. The coefficient of variation (CV) of soil salinity ranged from 5.95 to 18.59%, indicating weak to moderate variability. The spatial distributions of salinity differed in the surface layers at the four sampling scales, indicating obvious peaks and valleys in the three-dimensional map. Salinity in each layer was not completely independent due to the climate, hydrology, water resources, and parental soil material and so was spatially correlated, with bottom and surface of the correlation abatin with depth. Ordinary kriging could estimate the values of selected soil variables with inappropriate data and at unsampled locations, but estimating the salinity in deep soil using cokriging by measuring the salinity in the surface soil was more accurate.

The design and calibration of three simple flumes for flow measurements in open channels are discussed. The flumes are designed based on principles of critical flow in open channels. Critical flow is created through the contraction of the flow cross section by installing vertical cylindrical columns in an open channel. Calibrated equations are developed for each of the three flumes by combining the Pi Theorem principle with laboratory scale physical models. The three flumes are designed for application in prismatic (trapezoidal, rectangular, and circular) channels. The calibrated equations can be used for design and calibration of the flumes regardless of the flumes or channel dimensions. The equations are validated using field scale flumes, and a design example is provided for free flow conditions.

Sluice gates are commonly used in canals for control and measurement of the flow. The discharge under sluice gates can be determined through the energy-momentum method (EM), the orifice flow rate equations and the application of the $\mathrm{\Pi }$-theorem of the dimensional analysis. The different discharge methods available, for free and submerged hydraulic jump including the transition between flows, were compared with experimental data. The performance of the different calibration methods was analyzed. The test program was conducted in the laboratory flume and in the experimental irrigation canal of the University of Évora, Portugal. The test program shows that the evaluation of the discharge under sluice gates for free and submerged flows and for the transition between both flows through the methods based in the EM were those who had better results. For the studied gates openings, the results also show that the methods that consider the division of the submerged flow in partial and totally submerged did not improve the discharge results.

The problem posed here concerns water distribution from a main source to discrete demand locations through irrigation canals. A network is designed where the demand locations express the nodes of the network, which are connected by arcs that represent canals to be constructed. The construction cost of each canal depends on various factors such as land structure, topography, etc. The amount of water conveyed per unit of time down a canal path from the main source to a specific demand location is equal to the minimum capacity of a canal in the corresponding path. The objective here is to determine a subset of canals that distributes per unit of time the maximum possible amount of water to every demand location at the minimum possible construction cost, taking into account canal capacity limitations. The problem is dealt with in the context of graph theory and a corresponding algorithm has been developed.