Hydraulic Measurements Research Articles

Verification of Methods for Determining Flow Resistance Coefficients for Floodplains with Flexible Vegetation

In terms of the hydraulic effect of plant flexibility, of particular note is the calculation formula that was proposed by Kouwen, which combines the roughness of the riverbed with the plant community parameter MEJ (including the modulus of elasticity). Kouwen’s method was developed on the basis of laboratory experiments with low vegetation (grasses). According to the authors of this work, the method can also be used to evaluate the resistance of medium vegetation (shrubs) deforming under the influence of water flow. The main objective of the presented research was to verify the application of Kouwen’s method in order to calculate the flow resistance coefficient λ for quasi-regular formed plant obstructions (e.g., basket willow plantations). In a water laboratory, a comprehensive study of the biomechanical and hydraulic properties was carried out for flexible shrubs in floodplains. The results of the hydraulic measurements were compared with the results of the calculations that were made by four various methods using the Chezy-Manning, Garbrecht/Pasche, Lindner/Kaiser, and Kouwen formulas. For all of the flows through the vegetated zone that was tested, the best results were obtained when using the Kouwen calculation procedure and the worst were found for the Lindner formula, which did not include information on the plant flexibility.

Hydrodynamic Model-Based Evaluation of Sediment Transport Capacity for the Makhool-Samarra Reach of Tigris River

This paper implemented an HEC-RAS-based steady two-dimensional hydrodynamic model to evaluate the hydraulic characteristics and Sediment Transport Capacity (STC) of the Makhool-Samarra Reach of the Tigris River, where this part is not already investigated. This model was prepared with the aid of topographical surveys, hydraulic measurements, and laboratory tests, as well as recorded data. The main findings show that the flow velocities within most of the studied reach are considered high compared to the local and worldwide flow velocity ranges in natural rivers. Also, the Toffaleti sediment transport function with the Van Rijn fall velocity and the effective depth-to-width computation methods are the most compatible and suitable methods for computing the Sediment Transport Potential (STP) in the ‎studied reach. With the maximum flow, the computed STP was less than the average (5.7×106 tons/day) in 45% of the reach length, where the maximum STP is 8.7×106 tons/day. However, with the minimum flow, the STP intermittently fluctuates below the average (0.2×106 tons/day) in 48% of the reach length, where the minimum STP is 0.14×106 tons/day. Generally, these STPs are little more than the Tigris River in Mosul and much higher than that in Baghdad. Also, these STPs are considered high on a global scale, especially during high flow. Medium gravel is the larger grain gradation class that can be transported. It constitutes less than 0.00005 % of the STP. Furthermore, the STC computations clearly show that the suspended sediment is the dominant part of the STC and the bed material constitutes less than 0.002% of the STC of the total load. However, most of the STC ‎concerns the clay and very fine silt.

Drought response in Arabidopsis displays synergistic coordination between stems and leaves.

The synergy between drought-responsive traits across different organs is crucial in the whole-plant mechanism influencing drought resilience. These organ interactions, however, are poorly understood, limiting our understanding of drought response strategies at the whole-plant level. Therefore, we need more integrative studies, especially on herbaceous species that represent many important food crops but remain underexplored in their drought response. We investigated inflorescence stems and rosette leaves of six Arabidopsis thaliana genotypes with contrasting drought tolerance, and combined anatomical observations with hydraulic measurements and gene expression studies to assess differences in drought response. The soc1ful double mutant was the most drought-tolerant genotype based on its synergistic combination of low stomatal conductance, largest stomatal safety margin, more stable leaf water potential during non-watering, reduced transcript levels of drought stress marker genes, and reduced loss of chlorophyll content in leaves, in combination with stems showing the highest embolism resistance, most pronounced lignification, and thickest intervessel pit membranes. In contrast, the most sensitive Cvi ecotype shows the opposite extreme of the same set of traits. The remaining four genotypes show variations in this drought syndrome. Our results reveal that anatomical, ecophysiological, and molecular adaptations across organs are intertwined, and multiple (differentially combined) strategies can be applied to acquire a certain level of drought tolerance.

Characterizing groundwater heat transport in a complex lowland aquifer using paleo-temperature reconstruction, satellite data, temperature–depth profiles, and numerical models

Abstract. Heat is a naturally occurring, widespread groundwater tracer that can be used to identify flow patterns in groundwater systems. Temperature measurements, being relatively inexpensive and effortless to gather, represent a valuable source of information which can be exploited to reduce uncertainties on groundwater flow, and, for example, support performance assessment studies on waste disposal sites. In a lowland setting, however, hydraulic gradients are typically small, and whether temperature measurements can be used to inform us about catchment-scale groundwater flow remains an open question. For the Neogene Aquifer in Flanders, groundwater flow and solute transport models have been developed in the framework of safety and feasibility studies for the underlying Boom Clay formation as a potential host rock for geological disposal of radioactive waste. However, the simulated fluxes by these models are still subject to large uncertainties as they are typically constrained by hydraulic heads only. In the current study, we use a state-of-the-art 3D steady-state groundwater flow model, calibrated against hydraulic head measurements, to build a 3D transient heat transport model, for assessing the use of heat as an additional state variable, in a lowland setting and at the catchment scale. We therefore use temperature–depth (TD) profiles as additional state variable observations for inverse conditioning. Furthermore, a Holocene paleo-temperature time curve was constructed based on paleo-temperature reconstructions in Europe from several sources in combination with land surface temperature (LST) remotely sensed monthly data from 2001 to 2019 (retrieved from NASA's Moderate Resolution Imaging Spectroradiometer, MODIS). The aim of the research is to understand the mechanisms of heat transport and to characterize the temperature distribution and dynamics in the Neogene Aquifer. The simulation results clearly underline advection/convection and conduction as the major heat transport mechanisms, with a reduced role of advection/convection in zones where flux magnitudes are low, which suggests that temperature is also a useful indicator in a lowland setting. Furthermore, the performed scenarios highlight the important roles of (i) surface hydrological features and withdrawals driving local groundwater flow systems and (ii) the inclusion of subsurface features like faults in the conceptualization and development of hydrogeological investigations. These findings serve as a proxy of the influence of advective transport and barrier/conduit role of faults, particularly for the Rauw fault in this case, and suggest that solutes released from the Boom Clay might be affected in similar ways.

Anatomical determinants of gas exchange and hydraulics vary with leaf shape in soybean.

Leaf shape in crops can impact light distribution and carbon capture at the whole plant and canopy level. Given similar leaf inclination, narrow leaves can allow a greater fraction of incident light to pass through to lower canopy leaves by reducing leaf area index, which can potentially increase canopy-scale photosynthesis. Soybean has natural variation in leaf shape which can be utilized to optimize canopy architecture. However, the anatomical and physiological differences underlying variation in leaf shape remain largely unexplored. In this study, we selected 28 diverse soybean lines with leaf length to width ratios (leaf ratio) ranging between 1.1 and 3.2. We made leaf cross-sectional, gas exchange, vein density and hydraulic measurements and studied their interrelationships among these lines. Our study shows that narrow leaves tend to be thicker, with an ~30 µm increase in leaf thickness for every unit increase in leaf ratio. Interestingly, thicker leaves had a greater proportion of spongy mesophyll while the proportions of palisade and paraveinal mesophyll decreased. In addition, narrow and thicker leaves had greater photosynthesis and stomatal conductance per unit area along with greater leaf hydraulic conductance. Our results suggest that selecting for narrow leaves can improve photosynthetic performance and potentially provide a yield advantage in soybean.

Inferring decelerated land subsidence and groundwater storage dynamics in Tianjin–Langfang using Sentinel-1 InSAR

ABSTRACT To meet the growing demand for socioeconomic development, a large amount of groundwater is extracted from confined aquifers worldwide. The North China Plain has experienced considerable groundwater depletion and subsidence during the past six decades. In this study, we use Sentinel-1A/B SAR images from 2015 to 2020 to map the ground subsidence of the Tianjin–Langfang area. Three subsiding zones centered at Guangyang, Wuqing–Bazhou, and Jinghai are identified with maximum subsidence rates of 98.1, 121.8, and 104.7 mm/yr. Seasonal and long-term signals are separated from time series subsidence and hydraulic measurements using continuous wavelet transform to retrieve aquifer parameters. The long-term subsidence, which fits well with an exponential decaying model, remarkably slows down in our study area. The elastic skeletal storage coefficients range between 0.52×10−3 and 9.66×10−3. We then retrieve the spatial–temporal variations of total groundwater storage, recoverable groundwater storage, and irreversible groundwater storage. Groundwater storage depletion rates are apparently reducing, which benefits from the operation of the South-to-North Water Transfer Project and local groundwater management practices.

Aquifer feature estimation in Basara basin using a groundwater modeling system for smart agriculture

We estimate aquifer characteristics in the Basara basin using Groundwater Modeling System (GMS) software in this article. The 960 hydraulic head measurements are taken from 16 observation wells across 60 stress periods in the proposed research. Calibration of aquifer parameters produced hydraulic conductivity values ranging from 1.96 to 117.8 m/d. The specific yield values varied from (=0.31) to (>=0.06). The daily recharge rates ranged from (3.33 *10-4) to (1 *10-3). We examined six pumping scenarios for 2020-2024. (S1–S6). Groundwater levels often dropped further as pumping rates rose and recharging rates decreased. The lower contour elevation for scenario 6 is 745.43 m, while it was 748.39, 753.56, 753.56, 753.56, and 753.86 m for scenarios 5, 4, 3, 2, and 1. The findings of this study help policymakers plan for potential shortages in semi-arid areas. The available options can be reproduced elsewhere to provide a more precise and reliable groundwater solution.

Prediction of hydraulic fracture initiation pressure in a borehole based on a neural network model considering plastic critical distance

Prediction of the hydraulic fracture initiation pressure is essential for in-situ hydraulic fracturing design and stress measurement. The prediction models based on the theory of critical distance have been proofed to fit the abnormal initiation pressure caused by the bore size. However, the critical distance used by the previous models is not physics-based, which may result in errors for prediction. In addition, the laboratory determination of the critical distance neglected the boundary loading effect, causing an underestimating of the critical distance. This work aims to provide an efficient and accurate model for predicting the in-situ hydraulic fracture initiation pressure with consideration of a physic-based plastic critical distance. We first establish a universal analytical solution for stress distribution and plastic zone around a borehole in a cylindrical sample through ideal elastoplastic theory. Using the analytical solution, the plastic critical distance of shale rock is analyzed based on a hydraulic fracturing experiment, and compared with the one estimated by the previous methods. Then, a set of numerical simulation are carried out to build a data set of hydraulic fracture initiation pressure under different stresses, tensile strength, and ratio of plastic critical distance to borehole radius. Finally, the nonlinear relationship between these parameters is mapped by a deep neural network model. According to this study, the following conclusions are obtained: 1) The plastic critical distance increases as the loading stress increases. 2) The established neural network trained by numerical simulation results is plausible, meanwhile, with high precision and high efficiency. 3) Increase in stresses and tensile strength can strengthen the influence of critical plastic distance. 4) Kirsch’s approximate stress solution can bring an error for determination of the critical distance in lab-scale experiments.

Continuous three-dimensional stress monitoring in roof of coal mines for investigating the rockburst control effect with hydraulic fracturing

The occurrence of rockburst in coal mines is closely related to the stress in coal and rock mass. Through hydraulic fracturing measurements in roof, the three-dimensional stress in roof before and after hydraulic fracturing as well as during working face advancing was monitored, and the effect of hydraulic fracturing in roof on controlling rockburst was studied. The test results show that (1) after hydraulic fracturing, the three principal stresses in roof decreased remarkably, whose maximum reduction was about 20%, while the elastic strain energy in roof decreased by about 31% as well; (2) as the working face advanced, the three principal stresses in roof in front of the working face would increase continuously until reaching peaks and induce the strata fracture, and the variation of the elastic strain energy in roof was basically consistent with that of the magnitude of the stress; (3) with hydraulic fracturing, the position of the peak stress moved from 11 to 21 m in front of the working face, the peaks of the three principal stresses decreased, whose maximum reduction was about 32%, and the peak of the elastic strain energy in roof also significantly decreased by about 51%. The field investigation shows that hydraulic fracturing in roof can release the stress and elastic strain energy in coal and rock mass instantaneously, and will reduce the risk of rockburst; hydraulic fracturing in roof can be an effective pre-destressing method to reduce the stress and energy concentration in coal and rock mass during mining, and will prevent the risk of rockburst.

Unpiloted Aerial Vehicle (UAV) image velocimetry for validation of two-dimensional hydraulic model simulations

Non-intrusive image-based techniques for measuring surface river velocities have rapidly evolved as a cost-effective and safe means for quantifying flow patterns. Large-scale particle image velocimetry (LSPIV) can provide instantaneous surface velocities over a large spatial footprint rapidly and with little pre-calibration as compared to traditional techniques. Assessment of the spatial distribution of flow velocities in hydraulic models has been comparatively harder to achieve than assessment of depth due to logistical challenges but would be aided using large observational datasets that represent the variability and distribution of flow hydraulics. Additionally, the efficacy of image velocimetry in assessing the accuracy of outputs from 2D hydraulic models has not been addressed. Here, we demonstrate how LSPIV can be used to calibrate and validate 2D model predictions in a gravel bed river reach. LSPIV velocities are depth-averaged using standard velocity coefficients (α) and then using the Probability Concept (PC) - a probabilistic formulation of velocity distributions that accounts for non-standard velocity profiles, typical in field settings. UAV surveys were used to acquire video for LSPIV and imagery for Structure from Motion (SfM) topographic modelling. We use spatially dense acoustic doppler current profiler (aDcp) velocity data for benchmark assessment of the velocity outputs of HEC-RAS 2D model simulations. 2D model prediction error, based on seeded LSPIV velocities, was within range (4.2%) of the aDcp parametrised model, with improvements in modelled versus predicted velocity correlations (up to 7.7%) when using PC to depth average LSPIV velocities. Validation bias reduced significantly (11%) with tighter error distributions when compared to the aDcp based model. Although additional hydraulic measurements are required to parametrise the Probability Concept algorithm, the performance of 2D hydraulic models calibrated/validated with LSPIV velocities is on par with traditional techniques, demonstrating the potential of this non-intrusive, low-cost approach.

Assessment of the Rehabilitation of Watercourses (Study Case)

The goal of this study is to assess the rehabilitation of Bahr Awlad Mohamed canal.The canal was rehabilitated by installing lining trapezoidal cross-sections. Before and after the rehabilitation process, a field investigation, hydraulic and hydrographic measurements, and a mathematical model (Sobek – 1D) were conducted. According to the findings, the canal's rehabilitation improved average water velocity from 0.18 m/s to 0.32 m/s, the average Manning roughness coefficient from 0.065 m-1/3s to 0.020 m-1/3s, the water surface slope from 17 and 50 cm/km to 2 and 6 cm/km, the average areas of cross-sections reduced from 3.37 m2 to 3.07 m2, the average water width was reduced from 5.84 m to 4.83 m, the water losses were decreased by approximately 27.31 % from the canal's inlet discharge. Additionally, the water level fulfilled the requirements for water distribution, the canal banks were restored and widened, the hydraulic efficiency of the study canal was improved, alleviating downstream farmers' concerns and conserving water that could be utilized for irrigation, and saving time and maintenance cost. Finally, canal rehabilitation necessitates periodic maintenance, appropriate maintenance equipment, and a strategy of canal preservation. In addition, other canals in Egypt must be improved to determine the irrigation network's water-saving potential.

Recovery after long-term summer drought: Hydraulic measurements reveal legacy effects in trunks of Picea abies but not in Fagus sylvatica.

Climate change is expected to increase the frequency and intensity of summer droughts. Sufficient drought resistance, the ability to acclimate to and/or recover after drought, is thus crucial for forest tree species. However, studies on the hydraulics of mature trees during and after drought in natura are scarce. In this study, we analysed trunk water content (electrical resistivity: ER) and further hydraulic (water potential, sap flow density, specific hydraulic conductivity, vulnerability to embolism) as well as wood anatomical traits (tree ring width, conduit diameter, conduit wall reinforcement) of drought-stressed (artificially induced summer drought via throughfall-exclusion) and unstressed Picea abies and Fagus sylvatica trees. In P. abies, ER indicated a strong reduction in trunk water content after 5 years of summer drought, corresponding to significantly lower pre-dawn leaf water potential and xylem sap flow density. Vulnerability to embolism tended to be higher in drought-stressed trees. In F. sylvatica, only small differences between drought-stressed and control trees were observed. Re-watering led to a rapid increase in water potentials and xylem sap flow of both drought-stressed trees, and to increased growth rates in the next growing season. ER analyses revealed lower trunk water content in P. abies trees growing on throughfall-exclusion plots even 1 year after re-watering, indicating a limited capacity to restore internal water reserves. Results demonstrated that P. abies is more susceptible to recurrent summer drought than F. sylvatica, and can exhibit long-lasting and pronounced legacy effects in trunk water reserves.

KAJIAN RANCANG BANGUN ALAT UKUR DEBIT AMBANG LEBAR DENGAN VARIASI KEMIRINGAN HILIR

The modeling of broad crested weirs is expected to facilitate understanding, especially the behavior of the flow flowing through the measuring instrument. The flow behavior under consideration is hydraulic behavior, measurement accuracy, and discharge curve. In addition, there is a relationship between discharge and water level upstream and downstream of the spillway, as well as the relationship of the variation of discharge flowing through the broad crested weirs to the loss of energy height. From the results of this study, it was found that there was a relationship between discharge and water level upstream, downstream, water level above the threshold, and energy loss for wide-threshold spillway. The modeling of the broad crested weirs assumes that the Froude number that occurs in the model is the same as the Froude number that occurs in the field. So that the scale of discharge, time, velocity and volume will be able to represent the actual conditions in the field. The scale of length, width, and height of the prototype is 1: 100. The methodology used is to carry out testing in the hydraulics laboratory by varying Q1, Q2, Q3, Q4, …. Qn, to obtain variations in water level upstream and downstream of the broad crested weirs. From the results of the study, it was found that the energy loss was relatively small with a trend of Y = 101.66x2 - 0.7359x + 0.0017 with the slope of the broad crested weirs downstream is 1:2, Y = 467.84x2 - 1.7816x + 0.0022 for slope of the broad crested weirs downstream is 1:1.5, and Y = -1140,4x2 + 0.6383x + 0.0077 with the slope of the broad crested weirs downstream is 1:1 where Y is the energy loss in meters and X is the discharge in m3/sec.

Intra‐Specific Variability in Plant Hydraulic Parameters Inferred From Model Inversion of Sap Flux Data

AbstractUnderstanding plant hydraulic regulation is critical for predicting plant and ecosystem responses to projected increases in drought stress. Plant hydraulic regulation is controlled by observable, diverse plant hydraulic traits that can vary as much across individuals of the same species as they do across different species. Direct measurements of plant hydraulic traits from a range of ecosystems remain limited in comparison to other, more readily measured traits (e.g., specific leaf area). Furthermore, plant hydraulic trait measurements, often made at leaf or branch levels, are not easily scaled to whole‐plant values that are typically used to predict plant and ecosystem fluxes. In this study, multiple whole‐plant hydraulic parameters are inferred from observations of plant water use (i.e., sap flow), soil properties, and meteorological data. We use a Markov Chain Monte Carlo model inversion approach to obtain the best estimates and uncertainty of plant hydraulic parameters that capture whole‐plant effective embolism resistance and stomatal sensitivity to decreasing plant water potential. We then use the inferred values in the model to estimate whole‐tree water use and isohydricity. This approach reliably infers whole‐plant parameter values with enough specificity to resolve inter‐ and intra‐specific differences, and thus supplements time‐ and labor‐intensive direct measurements of traits.

On the hydraulics of flow in cracks in embankment dam cores

A major hazard to embankment dams is internal erosion and piping arising from concentrated leaks through transverse cracks in the core near the crest due to differential settlement or desiccation. This contribution summarises experiments and a formal boundary layer analysis of flow through such transverse cracks subject to near-horizontal pressure gradients. The critical hydraulic gradients, at which erosion in such cracks may initiate, occur at the downstream end of the crack. This location and the maximum crack width defines the local point most vulnerable to erosion. The hydraulic laboratory measurements are shown to be consistent with equivalent international standards describing depths at free overflows, in spite of the narrow vertical profile of the cracks, provided that the tendency towards laminar flow in very narrow cracks is incorporated within the modelling. A backwater model based on conventional representations of flow in narrow channels is verified qualitatively by hydraulic laboratory data. Flow-depth relationships, maximum crack wall hydraulic stresses, normalised hydraulic wall stress profiles and depth profiles along cracks are presented for the two principal crack geometries present in embankment dams. These characterisations are a significant improvement on the simplified methods previously used to assess internal erosion in transverse cracks in dams.

Data interpretation method in HF stress measurement for the total stress tensor determination in rock mass

The data interpretation method is validated for the hydraulic fracturing stress measurements for determining simultaneously all components of external stress tensor in rock mass in the vicinity of underground geotechnical structures. The analysis of the alternative patterns of 6 measurement boreholes reveals allowable drilling directions of boreholes to ensure the formulated problem resolvability. The analysis includes the solution of direct problems on finding “the normal stresses in the areas orthogonal to the axes of the boreholes at the known external stresses” and the solution of an inverse problem on finding the external stresses. In the proposed method, the input information may be the data obtained in the in-situ HF stress measurement. The numerical experiments with the synthetic input data determine allowable variations in orientation of measurement holes in directional drilling such that the measuring fault of external stresses is no thigher than 10%.

Evaluation of Water Level in Flowing Channels Using Ultrasonic Sensors

Monitoring flow in channels is difficult, expensive, and potentially dangerous; hence, alternatives minimizing these factors are sought and indirect methods to measure the flow based on water-level information, among others, are employed. Ultrasonic sensors along with Arduino are widely used to monitor levels in reservoirs; however, the accuracy of this method in turbulent flow regimes has not been evaluated. Therefore, in this study, we evaluated the level of open channel flows using a combination of Arduino and ultrasonic sensors whilst considering turbulence. Additionally, we statistically compared the simultaneous measurements of levels obtained using five ultrasonic sensors with those of five rulers filmed individually along an artificial channel, for four permanent and two transient regimes. The results showed that the errors in measurements increased with increasing turbulence. These errors were within the range of hydraulic measurements (<0.020 m), indicating that the procedure is valid for experienced conditions. Therefore, the combination of Arduino and ultrasonic sensors is a technically and economically viable alternative. However, calibrating and validating the sensors for distances greater than 0.400 m should be performed with care because the bench tests performed in static conditions were limitedly accurate in measuring distances greater than 0.200 m.

Hierarchical Bayesian Inversion of Global Variables and Large‐Scale Spatial Fields

AbstractBayesian inversion is commonly applied to quantify uncertainty of hydrological variables. However, Bayesian inversion is usually focused on spatial hydrological properties instead of hyperparameters or non‐gridded physical global variables. In this paper, we present a hierarchical Bayesian framework to quantify uncertainty of both global and spatial variables. We estimate first the posterior of global variables and then hierarchically estimate the posterior of the spatial field. We propose a machine learning‐based inversion method to estimate the joint distribution of data and global variables directly without introducing a statistical likelihood. We also propose a new local dimension reduction method: local principal component analysis (local PCA) to update large‐scale spatial fields with local data more efficiently. We illustrate the hierarchical Bayesian formulation with three case studies: one with a linear forward model (volume averaging inversion) and two with non‐linear forward models (pumping tests and hydraulic head measurements), including a 3D case. Results show that quantifying global variables uncertainty is critical for assessing uncertainty on predictions. We show how the local PCA approach accelerates the inversion process. Furthermore, we provide an open‐source Python package (https://github.com/lijingwang/hierarchicalBayes.git) on the hierarchical Bayesian framework including three case studies.

过度渗透性回填的多级振弦式压力计水位测量的偏差

过度渗透性回填的多级振弦式压力计水位测量的偏差

Differential Hydraulic Properties and Primary Metabolism in Fine Root of Avocado Trees Rootstocks.

Avocados (Persea americana Mill.) are one of the crops with the highest water footprints in Chile and the production is at risk due to severe and frequent droughts. The current production is mostly based on sexually (seed) propagated rootstocks, while clonally propagated rootstocks are on the rise. In a recent study, we found differences in aerial, root growth and water use efficiency between trees grown on these two different rootstocks under controlled continuous fertigation and environmental conditions. In this study, we further describe possible mechanisms which drive the differences. Avocado cv. “Hass” grafted on “Dusa” (D, clonally propagated) and “Mexicola” (M, sexually propagated) rootstocks and different root segments (3, 5 and 8 cm from root tip) were investigated using a combination of hydraulic measurements and polar metabolite (GC-MS) techniques. The results show significant differences in root hydraulic properties, indicating that “Mexicola” fine roots have higher water uptake capacity. The polar metabolites analysis revealed 13 compounds significantly different between rootstocks while nine were found significantly different among root segments. Principal component analysis (PCA) revealed differences between rootstocks and root segments. The data presented here highlight the importance of considering key physiological knowledge in avocado rootstocks breeding programs to be better prepared for future challenging environmental conditions.