Direct Field Measurements Research Articles

Evaluation of Micrometeorological Models for Estimating Crop Evapotranspiration Using a Smart Field Weighing Lysimeter

Accurate estimation of crop water use, which is expressed as evapotranspiration (ET) is an important task for effective irrigation and agricultural water management. Although direct field measurement of actual evapotranspiration (ETa) is the most reliable method, practical and economic limitations often make it difficult to acquire, especially in developing countries. Consequently, crop evapotranspiration (ETc) is calculated using reference evapotranspiration (ETo) and crop-specific coefficients (Kc) to support irrigation water management practices. Several ETo models have been developed to address varying environmental conditions; however, their transferability to new environments often leads to under or over estimation of ETo, which has an impact on ETc estimation. This study evaluated the accuracy of 30 ETo micrometeorological models to estimate ETc under different seasonal and micro-climatic conditions using ETa data directly measured using a smart field weighing lysimeter as a benchmark. Local Kc values were derived from field-based measurements, while statistical metrics were applied for the evaluation process. A cumulative ranking approach was used to assess the accuracy and consistency of the models across four cropping seasons. Results demonstrated the Penman–Monteith model to be the most consistent model in estimating ETc, which outperformed other models across all cropping seasons. The performance of alternative models differed significantly with seasonal conditions, indicating their susceptibility to seasonality. The findings demonstrated the Penman–Monteith model as the most reliable approach for estimating ETc, which justifies its application role as a benchmark for validating other ETo models in data-limited areas. The study emphasizes the importance of site-specific validation and calibration of ETo models to improve their accuracy, applicability, and reliability in diverse environmental conditions.

Use of supervised and unsupervised approaches to make zonal application maps for variable-rate application of crop growth regulators in commercial cotton fields

BackgroundZonal application maps are designed to represent field variability using key variables that can be translated into tailored management practices. For cotton, zonal maps for crop growth regulator (CGR) applications under variable-rate (VR) strategies are commonly based exclusively on vegetation indices (VIs) variability. However, VIs often saturate in dense crop vegetation areas, limiting their effectiveness in distinguishing variability in crop growth. This study aimed to compare unsupervised framework (UF) and supervised framework (SUF) approaches for generating zonal application maps for CGR under VR conditions. During 2022–2023 agricultural seasons, an UF was employed to generate zonal maps based on locally collected field data on plant height of cotton, satellite imagery, soil texture, and phenology data. Subsequently, a SUF (based on historical data between 2020–2021 to 2022–2023 agricultural seasons) was developed to predict plant height using remote sensing and phenology data, aiming to replicate same zonal maps but without relying on direct field measurements of plant height. Both approaches were tested in three fields and on two different dates per field.ResultsThe predictive model for plant height of SUF performed well, as indicated by the model metrics. However, when comparing zonal application maps for specific field-date combinations, the predicted plant height exhibited lower variability compared with field measurements. This led to variable compatibility between SUF maps, which utilized the model predictions, and the UF maps, which were based on the real field data. Fields characterized by much pronounced soil texture variability yielded the highest compatibility between the zonal application maps produced by both SUF and UF approaches. This was predominantly due to the greater consistency in estimating plant development patterns within these heterogeneous field environments. While VR application approach can facilitate product savings during the application operation, other key factors must be considered. These include the availability of specialized machinery required for this type of applications, as well as the inherent operational costs associated with applying a single CGR product which differs from the typical uniform rate applications that often integrate multiple inputs.ConclusionPredictive modeling shows promise for assisting in the creation of zonal application maps for VR of CGR applications. However, the degree of agreement with the actual variability in crop growth found in the field should be evaluated on a field-by-field basis. The SUF approach, which is based on plant heigh prediction, demonstrated potential for supporting the development of zonal application maps for VR of CGR applications. However, the degree to which this approach aligns itself with the actual variability in crop growth observed in the field may vary, necessitating field-by-field evaluation.

Mapping River Flow from Thermal Images in Approximately Real Time: Proof of Concept on the Sacramento River, California, USA

Image velocimetry has become an effective method of mapping flow conditions in rivers, but this analysis is typically performed in a post-processing mode after data collection is complete. In this study, we evaluated the potential to infer flow velocities in approximately real time as thermal images are being acquired from an uncrewed aircraft system (UAS). The sensitivity of thermal image velocimetry to environmental conditions was quantified by conducting 20 flights over four days and assessing the accuracy of image-derived velocity estimates via comparison to direct field measurements made with an acoustic Doppler current profiler (ADCP). This analysis indicated that velocity mapping was most reliable when the air was cooler than the water. We also introduced a workflow for River Velocity Measurement in Approximately Real Time (RiVMART) that involved transferring brief image sequences from the UAS to a ground station as distinct data packets. The resulting velocity fields were as accurate as those generated via post-processing. A new particle image velocimetry (PIV) algorithm based on staggered image sequences increased the number of image pairs available for a given image sequence duration and slightly improved accuracy relative to a standard PIV implementation. Direct, automated geo-referencing of image-derived velocity vectors based on information on the position and orientation of the UAS acquired during flight led to poor alignment with vectors that were geo-referenced manually by selecting ground control points from an orthophoto. This initial proof-of-concept investigation suggests that our workflow could enable highly efficient characterization of flow fields in rivers and might help support applications that require rapid response to changing conditions.

Calibration of base saturation flow rate at pretimed signal intersection utilizing Bayesian linear regression considering morning and evening peak hour observations

Abstract Base saturation flow is a critical constraint used for evaluating the capacity of signalized intersections. The Indonesian Highway Capacity Manual (IHCM, 2023) is frequently used for signalized intersection planning in Indonesia. In heterogeneous traffic environments, the driver characteristics and behaviors exhibit significant variations. However, the base saturation flow was also influenced by traffic volume during the observation period. This study modeled the base saturation flow by analyzing differences in morning and afternoon peak hour data. The objective was to examine the base saturation flow at pretimed signal in Banda Aceh, with a focus on traffic volume fluctuations during peak hours. Four intersections were investigated in this study. Unmanned aerial vehicles were employed to record discharge flow pattern within targeted signalized intersection. Manual timing was conducted using stopwatches and geometric road data were collected through direct field measurements. Bayesian linear regression with a Gibbs sampling approach was utilized to recalibrate the saturation flow rate coefficients. The base saturation flow during the morning peak is 284 We, while in the afternoon peak, it is 285 We, with We representing the effective intersection approach.

Comparison of Direct Magnetic Field Measurements in a Sunspot by Ten Spectral Lines of Fe I, Fe II, Ti I, and Ti II

Comparison of Direct Magnetic Field Measurements in a Sunspot by Ten Spectral Lines of Fe I, Fe II, Ti I, and Ti II

Waterfalls Alter Reach‐Scale Fluvial Erosion Rates: Evidence From Field Data and Process Modeling

AbstractWaterfalls are often interpreted as transient, upstream‐propagating features that mark changes in external conditions. Thus, waterfalls are commonly used to infer past tectonic and climatic forcing, making understanding the controls on waterfall erosion central to predicting how external perturbations move through landscapes. Surprisingly, there exist few direct field measurements of waterfall erosion, and existing waterfall retreat measurements are rarely paired with measurements of waterfall morphology and frequency, which, theory suggests, modulate retreat rates. This lack of data limits our ability to test existing theory and explore how waterfalls alter reach‐scale bedrock erosion rates. Here, we use cosmogenic 10Be accumulated in bedrock riverbeds to measure erosion rates in fluvial reaches with varying waterfall frequency and morphology. We find that waterfall‐rich reaches erode one to five times faster than the landscape average, and that reach‐averaged erosion rates increase with increasing waterfall frequency. We develop a new, process‐based model combining waterfall and planar‐channel erosion to explore mechanistic controls on the relative erosion rate between waterfall‐rich and waterfall‐free reaches. This model predicts that reach‐averaged erosion rates increase with waterfall frequency at low sediment supply, consistent with our field measurements, but that waterfalls can also slow reach‐averaged erosion rates for high sediment supply, large grain sizes, low water discharge, or large plunge pools. Our work is consistent with previous suggestions that waterfall erosion rates may decrease in low drainage areas and can influence long‐profile morphology.

Calibrating Satellite Maps With Field Data for Improved Predictions of Forest Biomass

ABSTRACTSpatially explicit quantification of forest biomass is important for forest‐health monitoring and carbon accounting. Direct field measurements of biomass are laborious and expensive, typically limiting their spatial and temporal sampling density and therefore the precision and resolution of the resulting inference. Satellites can provide biomass predictions at a far greater density, but these predictions are often biased relative to field measurements and exhibit heterogeneous errors. We developed and implemented a coregionalization model between sparse field measurements and a predictive satellite map to deliver improved predictions of biomass density at a 1 resolution throughout the Pacific states of California, Oregon and Washington. The model accounts for zero‐inflation in the field measurements and the heterogeneous errors in the satellite predictions. A stochastic partial differential equation approach to spatial modeling is applied to handle the magnitude of the satellite data. The spatial detail rendered by the model is much finer than would be possible with the field measurements alone, and the model provides substantial noise‐filtering and bias‐correction to the satellite map.

Comparison of direct magnetic field measurements in a sunspot by ten spectral lines of Fe I, Fe II, Ti I and Ti II

Comparison of direct magnetic field measurements in a sunspot by ten spectral lines of Fe I, Fe II, Ti I and Ti II

Study on the Interface Reinforcement Effect of Bamboo Grid in Filled Loess Embankment in a High and Steep Gully

A bamboo grid is a new type of reinforcement material, which can replace traditional geogrids in the reinforcement of embankments. In this study, the reinforcement effect of the bamboo grid that is only set at the interface between the filled and undisturbed soils of the filled loess embankment in a high and steep gully was investigated. The influence of reinforcement position and grid spacing on the reinforcement effect was studied by carrying out a large-scale direct shear test, numerical simulation, and field measurement. The results indicated that the bamboo grid could enhance the shear strength of the reinforcement interface. The interface shear strength first improved and then decreased with the decrease in grid spacing. The differential settlement was significantly reduced after the reinforcement of the bamboo grid at the interface. Compared with other reinforcement positions, setting the bamboo grid in the upper part of the embankment was the most efficient and economical. When the grid spacing became dense, the reinforcement effect was improved as the differential settlement decreased. However, the improvement in the reinforcement effect by decreasing the grid spacing was limited, which meant there was an optimal grid spacing.

Probing the magnetized gas distribution in galaxy groups and the cosmic web with POSSUM Faraday rotation measures

ABSTRACT We present initial results from the Polarization Sky Survey of the Universe’s Magnetism (POSSUM), analysing 22 817 Faraday rotation measures (RMs) with median uncertainties of 1.2 rad m$^{-2}$ across 1520 deg2 to study magnetized gas associated with 55 nearby galaxy groups ($z\lesssim 0.025$) with halo masses between $10^{12.5}$ and $10^{14.0}$ M$_\odot$. We identify two distinct gas phases: the intragroup medium (IGrM) within 0–2 splashback radii and the warm-hot intergalactic medium (WHIM) extending from 2 to 7 splashback radii. These phases enhance the standard deviation of residual (i.e. Galactic foreground RM-subtracted) RMs by $6.9\pm 1.8$ rad m$^{-2}$ and $4.2 \pm 1.2$ rad m$^{-2}$, respectively. Estimated magnetic field strengths are several μG within the IGrM and 0.1–1 μG in the WHIM. We estimate the plasma $\beta$ in both phases, and show that magnetic pressure might be more dynamically important than in the ICM of more massive clusters or sparse cosmic web filaments. Our findings indicate that ‘missing baryons’ in the WHIM likely extend beyond the gravitational radii of group-mass haloes to Mpc scales, consistent with large-scale, outflow-driven ‘magnetized bubbles’ seen in cosmological simulations. We demonstrate that RM grids are an effective method for detecting magnetized thermal gas at galaxy group interfaces and within the cosmic web. This approach complements X-ray and Sunyaev-Zel’dovich effect methods, and when combined with fast radio burst dispersion measures, data from the full POSSUM survey – comprising approximately a million RMs – will allow direct magnetic field measurements to further our understanding of baryon circulation in these environments and the magnetized universe.

Differential Rotation of CoRoT Stars and a Kepler Binary Star from Starspot Transit Mapping

Abstract While direct magnetic field measurements are rare for slowly rotating stars, spots observed during planetary transits provide a potential indicator of magnetic activity on stellar surfaces. Moreover, the rotation of the stellar surface can be probed by monitoring the spots’ position with time in subsequent transits. This study investigates the dynamic interplay of rotational shear and stellar rotation rate in six stars of spectral types F to M, all hosting exoplanets observed by the CoRoT space mission, except for one binary star from Kepler. The analysis, facilitated by the ECLIPSE code, unveils the physical properties of stellar spots, including radius, intensity, temperature, and position. The five CoRoT stars exhibit spot characteristics consistent with those observed in solar type stars. The determination of a spot longitude during different transits allows for the inference of the star’s differential rotation profile, revealing a decreasing trend of rotational shear with the mean stellar rotation period, given by Δ Ω ∝ P ¯ − 0.9 . This implies that, at least for slow rotators (mean rotation period >5 days), as stars age, their differential rotation decreases. Additionally, the six stars analyzed here seem to fall into two categories, according to their spot flux deficit: those with ΔF spot > 0.005 and those with ΔF spot < 0.002.

Direct measurement of multi-angle evanescent field by whispering gallery mode of the microsphere and fluorescent spots in an optical waveguide fluorescence microscopy

Evanescent field (EF) has been widely applied in various micro-imaging techniques for its ability to excite surfaces. However, measuring the multi-angle EF remains challenging. In this paper, the whispering gallery mode (WGM) is observed in an excited microsphere on an optical waveguide (OWG) with a thickness of 0.6 mm, which is used to determine the diameter of the excited microsphere. A simple and nondestructive measurement method for multi-angle OWG-EF is proposed, which is based on the reliable diameter of the microsphere, determined by WGM and the TIRF spots. The measurement result for multi-angle OWG-EF shows a dynamic range between ∼180 and ∼2400 nm, which shows good agreement with the simulation results. The method synchronization possible for EF measurements and fluorescent experiments.

First attempt to measure macroplastic fragmentation in rivers

Direct field measurements of macroplastic fragmentation during its transport in rivers are currently unavailable, and there is no established method to perform them. Previous studies have showed that macroplastic fragmentation results in the production of harmful microplastics, and river channels can be hotspots for this process. Therefore, obtaining information about this process is crucial for quantifying the production of secondary microplastics in rivers and assessing the related risks for riverine biota and human health. Here, we propose a simple low-cost methodology for quantifying riverine macroplastic fragmentation by conducting repeated measurements of the mass of tagged macroplastic items before and after their transport in the river. As a proof-of-concept for this method, we conducted a 52–65 day experiment that allowed us to measure a median fragmentation rate of 0.044 ± 0.012 g for 1-liter PET bottles during their transport at low to medium flow in the middle mountain Skawa River in the Polish Carpathians. Using the obtained data (n = 42), we extrapolated that during low to medium flows, the median yearly mass loss of PET bottles in the study section is 0.26 ± 0.012 g/year (0.78 ± 0.036 % of bottle mass), and the median rate of bottle surface degradation is 3.13 ± 0.14 μm/year. These estimates suggest a relatively high fragmentation rate for a PET bottle in a mountain river even under low to medium flow conditions without high-energy transport. We discuss how our simple and relatively low-cost methodology can be flexibly adapted and future optimized to quantify macroplastic fragmentation in various types of rivers and their compartments, informing future mitigation efforts about the rates of formation and dispersion of secondary microplastics.

Invasive neophytes alter ecological functions and services of riparian hardwood forests

Riparian hardwood forests, now rare in Europe, occur in small patches within agricultural landscapes and are important biodiversity hotspots protected by the EU Habitats Directive and monitored. They play a vital ecological role and provide essential ecosystem services (ES). Recent studies indicate their unfavourable conservation status with a negative trend reported by EU Member States. One of the most visible symptoms of the degradation of riparian hardwood forest is the invasion of alien plant species which can radically change ecosystem functions. In this work, we use plant functional trait analysis to develop proxies and quantify an impact of invasive alien species, specifically invasive neophytes, on specific functions of riparian hardwood forests and their potential to provide five relevant regulating services. Data from 249 phytosociological relevés across 83 Natura 2000 habitat monitoring sites in Poland were analyzed.Our findings indicate that invasive neophytes negatively affect the potential for maintaining nursery populations and habitats, as well as regulation of the chemical condition of freshwaters by these forests. On the other hand, they do not significantly influence the local climate conditions and the forests’ potential to produce antimicrobial compounds. We recommend integrating an ES assessment based on plant functional traits into habitat monitoring. This approach is cost-effective, leveraging existing data, and its results could be used in some cases as a premise for initiating additional environmental monitoring based on direct field measurements.

Quantifying form resistance is essential for estimating summer low and bankfull flow from stream survey channel morphology

Reliable estimates of low flow and flood discharge at ungaged locations are required for evaluating stream flow alteration, designing culverts and stream crossings, and interpreting regional surveys of habitat and biotic condition. Very few stream gaging stations are located on small, remote streams, which typically have complex channel morphology. Adequate gaging is also lacking on larger streams that are remote, smaller than those typically gaged, or have channel morphology not conducive to installation of gages. Complex channels typically contain large scale hydraulic roughness elements that dominate flow patterns (i.e., form roughness), making it difficult to measure channel cross-section area and water velocity, or to measure channel volume even where discharge is known. In channels with large channel form roughness, it is equally difficult to estimate discharge using commonly applied equations based on slope and channel dimensions or basin area. We employed a novel approach that explicitly accounts for hydraulic resistance from large wood and riffle-pool morphology (form roughness) in calculating low flow and bankfull discharge from stream and river physical habitat data collected from 4229 stream and river sites in the conterminous US (CONUS) sampled in 2008–9 and 2013–14 as part of the US Environmental Protection Agency's National Rivers and Streams Assessment (NRSA). Hydraulic resistance derived from form roughness clearly dominated resistance derived from bed particles (particle resistance) during summer low flows in wadeable streams across the spectrum of channel slopes and substrate sizes smaller than boulders. Under bankfull conditions, the influence of form resistance relative to particle resistance was diminished, but form resistance still dominated except in large low gradient rivers lacking complex channels, and in streams or rivers with boulder-size bed particles. We validated our hydraulic resistance estimates by comparing measured discharges with calculated discharges that used those hydraulic resistance estimates along with measured NRSA channel morphology data. Morphology-based summer discharge (low flow) estimates and direct field measurements of discharge in 2333 wadeable CONUS streams showed reasonable agreement (median difference < 2.5×) for discharges ranging from 3.6 × 10−5 to 123 m3/s and drainage areas of 0.12 to 171,000 km2. In a subset of 759 of NRSA's larger wadeable stream and non-wadeable river sites where nearby U.S. Geological Survey (USGS) gage data were available and adequate, our morphology-based summer discharge estimates agreed fairly well (median difference < 2.0×) with USGS 20-yr average August mean flows ranging from 0.003 to 16,000 m3/s. Similarly, morphology-based estimates of bankfull flow ranging from 0.3 to 100,000 m3/s agreed reasonably well with the 1.5-yr recurrence interval flood in these gaged sites (median deviation <2.2×). These findings demonstrate the importance of quantifying flow resistance from large-scale form roughness features in natural channels and provide a novel approach for estimating discharge from widely available survey data. This will allow examination of discharge and its ecological influence across the full range of stream and river sizes sampled by NRSA or other synoptic surveys where comprehensive measures of biota, physical habitat, and chemistry are also made. Although these morphology-based estimates exhibit some variability, they are adequate for examining regional patterns in discharge and flow alteration and their association with instream biota and anthropogenic disturbances, providing summer low and bankfull flow information where reliable estimates are lacking.

Estimating the soil water retention curve by the HYPROP-WP4C system, HYPROP-based PCNN-PTF and inverse modeling using HYDRUS-1D

Due to the difficulty of direct field measurement, soil hydraulic properties are often obtained in laboratory settings using small undisturbed soil samples or estimated indirectly through pedotransfer functions (PTFs). The pseudo-continuous pedotransfer function (PCNN-PTF) is a neural network-based approach for estimating soil hydraulic properties. The main objective of this study was to use field soil moisture and tension data to assess soil water retention curves obtained from the HYPROP-WP4C system and the HYPROP-based PCNN-PTF. The in-situ soil water retention data were simultaneously acquired using Acclima TDT and MeterGroup MPS-6 sensors (every 30 min, May to September 2020) from 11 hybrid bermudagrass plots under different irrigation treatments in Riverside, California. We utilized extended evaporation and dewpoint methods using HYPROP-WP4C (Meter Group Inc., USA) devices to obtain lab-measured SWRCs. In addition, SWRCs were estimated from Rosetta (Schaap et al., 2001) and by inverse modeling in HYDRUS-1D utilizing in-situ moisture retention data. Although the hysteresis impacted field data, overall, there was a good agreement between the in-situ and lab water retention data for most samples, especially within the pF range of 2–3.5. The PCNN-PTF outperformed Rosetta in estimating laboratory (RMSE=0.034 cm3 cm−3 vs 0.063 cm3 cm−3) and in-situ soil moisture data (RMSE=0.048 cm3 cm−3 vs 0.082 cm3 cm−3). Inverse modeling of in-situ data also performed well in estimating the SWRC (RMSE=0.043 cm3 cm−3); however, further attention is required in dry and saturated soil conditions. We developed a simple, free, and easy-to-access tool called PC-PTF for estimating the SWRC using the PCNN-PTF model evaluated in this study. The PC-PTF can be accessed from the Verdi Water Management Group website: http://www.ucrwater.com/software-and-tools.html.

Handheld In Situ Methods for Soil Organic Carbon Assessment

Soil organic carbon (SOC) assessment is crucial for evaluating soil health and supporting carbon sequestration efforts. Traditional methods like wet digestion and dry combustion are time-consuming and labor-intensive, necessitating the development of non-destructive, cost-efficient, and real-time in situ measurements. This review focuses on handheld in situ methodologies for SOC estimation, underscoring their practicality and reasonable accuracy. Spectroscopic techniques, like visible and near-infrared, mid-infrared, laser-induced breakdown spectroscopy, and inelastic neutron scattering each offer unique advantages. Preprocessing techniques, such as external parameter orthogonalization and standard normal variate, are employed to eliminate soil moisture content and particle size effects on SOC estimation. Calibration methods, like partial least squares regression and support vector machine, establish relationships between spectral reflectance, soil properties, and SOC. Among the 32 studies selected in this review, 14 exhibited a coefficient of determination (R2) of 0.80 or higher, indicating the potential for accurate SOC content estimation using in situ approaches. Each study meticulously adjusted factors such as spectral range, pretreatment method, and calibration model to improve the accuracy of SOC content, highlighting both the methodological diversity and a continuous pursuit of precision in direct field measurements. Continued research and validation are imperative to ensure accurate in situ SOC assessment across diverse environments. Thus, this review underscores the potential of handheld devices for in situ SOC estimation with good accuracy and leveraging factors that influence its precision. Crucial for optimizing carbon farming, these devices offer real-time soil measurements, empowering land managers to enhance carbon sequestration and promote sustainable land management across diverse agricultural landscapes.

Morphometric characteristics of Lake Limboto as critical lake in Gorontalo Province, Indonesia

This research aims to investigate the factors leading to siltation in Lake Limboto by analyzing its morphometric characteristics gathered through direct field measurements and remote sensing using Geographic Information System (GIS). Lake Limboto covers an approximate surface area of 26.09 square kilometers, boasts a maximum depth of 4 meters, and maintains an average depth of 2.83 meters. The Shoreline Development Index (SDI) stands at approximately 2.57, indicating an irregular shape of the lake's water body, while the Lake Volume Development (VD) index, at 2.12, suggests a generally flat lake bottom. The Relative Depth (Zr) registers at around 0.69%, as observed from the water turbidity level. The lakebed relief in the vicinity of the lake's periphery is predominantly flat and shallow, particularly in the western, northern, and southern regions, with depths measuring less than 2 meters. In contrast, the lakebed relief in the central and eastern sections tends to be less flat but still features depths of less than 4 meters. Siltation in Lake Limboto primarily results from high sediment input originating from erosion processes, agricultural activities, and settlements in the surrounding area.

Hydrogeological parameterisation of the Daruvar thermal aquifer: integration of fracture network analysis and well testing

Highly fractured Mesozoic carbonate rocks are the main reservoir of many geothermal resources in northern Croatia, being of environmental, cultural, and economic value for the local and regional communities. The Daruvar thermal springs (temperatures &lt; 50°C) represent the outflow area of an intermediate scale, tectonically controlled, hydrothermal system hosted in Triassic carbonate rocks. Several investigations have been conducted in the Daruvar area detailing the architecture of regional and local fracture networks and quantifying the hydrogeological parameters of the thermal aquifer. In this work, an integrated approach based on structural and hydrogeological investigations was employed to model the network of fractures in the reservoir and quantify its impact on the hydraulic properties. Structural investigations were conducted in the Batinjska Rijeka quarry, considered as an outcrop analogue of the thermal aquifer, employing both a classical field approach and the virtual quantitative analysis of a 3D digital outcrop model. Structural analysis of the digital outcrop model allowed identification of two sub-vertical systems of discontinuities, dipping to the NW and the WSW respectively, in accordance with the data collected through direct field measurements. The main geometric features of the discontinuity network and their statistical distributions were employed to construct discrete fracture network models at both the outcrop scale (approximately 100 m) and the aquifer scale in Daruvar (approximately 700 m). Calibration of the input parameters allowed modelling of porosity and permeability values that reproduce the field values assessed through pumping tests, well tests, and well logging. This work highlights the importance of integrating geological and hydrogeological investigations to obtain a more reliable reconstruction and quantification of the processes driving the fluid flow in fractured aquifers and affecting the spatial distribution of their hydraulic properties.

Menjelajahi Geografi melalui Pembelajaran Berbasis Proyek: Integrasi Pengukuran dan Pemetaan dalam Pembuatan Maket

Project-based learning has been implemented at Karangturi High School in Geography teaching for 10th-grade students, covering basic geography concepts and basic mapping materials. This project involves collaboration with the Physics subject in the measurement material. The focal point of this project is the creation of a school garden scale model, starting with direct field measurements as part of outdoor learning implementation. The dimensions of the garden are then calculated using a predetermined scale, and the garden model is constructed accordingly. This approach not only introduces basic geography concepts and basic mapping but also integrates physics concepts in measurement and scale. Through this project, students not only learn theory but also apply it directly in real-world contexts, enhancing their understanding of geography concepts and practical skills such as measurement and model making. Research findings indicate that this project-based learning in Geography is effective in improving students' understanding of basic geography concepts, basic mapping, and measurement, as well as enhancing their engagement and learning motivation. Practical implications of this research suggest that project-based learning approaches can be beneficial strategies in enhancing the effectiveness of Geography education in high schools, by integrating various subjects and encouraging active student engagement through engaging and relevant learning experiences.