Water Depth Data Research Articles

Effect of surcharge on gully-manhole flow

In an urban drainage system, surface system and buried system are connected through several linking elements like gullies and manholes. To model an urban flood through a 1D or 2D routing model, proper representation of these linking elements is mandatory. This paper focuses on the effects on inline manhole head loss coefficient and gully flow due to change in manhole surcharges to get knowledge of their characteristics, flow patterns and influence in the overall flow. The solver interFoam with VOF capability under open source CFD toolbox OpenFOAM® is used for the numerical simulations. The CFD model created is a real scale model following the experimental setup installed at the University of Coimbra. The CFD model results were compared with discharge and water depth data at the manhole and velocity data at the gully, measured from the physical model. The manhole head loss coefficient was found very high at low surcharge level and reaching a constant value of 0.3 for higher surcharge levels. The gully flow was found to follow typical orifice flow equation with different discharge coefficients for different water depth conditions of the manhole. Three different surcharged zones were identified at the manhole on which discharge coefficients are dependent. The shear stress pattern at the manhole floor is also found varying due to surcharge depth as well as the gully flow. The variation showed distinctive configuration at different surcharge zones.

Derivation of Bathymetry from High-resolution Optical Satellite Imagery and USV Sounding Data

ABSTRACTRemote sensing bathymetry inversion can quickly obtain water depth data of large areas, but this process relies on a large number of in-situ depth data points. USV-based (Unmanned Surface Vehicle) technique can obtain the bathymetry data of shallow water where ordinary ships are inaccessible, but this technique is inefficient and generally only data along survey line can be collected. The combination of USV and high-resolution remote sensing provides a new solution for water depth surveying and mapping around an island. This paper focuses on the key techniques, using USV sounding data and GeoEye-1 multispectral remote sensing images covering the region of Wuzhizhou island in the experiment. The results show that the MAE (Mean Absolute Error) of USV sounding is 0.25 m, while the MRE (Mean Relative Error) is 1.41%, and the MRE of remote sensing bathymetry aided by USV sounding can be controlled within 20%. Errors are mainly from areas shallower than 5 m, and are also affected by the USV sounding position accuracy. It shows that it is feasible to combine the USV sounding and high-resolution remote sensing bathymetry, and this technique has broad application prospects in the field of bathymetry in large shallow areas.

Improved structure of vertical flow velocity distribution in natural rivers based on mean vertical profile velocity and relative water depth

Abstract Logarithmic, power, and parabolic distribution laws were proven to be efficient for the prediction of vertical velocity distribution. Traditionally, the distribution formulas involve the friction velocity (u*) and the depth (y) of the measurement point. The low availability of friction velocity and limitation of real water depth data hindered the promotion and comparison of the available flow velocity formulas. In this paper, we proposed a new formula structure adopting a relative flow velocity based on mean vertical velocity (u/ū) and dimensionless relative water depth (y/H). The observations showed the following. (1) The substitution of u* and y with u/ū and y/H were reliable and applicable. Parabolic logarithmic and power fitting curves worked well, with an error of 7%, 10%, and 11%, respectively. (2) In water depth direction, the predicted results of the middle depth of the vertical profiles tend to be more reliable and precise. The highest estimated error appeared in the area near the water surface. (3) Higher catchment slope resulted in larger coefficients and constants in logarithmic and power fitting. (4) In the rivers with higher width-to-depth ratio, the maximum profile velocity occurred closer to the water surface, and mean profile velocity tended to happen more at the bottom.

A spatial resolution effect analysis of remote sensing bathymetry

A spatial resolution effect of remote sensing bathymetry is an important scientific problem. The in situ measured water depth data and images of Dongdao Island are used to study the effect of water depth inversion from different spatial resolution remote sensing images. The research experiments are divided into five groups including QuickBird and WorldView-2 remote sensing images with their original spatial resolution (2.4/2.0 m) and four kinds of reducing spatial resolution (4, 8, 16 and 32 m), and the water depth control and checking points are set up to carry out remote sensing water depth inversion. The experiment results indicate that the accuracy of the water depth remote sensing inversion increases first as the spatial resolution decreases from 2.4/2.0 to 4, 8 and 16 m. And then the accuracy decreases along with the decreasing spatial resolution. When the spatial resolution of the image is 16 m, the inversion error is minimum. In this case, when the spatial resolution of the remote sensing image is 16 m, the mean relative errors (MRE) of QuickBird and WorldView-2 bathymetry are 21.2% and 13.1%, compared with the maximum error are decreased by 14.7% and 2.9% respectively; the mean absolute errors (MAE) are 2.0 and 1.4 m, compared with the maximum are decreased by 1.0 and 0.5 m respectively. The results provide an important reference for the selection of remote sensing data in the study and application of the remote sensing bathymetry.

NUMERICAL STUDY ON THE INFLUENCE OF INFILTRATION ON SWASH HYDRODYNAMICS AND SEDIMENT TRANSPORT IN THE SWASH ZONE

Infiltration and exfiltration processes have a significant influence on the hydrodynamics of the swash zone. Such processes need to be taken into account in the modelling of cross-shore sediment transport and the prediction of beach profile evolution. This paper presents a numerical study of the swash hydrodynamics using a 2D Volume-Averaged Reynolds-Averaged Navier-Stokes model, which was calibrated and validated against new experimental data. The model was used to simulate wave run-up from regular waves over permeable and impermeable fixed slopes. Swash flow velocities and water depth data were obtained from the simulations and used to estimate bed shear stresses at three different locations on the beach slope. The results show that infiltration can have opposing effects on the bed shear stress when compared to equivalent swash on an impermeable slope. During the uprush phase, stresses are directly increased due to boundary layer thinning, whereas, during the backwash phase, there is a significant reduction of flow leading to a decrease in the bed shear stresses.

Classifying the sedimentary environments of the Xincun Lagoon, Hainan Island, by system cluster and principal component analyses

An understanding of the sedimentary environment in relation to its controlling factors is of great importance in coastal geomorphology, ecology, tourism and aquaculture studies. We attempt to deal with this issue, using a case study from the Xincun Lagoon, Hainan Island in southern China. For the study, surficial sediment samples were collected, together with hydrodynamic and bathymetric surveys, during August 2013. Numerical simulation was carried out to obtain high-spatial resolution tidal current data. The sediment samples were analyzed to derive mean grain size, sorting coefficient, skewness and kurtosis, together with the sand, silt and clay contents. The modern sedimentary environments were classified using system cluster and principal component analyses. Grain size analysis reveals that the sediments are characterized by extremely slightly sandy silty mud (ESSSM) and slightly silty sand (SSS), which are distributed in the central lagoon and near-shore shallow water areas, respectively. Mean grain size varies from 0 to 8.0Ф, with an average of 4.6Ф. The silt content is the highest, i.e., 52% on average, with the average contents of sand and clay being 43% and 5%, respectively. There exists a significant correlation between mean size and water depth, suggesting that the surficial sediments become finer with increasing water depth. Cluster analyses reveals two groups of samples. The first group is characterized by mean grain size of more than 5.5Ф, whilst the second group has mean grain size of below 3.5Ф. Further, these groups also have different correlations between mean grain size and the other grain size parameters. In terms of the tidal current, the average values of the root mean square velocity (RMSV) are 7.5 cm/s and 6.9 cm/s on springs and neaps, respectively. For the RMSVs that are higher than 4 cm/s, a significant positive correlation is found between the content of the 63–125 μm fraction and the RMSV, suggesting that the RMSV determines the variability of the very fine sand fraction. Based on system cluster and principal component analyses (PCA), the modern sedimentary environments are classified into three types according to the grain size parameters, RMSVs and water depth data. The results suggest the importance of grain size parameters and high-spatial resolution hydrodynamic data in differentiating the coastal sedimentary environments.

Passive acoustic monitoring of bed load discharge in a large gravel bed river

AbstractSurrogate technologies to monitor bed load discharge have been developed to supplement and ultimately take over traditional direct methods. Our research deals with passive acoustic monitoring of bed load flux using a hydrophone continuously deployed near a river bed. This passive acoustic technology senses any acoustic waves propagated in the river environment and particularly the sound due to interparticle collisions emitted during bed load movement. A data set has been acquired in the large Alpine gravel‐bedded Drau River. Analysis of the short‐term frequency response of acoustic signals allows us to determine the origin of recorded noises and to consider their frequency variations. Results are compared with ancillary field data of water depth and bed load transport inferred from the signals of a geophone array. Hydrophone and geophone signals are well correlated. Thanks to the large network of deployed geophones, analysis of the spatial resolution of hydrophone measurements shows that the sensor is sensitive to bed load motion not only locally but over distances of 5–10 m (10–20% of river width). Our results are promising in terms of the potential use of hydrophones for monitoring bed load transport in large gravel bed rivers: acoustic signals represent a large river bed area, rather than being local; hydrophones can be installed in large floods; they can be deployed at a low cost and provide continuous monitoring at high temporal resolution.

南海新生代地壳减薄特征分析

拉伸因子β是直接反映地壳减薄程度的参数。为了分析南海新生代以来地壳减薄特征，对比南、北部的差异性演化，利用网格密度为1˚ × 1˚全球地壳模型CRUST 1.0提供的南海地壳厚度数据，结合NGDC提供的水深数据，在假设南海拉伸前的地壳厚度为32 km的基础上，通过地壳减薄量计算了拉伸因子β，并绘制了南海拉伸因子分布图。拉伸因子计算结果介于1~4.2之间，其中最大值在南海南部的双子群礁附近取得，最小值分布在北部湾陆架。拉伸因子β的分布规律表明南海南部减薄程度靠近海盆突然增强，北部则是由陆架至海盆逐渐加强；总体而言，南海北部减薄程度大于南部减薄程度，西部减薄程度最低。 The stretching factor β is a parameter which directly reflects the extent of crustal thinning. In order to analyze the characteristics of crustal thinning in the South China Sea, β is calculated by the crustal thinning. Applying the continental crustal model of the global crustal model CRUST 1.0 with the grid of 1˚ × 1˚, combined with the water depth data from NGDC and on the assumption that the crustal thickness is 32 km, the distribution of β in the South China Sea is analyzed. The results of β are between 1 and 4.2; the maximum is obtained in the vicinity of the Gemini reefs in the southern South China Sea, and the minimum is distributed in the Beibu Gulf shelf. The distribution of β indicates that the degree of thinning in the southern part of the South China Sea is gradually enhanced near the basin, and the northern part is gradually strengthened from the shelf to the ba-sin. Overall, the degree of thinning in the northern part of the South China Sea is greater than that in the south.

基于阵列代数的测深数据拟合方法

传统水深测量涉及到大量离散的、分布不规则的水深数据，针对传统拟合方法计算复杂、速度慢的问题，该文将阵列代数思想应用于测深网格拟合。以双二次多项式拟合为例，建立了阵列代数最小二乘解模型，给出了基于正规方程的双二次矩阵方程的最小二乘解法；给出了改进拟合法实现的基本步骤，最后通过实验数据对反距离加权法、全局多项式法及阵列代数最小二乘拟合方法求得未知点水深的效率及精度进行比较。结果表明，在水深测量中引入阵列代数拟合结果效率要高于另外两种方法，可应用于水深测量数据网格化处理中。 The traditional bathymetric survey involves a large number of discrete, irregularly distributed wa-ter depth data. In order to solve the problem of complex calculation and slow speed of traditional fitting method, the idea of array algebra is applied to the fitting of the sounding grid. The least squares solution of the array algebra is established by taking the biquadratic polynomial fitting as an example, and the least square solution of the quadratic matrix equation with the help of the normal equation is given. Moreover, the paper gives the basic steps to achieve the improved quasi legal, efficiency and accuracy of the experimental data to determine unknown point water depth on the inverse distance weighted method, global polynomial interpolation and least square fitting method of array algebra is compared. The results show that the efficiency of array algebra fitting is better than that of the other two methods, and can be applied to the data processing of hydrology survey.

Hydrodynamic Modeling of Nokoué Lake in Benin

Nokoué Lake is a complex ecosystem, the understanding of which requires control of physical processes that have occurred. For this, the Surface Water Modeling System (SMS) hydrodynamic model was calibrated and validated on the water depth data. The results of these simulations show a good match between the simulated and observed data for bottom roughness and turbulent exchange coefficients, of 0.02 m−1/3·s and 20 m2/s respectively. Once the ability of the model to simulate the hydrodynamics of the lake is testified, the model is used to simulate water surface elevation, exchanged flows and velocities. The simulation shows that the tidal amplitude is maximum at the inlet of the channel and decreases gradually from the inlet towards the lagoon’s main body. The propagation of the tidal wave is characterized by the dephasing and the flattening of the amplitude tide, which increases as we move away from the channel. This dephasing is characterized by a high and low tides delay of about 1 or 4 h and also depends on the tide amplitude and location. The velocities inside the lake are very low and do not exceed 0.03 m/s. The highest are obtained at the entrance of the channel. In a flood period, in contrast with the low-water period, incoming flows are higher than outflows, reinforced by the amplitude of the tide. An average renewal time of the lake has been estimated and corresponds during a flood period to 30 days for an average amplitude tide and 26.3 days on a high amplitude tide. In a low water period it is 40.2 days for an average amplitude tide and 30 days for a high amplitude tide. From the results obtained, several measures must be taken into account for the rational management of the lake water resources. These include a dam construction at the lake upstream, to control the river flows, and the dredging of the channel to facilitate exchanges with the sea.

Detection of Seabed Rock Using Airborne Bathymetric Lidar and Hyperspectral Data in the East Sea Coastal Area

The distribution of seabed rock in the coastal area is relevant to navigation safety and development of ocean resources where it is an essential hydrographic measurement. Currently, the distribution of seabed rock relies on interpretations of water depth data or point based bottom materials survey methods, which have low efficiency. This study uses the airborne bathymetric Lidar data and the hyperspectral image to detect seabed rock in the coastal area of the East Sea. Airborne bathymetric Lidar data detected seabed rocks with texture information that provided 88% accuracy and 24% commission error. Using the airborne hyperspectral image, a classification result of rock and sand gave 79% accuracy, 11% commission error and 7% omission error. The texture data and hyperspectral image were fused to overcome the limitations of individual data. The classification result using fused data showed an improved result with 96% accuracy, 6% commission error and 1% omission error.

Sentinel-1 bathymetry for North Sea palaeolandscape analysis

ABSTRACTSubmerged palaeolandscapes can contain pristine underwater heritage. Regular monitoring of these areas is essential to assess and mitigate threats from development including construction, mining, and commercial trawling. While bathymetry alone may be insufficient to detect submerged palaeolandscape features, it can nonetheless recognize previously mapped structures that have a topographic expression. The Sentinel-1 constellation will provide unprecedented access to freely available, high-resolution Synthetic Aperture Radar (SAR) data, acquired systematically and with long-term continuity, and may constitute a cost-effective solution for the monitoring of submerged palaeolandscapes. The article shows the application of a recently developed bathymetric algorithm to Sentinel-1 SAR data over a region of the southern North Sea. Results show general agreement with water depth data obtained from the European Marine Observation and Data Network portal for bathymetry (EMODnet). To assess the support that SAR bathymetry can provide to the analysis of submerged palaeolandscapes, the Sentinel-1-derived water depths were compared to a palaeolandscape map of the same area produced by the North Sea Palaeolandscapes Project (NSPP). Results show a clear correspondence between certain topographic structures identified in the Sentinel-1 water depth map and features interpreted by the NSPP as early Holocene lakes, rivers, and landscape topography.

The Effects of Dredging on Tidal Range and Saltwater Intrusion in the Pearl River Estuary

ABSTRACT Yuan, R. and Zhu, J., 2015. The effects of dredging on tidal range and saltwater intrusion in the Pearl River estuary. A dredging project in the Pearl River estuary would influence the topography, water dynamics, and mass transport process. The effects of dredging in the channel of the Pearl River estuary on tidal range and saltwater intrusion were studied using a hydrodynamic model (finite volume coastal ocean model) and historical water depth data. The measured data showed that the tidal range decreased and saltwater intrusion increased in the North River. The tidal range increased and saltwater intrusion decreased in the West River in recent decades from the 1980s. The simulations in this study showed that after dredging (1) the upstream flow split ratio in the river changed (i.e. more freshwater flowed through the Sanshui station), whereas less freshwater flowed through the Makou station; (2) the tidal range increased in the West River network and decreased in the downstream reaches of the No...

Study on the Siltation in the Intake of Nuclear Power Plant Using Longterm Water Depth Monitoring and Coupled Modeling

Scarce natural resources make it imperative for Korea to exploit nuclear power plant technology to supply energy for industrial purposes not to mention for everyday usage. Korea’s nuclear power plant started when Gori Nuclear Plant started its operation in 1978 and as of today, there are 4 nuclear plants nationwide including the Gori Nuclear Plant, making up 38.2% of all of Korea’s energy supply. Since ‘waste heat’ is generated as a result of plant operation, sea water is needed for cooling purposes and therefore plants are situated near coastal areas. However, the effect on the coastal area such as erosion, deposition, and siltation from the construction of the plant itself is subject of continuing controversy and another being the effects on the coastal environment from warm water that is produced after the cooling process. Generally, topographic change is maintained in equilibrium by the tidal currents’ reciprocating motion in the coastal areas where there are dominant tidal currents. However, artificial action on the current flow for operating a nuclear plant operation at the intake and the outlet breaks the equilibrium of the tides and this in the end results in disturbing the equilibrium condition of bottom topography. This research used the results of long term investigation data of water depth and data of flow discharge conducted inside the intake to investigate erosion and the change in siltation at the intake of the nuclear power plant. After having analyzed the changes in water depth of the intake area, the results confirmed that there are 100~140cm/year and 80~300 cm/year of excess siltation at the middle area and both sides, respectively. After artificial dredging which is conducted every two years, siltation had proceeded at a substantial pace, and after some time, the pace has slowed down to its normal rate, going towards equilibrium condition. This research used the siltation pace change acquired from monitoring results to formulate coupled model in order to predict the change of water depth which will take place due to artificial construction of the intake in the future more precisely.

Morphological evolution of the South Passage in the Changjiang (Yangtze River) estuary, China

Estuarine morphology of the world's major large rivers have experienced great changes due to intensive anthropogenic activities and natural forcings, especially in the Changjiang Estuary located at the end of the longest river in Asia. This study focuses on morphological changes of the South Passage (SP), which is one of the 4 channels in the branching estuary at the mouth of the Changjiang (Yangtze River), China. A multivariate analysis technique of Empirical Orthogonal/Eigen Function (EOF) method was used to examine the major modes of change in the long-term (over 26 years) water-depth data. The results show that the morphological changes at the SP could be divided into two stages: between 1987 and 1997, the SP had a single stable channel with closure of a cross-channel. Between 1997 and 2012, SP displayed southeastward elongation of a spit into the main channel, and westward shoal incision by a cross-channel. The opening of the SP developed a two-channel morphology, which stabilized and showed infilling during 2003–2012. The average deposition rate was 10 cm/yr. In the past 30 years, the most dominant morphological changes of SP included the deposition around the upstream opening of the channel. The second most important pattern of morphological change was related to the downstream elongation, retreat, and lateral migration of the spit of the Jiangyanan Shoal, which resulted in the two-channel configuration of the SP. Additionally, these morphological changes were not triggered by the decline of the distal sediment source from the upstream, but due to the input of proximal sources of the shoal at the upstream opening of the SP and spill-over sediment from the North Passage via a short-cut-channel.

Predicted changes in interannual water-level fluctuations due to climate change and its implications for the vegetation of the Florida Everglades.

The number of dominant vegetation types (wet prairies, sawgrass flats, ridges and sloughs, sloughs, and tree islands) historically and currently found in the Everglades, FL, USA, as with other wetlands with standing water, appears to be primarily a function of the magnitude of interannual water-level fluctuations. Analyses of 40 years of water-depth data were used to estimate the magnitude of contemporary (baseline) water-level fluctuations in undisturbed ridge and slough landscapes. Baseline interannual water-level fluctuations above the soil surface were at least 1.5 m. Predicted changes in interannual water-level fluctuations in 2060 were examined for seven climate change scenarios. When rainfall is predicted to increase by 10 %, the wettest scenario, the interannual range of water-level fluctuation increases to 1.8 m above the soil surface in sloughs. When rainfall is predicted to decrease by 10 % and temperatures to increase by 1.5 °C, the driest scenario, the range of interannual range of water-level fluctuations is predicted to decrease to 1.2 m above the soil surface in sloughs. A change of 25-30 cm in interannual water-level fluctuations is needed to change the number of vegetation types in a wetland. This suggests that the two most extreme climate change scenarios could have a significant impact on the overall structure of wetland vegetation, i.e., the number of vegetation types or zones, found in the Everglades.

Amphibian Community Responses to Playa Restoration in the Rainwater Basin

Alterations to wetland hydrology associated with conversion of grassland watersheds to croplands can alter functional components that drive many wetland ecosystem services. Biodiversity provisioning is one of many services that can be negatively impacted by grassland conversions. Our objective was to compare amphibian communities of playa wetlands in native grassland versus cropland watersheds and to determine if restoration of cropland wetlands via sediment removal improved these habitats for amphibians. We collected amphibian species richness, water depth, wetland area, and emergent plant cover data from 34 playa wetlands in 2008 and 32 playa wetlands in 2009. Playas were selected to include those within natural grassland watersheds (i.e., reference playas), cropland watersheds, and restored watersheds within the Rainwater Basin (RWB) of Nebraska. While we did not detect a difference in amphibian species richness among land-use types in 2008, in 2009 (a dry year within the RWB) amphibian species richness averaged nearly two times greater in restored playas (3.18) compared to cropland playas (1.70). Average water depth (2008 and 2009) and playa area (2008 only) were best predictors of amphibian species richness. Restored playas provided the most reliable water availability for amphibians in the RWB where 90 % of the wetlands have been drained.

Origin of Taiwan Canyon and its effects on deepwater sediment

The continental slope of the Taiwan Shoal, which has cultivated numerous submarine canyons, is located in a passive continental margin environment. However, the trend of the Taiwan Canyon, with its 45° intersection angle, is obviously different from that of the erosion valley downward along the continental slope. A distinct break is present in the lower segment of the Taiwan Canyon, which then extends from west to east parallel to the continental slope until finally joining the Manila Trench. By utilizing multiple-beam water depth data, high-resolution seismic data, and sediment cores, this study describes the topographic characteristics of the Taiwan Canyon and provides a preliminary discussion on the origin of the Taiwan Canyon and its effect on deepwater sediment. The terrain, landform, and sediment of the Taiwan Canyon exhibit segmentation characteristics. The upper segment is characterized primarily by erosion, downward cutting with a V shape, and wide development of sliding, slumping, and other gravity flow types. The middle segment is characterized mostly by U-shaped erosion-sedimentation transition and development of an inner levee. The lower segment is characterized primarily by sedimentation and development of a sediment wave. The bottom current has a significant reworking effect on the interior sediments of the canyon and forms reworked sands. The formation and evolution of the Taiwan Canyon is closely related to sediment supply, gravity sliding (slumping), faulting activities, and submarine impaling. Given the sufficient terrigenous clastic supply, the sediments along the continental shelf edge continuously proceed seaward; gliding and slumping in the front edge provide driving forces for the formation of the canyon. Faulting activities result in stratum crushing, and the gravity flow takes priority in eroding the relatively fragile stratum. Thus, the direction of the extension of the canyon crosses the surrounding erosion valley obliquely. Seamounts are formed through submarine impaling. Owing to seamount blocking, the lower segment of the canyon is turned toward the east-west direction. Large amounts of sediments overflow at the turning, forming sediment waves.

Penentuan Keserataan Tanah Sawah Melalui Alat Pengukur Kedalaman Air

Land levelling is important to obtain a high yield because it can affect the germinantion and growth of rice plants. In addition, the water requirement with certain level at each stage should be treated with care to maximize the rice production. Currently the farmers use their naked eye to measure the land leveling and the result is not accurate. Therefore, a tool to measure the level of water depth and determine the status of land levelling in the fields is required. Status of land levelling is determined using water depth data obtained. The tool consists of several components such as base plate, mainframe, microcontrollers, sensors, GPS, screen display and data logger. By using 10m x 10m grid point method, the data obtained is to be generated into a levelness mapping. Therefore, the levelness map generated from this hand tool can be used to detect uneven land and aids the levelling work.

Regional prediction of basin-scale brown trout habitat suitability

Abstract. In this study we propose a novel method for the estimation of ecological indices describing the habitat suitability of brown trout (Salmo trutta). Traditional hydrological tools are coupled with an innovative regional geostatistical technique, aiming at the prediction of the brown trout habitat suitability index where partial or totally ungauged conditions occur. Several methods for the assessment of ecological indices are already proposed in the scientific literature, but the possibility of exploiting a geostatistical prediction model, such as Topological Kriging, has never been investigated before. In order to develop a regional habitat suitability model we use the habitat suitability curve, obtained from measured data of brown trout adult individuals collected in several river basins across the USA. The Top-kriging prediction model is then employed to assess the spatial correlation between upstream and downstream habitat suitability indices. The study area is the Metauro River basin, located in the central part of Italy (Marche region), for which both water depth and streamflow data were collected. The present analysis focuses on discharge values corresponding to the 0.1-, 0.5-, 0.9-empirical quantiles derived from flow-duration curves available for seven gauging stations located within the study area, for which three different suitability indices (i.e. ψ10, ψ50 and ψ90) are evaluated. The results of this preliminary analysis are encouraging showing Nash-Sutcliffe efficiencies equal to 0.52, 0.65, and 0.69, respectively.