Wave Height Distribution Research Articles

Wave Height Interval Distribution Method Based on Nonlinear Shallow Water Wave Function

Li, X.; Zhao, Y., and Jin, H., 2020. Wave height interval distribution method based on nonlinear shallow water wave function. In: Yang, Y.; Mi, C.; Zhao, L., and Lam, S. (eds.), Global Topics and New Trends in Coastal Research: Port, Coastal and Ocean Engineering. Journal of Coastal Research, Special Issue No. 103, pp. 843–846. Coconut Creek (Florida), ISSN 0749-0208.In order to improve the ability to analyze and judge the interval distribution of wave height, it is necessary to estimate the interval distribution of wave height. An interval distribution estimation method of wave height based on nonlinear shallow water wave function is proposed. A statistical time series analysis model for estimating the interval distribution of sea wave height is constructed, large data mining and feature extraction for estimating the interval distribution of sea wave height are carried out by adopting a large data feature detection method, ordered clustering of statistical feature sequences of the interval distribution of sea wave height is carried out based on a nonlinear shallow water wave function estimation idea, information clustering and attribute merging in the process of estimating the interval distribution of sea wave height are carried out by combining a fuzzy C-means clustering analysis method. The feature quantity of association rules of statistical time series of wave height interval distribution is extracted, and the association rule set of statistical time series of wave height interval distribution is analyzed by using principal component analysis method, so as to realize accurate estimation of wave height interval distribution quantity in weighted Markov chain. The simulation results show that the method has high accuracy in estimating the interval distribution of wave height and improves the quantitative analysis capability of the interval distribution of wave height.

Bivariate regional extreme value analysis for significant wave height and wave period

This paper presents a bivariate regional frequency analysis applied to vectors of extreme significant wave heights and concurrent zero up-crossing wave period over an area in the North Atlantic ocean. The analysis is based on a bivariate index-wave/period approach and the assumption of a common regional growth curve within homogeneous regions. The main benefits of performing a regional frequency analysis as opposed to at-site analysis based on data from one location only are twofold: It may give more accurate predictions of extreme conditions due to the increased amount of data made available for the statistical analysis, and results for ungauged locations can be obtained easily by interpolation of the index wave/period. Previous regional frequency analyses for ocean waves have been restricted to the univariate case. However, design conditions for marine and coastal structures will typically be characterised by the joint distribution of several metocean variables. Hence, it is useful to perform multivariate analyses of the extreme ocean environment. As a minimum, information about the joint distribution of significant wave height and period is often needed. This paper outlines the various steps involved in a bivariate regional frequency analysis and presents the results of such an analysis applied to data covering the North Atlantic ocean over a period of 30 years.

Wave characteristics in the nearshore waters of Sanmen bay

The wave characteristics in the bay of central coast of Zhejiang are studied based on the AWAC-measured data for 1 year off Sanmen at 7.5 m water depth. The observed wave parameters are analyzed by statistical analysis and linear regression analysis, and moreover the variations of wave parameters and wave spectra in Sanmen Bay under the influence of typhoon are discussed. The results show that: The dominant wave direction and the strong wave direction are both E due to the topography of Sanmen Bay, while the one-tenth wave height (H1/10) is mainly under 0.8 m with a typical Rayleigh distribution of wave height. Due to the influence of typhoon Talim, the maximum wave height (Hmax) of 2.71 m was observed on 14 September 2017. The wave spectra estimated during typhoon Talim are mainly double-peaked, and the sea waves are mixed waves consisting of swells and wind-seas, when the low frequency swells about 0.08 Hz are in a dominant position and the high frequency wind-seas about 0.3 Hz are relatively weak. This study will be important as reference in the design of offshore structures as well as for disaster prevention and mitigation.

Risk Analysis of Marine Environmental Elements Based on Kendall Return Period

Against the background of global warming and rising sea levels, the threat of typhoon disasters to marine engineering structures has become increasingly serious. Therefore, the research on the design standards of marine environmental elements has become an important topic. In this study, two-dimensional joint distributions of wave height and surge height, surge height and wind speed, and wave height and wind speed were constructed based on the Gumbel–Hougaard (G-H) Copula function according to the data of marine environmental elements under extreme sea conditions from Naozhou observation station in the sea waters of western Guangdong, and the Kendall return period is introduced. The joint return periods, co-occurrence return periods, and Kendall return periods of joint distributions were calculated, along with the latter’s corresponding design values of environmental elements. The results showed that the Kendall return periods and the corresponding design values are between two kinds of traditional return periods. After analysis, the conclusion is that the Kendall return period can reflect the occurrence regularity of marine hydrological events more accurately, and the design values of marine environmental elements calculated under this standard can reasonably lower the investment under the premise of ensuring structural safety. Therefore, the Kendall return period can serve as the new selection for marine engineering design and risk management.

A numerical model for simulation of near-shore waves and wave induced currents using the depth-averaged non-hydrostatic shallow water equations with an improvement of wave energy dissipation

This study proposes a numerical model based on the depth-integrated non-hydrostatic shallow water equations with an improvement of wave breaking dissipation. Firstly, studies of parameter sensitivity were carried out using the proposed numerical model for simulation of wave breaking to understand the effects of the parameters of the breaking model on wave height distribution. The simulated results of wave height near the breaking point were very sensitive to the time duration parameter of wave breaking. The best value of the onset breaking parameter is around 0.3 for the non-hydrostatic shallow water model in the simulation of wave breaking. The numerical results agreed well with the published experimental data, which confirmed the applicability of the present model to the simulation of waves in near-shore areas.

Analysis of Wave Fields under Tropical Cyclones in the South China Sea

Sun, W.; Shao, Z.; Liang, B., and Gao, H., 2020. Analysis of wave fields under tropical cyclones in the South China Sea. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 126–130. Coconut Creek (Florida), ISSN 0749-0208.The study of wave fields under extreme weather conditions, such as tropical cyclones, is becoming increasingly important for ocean engineering. In this work, wave simulation under a tropical cyclone is carried out in the South China Sea (SCS). The SWAN model is driven by the blended wind field. In this model, the wind input term and whitecapping dissipation term are specifically studied to obtain a reliable model result. During tropical cyclones Doksuri and Kai-tak in 2012, the waves are simulated in the SCS, and the simulated significant wave heights are validated by the measured data at buoys B1, B2 and B3. The validation results show that the simulated values match the measured values well. By the simulated significant wave heights, the wave field is analyzed during the tropical cyclone. In the mean and maximal conditions, the wave fields are studied with the tropical cyclone track. The maximal significant wave heights at the buoy locations are associated with the corresponding spatial distribution of significant wave heights in the SCS, which can reflect the effect of the tropical cyclone on the wave at a specified point.

The Study of Ocean Wave and Wave Power Observations by Synthetic Aperture Radar in Nearshore Waters

Wan, Y.; Zheng, C.W.; Zhang, J.; Dai, Y.; Li, L.; Qu, X., and Zhang, X., 2020. The Study of Ocean Wave and Wave Power Observations by Synthetic Aperture Radar in Nearshore Waters. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.),Air-Sea Interaction and Coastal Environments of the Maritime Polar Silk Roads.Journal of Coastal Research, Special Issue No. 99, pp. 9-15. Coconut Creek (Florida), ISSN 0749-0208.Based on 2 RADARSAT-2 SAR (Synthetic Aperture Radar) SLC (Single Look Complex) data and the cross-spectrum method, the distributions of significant wave heights and mean wave periods of ocean wave were inverted, and the distributions of the wave power density, which can represent the wave power, were calculated. Some comparisons between the results of the SAR and those of the ECMWF (European Center for Medium-Range Weather Forecasts) dataset were carried out, and the observation ability for the distribution characteristics of wave and wave power by the SAR was studied in detail. The results show that compared with buoys, which are single-point observations, and wave models, which are simulated observations, the SAR is an ideal tool for extensive wave observations in nearshore waters. The advantage of SAR observations is that some fine structure and microcosmic changes in wave and wave power can be found, which helps us understand the internal structure and transformation patterns of wave better. Therefore, the SAR showed extremely extensive application prospects in the field of wave observations. The contributions in this paper will provide some references for researchers aiming for ocean wave detection by remote sensing and promote the application level of SAR in the detection of wave and wave power.

Numerical Investigation of Irregular Waves and Induced Currents in the Modaomen, Pearl River Estuary

Liu, C.; Liang, Y.; Liu, X., and Zhang, X., 2020. Numerical investigation of irregular waves and induced currents in the Modaomen, Pearl River Estuary. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 181–188. Coconut Creek (Florida), ISSN 0749-0208.The Modaomen Estuary has evolved from a runoff-dominated to runoff-and-wave-dominated estuary; thus, waves have become an important dynamic force. However, the nearshore irregular waves and wave-induced currents in the Modaomen Estuary have not been well studied. For the first time, a coupled wave-current model was developed in which the wave properties were calculated by the hyperbolic mild-slope equation, and the flow motion was simulated using a depth-averaged shallow water equation that was modified by introducing wave radiation stresses. The computational capability of this model was well calibrated by laboratory data from published references. Subsequently, the validated model was employed to analyze the wave height distributions, flow field characteristics and residual current under irregular waves, as well as to determine the differences in the above results with the scenarios under pure wave or pure tide. The results showed that the irregular wave heights reach 0.75 m near the sand bar and its surrounding shoals, reach 0.7 m in the main channel, and are approximately 0.3 m in the wave shadow area behind the Sisha shoal, which is more powerful than that under regular waves. The effect of waves on the current at the maximum ebb tide is greater than that at the maximum flood tide, especially in the estuarine shoal zone. Compared with the current velocity under pure tide, the residual current velocity is larger, and the vortex scale and the sediment transport route are all prominent under the combined wave and tide.

Predicting wave heights for marine design by prioritizing extreme events in a global model

In the design process of marine structures like offshore wind turbines the long-term distribution of significant wave height needs to be modelled to estimate loads. This is typically done by fitting a translated Weibull distribution to wave data. However, the translated Weibull distribution often fits well at typical values, but poorly at high wave heights such that extreme loads are underestimated. Here, we analyzed wave datasets from six locations suitable for offshore wind turbines. We found that the exponentiated Weibull distribution provides better overall fit to these wave data than the translated Weibull distribution. However, when the exponentiated Weibull distribution was fitted using maximum likelihood estimation, model fit at the upper tail was sometimes still poor. Thus, to ensure good model fit at the tail, we estimated the distribution’s parameters by prioritizing observations of high wave height using weighted least squares estimation. Then, the distribution fitted well at the bulks of the six datasets (mean absolute error in the order of 0.1 m) and at the tails (mean absolute error in the order of 0.5 m). The proposed method also estimated the wave height’s 1-year return value accurately and could be used to calculate design loads for offshore wind turbines.

Numerical Analysis of Nonlinear Shoaling Process of Random Waves - Centered on the Evolution of Wave Height Distribution at the Varying Stages of Shoaling Process

항 외곽시설 ì‹ ë¢°ì„± 설계가 í•©ë¦¬ì ìœ¼ë¡œ 구현하기 위해서는 우리나라 해양환경 특성이 반영된 í™•ë¥ ëª¨í˜•ì´ 필요하며 이러한 시각에서 본 연구에서는 천 해역 í™•ë¥ ëª¨í˜• 개발을 위한 기초연구의 일부로 불규칙 파랑 천수 ê³¼ì •ì„ 수치 모의하였다. 수치 모의는 자연해안에서 흔히 관측되는 사주가 원빈에 형성된 해안을 대상으로 수행하였으며 파랑모형은 spatially filtered Navier-Stokes Eq., LES[Large Eddy Simulation], one equation dynamic Smagorinsky turbulence closure 등으로 구성하였다. 불규칙 파랑은 우리나라 동해안에서 관측되는 너울 특성을 반영하기 위해 다양한 첨두 증강계수를 지니는 JONSWAP 스펙트럼과 random phase method를 사용하여 모의하였다. íŒŒê³ ë¶„í¬ì˜ 모수는 ë¨¼ì € 수치 모의에서 관측된 ìžìœ ìˆ˜ë©´ 시계열 자료를 threshold crossing method로 파별 해석[wave by wave analysis]하여 개별 파랑을 íŠ¹ì •í•˜ê³ , 이어 ì´ë ‡ê²Œ íŠ¹ì •ëœ 파마루와 파곡 빈도 해석결과로부터 산출하였다. 모의결과 현재 천 해역 íŒŒê³ ë¶„í¬ë¥¼ 대표하는 ìˆ˜ì • Glukhovskiy íŒŒê³ ë¶„í¬ëŠ” 큰 íŒŒê³ ì™€ 작은 íŒŒê³ ë°œìƒí™•ë¥ ì€ 과다하게, 중간 크기 íŒŒê³ ë°œìƒí™•ë¥ ì€ 과소하게 평가하는 것으로 모의 되었으며, 이에 반해 본 ë ¼ë¬¸ì—ì„œ ì œì‹œëœ íŒŒê³ ë¶„í¬ì˜ 경우 일치도가 상당하였다. 또한, ì „ìˆ í•œ ìˆ˜ì • Glukhovskiy íŒŒê³ ë¶„í¬ì™€ì˜ 간극은 쇄파역에서 ì œì¼ í˜„ì €í•˜ê²Œ 관측되어 ìˆ˜ì • Glukhovskiy íŒŒê³ ë¶„í¬ë¥¼ 쇄파역 ì–¸ì €ë¦¬ì— 거치되는 외곽시설 ì‹ ë¢°ì„± 설계에 ì ìš©í•˜ëŠ” 일은 지양되어야 í• ê²ƒìœ¼ë¡œ 판단된다. 핵심용어: 천해역 íŒŒê³ ë¶„í¬, 증강계수, JONSWAP 스펙트럼, ìˆ˜ì • Glukhovskiy íŒŒê³ ë¶„í¬, LES[Large Eddy Simulation], spatially filtered Navier-Stokes Eq., one equation dynamic Smagorinsky turbulence closure

Long-term variations of wind and wave conditions in the Taiwan Strait

Research on the long-term characteristics of ocean conditions is becoming increasingly necessary as the impact of climate change is becoming conspicuous. This study measured the variabilities of wind and wave by simulating the wind speeds and significant wave heights from 1988 to 2017 over the Taiwan Strait. The validation shows that the simulated results are in agreement with the observations. From analysis of the annual, seasonal, and monthly distributions of wind speeds and significant wave heights, the maximum wind speed and significant wave height appear in January, with the maximum wind speed reaching 12 m/s and maximum significant wave height reaching 2.8 m. Additionally, the long-term trends of the wind speeds and significant wave heights are studied, and, during the 30 years, the wind and wave variation trends are found to increase significantly. Furthermore, the linear trends of the wind speeds and significant wave heights at three points are analyzed, which present the temporal variations of wind and wave over the Taiwan Strait.

Spatio-Temporal Distribution and Variability of High Threshold Wind Speed and Significant Wave Height for the Indian Ocean

Space-borne satellites provide extensive coverage of measuring sea surface wind field and wave heights on a global scale. The present study provides a comprehensive assessment of distribution of extreme wind and wave fields over the Indian Ocean (IO) utilizing satellite-based scatterometer and altimeter datasets. Merged scatterometer data from ERS-1/2, QuikSCAT, and ASCAT for a period of 27 years produced continuous record of wind speed, whereas the calibrated altimeter data for different satellite missions provided information on the significant wave height. A comparison study between merged scatterometer and calibrated altimeter derived long-term maximum wind speed shows an overestimation of altimeter product by an average measure of 3 m/s and higher as compared to the scatterometer winds in 92.8% of the total observational points considered. A decadal variability was observed in the inter-annual spatial distribution of the 90th and 95th percentile winds for the study region. Interestingly, the study reveals a declining trend in the dispersion of higher waves (90th, 95th, and 99th percentiles) in the entire IO except the South China Sea. Further, 2011 onwards there is an increasing trend in the annual distribution of extreme winds and waves for the Extra-tropical South Indian Ocean having implications on the generation of swell wave fields.

Identifikasi Pendekatan Shallow Water Equation Dalam Simulasi 2D Gelombang Tsunami di Pantai Keburuhan Purworejo

Kabupaten Purworejo merupakan salah satu dari lima daerah yang terkena dampak run-up tsunami Jawa 17 Juli 2006. Berdasarkan hasil Rapid Survey oleh BPDP dan BPPT, sepanjang Pantai Keburuhan merupakan lokasi terjadinya run-up tsunami di Kabupaten Purworejo di koordinat 109.912 LS -7.85 BT sebesar 1,7 meter. Tujuan dari penelitian ini adalah memperkirakan waktu tempuh tsunami, distribusi tinggi gelombang tsunami dan daerah jangkauan tsunami akibat dampak gempa tsunami Jawa 17 Juli 2006 di Pantai Keburuhan, Purworejo. Metode yang digunakan adalah metode deskriptif analitis dengan pendekatan kuantitatif. Data yang digunakan pada penelitian ini adalah titik tinggi, batimetri, parameter gempa, peramalan pasang surut wilayah perairan Pantai Keburuhan, data citra Geo Eye 1, dan kelerengan pantai. Pemodelan tsunami menggunakan perangkat lunak COMCOT v1.7 dengan kejadian gempa Jawa 17 Juli 2006. Berdasarkan pengolahan data, diketahui bahwa kecepatan gelombang maksimal sebesar 3.8788 m/s. Pada menit ke- 40, amplitudo awal gelombang tsunami sebesar 1.644 meter telah mencapai Pantai Keburuhan. Daerah jangkauan tsunami terluas dan jarak jangkauan maksimum terjauh terjadi di Pantai Keburuhan adalah 1,23 km2 dan 1,4 km. Berdasarkan hasil verifikasi dengan nilai RSR sebesar 0,26. Hasil validasi simulasi tsunami menggunakan COMCOT v1.7 diketahui bahwa tinggi run-up tsunami model sudah cukup sesuai dengan data run-up yang terjadi saat kejadian, dengan nilai RSR sebesar 0,29 dan CF sebesar 1,63.

Environmental Assessment of Xinhe Beach Development

The proliferation of beach renovation is affecting the change of the landform of the coast and threatening the ecological environment. Therefore, it is necessary to assess the impact on the environment after the beach is transformed. The survey area is located near the Shipu fishing port in the south of Ningbo City, Zhejiang Province. Based on the Delft-3D grid nesting model and wave-fluid coupling model, the astronomical tide and hydrodynamic environment of the 30 days before the construction were simulated. After the beach was rebuilt and sand was added and the spur dike was added, the astronomical tide and hydrodynamic environment were again simulated. Finally, based on the simulated data, the water level, velocity field, effective wave height distribution, and siltation and siltation of Xinhe Beach were obtained. Xinhe Beach's environmental damage risk indicators can be evaluated based on water level, velocity field, effective wave height direction and sediment erosion and deposition. Artificial sanding and construction of spur dikes will change the hydrodynamics and scouring and siltation of Xinhe Beach, but have little effect on the coastal terrain and ecological environment.

Some probabilistic properties of surf parameter

• Average statistical properties of surf parameters. • Surf parameter for individual waves. • Spectral surf parameter representing a sea state characteristic. • Results using data typical for field conditions are provided. • Example of calculating wave runup elevation. This article is supplementary to Myrhaug (2018) and presents some probabilistic properties of the surf parameter for individual waves and the spectral surf parameter for sea states by using distributions based on data from the Norwegian continental shelf. The average statistical features given by the mean value and the standard deviation of the two surf parameters are considered. Examples of results for the surf parameter are provided for a Phillips spectrum and a family of JONSWAP spectra for wind sea, and for sea states using a joint frequency table of significant wave height and mean zero-crossing wave period for combined wind sea and swell. The spectral surf parameter results are obtained by using a joint distribution of significant wave height and spectral surf parameter, and the mean statistical properties are given for joint frequency tables of significant wave height and mean zero-crossing wave period from three deep water locations on the Norwegian continental shelf. It is also demonstrated how the results can be applied to calculate the vertical wave runup elevation for breaking waves.

Unravelling the Relationship Between Microseisms and Spatial Distribution of Sea Wave Height by Statistical and Machine Learning Approaches

Global warming is making extreme wave events more intense and frequent. Hence, the importance of monitoring the sea state for marine risk assessment and mitigation is increasing day-by-day. In this work, we exploit the ubiquitous seismic noise generated by energy transfer from the ocean to the solid earth (called microseisms) to infer the sea wave height data provided by hindcast maps. To this aim, we use a combined approach based on statistical analysis and machine learning. In particular, a random forest model shows very promising results in the spatial and temporal reconstruction of sea wave height by microseisms. The observed dependence of input importance from the distance sea grid cell-seismic station suggests how the reliable monitoring of the sea state in a wide area by microseisms needs data recorded by dense networks, comprising stations evenly distributed along the coastlines.

Assessment of wave height distributions using an extensive field database

The present paper investigates the short-term statistical distribution of wave heights. Specifically, some of the most commonly applied wave height distributions are assessed using field measurements. The latter comprise of wave radar observations from 10 different locations in the North Sea and cover water depths between 7.7 m and 45 m. In total, the field database includes more than 200 million waves, making it one of the largest of its kind in this water depth regime. In using these data, the accuracy of existing wave height distributions has been examined and guidance is provided concerning the best performing models and their domain of applicability. Additionally, insights concerning the influence of key met-ocean parameters are also provided. Taken together, the results in this paper present an overview of the statistical behaviour of wave heights in finite water depths, as observed in the field.

Pandeglang regency spatial evaluation based on tsunami hazard potential

The coastal area of Pandeglang Regency is one area that has the potential to be affected by the tsunami. The existence of the Krakatau Anak Volcano and plate subduction paths in the Sunda Strait cause Pandeglang Regency to become one of the regions that has a tsunami potential. One of the steps to anticipate the tsunami disaster is to do spatial planning that has considered the potential tsunami hazard. The purpose of this research is to evaluate the spatial area of Pandeglang Regency based on the identification of potential tsunami hazards. The identification of potential tsunami hazards is done by modeling the potential distribution of tsunami wave heights in coastal areas using GIS modeling. The results of the identification of potential tsunami hazards on the coast of Pandeglang Regency showed that an area of 194.15 hectares of residential land and the location of existing activities had the potential to be affected by the tsunami. The total area of the coastal area of Pandeglang Regency which was potentially affected by the tsunami hazard reached 1483.26 hectares. The results of a review of the Pandeglang Regency's spatial plan showed that 488.22 hectares of land were found in the planned residential spatial patterns that were potentially affected by the tsunami. Therefore, the regional spatial plan of Pandeglang Regency in the study area needs to be evaluated by changing the function of residential land that has the potential to be affected by the tsunami hazard to the border of the beach or other open land.

Validating Ocean Wind Wave Global Hindcast with Visual Observations from VOS

Joint analysis of wind wave characteristics derived from Voluntary Observing Ships data (VOS) and the third-generation spectral wave model WAVEWATCH III v.5.16 hindcast is presented. Global distributions of significant wave heights and mean periods in both datasets demonstrate good qualitative and quantitative agreement, especially in regions with a high spatiotemporal density of observations. Simulation results and visually observed wind sea and swell show perfectly consistent patterns of directional steadiness. However, wind sea heights in WW3 are overestimated predominantly in stormy regions, while swell heights are globally underestimated. The reasons for these discrepancies in assessment of wave system components are investigated in the framework of various wave regime analyses.

Modelling long-term joint distribution of significant wave height and mean zero-crossing wave period using a copula mixture

Ocean waves are a natural combination of wind sea and swell. Considering this physical process, by comparing the magnitudes of splitting wind sea and swell energy, long-term wave climate can be classified into four basic components: pure wind sea, pure swell and two classes of combined seas, wind sea stronger and swell stronger. From one position in the North Atlantic Ocean, across seasonal analysis on the 44-year (1958–2001) hindcast wave data calculated by WAM in the HIPOCAS project, it was found that the four wave components behave distinctly. Hence, in this study, we propose using a mixture of distributions to perform the copula-based statistical modelling of significant wave height and mean zero-crossing wave period. A case study was dedicated to testify the univariate and bivariate capacity of fitting, the results demonstrate that: 1) compared to straightforward fitting a distribution to data, estimating the marginal distribution of the sea state parameter as a mixture of the four components can improve goodness-of-fit; 2) the proposed copula mixture model can provide an outstanding fit to the bivariate wave data, outperforming those constructed by copulas belonging to Symmetric, Khoudraji-Liebscher and Product families, as well as the classical Conditional Modelling Approach.