bluuebunny/crossref_metadata_2025 huggingface dataset:
Lidar-assisted control in wind turbine design: Where are the potential benefits?
Authors: Canet H , Löw S , Bottasso CL
Published: September 2020

This study explores the potential benefits of considering Lidar-assisted control (LAC) at the first stages of wind turbine design. The proposed methodology starts with a load analysis of several reference wind turbines to understand which design constraints can be influenced by the use of LAC. The blade and tower of each analyzed model are redesigned considering LAC-induced reductions in key driving quantities. Preliminary results suggest modest reductions in LCOE with potentially significant benefits limited to the tower. The study also discusses the requirements on LAC system purchase and O&M costs, for both onshore and offshore machines, to achieve a reduction in LCOE.
Efficient structural optimisation of a 20 MW wind turbine blade
Authors: Scott S , Greaves P , Weaver P M , Pirrera A , Macquart T
Published: September 2020

This paper presents, through the structural design of a 20 MW wind turbine blade, a selection of novel analysis and optimisation methods for wind turbines. These methods are integrated in the software—Aeroelastic Turbine Optimisation Methods (ATOM). A key feature is the novel, computationally-efficient piecewise linear model for running rapid design load case simulations (up to 16 times speed-up over conventional methods). Further, a comprehensive set of realistic design constraints is also proposed to ensure structural feasibility and aeroelastic stability. To demonstrate these methods, a sequential gradient-based optimisation process is employed, relying on the globally convergent method of moving asymptotes (GCMMA). The process begins with an aerodynamic optimisation to generate twist distributions, followed by an iterative loop during which load envelope updates and ‘frozen-load’ blade structural optimisations are performed independently. Aeroelastic loads are therefore considered, but are not directly optimised for. The present study investigates the structural design of a 20 MW wind turbine blade with hybrid carbon-glass spar caps. The optimised 122 m blade is found to have a mass of 83,622 kg, which decreases to 81,396 kg (-2.66%) with the addition of sweep. The GCMMA is found to converge successfully at each structural optimisation step. By contrast, the iterative loop is observed to oscillate, albeit within small bounds. Finally, results suggest that convergence of multi-step optimisation methods for aeroelastic blade design may not be guaranteed if design variables inducing aeroelastic couplings are considered.
Integration of System Level CFD Simulations into the Development Process of Wind Turbine Prototypes
Authors: Arnold Matthias , Wenz Florian , Kühn Timo , Lutz Thorsten , Altmikus Andree
Published: September 2020

During the development process of wind turbines, there is a rising demand for detailed flow and multi-physics analyses. Especially the system level computational fluid dynamics (CFD), focusing not on a single component or aspect, but on the turbine as a system of geometric and dynamic properties can be used to improve the turbine quality and time to market. In this paper the integration of the system level CFD into the development process of Enercon wind turbines is introduced. Further two example applications are detailed presenting the benefits of CFD based nacelle anemometer calibration and a risk assessment study based on aero-servo-elastic CFD simulations.
Study on influence of blade icing on operational characteristics of wind turbine at cold climate
Authors: Goshima N , Maeda T , Kamada Y , Tada T , Hanamura M , Pham H H , Iwai K , Fujiwara A , Hosomi M
Published: September 2020

In this paper, the icing effect on wind turbine is investigated. The sectional aerodynamic performance of iced blade was measured in wind tunnel with icing airfoil models. The analysis conducted by using FAST using the measured sectional performance was conducted to investigate the degradation in wind turbine performance and added load due to icing. Frequency analysis was also conducted with the time series data calculated by using FAST. As the results, the power output at the rated wind speed for the icing case is smaller than that for the clean case and the maximum rotor thrust for the icing case is smaller than the clean case. The wind speed at which the turbine’s rated power is reached for the icing case was higher than that for the clean case.
Optimization of the erosion-safe operation of the IEA Wind 15 MW Reference Wind Turbine
Authors: Skrzypiński W R , Bech J I , Hasager Ch B , Tilg A-M , Ch Bak F Vejen
Published: September 2020

The work describes modelling of erosion of the IEA 15 MW Reference Wind Turbine. Five-year worth of historical time series including wind speed, rain intensity and price of energy was used in the modelling. The work included erosion-safe operation of the turbine where the tip speed was limited during rain events to prevent erosion. The tip-speed limit was defined as a function of rain intensity and price of energy, the distribution of which was subject to an optimization. The objective for the optimization was to maximize the profit. The factors taken into account in the modelling and optimization were: the loss in power curve due to erosion, and the cost of repair and associated downtime. The results indicated that for this particular turbine it would be sufficient to define the tip-speed limit as a function of rain intensity alone. The model showed that 88% of the overall profit loss due to erosion could be saved by running the turbine in the erosion-safe operation. Although some inaccuracy may be associated with the modelling, the results strongly indicate that a significant amount of money could be saved by utilizing the erosion-safe operation on offshore turbines.
The influence of the bound vortex on the aerodynamics of curved wind turbine blades
Authors: Li Ang , Gaunaa Mac , Pirrung Georg Raimund , Ramos-García Néstor , González Horcas Sergio
Published: September 2020

Passive load alleviation on wind turbine blades can be achieved through geometric bend-twist coupling, for example by sweeping the blade backwards. In order to obtain the correct load distribution of a curved blade with in-plane sweep and/or out-of-plane dihedral, the influence of the blade shape on the aerodynamics must be modelled correctly. This includes the influence of the curved bound vortex, and it is especially important when designing a wind turbine blade with aeroelastic tailoring. In this paper, the background for modelling the curved bound vortex influence will be described in detail and a modified method is proposed. The proposed method of bound vorticity modelling is compared for curved and straight translating wings as well as wind turbine blades with results from a panel code and a Navier-Stokes solver. From this comparison, the advantages of the current modification with respect to the other lifting-line implementations are shown. The method proposed in the present work is general and applicable to any lifting-line like model.
Validation of analytical body force model for actuator disc computations
Authors: Sørensen Jens N , Andersen Søren J
Published: September 2020

A new analytical model for representing body forces in numerical actuator disc models of wind turbines is compared to results from a BEM model. The model assumes the rotor disc being subject to a constant circulation, modified for tip and root effects. The advantage of the model is that it does not depend on any detailed knowledge concerning the actual wind turbine being analysed, but only requires information of the thrust coefficient and tip speed ratio. The model is validated for different turbines operating under a wide range of operating conditions. The comparisons show generally an excellent agreement with the BEM model, with, however, some deviations of the tangential force in the root area and at small values of the thrust coefficient.
On the importance of the beam reference line
Authors: Couturier P J , Mailly L , Molitor D , Wang Q
Published: September 2020

The development of a new beam reference line to improve bend-twist response modelling is presented. The beam reference line is derived as the locus of the cross-section elastic energy centres under pure bending moment. The performance of the new reference line is assessed via experimental measurements performed on a Siemens Gamesa wind turbine blade. Bend-twist modelling capability is assessed by comparing the location of the zero-twist rotation line and zero-twist-rate lines.
Comparison of a radially resolved dynamic inflow pitch step experiment to mid-fidelity simulations and BEM
Authors: Berger Frederik , Höning Leo , Herráez Iván , Kühn Martin
Published: September 2020

In this paper a detailed comparison of the experimental and numerical results of a scaled wind turbine model in a wind tunnel subjected to fast pitching steps leading to the so-called dynamic inflow effect is presented. We compare results of an Actuator Line LES tool, a vortex code and four engineering models, to the experiment. We perform one and two time constant model analysis of axial wake induction and investigate the overshooting of integral loads. Our results show, that the effect is captured better by the two time constant models than by the one time constant models. Also the experiment and mid-fidelity simulations are best described by a two time constant fit. We identify the best dynamic inflow model to be the 0ye model. Different possibilities for the improvement of dynamic inflow models are discussed.
Investigation of the individual load distribution of a blade bearing test rig by means of finite element simulation
Authors: Leupold S. , Schelenz R. , Jacobs G.
Published: September 2020

To carry out fatigue tests on the blade bearing test rig used in this work, knowledge of the maximum contact pressure and position of the contact ellipse in each rolling contact is necessary. Since these cannot be measured directly, a detailed FE-model of the blade bearings and the test rig components is set up. Previous studies use non-linear spring to simplify the raceway ball interaction. In this paper each rolling contact is modelled with a surface to surface interaction. This allows the evaluation of the maximum contact pressure and the distance between the contact area and the edge of the raceway. Furthermore, measurements of the relative displacement between the outer and inner ring for different load steps were carried out and show a good correlation with the simulation results.
Wind tunnel tests for vortex generators mitigating leading-edge roughness on a 30% thick airfoil
Authors: Gutiérrez R , Llórente E , Echeverría F , Ragni D
Published: September 2020

In this study, the aerodynamic performance of a thick airfoil is analysed, after installing leading-edge roughness to emulate a severe state on the airfoil surface. The impact on aerodynamic coefficients has been quantified using two roughness methods: zig-zag tape and sandpaper. Wind tunnel tests are carried out at a Reynolds number of 3•106. At low angles of attack, zig-zag tape and sandpaper provide comparable lift and drag coefficients but significant variations of these coefficients are obtained for high angles of attack. Stalled flow is the cause of the most significant variation on the airfoil performance between smooth and rough surface states. Vortex generators are adapted to recover the lift coefficient value previously given by the airfoil under smooth conditions. As a result, vortex generators are able to reduce the loss of lift and the sensitivity of the airfoil to the rough state.
Exploiting the limit of BEM solvers in moonpool type floaters
Authors: Ntouras Dimitris , Manolas Dimitris , Papadakis George , Riziotis Vasilis
Published: September 2020

Solvers based on Boundary Element Method (BEM) are fast and they have proven to provide accurate results in a wide range of applications. On the other hand, computational fluid dynamics (CFD) solvers are high-fidelity tools able to account for viscous effects. However, they are computationally demanding. In the present work, the limitations of BEM solvers are exploited considering the case study of a moonpool type floater in which the viscous effects near the sharp edges of the body (vortex shedding) are not negligible. The BEM results are compared with the results from an unsteady Reynolds averaged Navier-Stokes (URANS) CFD solver and experimental data, while viscous corrections of the BEM method are assessed.
Plasma Actuation for Mitigation of Fluctuating Loads on Airfoils: An Experimental Study
Authors: Rezaeiha Abdolrahim , Kotsonis Marios
Published: September 2020

Wind tunnel measurements are performed to investigate the potential for mitigation of aerodynamic load fluctuations on airfoils, as the main source of fatigue for wind turbines, using plasma actuators. The experiment consists of aerodynamic force measurements using six strain gauges and 2-component velocity measurements using particle image velocimetry (PIV). The analysis is focused on the aerodynamic loads, the mean flow, the turbulent kinetic energy and the proper orthogonal decomposition (POD) modes and their energy budget. The main findings are: (i) the actuation increased the lift coefficient for all the range of a, with an average and maximum increment of 0.05 and 0.1, per unit span of the actuator; (ii) the actuation deflects the airfoil near wake downward, resulting in the so-called virtual cambering effect; (iii) the actuation increases the TKE near the trailing edge, which could increase the airfoil trailing-edge noise; (iv) the POD analysis reveals that the actuation increases the size of the vortical structures in the near wake and the energy budget of the first POD modes, esp. at high angles of attack prior to stall.
Effect of wind directionality on fatigue life of monopile support structures for offshore wind turbines
Authors: Nozari A , Kuchma D , Hines E M
Published: September 2020

The U.S. offshore wind industry can expect higher costs due to the lack of domestic experience with offshore wind technology. A key factor of the capital expenditure related to offshore wind farms is the cost of the support structures of offshore wind turbines. Therefore, improvements to the reliability of support structures under ultimate and fatigue loading conditions will help reduce the levelized cost of energy of offshore wind. This study presents a framework that accounts for the wind directionality by assuming a distinct and independent wind speed distribution per each wind direction and investigates its effect on the fatigue life of offshore wind turbine support structures. A monopile support structure in a potential wind site close to a National Oceanic and Atmospheric Administration buoy in the north-eastern US waters is used in this study. Fatigue damage assessment is performed for the normal operational condition of wind turbine, and the results are presented considering both cathodic protection and free corrosion conditions at the mudline level of the monopile. The location and extent of the predicted fatigue damages are found to vary due to accounting for the wind directionality.
Effect of varying fidelity turbine models on wake loss prediction
Authors: Liew Jaime , Raimund Pirrung Georg , Meseguer Urbán Albert
Published: September 2020

Wind farm simulations are widely used in estimating energy yield and for optimal wind farm layout design. In the early design stages of a wind farm, low fidelity wind turbine models are used to estimate the farm power output, often due to incomplete knowledge of the turbine characteristics and the additional complexities. The discrepancies introduced in a wind farm simulation as a result of using low fidelity models can often be overlooked, leading to a misrepresentation of a wind farm’s yield. In this paper, the discrepancies between five levels of fidelity for two turbine designs are quantified, focusing on the produced wake and the downstream flow effects. Two high fidelity aeroelastic turbine models and three low fidelity models are described, where the wake is produced using the Dynamic Wake Meandering (DWM) model for each turbine and model. The results provide insight into the expected uncertainties in wake simulations as a result of changing the turbine fidelity level.
Cross-correlation-based approach to align turbulent inflow between CFD and lower-fidelity-codes in wind turbine simulations
Authors: Wenz F , Boorsma K , Lutz T , Krämer E
Published: September 2020

In cases with turbulent inflow, the analysis of the temporal development of forces could provide more insight into differences in calculated fatigue loads of wind turbines. While lifting-line-codes and the Blade-Element-Momentum (BEM) approach do not resolve the inflow, Computational Fluid-Dynamic (CFD) codes resolve the entire flow field. A comparison of time series between the different codes therefore requires a consistent input of the background turbulence. This was enabled by extracting the turbulent velocity field from empty box (without rotor) CFD simulations at the anticipated rotor position. The presence of a rotor in the CFD simulations leads to a delay in the inflow due to the induced velocity. This blockage effect of the rotor was quantified by a cross-correlation. The velocity field extracted from the simulation of the empty box was shifted by the resulting temporal offset before it was used as lifting-line-code or BEM input. Thus, a time-dependent load comparison between the codes could be performed. It was found that the difference in load predictions between CFD and BEM seems to be larger at peak values. For cases with high thrust coefficient or high turbulence intensity, a simpler analytical approach resulted in significantly higher temporal offsets than the cross-correlation.
Synthetic wind speed generation for the simulation of realistic diurnal cycles
Authors: Ambrosio D D , Schoukens J , Troyer T De , Zivanovic M , Runacres M C
Published: September 2020

Synthetic wind-speed generators can provide a detailed characterisation of the wind variability at different time scales. A keen interest in the availability of synthetic wind speeds has recently risen in wind power modelling applications. In particular, a proper simulation of the diurnal and annual variability of the wind speed is sought that can lead to a more efficient grid integration of this renewable source. This paper proposes a statistical model for generating synthetic wind speeds consistent with both the probability density function and the spectral density function of a measured wind-speed dataset and that simulates accurately its average diurnal variation. To test the proposed methodology, multiple synthetic time series are generated using three long-term wind-speed time series recorded at a meteorological site in the Netherlands. The accuracy in terms of the statistical descriptors of the generated time series and their average diurnal variation is assessed with respect to the target data. We show that the average diurnal cycles present in all the three measured time series are always reproduced accurately, and that the statistical descriptors of the target dataset are constantly matched with high accuracy. Possible advantages of the present approach in terms of power system modelling are discussed.
Development of a streamline wake model for wind farm performance predictions
Authors: Sessarego Matias , Feng Ju , Friis-Møller Mikkel , Xu Yun , Xu Mengying , Zhong Shen Wen
Published: September 2020

In the present paper a new streamline model for wake development based on a streamline topology is applied and compared with different approaches for modeling the wind turbine wakes. The contribution of the present work is the comparison of the streamline-and straight-wake models as well as the different wake models, e.g., Jensen and Gaussian. The models have been applied to two wind farm cases. The results from the first case are compared against SCADA measurements and computational fluid dynamics simulations (CFD). The CFD simulations are performed using Reynolds-Averaged Navier Stokes (RANS) together with the actuator disc (AD) approach. The mean percent difference in power using the different wake models ranged between 19-20%. Mean percent difference in power for the AD-RANS was approximately 20%. For the second wind farm case only wake models are compared and approximately ±1% difference exists between them. The present work shows that the streamline topology of the wind turbine wake flow as well as the wake models have an effect on the performance prediction of wind farms.
On the dynamic response of a pitch/torque controlled wind turbine in a pulsating dynamic wake
Authors: Cacciola S , Bertozzi A , Sartori L , Croce A
Published: September 2020

The interaction between wakes and rotors is typically detrimental in terms of the overall power production of a wind farm. The recently studied wind farm controllers represent a promising way to increase the energy harvested through the mitigation of the effects induced by wake impingement. Recently, a novel methodology, based on a dynamic variation of induction, has been proposed as an alternative to steady induction and wake redirection controls. According to this new technology, a periodic collective motion of blade pitch generates a dynamic induction, associated with a stronger flow mixing and therefore a faster wake recovery. Although this technique proved to be effective in terms of power increase, both in numerical simulations and in wind tunnel experiments, much is to be done in order to demonstrate its feasibility. In particular, the impact of dynamic induction control in terms of downstream turbine dynamics has not been yet analyzed in detail. This paper presents a CFD-based analysis aimed at describing the response of a downstream rotor inside the wake of an upstream machine performing dynamic induction control. Specifically, the periodic induction entails a pulsating flow downstream which interacts significantly with the aero-servo-elastic dynamics of the downstream turbines. For low wind speeds, such an oscillating flow may trigger a shut-down/start-up sequence any time the velocity results lower than the cut-in speed.
Tilted wind turbines in farm configuration for improved global efficiency
Authors: Trigaux Francois , Moens Maud , Chatelain Philippe , Winckelmans Grègoire
Published: September 2020

The advance in wind turbine technology has led to a tendency to gather the turbines into wind farms to benefit from economies of scale. However, the farm configuration often leads to a drastic power loss due to the interactions between the turbines. To mitigate this issue, the turbines are typically misaligned with the dominant wind direction to deviate their wake. In this paper, a tilt-induced wake deviation strategy is studied in a farm configuration using large eddy simulation of an atmospheric boundary layer and an actuator line model for the blade. The results show an effective wake deviation and a significant increase of the total power production of the farm. The evolution of the time-averaged and unsteady loads is also assessed in the wind farm, and the resulting damage equivalent load is shown to be reasonably modified when the turbines are tilted. The tilted configuration is also compared with a wind farm with yawed turbines and is found to lead to a larger power output for a reduced damage equivalent load.
Numerical study on the Wave Boundary Layer, its interaction with turbulence and consequences on the wind energy resource in the offshore environment
Authors: Paskin Liad , Perignon Yves , Conan Boris , Aubrun Sandrine
Published: September 2020

The wind energy farming in the offshore environment is characterized by ever-increasing structures and costs, for which reducing structural damage and maximizing production become an imperative. Such challenge is faced by site planning, intelligent design and active control systems that ultimately require a fine Atmospheric Boundary Layer (ABL) description. Contributing to refine the wind flow description in the offshore environment for engineering purposes, this work considers: (i) The interaction between turbulent and Wave Induced fluctuations, pronounced in the lower portion of the Marine ABL (MABL): Region so-called Wave Boundary Layer (WBL); (ii) The impact of the WBL in the flow above it.

Focusing in the MABL sustained by non-equilibrium old-seas in neutral atmospheric conditions, the free-surface position and velocities are here prescribed into a Large Eddy Simulation (LES) according to a fifth order Stokes solution. The swell disturbances on the WBL are explored through mean profiles and spectral analyses. An original definition of the Wave Induced flow is presented, considering correlated turbulent and Wave Induced motions thus accessing the coupled dynamics between those fields and allowing the evaluation of the WBL height. Employing the proposed decomposition, the turbulent flow characteristics are recovered as expected in a flat bottom ABL, though some of its scales change considerably, forced by the WBL existent below.
Inverse Directional Simulation: an environmental contour method providing an exact return period
Authors: Dimitrov Nikolay
Published: September 2020

This study presents an improved approach for drawing environmental contours, derived from the inverse First Order Reliability Method (iFORM). It is shown that the approach used in the iFORM method is not accurate as it only takes into account a fraction of the probability space behind the contour line-which means that the iFORM method provides inherently non-conservative environmental contours. iDS, an alternative solution based on the chi-square distribution is suggested, and its adequacy is demonstrated with a Monte Carlo simulation. An expression is derived for computing sector-constrained environmental contours where the exceedance probability is contained within specific range of interest for one or more variables. The newly suggested environmental contour methods are applied on measured wind and turbulence time series and compared with the iFORM method.
A new method to characterize the curled wake shape under yaw misalignment
Authors: Sengers B.A.M. , Steinfeld G. , Heinemann D. , Kühn M.
Published: September 2020

Wake Redirection Control due to intentional yaw misalignment is a promising method to enhance power yield at wind farm level. A turbine misaligned with the inflow wind produces a curled wake shape, which is currently not accounted for in wake tracking algorithms. This study proposes a new 2D wake description specifically designed to account for the non-elliptic shape of the redirected wake. The performance of this new method is evaluated by employing a Large Eddy Simulation model at different atmospheric stratifications. A comparison with traditionally used approaches indicates an improvement in describing wake shape and center position, and consequently a significantly higher accuracy in the power estimation of a virtual downstream turbine. A brief outlook suggests that this wake tracking algorithm is suited to study the effect of the most influential atmospheric and operational parameters on wake propagation under yaw misalignment and the development of a physically based empirical wake parameterization.
Quantification of rotor thrust and momentum deficit evolution in the wake using Nalu-Wind simulations
Authors: Herges Thomas , Kelley Christopher , Hsieh Alan , Brown Kenneth , Maniaci David , Naughton Jonathan
Published: September 2020

Nalu-Wind simulations of the neutral inflow Scaled Wind Farm Technology (SWiFT) benchmark were used to analyze which quantities of interest within the wind turbine wake and surrounding control volume are important in performing a momentum deficit analysis of the wind turbine thrust force. The necessary quantities of interest to conduct a full Reynolds-Averaged Navier-Stokes (RANS) formulation analysis were extracted along the control volume surfaces within the Nalu simulation domain over a 10 minute period. The thrust force calculated within the wake from two to eight diameters downstream using the control volume surfaces and the full RANS approach matched the thrust force that the wind turbine applied to the flowfield. A simplified one-dimension momentum analysis was included to determine if the inflow and wake velocities typically acquired during field campaigns would be sufficient to perform a momentum deficit analysis within a wind turbine wake. The one-dimensional analysis resulted in a 70% difference relative to the coefficient of thrust (Ct
) determined by the full RANS method at 2D downstream and a 40% difference from 5D to 8D, where D is the diameter of the turbine. This suggests that the quantities typically captured during field campaigns are insufficient to perform an accurate momentum deficit analysis unless streamwise pressure distribution is acquired, which reduced the relative difference to less than 10% for this particular atmospheric inflow.
Favorable wind states in wind energy production at La Rumorosa I wind farm
Authors: Magali Arellano-Vazquez , Marlene Zamora-Machado , Robles M. , Jaramillo O. A.
Published: September 2020

This work introduces a statistical method that identifies wind states present in the wind farm La Rumorosa by analyzing wind speed and nacelle position (wind direction). These states contribute to the generation of wind power in microscale, mesoscale, and macroscale phenomena. The data were obtained from five wind turbines at the onshore and anemometric tower in La Rumorosa located on the border with the state of California, USA. The contribution of wind states and their impact on the annual power production in the wind farm was observed using this method. It is concluded that the method reliably identifies wind patterns with low computational effort.
Spatial adaptation of Rusunawa Muara Baru residents, North Jakarta in livelihood activities
Authors: Nindyatama N , Setiadi H , Rizqihandari N
Published: September 2020

Illegal settlements are a form of increasing demand for settlements in the capital city of Jakarta triggered d by urbanization. One of them is in Waduk Pluit, North Jakarta. This situation forced government to hold the normalization and relocation towards Rusunawa Muara Baru in 2015 to restore the function of the reservoir and restrain the urban settlement infrastructure. This research is a qualitative study using a humanistic geographical approach as its foundation. This research aims to determine changes in their residential characteristics and their basic needs as well as to identify the new form of adaptations in their livelihood activities after relocation. The results showed that residents who have relocated value the positive physical environment in their new housing but also increase in their basic needs, mainly due to rental fees. This condition causes residents to adapt by having additional jobs. Some residents who didn’t have additional jobs, work in the services sector. Otherwise, some residents maintain it with same or different types of business. The business space location determines the type of business, this causes some of them to change the type of business based on market conditions around their business space. They use public space as additional jobs’ location.
Characteristic of popular culinary place in Kelurahan Tamalanrea Indah based on Universitas Hassanudin student’s Mental Maps
Authors: Maharani N , Setiadi H , Rizqihandari N
Published: September 2020

Mental maps concept emerged in discussions among experts since the 1960s where the concept was combined using participatory in exploring the visualization of the city and spatial preferences. This study discusses the characteristics of popular eating places based on an evaluation of spatial products in the discussion of space. For comparison purposes, it takes participants who need to fill in the required form about the characteristics of the eating place based on their favorite places to eat and analyze the printed map and mental map. Universitas Hassanudin students are selected as research participants. They chose to map three of their favorite eating places in Tamalanrea Indah Village as a basis to determine their popular eating places while revealing their mental maps. In total, there are 10 participants which produced 18 names of favorite eating places. Ten respondents who were willing to fill in the map, and evaluate the mental maps, is compared. From the data obtained, the three most popular places to eat in Tamalanrea Indah Village that were successfully validated were Bokatana, Waroeng Dian and Warung Alhamdulillah. In general, the mental map produced is based on the variable length of stay and length of study at the Universitas Hassanudin which affects the accuracy of the mental maps, while for popular eating places students are selected based on the distance from the faculty to compare the distance of the residence.
Contribution of Tanjung Lesung Beach tourism destinations to communities in Panimbang District, Pandeglang Regency, Banten
Authors: Amanda R , Tambunan R P , Waryono T
Published: September 2020

Tanjung Lesung Beach is a government priority to be developed because it entered the Special Economic Zone which was inaugurated on February 2015. This coastal area was chosen as a special economic zone because it has criteria as SEZ in accordance with Law Number 39 of 2009 concerning Special Economic Zones. However, currently, Tanjung Lesung Beach has experienced a decline in tourists due to the Sunda Strait tsunami on December 22, 2018. This study aims to analyze the right strategy to develop the Tanjung Lesung Beach tourist attraction to attract tourists and identify its contribution to the surrounding community. Based on the results of the tsunami research that befell Pandeglang District, it greatly affected the interest of tourists to visit and also resulted in some tourist facilities being paralyzed. After the classification of the feasibility of developing a tourist attraction with the ADO-ODTWA method can be concluded after the tsunami 73.1% Tanjung Lesung Beach is still feasible to develop and has high potential. In terms of the social and economic aspects of this tourist attraction, it contributes to society such as many surrounding communities who work as hotel employees in the region, build infrastructure, and build new businesses. Various new businesses began to emerge such as managing homestays, inn, villa tenants, boat rentals, culinary tours, crafts, arts.
Dayak Iban Tribe shifting cultivation system pattern using unmaned aerial vehicle and Landsat Data in Mensiau Village
Authors: Pribadi U A , Supriatna  , Rokhmatulloh  , Afdhalia F
Published: September 2020

Shifting cultivation by Dayak Iban Tribe in Mensiau Village have several stages, namely burn the land, rice cultivating for two or three planting seasons, and abandoned for reforestation. Vegetation growth through several stages on one cycle, ideally started from burn scar, rice field, bushes, young secondary regrowth, old secondary regrowth, then become secondary forest, so that cycle needs 20 years. The aim of this study is to identify the spatial characteristic of shifting cultivation from UAV data, calculating the change on cycle from Landsat NDVI temporal analysis, also calculating the distance from home and access to the field using Euclidean Distance Analysis. The result shows most of shifting cultivation happen on hilly area with 15-25% slope and Ultisol soil type. NDVI analysis for some field shown increasing of cycle time from 3 to 5 year, and distance analysis reveal that shifting cultivation mostly take place near the roads.
Household shopping behavior in Depok City
Authors: Hanif A K , Nurlambang T , Sumadio W
Published: September 2020

Distribution of malls in Depok City is not even throughout the city. Most malls are located in the city center. Distance between malls is relatively close. While most malls are in the center of the city, quite a lot of residential areas are located far from them. The aim of this study is to determine the patterns of shopping behavior of family household needs in Depok City. Respondents are obtained by distributing questionnaires to households throughout the city using systematic random sampling method. The result shows that households choose a regional mall that is more complete than other malls in choosing shopping site to buy their needs, even though the distance is farther. This happens especially if the shopping activities are carried out with other activities, such as entertainment. Variables that influence shopping behavior are length of stay and type of transportation mode. The variables that are taken into account as the main consideration are completeness of facilities and types of goods that are sold. The conclusion of this study shows that close distance to malls does not affect household behavior in shopping. However, shopping behavior is influenced by the household’s knowledge of the area and accessibility of transportation modes.
Local wisdom of traders and characteristics of traditional market in Pariaman City and its surrounding
Authors: Nuryanti A W , Setiadi H , Rizqihandari N
Published: September 2020

Minangkabau has a strong reputation as an entrepreneur society, mainly based on their involvement in trade (galeh). This society created some famous trading cities along with the east coast of Sumatera that has been thriving as homes of diverse culture, and Pariaman City as one of them. As a trading city, there are various marketplaces across Pariaman and its surrounding that influenced from this mixed culture. By the qualitative method and descriptive approach, the purpose of this study is to examine the distribution of marketplaces and how the specific local wisdom creates their level of traditionalism. Field observations and some in-depth interviews were held to identify how the kinship system may affect their trade networking at each marketplace. The type of Minangkabau markets is determined by the variety of its commodities, which is defined by their stall owner. The owner who inherits their stalls sells local and traditional commodities because they have strong relationships and also the obligation with their kinship. The owner who bought independently can sell various products freely. The “Balai days” event brings together the Minangkabau sellers (rantau and darek) is the principal identity of the traditional Minangkabau market across Pariaman area. The more traditional market, the less-strategic area it places, and the less traditional is the reverse.
The pattern of visiting restaurants in Glagah Beach, Kulon Progo Regency, Yogyakarta
Authors: Hudayanti C , Setiadi H , Rizqihandari N
Published: September 2020

Nowadays, culinary tourism is not just a transient phenomenon but also has become an attraction and the main destination for travelling. Therefore, restaurants are believed to be able to become the main element that functions as an adhesive in a tourist attraction. In this study, the restaurant is the focus of the research, namely Seafood restaurants located in Glagah Beach Tourism Object, Kulon Progo Regency, Yogyakarta. This study aims to analyze the attractiveness of restaurants and patterns of visiting seafood restaurants in Glagah Beach Tourism Objects. The variables used in this study include the uniqueness of restaurants, consumer characteristics, and tourist characteristics. The results showed that the attraction of seafood restaurants was more significant than the other of Glagah Beach attraction. The pattern of visiting restaurants formed at seafood restaurants is the result of weekday and weekend visits from local visitors, sub-regional visitors, and regional visitors.
Livelihoods sustainability pattern in Sangrawayang Village, Simpenan District, Sukabumi Regency
Authors: Kamiludin F , Setiadi H , Sumadio W
Published: September 2020

Season changes influenced the fishers’ job. Their economic life is not stable. Therefore, fishers in Indonesia, especially in Java Island, also cultivate the land. Whenever their area has good access, they have more than two types of job. Sanggrawayang village in Sukabumi District is a fishing village whose fishers earn its income from farming as well. Since 2016, dwellers also have begun working in the service sector, namely services related to tourism activities. This study tries to find out the fishing activities sustainability by using Sustainability Livelihood Approach. By conducting semi-structured interviews with 20 fishers, we can classify the fishermen into three groups, namely fisher laborers, individual fishers, and fishers that own business. Most of the residents are labor fishermen. The result showed that with limited financial and working capital, laborers had more types of work. Their strategy to maintain fishers’ activities is by developing themselves in the services field, both related to fishermen and agricultural activities, as well as in the tourism sector. While fishery business owner who have high financial capital, significant working capital, and extensive networks, are more focused on working in the fishermen sector. Expansion of work in fishermen is carried out by business owner by renting boats and expanding fishing activities by acting as a middle person and distributors as well. The government program is needed to maintain the fishermen smallholder livelihood. This program is designed to be in line with the culture of fishers in Sukabumi.
The economic value of peri-urban wetland ecosystem services in Phnom Penh, Cambodia
Authors: Ro C , Sovann C , Bun D , Yim C , Bun T , Yim S , Irvine K N
Published: September 2020

Boeng Cheung Aek is a large peri-urban wetland in south Phnom Penh, Cambodia that provides multiple ecosystem services, but increasing urban development has initiated an ambitious program of in-filling. In an effort to demonstrate the importance of the wetland to city planners, we have undertaken this research to document and value the ecosystem services provided by Boeng Cheung Aek. Using a mixed method approach of geospatial technology, household surveys, market value, and avoided cost assessments, we determined the economic value for wastewater treatment, food, and water provisioning in the wetlands is $30.12 millionUSD per year, but with a range of $15.71-$48.96 million USD per year.
Tea smallholder sustainability, a case study in Cisitu Village, West Java, Indonesia
Authors: Imam M I K , Setiadi H , Sumadio W
Published: September 2020

These days tea smallholders are facing droughts due to climate change. The government has several programs that aim at helping tea smallholders to solve their problems. The objective of this paper is to examine the sustainable livelihood approach of the tea smallholders by integrating the government programs and the resources that they have. Data is collected through semi-structured interviews with 15 tea smallholders in Cisitu Village in West Java. This village is about 25 kilometres from Sukabumi City, the capital city of the district of Sukabumi. Our analysis shows that smallholders with small resources tend to become poorer. Besides the limitation of their resources, the government programs do not seem to facilitate them. On the other hand, smallholders with strong and diverse assets gain benefits from the government programs. However, social capital is the main resource that could support poor smallholders to relieve their financial pressure. By joining the farmer group institutions, farmers will be supported to fulfil their farming needs. Besides the group institutions, almost all smallholders support their financial needs by running grocery stalls, planting cash crops, or having other another job in other areas
Transportation mode choice of workers in Cikupa Village, Cikupa Sub-district, Tangerang Regency, Banten Province
Authors: Hansa F , Susilowati M H D
Published: September 2020

In carrying out a travel plan, people will have to consider a lot of things such as distance and their financial abilities as well as various other considerations so that they are able to pick the most suitable transportation mode to reach their destination. This includes making a trip to one’s workplace. This research was conducted in Cikupa Sub-district, which is a sub-district with the highest number of workers in Tangerang Regency, as well as an industrial central area surrounded by regular and irregular settlements with differences in settlement quality, derived from settlement patterns, accessibility, and existing facilities, resulting in differences in the choice of transportation modes for work. This study aimed to analyze the transportation mode choice by workers in Cikupa Village and the variables that influence it. The variables studied were the travel-based characteristics including travel costs, travel time, and distance traveled. Variables were processed and analyzed with spatial analysis methods supported by statistical methods of chi-square and contingency coefficient. The results showed that the majority of workers in Cikupa Sub-district use private vehicles, mainly motorcycle. The results of the statistical test indicated that the only variables that greatly influenced the choice of transportation modes are travel costs and travel time.
Routing the highway development by using SuperMap Least Cost Path Analysis (LCPA) and Multi-Criteria Decision Analysis (MCDA) and its assessment toward spatial planning
Authors: Januadi M I , Nabila D N U
Published: September 2020

Highway as road network connectivity plays an important component in regional development that can overcome inter-regional development gaps. Spatial planning and cost priorities of the highway projects must be considered when examining the optimal highway routes, especially in areas that have varied slope characteristics like in Sukabumi-Cianjur area. Therefore, analysis and modeling are needed to show the choice of effective and efficient highway routes amid environmental condition in the region. Least Cost Path Analysis (LCPA) and Multi-Criteria Decision Analysis (MCDA) can be used to determine the optimal route of a road network. This modeling uses various criteria such as topography, geology, land use, and multi-hazard areas with three MDCA and LCPA simulation models. Based on the suitability of highway development with spatial planning in 2030 using scoring assessment, the optimal highway route from Sukabumi-Cianjur is LCPA-MDCA 1 with total score 69.06 and 49% length of the route that is suitable. Meanwhile LCPA-MDCA 3 shows total score 65.6 with 48,8% length that is suitable, and the least optimal route is LCPA-MDCA 2 with total score 65.48 and 44,6% length of the route that is suitable.
Estimation of changes in the lake water level and area using remote sensing techniques (Case study: Lake Toba, North Sumatra)
Authors: Aziz F , Kusratmoko E , Mandini M D
Published: September 2020

The decline in water level that occurred in Lake Toba, North Sumatra lately has become an important issue for the local government and the community around the lake. Climate factors also have a great impact especially when the extreme conditions ENSO and IOD occurred. The purpose of this research is to look at the relationship between rainfall and the ENSO and IOD through the changing of Lake Toba’s water surface level and area. Monitoring of the dynamics of the water surface level and area of Lake Toba can be analyzed through remote sensing by using Landsat imagery to be more effective and efficient. Then the image is processed by using the MNDWI (Modified Normalized Difference Water Index) method to separate water bodies from the land. Retrieval of Landsat imagery was taken in the range of 2008 - 2017, then selected years when the conditions of ENSO and IOD occurred. The results showed in 2008, which was the La-Nina year followed by a positive IOD, the surface area of water decreased to 4.45 km2 from the average area, but in 2015 when the El-Nino phase followed by positive IOD the water surface area increased to 4.7 km2 from the average area. ENSO and IOD did not have much influence on rainfall in the Lake Toba region but slightly affected the water surface level and area of Lake Toba.