scholarly journals Flood Inundation Modeling Using Geomorphic Approaches, UAV, and GIS

2020 ◽  
Vol 4 (1) ◽  
pp. 335-342
Author(s):  
Dhoni Wicaksono ◽  
Lufti Gita Iriani ◽  
Hendy Fatchurohman ◽  
Taufik Hery Purwanto ◽  
Dwi Setyo Aji ◽  
...  
Keyword(s):  
Aerial Photographs ◽  
Mitigation Measures ◽  
Flood Inundation ◽  
Digital Elevation ◽  
Aerial Vehicle ◽  
The Indian Ocean ◽  
Elevation Model ◽  
Flood Inundation Modeling ◽  
Inundation Modeling ◽  
Special Region

Flood is one of the most frequently occurring natural disasters in Indonesia. At the end of 2017, Tropical Cyclones Cempaka and Dahlia formed over the Indian Ocean, inducing extreme rains and floods in some parts of Java Island. The Special Region of Yogyakarta was among the most affected areas, especially along the Oyo River section in Imogiri District. This research was designed to identify and map the flood-prone areas in the district as part of flood mitigation measures. For this purpose, The Unmanned Aerial Vehicle (UAV) technology was used to not only provide a detailed and up-to-date description but also produce aerial photographs (orthoimages) and Digital Elevation Model (DEM). These two products were inputted to the inundation modeling developed with a geomorphic approach and simulated in a Geographic Information System (GIS). In terms of accuracy, the resulting models were quite reliable for mapping on a detailed scale and only slightly deviated from the traced inundation in the field. Also, five areas (sub-village) were found with the highest vulnerability to floods, namely, Trukan, Butuh, Dogongan, Siluk Satu, and Kedung Miri.

scholarly journals Pemanfaatan Foto Udara Format Kecil untuk Ekstraksi Digital Elevation Model dengan Metode Stereoplotting

2017 ◽  
Vol 31 (1) ◽  
pp. 73 ◽  
Author(s):  
Taufik Hery Purwanto
Keyword(s):  
Digital Elevation Model ◽  
Unmanned Aerial Vehicle ◽  
Aerial Photography ◽  
Digital Camera ◽  
Aerial Photographs ◽  
Test Results ◽  
Accuracy Test ◽  
Digital Elevation ◽  
Aerial Vehicle ◽  
Elevation Model

Perkembangan Unmanned Aerial Vehicle (UAV) sebagai wahana dan kamera digital non-metrik sebagai sensor semakin mempermudah dalam akuisisi data foto udara Foto Udara Format Kecil (FUFK). Penelitian ini bertujuan menerapkan metode stereoplotting digital untuk menghasilkan Digital Elevation Model (DEM) dari FUFK hasil pemotretan udara dengan wahana UAV sebagian bukit Jering yang merupakan lokasi pembangunan perumahan murah bersubsidi Godean Jogja Hill’s. Metode penelitian ini meliputi: proses perencanaan (perencanaan jalur terbang, pelaksanaan pemotretan udara), pengolahan data (kalibrasi kamera, koreksi foto udara, stereoplotting, interpolasi), dan uji akurasi. Hasil penelitian adalah blok FUFK dan DEM dengan metode stereoplotting. Kesimpulan dari penelitian ini adalah FUFK yang diperoleh dari UAV memiliki distorsi lensa yang cukup besar, oleh karena itu stereoplotting interaktif dapat diterapkan pada FUFK dengan hasil yang cukup baik jika FUFK yang digunakan telah terkoreksi dari distorsi, terutama distorsi lensa. Akurasi absolut DEM yang dihasilkan memiliki HRMSE sebesar 0.073 meter dengan horizontal accuracy yang mencapai 0.121 meter, sedangkan RMSEz yang dimiliki hanya mampu mencapai 0.482 meter dengan vertical accurasi yang mencapai 0.793 meter pada tingkat kepercayaan 90%. Berdasarkan DEM yang diperoleh, maka dapat digunakan untuk merepresentasikan konfigurasi permukaan bukit dan menghitung volume sebagian bukit Jering yang telah dikeruk sebesar 55.953,813 m3. The development of Unmanned Aerial Vehicle (UAV) as a vehicle and non-metric digital camera as a sensor further simplify the data acquisition of Small Format Aerial Photography (SFAP). This study aims to apply digital stereoplotting method for generating Digital Elevation Model (DEM) of SFAP results of aerial photography with UAV on the Jering hill which is cheap subsidized housing location named Godean Yogyakarta Hill’s. This research method includes: flight planning (flight paths, aerial photography acquisition), data processing (camera calibration, correction of aerial photographs, stereoplotting, interpolation), and accuracy test. Results of the research was SFAP block and DEM generated from stereoplotting method. The conclusion of this study is SFAP obtained from UAV has a lens distortion is large, and therefore can be applied to interactive stereoplotting SFAP with fairly good results if SFAP used has been corrected of distortion, especially distortion lens (idealized). The absolute accuracy of the resulting DEM have HRMSE of 0,073 meters with a horizontal accuracy which reaches 0,121 meters, while RMSEz only able to reach 0,482 meters with a vertical accuracy which reaches 0793 meters at 90% confidence level. Based on the DEM obtained, it can be used to represent the surface configuration and to calculate the volume partially Jering hill that has been dredged out for is 55.953,813 m3.  

scholarly journals MODEL PENDUGAAN DIAMETER POHON BERBASIS CITRA UNMANNED AERIAL VEHICLE (UAV) PADA HUTAN HUJAN TROPIS PAPUA: STUDI DI PULAU MANSINAM PAPUA BARAT (Model of Tree Diameter Estimation Based on Unmanned Aerial Vehicle (UAV) Image in Papua Tropical Rain Forest: a Study in Mansinam Island Papua Barat)

2021 ◽  
Vol 5 (1) ◽  
pp. 16-30
Author(s):  
Francine Hematang ◽  
◽  
Agustinus Murdjoko ◽  
Hendri Hendri ◽  
◽  
...  
Keyword(s):  
Digital Elevation Model ◽  
Unmanned Aerial Vehicle ◽  
Land Surface ◽  
Aerial Photographs ◽  
Aerial Photos ◽  
Digital Elevation ◽  
Aerial Vehicle ◽  
Papua Barat ◽  
Elevation Model ◽  
Uav Image

Abstract Unmanned aerial vehicles (UAV) have often been used for various purposes, not only for photography but also have been used for science in various scientific fields, including forestry. UAV has the ability to move freely in the air and record objects on the ground with high spatial resolution and wide area coverage. This study aimed to estimate the diameter at breast height (DBH) based on the image generated from the UAV. UAV was used to obtain aerial photographs taken at an altitude of 150 m above the land surface in four sample areas of 27 ha at the study site. Aerial photos were processed using agisoft photoscan software to produce a Digital Elevation Model (DEM) and orthophoto. Tree crowns were delineated from orthophoto and analyzed to obtain crown area and diameter. DBH measurements in the field were carried out on 206 sample trees used to build a DBH estimator model. The correlation test results showed that the crown diameter has a high correlation with DBH so that this variable was used as an independent variable. The best DBH estimator model was the polynomial model with the equation y = 0.0118744 x² + 1.08835 x + 22.8125, where y is DBH and x is the canopy diameter of the aerial photo interpretation results. Estimating DBH using UAV has several benefits, such as reducing time, cost and labour. Abstrak Unmanned aerial vehicle (UAV) sudah sering digunakan untuk berbagai tujuan, bukan hanya untuk fotografi, namun telah dimanfaatkan untuk sains di berbagai bidang keilmuan, termasuk bidang kehutanan. UAV memiliki kemampuan bergerak dengan bebas di udara dan merekam objek di darat dengan resolusi spasial tinggi, dan cakupan areal yang luas. Penelitian ini bertujuan untuk melakukan pendugaan diameter setinggi dada (DBH) berdasarkan citra yang dihasilkan dari UAV. UAV digunakan untuk memperoleh foto udara yang diambil pada ketinggian 150 m di atas permukaan darat pada empat areal sampel seluas 27 ha di lokasi penelitian. Foto udara diproses dengan menggunakan perangkat lunak agisoft photoscan untuk menghasilkan Digital Elevation Model (DEM) dan ortofoto. Tajuk pohon dideliniasi dari ortofoto dan dianalisis untuk memperoleh luas dan diameter tajuk. Pengukuran DBH di lapangan dilakukan terhadap 206 pohon sampel yang selanjutnya digunakan untuk membangun model penduga DBH. Hasil uji korelasi menunjukkan bahwa diameter tajuk mempunyai korelasi yang tinggi dengan DBH sehingga variable ini digunakan sebagai variable bebas. Model terbaik penduga DBH adalah model polinomial dengan persamaan y = 0,0118744 x² + 1,08835 x + 22,8125, dengan y adalah DBH dan x adalah diameter tajuk hasil interpretasi foto udara. Pendugaan DBH menggunakan UAV memiliki beberapa manfaat seperti mampu mengurangi waktu, biaya dan tenaga kerja.

scholarly journals Visible and near-infrared digital images for determination of ice velocities and surface elevation during a surge on Osbornebreen, a tidewater glacier in Svalbard

1997 ◽  
Vol 24 ◽  
pp. 255-261 ◽  
Author(s):  
Cecilie Rolstad ◽  
Jostein Amlien ◽  
Jon-Ove Hagen ◽  
Bengt Lundén
Keyword(s):  
Velocity Field ◽  
Near Infrared ◽  
Aerial Photographs ◽  
Correlation Technique ◽  
Digital Elevation ◽  
Compressive Flow ◽  
Tidewater Glacier ◽  
Extension Zone ◽  
Elevation Model ◽  
Cross Correlation Technique

A field of vectors showing the average velocity of the surging glacier Osbornebreen, Svalbard, was determined by comparing sequential SPOT (Système pour l’Observation de la Terre) and Landsat thematic mapper images. Crevasses which developed during the initial phase of the surge in the winter of 1986–87 were tracked using a fast Fourier chip cross-correlation technique. A digital elevation model (DEM) was developed using digital photogrammetry on aerial photographs from 1990. This new DEM was compared with a map drawn in 1966. The velocity field could be almost entirely determined with 1 month separation of the images, but only partly determined with images 1 year apart, due to changes of the crevasse pattern. The velocity field is similar to that found for Kronebreen, a continuously fast-moving tidewater glacier. No distinct zones of compressive flow were present and the data gave no evidence of a compression zone/surge front traveling downstream. The velocity field, the rapid advance of the terminus and the development of transverse crevasses in the upper accumulation area within a 6 month period may indicate that the surge developed as a zone of extension starting near the terminus and propagating quickly upstream. The crevasse pattern in the images is therefore interpreted to be the result of the extension zone traveling upstream, and, as the whole glacier starts to slide, the crevasse pattern alters according to the bedrock topography.

scholarly journals Terrain-Based Shadow Correction Method for Assessing Supraglacial Features on the Greenland Ice Sheet

2021 ◽  
Vol 2 ◽  
Author(s):  
Sasha. Z. Leidman ◽  
Åsa K. Rennermalm ◽  
Richard G. Lathrop ◽  
Matthew. G. Cooper
Keyword(s):  
Land Surface ◽  
Greenland Ice Sheet ◽  
Correction Method ◽  
Correction Coefficient ◽  
Digital Elevation ◽  
Aerial Vehicle ◽  
Sediment Cover ◽  
Elevation Model ◽  
Uav Images ◽  
Gis Software

The presence of shadows in remotely sensed images can reduce the accuracy of land surface classifications. Commonly used methods for removing shadows often use multi-spectral image analysis techniques that perform poorly for dark objects, complex geometric models, or shaded relief methods that do not account for shadows cast on adjacent terrain. Here we present a new method of removing topographic shadows using readily available GIS software. The method corrects for cast shadows, reduces the amount of over-correction, and can be performed on imagery of any spectral resolution. We demonstrate this method using imagery collected with an uncrewed aerial vehicle (UAV) over a supraglacial stream catchment in southwest Greenland. The structure-from-motion digital elevation model showed highly variable topography resulting in substantial shadowing and variable reflectance values for similar surface types. The distribution of bare ice, sediment, and water within the catchment was determined using a supervised classification scheme applied to the corrected and original UAV images. The correction resulted in an insignificant change in overall classification accuracy, however, visual inspection showed that the corrected classification more closely followed the expected distribution of classes indicating that shadow correction can aid in identification of glaciological features hidden within shadowed regions. Shadow correction also caused a substantial decrease in the areal coverage of dark sediment. Sediment cover was highly dependent on the degree of shadow correction (k coefficient), yet, for a correction coefficient optimized to maximize shadow brightness without over-exposing illuminated surfaces, terrain correction resulted in a 49% decrease in the area covered by sediment and a 29% increase in the area covered by water. Shadow correction therefore reduces the overestimation of the dark surface coverage due to shadowing and is a useful tool for investigating supraglacial processes and land cover change over a wide variety of complex terrain.

scholarly journals Rockfall Risk Analysis Based on Precise Topography using UAV

2020 ◽  
Vol 20 (4) ◽  
pp. 63-73
Author(s):  
Jaehee Choi ◽  
Namgyun Kim ◽  
Bongjin Choe ◽  
Byonghee Jun
Keyword(s):  
Point Cloud Data ◽  
University Campus ◽  
Digital Map ◽  
Cloud Data ◽  
The Road ◽  
Mountainous Regions ◽  
Digital Elevation ◽  
Surface Models ◽  
Aerial Vehicle ◽  
Elevation Model

In this study, the risk of rockfall on incision slopes adjacent to roads was evaluated using the RocFall program. The study area was a slope adjacent to the road leading to a university campus in Samcheok-si, Gangwon-do, with an area of 774 m<sup>2</sup> and an average slope of approximately 43°. A rock shed was installed at the lower zone of the slope. A 3D model of the terrain was generated based on point cloud data gathered using a UAV (unmanned aerial vehicle). Fast and accurate orthoimages were captured by UAV and high-resolution digital surface models (DSMs) were produced; these data were used to assess the risk of rockfall. Compared to terrain extraction using a digital elevation model (DEM) generated from an existing digital map, terrain extraction using a UAV was more effective in deriving results close to the actual situation in the field, especially for the analysis of rockfall jump height and kinetic energy. The necessity of constructing 3D topographic data using UAVs to predict rockfall disasters in mountainous regions was confirmed.

scholarly journals Flood Risk Management Methodology for Lakes and Adjacent Areas: The Lake Pamvotida Paradigm

Proceedings ◽  
2018 ◽  
Vol 7 (1) ◽  
pp. 21
Author(s):  
George Papaioannou ◽  
Athanasios Loukas ◽  
Lampros Vasiliades
Keyword(s):  
Risk Management ◽  
Natural Hazards ◽  
Flood Risk ◽  
Urban Areas ◽  
Hydrologic Modeling ◽  
Flood Risk Management ◽  
Flood Inundation ◽  
Hydrodynamic Simulations ◽  
Flood Inundation Modeling ◽  
Inundation Modeling

In recent decades, natural hazards have caused major disasters in natural and man-made environments. Floods are one of the most devasting natural hazards, with high levels of mortality, destruction of infrastructure, and large financial losses. This study presents a methodological approach for flood risk management at lakes and adjacent areas that is based on the implementation of the EU Floods Directive (2007/60/EC) in Greece. Contemporary engineering approaches have been used for the estimation of the inflow hydrographs. The hydraulic–hydrodynamic simulations were implemented in the following order: (a) hydrologic modeling of lake tributaries and estimation flood flow inflow to the lake, (b) flood inundation modeling of lake tributaries, (c) simulation of the lake as a closed system, (d) simulation of the lake outflows to the adjacent areas, and (e) simulation of flood inundation of rural and urban areas adjacent to the lake. The hydrologic modeling was performed using the HEC-HMS model, and the hydraulic-hydrodynamic simulations were implemented with the use of the two-dimensional HEC-RAS model. The simulations were applied to three soil moisture conditions (dry, medium and wet) and three return periods (T = 50, T = 100 and T = 1000 years) and a methodology was followed for the flood inundation modeling in urban areas. Upper and lower estimates on water depths, flow velocities and inundation areas are estimated for all inflow hydrographs and for varying roughness coefficient values. The proposed methodology presents the necessary steps and the results for the assessment of flood risk management and mapping for lake and adjacent urban and rural areas. The methodology was applied to Lake Pamvotida in Epirus, Greece, Ioannina.

Artificial neural network based hybrid modeling approach for flood inundation modeling

2021 ◽  
Vol 592 ◽  
pp. 125605
Author(s):  
Shuai Xie ◽  
Wenyan Wu ◽  
Sebastian Mooser ◽  
Q.J. Wang ◽  
Rory Nathan ◽  
...  
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Hybrid Modeling ◽  
Flood Inundation ◽  
Modeling Approach ◽  
Artificial Neural ◽  
Flood Inundation Modeling ◽  
Inundation Modeling
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