scholarly journals Fire on the Water Towers: Mapping Burn Scars on Mount Kenya Using Satellite Data to Reconstruct Recent Fire History

2019 ◽  
Vol 11 (2) ◽  
pp. 104
Author(s):  
Mary C. Henry ◽  
John K. Maingi ◽  
Jessica McCarty
Keyword(s):  
Digital Elevation Model ◽  
Fire History ◽  
Slope Aspect ◽  
Burned Area ◽  
Semiarid Region ◽  
Landsat 8 ◽  
Hydroelectric Power ◽  
Active Fire ◽  
Digital Elevation ◽  
Elevation Model

Mount Kenya is one of Kenya’s ‘water towers’, the headwaters for the country’s major rivers including the Tana River and Ewaso Nyiro River, which provide water and hydroelectric power to the semiarid region. Fires affect water downstream, but are difficult to monitor given limited resources of local land management agencies. Satellite-based remote sensing has the potential to provide long term coverage of large remote areas on Mount Kenya, especially using the free Landsat data archive and moderate resolution imaging spectroradiometer (MODIS) fire products. In this study, we mapped burn scars on Mount Kenya using 30 m Landsat 7 Enhanced Thematic Mapper Plus (ETM+) and Landsat 8 Operational Land Imager (OLI) derived dNBR (change in normalized burn ratio) and MODIS active fire detection and burned area data for fires occurring from 2004 to 2015. We also analyzed topographic position (elevation, slope, aspect) of these fires using an ASTER global digital elevation model (GDEM v2) satellite-derived 30 m digital elevation model (DEM). Results indicate that dNBR images calculated from data acquired about one year apart were able to identify large fires on Mount Kenya that match locations (and timing) of MODIS active fire points and burned areas from the same time period, but we were unable to detect smaller and/or older fires.

Geoinformation mapping of landscapes on the example of the Primorskiy Ridge (Baikal region)

2020 ◽  
Vol 954 (12) ◽  
pp. 20-30
Author(s):  
Yu.V. Vanteeva ◽  
Е.А. Rasputina ◽  
S.V. Solodyankina
Keyword(s):  
Digital Elevation Model ◽  
Remote Sensing Data ◽  
Landsat 8 ◽  
Topographic Wetness Index ◽  
Space Images ◽  
Topographic Position Index ◽  
Digital Elevation ◽  
Different Seasons ◽  
Position Index ◽  
Elevation Model

The authors present the results of geoinformation mapping the Primorskiy Ridge landscapes using Landsat 8 satellite images, the digital elevation model SRTM and the factor-dynamic classification of geosystems. At the first stage, the remote sensing data for different seasons were classified using the ISODATA method. Then, using the digital elevation model, the landforms were classified basing upon the topographic position index. According to combining the classification parameters of one of the space images and digital elevation model, each polygon is automatically assigned to a certain preliminary type of landscapes using boolean expressions. Legend adjustments were made basing upon the fieldwork materials. As a result, a digital landscape map of the southern part of the Primorsky Ridge was created; it reflects the landscape structure at the level of facies groups and contains attributive information about the landform, altitude, slope and aspect, topographic wetness index. The analysis of the landscape pattern showed a high fragmentation of landscape polygons, formed due to overlay operations, which indicates the need for generalization of landscape contours.

Assessment of Hydropower Potential Using Geospatial Technology in a Case Study of Guna-Tana Landscape Upper Abay Basin, Ethiopia

2020 ◽  
Author(s):  
Asirat Teshome ◽  
Yonas Tibebu ◽  
Endalkachew Addis
Keyword(s):  
Digital Elevation Model ◽  
Hydroelectric Power ◽  
Stream Network ◽  
Geospatial Technology ◽  
Gis Tools ◽  
Digital Elevation ◽  
Hydropower Potential ◽  
Elevation Model ◽  
Planning And Construction

Abstract Background: In this study, geospatial technology was used to assess potential sites for hydroelectric potential in the Ribb and Gumara Rivers of the Guna-Tana landscape of the upper Abay basin in Ethiopia. The important parameters used in this study were the Digital Elevation Model, the stream network, the stream elevation; the stream slope, the height difference, and the stream flow were analysed. In addition, the results obtained from the geospatial model, satellite data and GIS tools were used to identify the hydroelectric potential in the landscape. Results: Twenty sites with hydroelectric potential were identified within the 3528.16 km2 of the Guna-Tana landscape. The maximum power in the Ribb River was 48,389.98 kW, while in the Gumara River it was 41,984.01 kW. Therefore, the development of strategies to improve the decision-making process for hydroelectric power planning and construction is of utmost importance to support renewable energy production with minimal negative environmental social impacts. Conclusion: Therefore, this study revealed that the hydroelectric potential of a river basin could be correctly assessed using a digital elevation model, stream network data, within a GIS framework.

scholarly journals STUDI PENDAHULUAN PENGINDERAAN JAUH DAN SISTEM INFORMASI GEOGRAFIS UNTUK ANALISIS MEDAN SKALA TINJAU DI SEBAGIAN PROVINSI SUMATERA SELATAN

GEOMATIKA ◽  
2018 ◽  
Vol 24 (2) ◽  
pp. 107
Author(s):  
Heratania Aprilia Setyowati ◽  
Ratna Nurani ◽  
Sigit Heru Murti Budi Santosa
Keyword(s):  
Digital Elevation Model ◽  
Shuttle Radar Topography Mission ◽  
Landsat 8 ◽  
Digital Elevation ◽  
Elevation Model

<p class="Papertext">Beragam cara dapat digunakan untuk mengetahui karakteristik suatu wilayah, salah satunya adalah analisis medan yang merupakan studi sistematik yang memanfaatkan data penginderaan jauh untuk menggali asal muasal, riwayat geomorfologi, dan komponen suatu bentang lahan. Tujuan dari studi pendahuluan ini untuk mengetahui karakteristik medan yang ada di sebagian daerah Sumatera Selatan melalui analisis medan dengan pembuatan sekuen medan yang berbasis citra penginderaan jauh. Citra Landsat 8 digunakan untuk mendapatkan informasi tutupan lahan dan bentuk lahan. Citra SRTM (<em>Shuttle Radar Topography Mission</em>) digunakan untuk menghasilkan data DEM (<em>Digital Elevation Model</em>), <em>h</em><em>illshade</em>, dan <em>s</em><em>lope</em> yang selanjutnya diturunkan menjadi peta topografi. Peta Geologi digunakan untuk menurunkan informasi mengenai jenis tanah. Peta arah aliran dan akumulasi air digunakan untuk menurunkan informasi kondisi drainase. Selanjutnya semua peta di<em>overlay</em> dan digunakan untuk menarik garis sekuen medan sebagai dasar identifikasi karakteristik medan. Berdasarkan hasil studi pendahuluan ini, dapat dikenali bahwa karakteristik medan sebagian Sumatera Selatan berbentuk lahan vulkanik, struktural dan fluvial dengan proses geomorfologi berupa erosi vertikal, transportasi, deposisi, dan sedimentasi. Aplikasi Penginderaan Jauh dan SIG dengan metode sekuen medan dapat digunakan untuk mengetahui karakteristik medan suatu wilayah.</p><p><em><br /></em></p>

scholarly journals ANALISIS CITRA SATELIT LANDSAT 8 DAN DEMNAS UNTUK IDENTIFIKASI PROSPEK PANAS BUMI DI KABUPATEN ACEH TENGAH, PROVINSI ACEH

2021 ◽  
Vol 16 (3) ◽  
pp. 166-184
Author(s):  
Lano Adhitya Permana ◽  
Husin Setia Nugraha ◽  
Sukaesih
Keyword(s):  
Principal Component Analysis ◽  
Surface Temperature ◽  
Digital Elevation Model ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Principal Component ◽  
Landsat 8 ◽  
Fracture Density ◽  
Digital Elevation ◽  
Elevation Model

Gabungan beberapa analisis pada citra satelit Landsat dan Digital Elevation Model Nasional (DEMNAS) dapat dipergunakan untuk mengidentifikasi indikasi area prospek panas bumi. Analisis dilakukan di Kabupaten Aceh Tengah yang diawali dari informasi keberadaan mata air panas pada peta geologi regional lembar Takengon. Metoda penginderaan jauh seperti metoda Fault and Fracture Density (FFD) dan interpretasi circular feature diterapkan pada citra DEMNAS. Sedangkan metoda Land Surface Temperature (LST) dan Direct Principal Component Analysis (DPCA) diterapkan pada citra Landsat 8. Kenampakan circular feature, anomali LST dan indikator adanya mineral ubahan bersuhu tinggi, dapat digunakan untuk memperkirakan keberadaan sumber panas. Sedangkan penerapan FFD digunakan untuk memperoleh indikator adanya zona dengan permeabilitas tinggi yang diperlukan dalam sistem panas bumi.   Hasil penelitian menunjukkan bahwa indikasi sumber panas diperkirakan berada pada komplek vulkanik Gunung Telege yang berada di daerah Kecamatan Atu Lintang. Hal ini diperlihatkan dengan adanya circular feature dan anomali LST yang terdapat di daerah tersebut. Penerapan metoda FFD mengindikasikan adanya zona outflow yang berada di sekitar manifestasi mata air panas yang terletak di sebelah barat laut Gunung Telege. Sedangkan dari hasil penerapan metoda DPCA sulit untuk diinterpretasi dikarenakan belum adanya pemisahan yang tegas antara indikator zona argilik lanjut dan zona propilitik dari hasil DPCA tersebut. Hal ini kemungkinan disebabkan adanya nilai pencampuran antar beberapa indikasi mineral dalam satu piksel yang sama. Secara umum, penggunaan metoda penginderaan jauh di Kabupaten Aceh Tengah dapat membantu untuk memberikan petunjuk awal adanya kemungkinan sistem panas bumi di daerah tersebut

scholarly journals Semi-automated Technique to Extract Boundary of Valley/mountain Glaciers using Glacio-morphological Information from Digital Elevation Model

2014 ◽  
Vol XL-8 ◽  
pp. 511-516
Author(s):  
M. Chakraborty ◽  
S. Panigrahy ◽  
S. Kundu
Keyword(s):  
Digital Elevation Model ◽  
Optical Data ◽  
Slope Aspect ◽  
Western Himalayas ◽  
Area Measure ◽  
Boundary Area ◽  
Mountain Glaciers ◽  
Digital Elevation ◽  
Automated Technique ◽  
Elevation Model

A semi automated technique has been developed to extract the spatial extension of valleys and mountain glaciers. The method is based on morphological properties of glaciated area extracted from Digital Elevation Model (DEM). Identification of glacial boundary based on spectral information from optical remote sensing imageries produces errors due to misclassification of debris-covered ablation area with surrounding rocky terrain and perennially snow-covered slope with debris free glaciated area. Elevation information DEM of Shuttle Radar Topography Mission (SRTM), CartoDEM and ASTER DEM have been used. A part of western Himalayas was selected as the study area that contains large glaciated basins, e.g., Bhagirathi, Baspa, Chandra basin. First order derivatives, slope aspect, and second order derivatives like, profile and plan curvatures are computed from the DEM. The derivatives are used to quantify and characterise the morphological aspects of the glaciated area and used in the decision rule models to generate the glacial boundaries. The ridge lines of the study areas are also generated from the plan curvature and used in the model to delineate the catchments areas of the glaciers. The slope based boundary is checked for consistency with the boundary from profile curvature and combined manually to generate the final glacier boundary. Area and length under the derived boundary of Gangotri glacier of Bhagirathi catchments are 90.25 sq km and 30.5 km. The result has been checked with high resolution optical data. This objective approach is important to delineate glaciated area, measure the length, width and area and generate glacial hypsometry, concentration factor of the glaciers. Accuracy of the result depends up on the quality of the DEM. DEM generated by SAR interferometric technique is found superior over DEM generated from other interpolation techniques.

scholarly journals Application of an Index-Based Approach in Geospatial Techniques for the Mapping of Flood Hazard Areas: A Case of Cape Coast Metropolis in Ghana

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3483
Author(s):  
Samuel Yaw Danso ◽  
Yi Ma ◽  
Yvonne Dodzi Ami Adjakloe ◽  
Isaac Yeboah Addo
Keyword(s):  
Digital Elevation Model ◽  
Flood Hazard ◽  
Landsat 8 ◽  
Soil Drainage ◽  
Cape Coast ◽  
Geospatial Techniques ◽  
Digital Elevation ◽  
African Soil ◽  
High Flood ◽  
Elevation Model

Floods remain one of the disasters that destroy properties, livelihoods, and in extreme situations, take lives. As a way of prevention, geospatial applications have been employed in many cities to map flood zones and predict floods. For a country such as Ghana, floods have been ranked as the second fatal disaster after epidemics leading to several kinds of research to resolve them. To date, the Cape Coast Metropolis (CCM) has received little attention in terms of research, though flood cases in the area continue to escalate. This study, therefore, examines the use of geospatial techniques as tools in addressing flood problems in the CCM of Ghana. From a Digital Elevation Model, hydrologic variables were generated using the ArcGIS software (Esri, Redlands, CA, USA). The soil drainage classification for the study was generated from a downloaded African Soil Grid Drainage map, while other important factors that influenced flooding in the CCM were obtained from Landsat 8 imagery. Over 21% of the CCM was classified as high flood hazard zones with areas around the river Kakum estuary being flood hotspots. It is, therefore, recommended that the CCM Assembly fund dredging of streams/rivers and promote afforestation along river banks to reduce the risk of flooding within the metropolis.

Evaluation of rainfall-induced large-scale landslide potential using Scoops3D

2020 ◽  
Author(s):  
Jie-Lun Chiang ◽  
Chia-Ming Kuo
Keyword(s):  
Digital Elevation Model ◽  
Groundwater Level ◽  
Large Scale ◽  
The United States ◽  
Equilibrium Analysis ◽  
Slope Aspect ◽  
Seismic Zone ◽  
Landslide Area ◽  
Digital Elevation ◽  
Elevation Model

&lt;p&gt;Taiwan is located in the Pacific volcanic seismic zone and frequently suffers from landslides and debris flow caused by typhoons. On average, there are four typhoons which may cause tremendous disasters such as massive landslides in Taiwan mainly from July to September every year. The aim of this study is to evaluate the development of large-scale landslide area under various cumulative rainfalls. The study area of this study is Liouquei, Kaohsiung in southern Taiwan. Firstly, the relationship of rainfall and groundwater level were built. The equation of change of groundwater level and rainfall is h=38.2R, R&lt;sup&gt;2&lt;/sup&gt;=0.83. Then, 10m digital elevation model (10m-dem) was used to evaluate elevation, slope, aspect and etc. Finally, geology and 10m-dem were used to build Scoops3D model of Liouquei area.&lt;/p&gt;&lt;p&gt;Scoops3D, which is released by the United States geological survey (USGS), evaluates slope stability throughout a digital landscape represented by a digital elevation model (DEM). The program uses a three-dimensional (3D) method of columns limit-equilibrium analysis to assess the stability of many potential landslides (typically millions) within a user-defined size range. We simulated the potential landslide area under a cumulative rainfall in 24 hours from 800mm~1600mm. The results show that landslide area contributed 65%~76% of the entire potential large-scale landslide area.&lt;/p&gt;

scholarly journals A 30 m terrace mapping in China using Landsat 8 imagery and digital elevation model based on the Google Earth Engine

2021 ◽  
Vol 13 (5) ◽  
pp. 2437-2456
Author(s):  
Bowen Cao ◽  
Le Yu ◽  
Victoria Naipal ◽  
Philippe Ciais ◽  
Wei Li ◽  
...  
Keyword(s):  
Digital Elevation Model ◽  
Google Earth ◽  
Landsat 8 ◽  
Spectral Features ◽  
Error Matrix ◽  
Cropland Area ◽  
Digital Elevation ◽  
Multi Temporal ◽  
Google Earth Engine ◽  
Elevation Model

Abstract. The construction of terraces is a key soil conservation practice on agricultural land in China providing multiple valuable ecosystem services. Accurate spatial information on terraces is needed for both management and research. In this study, the first 30 m resolution terracing map of the entire territory of China is produced by a supervised pixel-based classification using multisource and multi-temporal data based on the Google Earth Engine (GEE) platform. We extracted time-series spectral features and topographic features from Landsat 8 images and the Shuttle Radar Topography Mission digital elevation model (SRTM DEM) data, classifying cropland area (cultivated land of Globeland30) into terraced and non-terraced types through a random forest classifier. The overall accuracy and kappa coefficient were evaluated by 10 875 test samples and achieved values of 94 % and 0.72, respectively. For terrace class, the producer's accuracy (PA) was 79.945 %, and the user's accuracy (UA) was 71.149 %. The classification performed best in the Loess Plateau and southwestern China, where terraces are most numerous. Some northeastern, eastern-central, and southern areas had relatively high uncertainty. Typical errors in the mapping results are from the sloping cropland (non-terrace cropland with a slope of ≥ 5∘), low-slope terraces, and non-crop vegetation. Terraces are widely distributed in China, and the total terraced area was estimated to be 53.55 Mha (i.e., 26.43 % of China's cropland area) by pixel counting (PC) method and 58.46 ± 2.99 Mha (i.e., 28.85 % ± 1.48 % of China's cropland area) by error-matrix-based model-assisted estimation (EM) method. Elevation and slope were identified as the main features in the terrace/non-terrace classification, and multi-temporal spectral features (such as percentiles of NDVI, TIRS2, and BSI) were also essential. Terraces are more challenging to identify than other land use types because of the intra-class feature heterogeneity, interclass feature similarity, and fragmented patches, which should be the focus of future research. Our terrace mapping algorithm can be used to map large-scale terraces in other regions globally, and our terrace map will serve as a landmark for studies on multiple ecosystem service assessments including erosion control, carbon sequestration, and biodiversity conservation. The China terrace map is available to the public at https://doi.org/10.5281/zenodo.3895585 (Cao et al., 2020).

scholarly journals Flood modelling using satellite-based precipitation estimates and digital elevation model in eastern Iraq

2018 ◽  
Vol 6 (1) ◽  
pp. 72 ◽  
Author(s):  
Zaidoon Abdulrazzaq ◽  
Nadia Aziz ◽  
Abdulkareem Mohammed
Keyword(s):  
Digital Elevation Model ◽  
Rainfall Intensity ◽  
Tropical Rainfall Measuring Mission ◽  
Rain Gauge ◽  
Landsat 8 ◽  
Flood Prediction ◽  
Tropical Rainfall ◽  
Digital Elevation ◽  
Elevation Model ◽  
The Relationship

Increasingly available and a virtually uninterrupted supply of satellite-estimated rainfall data is gradually becoming a cost-effective source of input for flood prediction under a variety of circumstances. The study conducted in Wasit province/Eastern Iraq when a flood occurs due to heavy rainfall in May 2013. In this study the capability of Tropical Rainfall Measuring Mission (TRMM) rainfall daily data have been used to estimate the relationship between measured precipitation and the Digital Elevation Model (DEM), also to study the relationship between rainfall intensity and flood waters areas. Rainfall estimation by remote sensing using satellite-derived data from the Tropical Rainfall Measuring Mission (TRMM) is a possible means of supplementing rain gauge data, having the better spatial cover of rainfall fields. The approach used throughout this paper has integrated recently compiled data derived from satellite imagery (rainfall, and digital elevation model) into a GIS geodatabase to study the relationship between rainfall intensity and floodwater's areas then the results' comparison with the Normalized Difference Water Index (NDWI) after the flood. ArcGIS software has been used to process, analyze the archived Tropical Rainfall Measuring Mission (TRMM) precipitation data, and calculate NDWI from Landsat 8 images. In conclusions, the study explains the flood-area clearly captured by the TRMM measurements; and the region’s water increased. Also, good correlation between measured precipitation and the Digital Elevation Model (DEM) has been detected.

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