MAPPING MULTI-SCALED LANDSCAPE TYPOLOGY OF LANG SON PROVINCE

2021 ◽  
Vol 66 (3) ◽  
pp. 207-220
Author(s):  
Dung Bui Thi Thanh

The landscape of a territory is generated by natural components, and it is also influenced by human activities. The complexity of factors making up landscape and the relationship between them with humans has created a diverse and complex differentiation of landscape in Lang Son province. Three factors reflecting typical characteristics of Lang Son landscape: Digital Elevation Model (DEM), soil, and land cover have been selected in this study. The concept of multiscaled landscape classification based on the European Landscape Convention (ELC) is applied for combining the holistic with parametric approaches and combining typological with multi-scaled landscape classifications. A number of possible combinations between 9 land cover variables, 9 soil combination variables, and 5 topographic variables have yielded 40 landscape units for Lang Son province. The obtained results are basic documents for contributing to modern and practical landscape research on the one hand, and to territory planning for sustainable development of Lang Son on the other hand.

2011 ◽  
Vol 8 (3) ◽  
pp. 4381-4425
Author(s):  
S. Gharari ◽  
F. Fenicia ◽  
M. Hrachowitz ◽  
H. H. G. Savenije

Abstract. This paper presents a new type of hydrological landscape classification based on dominant runoff mechanisms. Three landscape classes are distinguished: wetland, hillslope and plateau, corresponding to three dominant hydrological regimes: saturation excess overland flow, storage excess sub-surface flow, and deep percolation. Topography, geology and land use hold the key to identifying these landscapes. The height above the nearest drain (HAND) and the surface slope, which can be readily obtained from a digital elevation model, appear to be the dominant topographical parameters for hydrological classification. In this paper several indicators for classification are tested as well as their sensitivity to scale and sample size. It appears that the best results are obtained by the simple use of HAND and slope. The results obtained compare well with field observations and the topographical wetness index. The new approach appears to be an efficient method to "read the landscape" on the basis of which conceptual models can be developed.


2018 ◽  
pp. 67-75
Author(s):  
Nenad Marković ◽  
Miroslava Marković

At the end of November/beginning of December 2014, an ice wave hit the whole of Eastern Serbia and caused extensive ice and snow breaks in the forest areas managed by SE `Srbijašume` - Forest Estates of Niš, Boljevac, Kruševac, Despotovac and Kučevo. The areas affected were determined by identifying all the affected units of forest division - with the lowest accuracy at the level of forest stands and, where possible by GPS recording in the field in order to ensure greater accuracy. The identified areas were presented in GIS mapping software. The total area affected by ice breaks amounted to 19,419.78 ha. It included 8,301.01 ha of high forests, 8,997.37 ha of coppice forests and 2,121.40 ha of artificially-established stands. Considering the size of the forest area affected by ice breaks on the one hand, and the huge environmental impact of forests on the other hand, this phenomenon may be considered a natural disaster. Having identified the affected forest areas, an analysis of the relationship between orographic characteristics and ice break occurrence was carried out with the use of GIS tools. The following orographic characteristics were studied: the elevation, the terrain aspect and the slope, all obtained from the digital elevation model (DEM) at a resolution of 1 arc-second. Elevation had the greatest influence on the occurrence of ice breaks. The largest area affected (ca.17,000 ha) was in the range from 600 to 900 m above sea level, i.e. in the belt of low-mountain relief. Regarding the aspect of the investigated terrain, the largest areas affected by ice breaks had northern (ca. 4,000 ha) and northeastern aspects (ca. 3,500 ha), while the remaining areas were equally distributed in all other aspects. The slope was not found to have any significant effects on the occurrence of ice breaks. This disaster brought about most severe and extensive consequences in broad-leaved and coniferous ecosystems and the environment in general, with long-term adverse effects such as changing soil water regimes, erosion, declining atmospheric oxygen levels and reduced carbon accumulated in biomass.


2011 ◽  
Vol 15 (11) ◽  
pp. 3275-3291 ◽  
Author(s):  
S. Gharari ◽  
M. Hrachowitz ◽  
F. Fenicia ◽  
H. H. G. Savenije

Abstract. This paper presents a detailed performance and sensitivity analysis of a recently developed hydrological landscape classification method based on dominant runoff mechanisms. Three landscape classes are distinguished: wetland, hillslope and plateau, corresponding to three dominant hydrological regimes: saturation excess overland flow, storage excess sub-surface flow, and deep percolation. Topography, geology and land use hold the key to identifying these landscapes. The height above the nearest drainage (HAND) and the surface slope, which can be easily obtained from a digital elevation model, appear to be the dominant topographical controls for hydrological classification. In this paper several indicators for classification are tested as well as their sensitivity to scale and resolution of observed points (sample size). The best results are obtained by the simple use of HAND and slope. The results obtained compared well with the topographical wetness index. The HAND based landscape classification appears to be an efficient method to ''read the landscape'' on the basis of which conceptual models can be developed.


2017 ◽  
Vol 1 (2) ◽  
pp. 642-660 ◽  
Author(s):  
Irmela Herzog

The aim of this contribution is on the one hand to map pre-industrial long distance roads located in a hilly region east of Cologne, Germany, as exactly as possible and on the other hand to assess the accuracy of least-cost approaches that are increasingly applied by archaeologists for prehistoric road reconstruction. Probably the earliest map covering the study area east of Cologne dates back to 1575. The map is distorted so that rectification is difficult. But it is possible to assess the local accuracy of the map and to transfer the approximate routes to a modern map manually. Most of the area covered by the 1575 map is also depicted on a set of more accurate maps created in the early 19th century and a somewhat later historical map set (ca. 1842 AD). The historical roads on these rectified historical maps close to the approximate roads were digitized and compared to the outcomes of least-cost analysis, specifically least-cost paths and accessibility maps. Based on these route reconstructions with limited accuracy, Lidar data is checked to identify remains of these roads. Several approaches for visualizing Lidar data are tested to identify appropriate methods for detecting sunken roads. Possible sunken roads detected on the Lidar images were validated by checking cross sections in the digital elevation model and in the field.


2001 ◽  
Vol 34 (1) ◽  
pp. 29 ◽  
Author(s):  
Ε. ΜΑΝΟΥΤΣΟΓΛΟΥ ◽  
Ε. ΣΠΥΡΙΔΩΝΟΣ ◽  
Α. SOUJON ◽  
V. JACOBSHAGEN

The island of Crete is situated near the front of an active plate margin. Therefore, it is of great interest in the framework of the International Continental Drilling Project (I.C.D.P.). A short review of the digital modelling methods, their applications in the geosciences and the associated advantages is also presented. The digital 3-dimensional geometric model of the geological structure of the Samaria Gorge region is based on the study of the stratigraphy and the tectonic evolution of the metamorphic rocks of the Plattenkalk group in SW Crete. Data from the geological map of Greece (Vatolakkos sheet, 1:50.000) and from the literature have been supplemented by geological mapping and structural analyses. In our study we applied interactive 3D CAD methods implemented in the integrated software package SURPAC2000. The surface geology has been draped over a digital elevation model of the topography in order to model the geometry of the subsurface structures. Two hypotheses about the geological structure of the region are examined: a) the one given by the existing geological map, which proposes a syncline structure and b) the one resulting from the combination of existing data, corrections carried out through repeated 3D simulations and new field observations. After distinguishing in the S of the study area the Trypali union, overthrusted on the Plattenkalk group, we propose an anticline structure with a NNE/SSW striking axis dipping to the NE.


2021 ◽  
Author(s):  
Pawan Thapa ◽  
Narayan Thapa

Abstract Background: The impact of flooding rises due to unplanned settlements, especially in developing and underdeveloped countries. This study tries to address these issues by mapping flood risk places and assessing their impact on population and household.Methods: This study used the dataset available in Google Earth Engine (GEE), Food and Agriculture Organization (FAO), Central Bureau Statistics (CBS), Earth Data for preparing slope, drainage density, digital elevation model, rainfall, land use map, and soil map. These maps create using GEE and QGIS through overlay analysis that has two factors. The one is influence and other slopes, and it has provided high and low value according to its role on flooding.Results: The risk assessment shows around twenty-four percent population is at higher risk, whereas more than three thousand settlements are prone to flooding. It depicts a significant increasing trend of floods in the Morang district.Conclusion: This settlement risk map can help determine the flood safe and very high-risk areas in the Morang district. It will support residential places' planning by the local government, urban planners, and community people to reduce flooding risk.


2021 ◽  
Author(s):  
Pawan Thapa ◽  
Narayan Thapa

Abstract Background: The impact of flooding rises due to unplanned settlements, especially in developing countries. This study tries to address these issues by mapping flood risk places and assessing their impact on population and household.Methods: This study used the dataset available in Google Earth Engine (GEE), Food and Agriculture Organization (FAO), Central Bureau Statistics (CBS), Earth Data for preparing slope, drainage density, digital elevation model, rainfall, land use map, and soil map. These maps create using GEE and QGIS through overlay analysis that has two factors. The one is influence and other slopes, and it has provided high and low value according to its role on flooding.Results: The risk assessment shows around twenty-four percent population is at higher risk, whereas more than three thousand settlements are prone to flooding. It depicts a significant increasing trend of floods in the Morang district.Conclusion: This settlement risk map can help determine the flood safe and very high-risk areas in the Morang district. It will support residential places' planning by the local government, urban planners, and community people to reduce flooding risk.


Geosciences ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 340 ◽  
Author(s):  
Marcelo Cando Jácome ◽  
Antonio Martínez-Graña

Mass movements in deformed areas of natural relief deformed by seismotectonic factors are one of the most destructive and recurrent natural hazards in the Republic of Ecuador, especially during intense rain periods, the El Niño phenomenon, or due to earthquakes such as the one that occurred on 16 April 2016 in the Ecuadorian coastline. This study proposes the application of Hydrological Model D8 and its derived morphometric parameters like slope, orientation of the slope, and curvatures, extracted from the high spatial resolution Digital Elevation Model (DEM), implemented in programs such as Rockworks 7 (gridzo), SURFER (downwards slope), ArcView (flowacc), and SAGA (curvatures) to obtain runoff flow, structural geological lineaments, and superficial deformations of the topographic relief that are the origin of erosion, superficial landslides, lateral propagation, of the rock–soil complex, mass flows, and deep gravitational deformations. This methodology has been validated in three locations with intense deformations: two in Ecuador and one in Spain. The DEM were obtained from the Ecuadorian Spatial Institute (ESI) (spatial resolution of 10 m), the Rural Technological Infrastructure and Information National System (SIGTIERRAS) (spatial resolution of 5 m), and the Council of Andalusia (spatial resolution of 5 m).


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