scholarly journals Inventory, Distribution and Geometric Characteristics of Landslides in Baoshan City, Yunnan Province, China

2020 ◽  
Vol 12 (6) ◽  
pp. 2433 ◽  
Author(s):  
Xiaoyi Shao ◽  
Siyuan Ma ◽  
Chong Xu ◽  
Lingling Shen ◽  
Yongkun Lu
Keyword(s):  
Spatial Distribution ◽  
Yunnan Province ◽  
Lower Boundary ◽  
Google Earth ◽  
Landslide Susceptibility Mapping ◽  
Slope Position ◽  
Large Set ◽  
Geologic Hazard ◽  
Geometric Characteristics ◽  
High Resolution Satellite Images

Inventorying landslides in mountainous areas is of great importance for prevention of geologic hazards. This study aimed to establish a detailed landslide inventory of Baoshan City, Yunnan Province, China, based on a large set of high-resolution satellite images from Google Earth. The landslides of this region were divided into two groups, i.e., recent landslides and old landslides. The spatial distribution and geometric characteristics of the two kinds of landslides were analyzed, respectively. Results show that 2427 landslides are present in the study area, including 2144 recent landslides and 283 old landslides with a total area of 7.2 km2 and 97.6 km2, respectively. The recent landslides occurred primarily at steep slopes with higher elevation, while old landslides took place at gentle terrains. For the slope position, most landslides, whether old or recent, cluster near ridges. The lower boundary of the recent landslides is far away from the valley, while the accumulation area of the old landslide is closer to the valley. The H/L (height to length) ratios are basically the same for all landslides, ranging from 0.2 to 0.5. Old landslides have larger mobility, as their travel distances are longer than recent landslides at the same height. The results would be helpful for further understanding the development and spatial distribution of the landslides in Southwest China, and also provide essential support for the subsequent landslide susceptibility mapping and geologic hazard assessment in this area.

scholarly journals Inventory and Distribution Characteristics of Large-Scale Landslides in Baoji City, Shaanxi Province, China

2021 ◽  
Vol 11 (1) ◽  
pp. 10
Author(s):  
Lei Li ◽  
Chong Xu ◽  
Xiwei Xu ◽  
Zhongjian Zhang ◽  
Jia Cheng
Keyword(s):  
Spatial Distribution ◽  
Loess Plateau ◽  
Large Scale ◽  
Google Earth ◽  
Shaanxi Province ◽  
Landslide Susceptibility Mapping ◽  
Slope Position ◽  
Slope Aspect ◽  
Distribution Characteristics ◽  
The Loess Plateau

Inventories of historical landslides play an important role in the assessment of natural hazards. In this study, we used high-resolution satellite imagery from Google Earth to interpret large landslides in Baoji city, Shaanxi Province on the southwestern edge of the Loess Plateau. Then, a comprehensive and detailed map of the landslide distribution in this area was prepared in conjunction with the historical literature, which includes 3440 landslides. On this basis, eight variables, including elevation, slope, aspect, slope position, distance to the fault, land cover, lithology and distance to the stream were selected to examine their influence on the landslides in the study area. Landslide number density (LND) and landslide area percentage (LAP) were used as evaluation indicators to analyze the spatial distribution characteristics of the landslides. The results show that most of the landslides are situated at elevations from 500 to 1400 m. The LND and LAP reach their peaks at slopes of 10–20°. Slopes facing WNW and NW directions, and middle and lower slopes are more prone to sliding with higher LND and LAP. LND and LAP show a decreasing trend as the distance to the fault or stream increases, followed by a slow rise. Landslides occur primarily in the areas covered by crops. Regarding lithology, the regions covered by the Quaternary loess and Cretaceous gravels are the main areas where landslides occur. The results would be helpful for further understanding the developmental characteristics and spatial distribution of landslides on the Loess Plateau, and also provide a support to subsequent landslide susceptibility mapping in this region.

scholarly journals Mapping Panax Notoginseng Plantations by Using an Integrated Pixel- and Object-Based (IPOB) Approach and ZY-3 Imagery

2021 ◽  
Vol 13 (11) ◽  
pp. 2184
Author(s):  
Zhiqi Yang ◽  
Jinwei Dong ◽  
Weili Kou ◽  
Yuanwei Qin ◽  
Xiangming Xiao
Keyword(s):  
Spatial Distribution ◽  
Yunnan Province ◽  
Vascular Diseases ◽  
Panax Notoginseng ◽  
Traditional Herbal Medicine ◽  
Target Class ◽  
Object Based ◽  
The Government ◽  
Level Scale ◽  
Iteration Analysis

Plantations of Panax notoginseng (PN), traditional herbal medicine for the prevention and treatment of vascular diseases, are expanding rapidly in China, especially in the Yunnan province of China, due to its increasing demands and prices and causing dramatic environmental concerns. However, existing information on its planting area and spatial distribution are limited. Here, we mapped the PN planting area by using a new integrated pixel- and object-based (IPOB) approach, the Random Forest (RF) classifier, and the high-resolution ZiYuan-3 (ZY-3) imagery. We improved the procedures of classification in three aspects: (1) a new spectral index—Normalized Difference PN Index (NDPI)—was proposed, (2) the efficiency and scale of segmentation were optimized by using the Bi-level Scale-sets Model (BSM), and (3) feature variables were selected through an iteration analysis from 99 feature variables (spectral, textural, geometric, and geographic). Compared with the pixel- and the object-based methods, the IPOB has the highest F1 score of 0.98 and also has high robustness in terms of user and producer accuracies (97% and 99%, respectively), following by the object-based method (F1 = 0.94) and the pixel-based method (F1 = 0.93). The high accuracy was expected since the target class has very distinctive spectral and textural characteristics. Although all three approaches showed reasonably high accuracies due to the application of the NDPI and optimized procedures, the result showed the outperformance of the proposed IPOB approach. The framework established in this study expects to apply for regional or national PN surveys extensively. The information on the area and spatial distribution of PN can guide the government on policy making for the planting and exporting of traditional Chinese medicine resources.

scholarly journals Correction of Very High-Resolution Satellite Images using Control Points Captured by Web Map Service (WMS) server: Google Earth

2020 ◽  
Vol 9 (8) ◽  
pp. 188-194
Keyword(s):  
Large Scale ◽  
Satellite Images ◽  
Google Earth ◽  
Ground Control ◽  
Control Points ◽  
Web Map ◽  
Ground Control Points ◽  
High Resolution Satellite Images ◽  
Map Scale ◽  
Map Service

The recent progress for spatial resolution of remote sensing imagery led to generate many types of Very HighResolution (VHR) satellite images, consequently, general speaking, it is possible to prepare accurate base map larger than 1:10,000 scale. One of these VHR satellite image is WorldView-3 sensor that launched in August 2014. The resolution of 0.31m makes WorldView-3 the highest resolution commercial satellite in the world. In the current research, a pan-sharpen image from that type, covering an area at Giza Governorate in Egypt, used to determine the suitable large-scale map that could be produced from that image. To reach this objective, two different sources for acquiring Ground Control Points (GCPs). Firstly, very accurate field measurements using GPS and secondly, Web Map Service (WMS) server (in the current research is Google Earth) which is considered a good alternative when GCPs are not available, are used. Accordingly, three scenarios are tested, using the same set of both 16 Ground Control Points (GCPs) as well as 14 Check Points (CHKs), used for evaluation the accuracy of geometric correction of that type of images. First approach using both GCPs and CHKs coordinates acquired by GPS. Second approach using GCPs coordinates acquired by Google Earth and CHKs acquired by GPS. Third approach using GCPs and CHKs coordinates by Google Earth. Results showed that, first approach gives Root Mean Square Error (RMSE) planimeteric discrepancy for GCPs of 0.45m and RMSE planimeteric discrepancy for CHKs of 0.69m. Second approach gives RMSE for GCPs of 1.10m and RMSE for CHKs of 1.75m. Third approach gives RMSE for GCPs of 1.10m and RMSE for CHKs of 1.40m. Taking map accuracy specification of 0.5mm of map scale, the worst values for CHKs points (1.75m&1,4m) resulted from using Google Earth as a source, gives the possibility of producing 1:5000 large-scale map compared with the best value of (0.69m) (map scale 1:2500). This means, for the given parameters of the current research, large scale maps could be produced using Google Earth, in case of GCPs are not available accurately from the field surveying, which is very useful for many users.

Paleogeography of the Sartan Glaciation of the Hamar-Daban Ridge (Southern Baikal Region)

2020 ◽  
Vol 26 (7) ◽  
pp. 17-32
Author(s):  
F. Enikeev ◽  
Keyword(s):  
Baikal Region ◽  
Lower Boundary ◽  
Google Earth ◽  
Aerial Photographs ◽  
Mountainous Regions ◽  
Mountain Valley ◽  
The Subject ◽  
Remote Identification ◽  
Glacial Landforms ◽  
The Last Glacial

Based on the methods of remote identification and spatial fixation of glacial relief forms with their subsequent geomorphological analysis, the lower boundary of the chionosphere, the glacier feeding areas, boundaries and glacier parameters of the maximum phase of the Last Glacial Maximum glaciers (MIS 2) of the mountainous regions of Southern Baikal region were established and a paleogeographic map was constructed. The object of this study was the dynamics of exogenous processes during the development of the permafrost zone in the Southern Baikal region. The subject of the study is the glacial landforms of the Late Neopleistocene of the Khamar-Daban ridge. Glaciers were reconstructed using absolute marks of destructive and accumulative traces using topographic maps, aerial photographs and satellite images. Paleogeographic constructions were carried out using computer programs Google Earth Pro and SAS. Planet release. The final generalization of the primary material was carried out on a topographic basis on a scale of 1:500,000. The results obtained made it possible to establish the depression of the snow boundary at the maximum of the last cooling at 1300…1400 m in relation to the current climatic and to reveal the features of deformation of the lower border of the chionosphere. The reconstruction of the paleogeographic situation showed the spread of simple and complex (dendritic) types of mountain-valley glaciers, as well as mesh and mountain-glaciation glaciers in some parts of the mountain top. It was established that in the region of the maximum depression of the snowy border, some glaciers reached the coast of Lake Baikal, which could contribute to dilution of secondary aureoles and the displacement of placer mineral deposits. On the southern slope of the Khamar-Daban ridge, the snow boundary passed at an altitude of 1800…2200 m, and glaciation was limited to the development of only circus and circus-valley glaciers of small sizes, contributing to the formation of placers far removed from indigenous sources

scholarly journals Low-Cost Archaeological Investigation and Rapid Mapping of Ancient Stone Tidal Weirs in the Penghu Archipelago Using Google Earth

2019 ◽  
Vol 11 (17) ◽  
pp. 4536 ◽  
Author(s):  
Lei Luo ◽  
Xinyuan Wang ◽  
Jie Liu ◽  
Wenwu Zheng ◽  
Jing Zhen ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Information System ◽  
Spatial Distribution ◽  
Low Cost ◽  
Google Earth ◽  
Gis Analysis ◽  
Archaeological Investigation ◽  
Rapid Mapping ◽  
The Taiwan Strait ◽  
Very High

This paper provides a brief history review of the use of ancient weirs in fishing on our planet, as well as a pilot study that involves investigating and mapping the coastal heritage of ancient stone tidal weirs (STWs) in the Penghu Archipelago which is located in the Taiwan Strait. The spatial distribution and morphological features of STWs across Penghu Archipelago were investigated and analyzed using very high-resolution (VHR) and freely available Google Earth (GE) imagery and geographic information system (GIS) analysis tools. A total of 539 ground-truthed STWs were identified from multiple temporal GE images, and these accounted for over 90% of the localized inventory databases. The proposed GE-based method was found to be more efficient, timely and effective compared to field and airborne surveys. This paper illustrates the utility of GE as a source of freely available VHR remote sensing imagery for archaeological surveys and heritage sustainability in coastal areas.

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