scholarly journals The Visual Grasp of the Fragmented Landscape

2018 ◽  
Vol 48 (2) ◽  
pp. 180-222
Author(s):  
Chunglin Kwa

Between 1925 and 1980, landscape ecology underwent important changes through the gradual imposition of the view from above, through the uses of aerial photography. A new concept emerged, “the smallest unit of landscape,” also called ecotope and land unit, expressing a direct visual grasp of the landscape. This article compares the view from above as introduced and promoted by geographers Carl Troll and Isaak Zonneveld, with its (problematic) history vis-à-vis a school of ecology, i.e., plant sociology, led by Josias Braun-Blanquet and Reinhold Tüxen. This school’s internal struggles with balancing the physiognomic gaze (at the ground) and numerical methods are discussed. In comparison, the geographers based themselves on the mechanical objectivity of standardized aerial surveys, whereas the plant sociologists relied on their subjective expert judgment of plant recognition together with the structural objectivity of their numerical methods. An important communality of both schools was their inductive building of a landscape from its constituent landscape fragments. Landscape fragments were identified through abstraction and categorization, emanating from a taxonomical style of science.

2019 ◽  
Vol 1 ◽  
pp. 1-2
Author(s):  
Hajime Yamamoto

<p><strong>Abstract.</strong> Today when online satellite images are just a click away, access to geographic information showing the latest images of the globe has dramatically expanded, and historico-geographic research based on such information is flourishing. However, in the study of Chinese history, historical research employing GIS or similar technologies is still in its infancy, since “historical” geographic information with a high degree of precision are lacking. From within the ambit of Chinese geographic information, this report specifically highlights aerial surveys effected during the Republic of China era. To start, we review the history of domestic aerial surveys during R. O. C. period. Then, focusing on Nanjing as an example, we proceed to introduce maps that were actually created based on aerial surveys.</p><p>Chinese aerial surveys date back to around 1930. At the Nationalist Party’s General Assembly in 1929, partisans proposed for the need for aerial surveys. In 1930, the “Aerial Photography and Survey Research Team” was formed within the General Land Survey Department at General Staff Headquarters (National Army of the Republic of China). Consequently, foreign technicians were invited to provide relevant education/training. In June 1931, China’s pioneer initiative in aerial photography took place in Zhejiang province. The aim of aerial surveys in those early days was to create maps for military purposes. Between 1932 and 1939, topographic maps of fortifications located in areas such as the Jiangnan district were prepared. Further, starting from around the same period until the Sino-Japanese War, land registry maps based on aerial surveys were also produced. After the Sino-Japanese War ended, the above-mentioned directorate handed over responsibility for aerial surveys to the Naval General Staff. However, in 1949 the Chinese Communist Party confiscated the maps theretofore produced.</p><p>Although the aerial photographs and the geographic information produced therefrom during the R. O. C. era were seized by the People’s Republic of China, in actuality, some had previously been transferred to Taiwan. The topographic maps of the Nanjing metropolitan area (一萬分一南京城廂附近圖), based on aerial surveys and drawn in 1932, are currently archived at Academia Historica in Taipei. Comprising a total of 16 sheets, these maps were drawn on a scale of 1:10,000 by the General Land Survey Department.</p><p>Similarly, other maps (各省分幅地形圖) produced by the General Land Survey Department, comprising a total of 56 sheets and partly detailing Nanjing, are now in the possession of Academia Sinica in Taipei. There was no information about photographing or making in these maps. But almost the same maps were archived at Library of Congress in Washington D. C. According to those maps at LC, based on aerial photographs taken and surveys conducted in 1933, these topographic maps (1:10,000 scale) were completed in 1936.</p><p>The examples introduced above are topographic maps based on aerial photography. However, starting in 1937, land registry maps were also created. Detailing the outskirts of Nanjing (1:1,000 scale) and comprising a total of 121 sheets, they are now archived at Academia Historica. While the land registry maps were produced in 1937, supplementary surveys were effected following the Sino-Japanese War in 1947.</p><p>Since the geographic information based on aerial surveys during the R. O. C. era in China were precise, they can serve as a source of manifold information. This report only delved into information developed by the Government of the R. O. C., but it is becoming evident that U. S. Armed Forces and Japan also produced geographic information of their own based on aerial surveys. If the comprehensive panorama captured by all three protagonists can be illuminated, further advances in Chinese historico-geographic studies employing geographic information will be forthcoming.</p>


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10923
Author(s):  
Fang Liu ◽  
Wanbin Wang ◽  
Jinliang Wang ◽  
Xingzi Zhang ◽  
Jing Ren ◽  
...  

Context Yunnan Province is an important ecological security barrier in China. This study investigated the temporal and spatial changes to landscape ecology and is of great significance for guiding landscape protection and future socio-economic development. Objectives To analyze the temporal and spatial changes of the landscape patterns at the county, river basin, and provincial levels, and clarify and describe the temporal and spatial differentiation characteristics of the landscape patterns in Yunnan Province. Methods Based on landscape ecology, GIS spatial analysis, and spatio-temporal change analysis, nine landscape pattern indices, and spatial autocorrelation for different years, were calculated. Results The landscape of Yunnan Province has evolved as a whole toward isolation. The indices of separation and fragmentation changed significantly from 2010 to 2015. From 2015 to 2018 the rate of fragmentation decreased. Fragmentation in the Nu Jiang and Irrawaddy River basins was less than in other basins. The landscape patterns of the Jinsha and Pearl River basins were relatively fragmented due to human activity, socioeconomic development, and utilization. The differences between the Lancang and Red River Basins were relatively small and at an intermediate level. Conclusions Spatial autocorrelation analysis indicated that there are three areas with typical clusters, namely the Hengduan Mountains where the degree of fragmentation of the landscape was low, while landscape connectivity and aggregation were high. The subtropical region of Southern Yunnan displayed high landscape heterogeneity, a complex shape index, and high connectivity and sprawl. Central Yunnan exhibited a fragmented landscape with poor connectivity and aggregation. These three regions correspond with “the three screens and two belts” in the Main Functional Planning Area of Yunnan Province.


1976 ◽  
Vol 3 (1) ◽  
pp. 25-29 ◽  
Author(s):  
N. L. Powell ◽  
G. J. Griffin ◽  
K. H. Garren ◽  
D. E. Pettry

Abstract Aerial surveys were conducted over portions of the peanut (Arachis hypogaea L.) growing region of Virginia during September, 1974. The flights were conducted to determine the spectral, spatial, and temporal characteristics of Cylindrocladium black rot disease in peanut fields utilizing false color infrared and natural color imagery. The disease, caused by the soil-borne fungus Cylindrocladium crotalariae (Loos) Bell and Sobers, was detected on imagery obtained at 19,803 m above mean sea level. The disease was easily detectable on either false color infared or natural color imagery at 3,504 m above mean sea level. With its unique spectral/spatial signature, the disease was distinguishable from other diseases of peanuts such as Sclerotinia blight. Disease patterns that were difficult to observe from the ground were easily detected with aerial photography. Analysis of field soil samples for C. crotalariae microsclerotia confirmed results of imagery analysis. Detection of the disease by aerial surveys will permit prompt control measures to minimize spread of the disease. Information from this study will provide permanent records that can be used to monitor the change in extent and severity of the disease in future growing seasons.


2021 ◽  
Vol 47 (2) ◽  
pp. 96-103
Author(s):  
Volodymyr Hlotov ◽  
Alla Hunina ◽  
Ihor Kolb ◽  
Vadim Kolesnichenko ◽  
Ihor Trevoho

The work aims to analyze and study the possibilities of using “Cetus” unmanned aerial vehicle (UAV) for performing topographic aerial surveys. The authors developed and tested aircraft-type UAV for topographic aerial photography. The studies were conducted on a specialized landfill, at which there is an appropriate number of situational points whose coordinates are determined with high accuracy. These points were used as both reference and control points. The obtained UAV aerial survey materials were subjected to a phototriangulation process to determine the orientation elements and to analyze, first and foremost, the angular orientation elements. The surveying was carried out on a mountainous territory, where the spatial coordinates of 37 situational points were determined by the method of ground-based GPS survey with an average accuracy of up to 0.05 m. These points were used as reference and control points. Aerial photography was performed in such a way that the scale of the images was as uniform as possible. The design solutions implemented in the Cetus UAV provide all the possibilities to perform aerial surveys of territories in strict compliance with the projected flight parameters. UAV equipment provides the necessary real-time correction of the position of the aerial camera. At the same time the optimum straightness of routes, stability of scales and mutual overlapping of pictures is reached. Regarding the accuracy of obtaining the spatial coordinates of the points of terrain objects, using “Cetus” UAV surveys, plans can even be made on a scale of even 1: 1000. As a result of the creation of the UAV “Cetus”, it became possible to perform the topographic aerial survey of the territories and to create large-scale orthophotos that fully meet the instructions. As a result of testing the “Cetus” UAV, it can be used in production processes when drawing up topographic plans for a large-scale series: 1: 1000 – 1: 5000, which will significantly save the cost of performing topographic work.


1976 ◽  
Vol 3 (1) ◽  
pp. 21-24
Author(s):  
N. L. Powell ◽  
D. M. Porter ◽  
D. E. Pettry

Abstract Aerial surveys were conducted over portions of Southampton County, Virginia, during the 1974 growing season. The flights were conducted to determine the spectral, spatial, and temporal characteristics of Sclerotinia blight in peanut (Arachis hypogaea L.) fields caused by the soil-borne fungus Sclerotinia sclerotiorum. Natural color and false color infrared imagery were used in the aerial surveys. Disease detection was best using false color infrared imagery. Sclerotinia blight, characterized by a unique spectral signature, can be detected on false color infrared imagery taken at 19,803 m above mean sea level. High altitude flights (19,803 m) were better for large area disease surveys. However, low altitude flights (3,504 m) gave better resolution for detailed study of individual fields. Aerial photography detected disease patterns which were difficult to observe from the ground. Early detection of the disease via aerial surveys could aid in minimizing disease severity. Imagery will also provide historical data that can be used in implementing control measures in subsequent growing seasons. Imagery evaluation indicates that Sclerotinia blight was widespread in the peanut growing region of Virginia during the 1974 growing season.


2019 ◽  
Vol 10 (4) ◽  
pp. 1045-1058
Author(s):  
A. A. Rybchenko ◽  
A. V. Kadetova ◽  
E. A. Kozyreva ◽  
A. A. Yuriev

The article reviews the experience of aerial surveys using a quadcopter DJI Inspire 1 PRO (unmanned aerial vehicle, UAV) for solving problems of engineering geodynamics. It describes the application of photogrammetry to estimate quantitative parameters of the studied objects, the experience of using UAVs to study flood processes in the Tunka valley (Russia) and erosion structures in the Ulaanbaatar agglomeration (Mongolia). The first UAV‐acquired data on debris flow alluvial fans and elementary drainage basins of erosion structures are presented. The ranges of UAV flight heights were 100–150 m and 1–30 m for local and detailed aerial photography surveys, respectively. Local surveys covered relatively large objects – debris flow alluvial fans and drainage basins. Detailed aerial photography aimed to investigate the granulometric compositions of debris flow deposits and to construct transverse profiles of erosion structures. Processed aerial photos provided a basis for a schematic map showing the distribution of accumu‐ lated debris flow deposits. The granulometric compositions of coarse fractions in the debris flow deposits were de‐ termined. Based on the survey results, 3D models of the fragments of the erosion structures and their cross‐sections were constructed.


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