scholarly journals Aerial Photography Used for Spatial Pattern Analysis of Late Blight Infection in Irrigated Potato Circles

2003 ◽  
Vol 93 (7) ◽  
pp. 805-812 ◽  
Author(s):  
Dennis A. Johnson ◽  
J. Richard Alldredge ◽  
Philip B. Hamm ◽  
Bruce E. Frazier
Keyword(s):  
Late Blight ◽  
Aerial Photography ◽  
Large Scale ◽  
Temporal Dynamics ◽  
Disease Incidence ◽  
Aerial Photographs ◽  
Spatial Pattern Analysis ◽  
Initial Inoculum ◽  
Disease Patterns ◽  
Commercial Potato

Spatial and temporal dynamics of late blight were investigated from color, infrared aerial photographs of five commercial potato fields in the Columbia Basin during epidemics in 1993, 1995, and 1998. Aerial photographs were taken one to four times at 6- to 21-day intervals. Photographs were scanned and pixels, representing approximately 1 m2 in the field, were used in the analysis. Late blight-infected plants were aggregated as indicated by runs analysis. Significant z-tests were computed for four directions during each sampling date in each of the five fields. Absolute z-values for runs analysis increased, indicating increasing aggregation in the four directions, as disease incidence increased in the early and midphases of the epidemics in each field. Variograms indicated the existence of autocorrelation among infected plants in four directions; the range of influence increased as disease incidence increased except at the highest levels of disease. Late blight was observed to spread in fields as foci. Late blight foci enlarged in size, produced distinct daughter foci, and coalesced. A field where initial inoculum likely originated from infected seed tubers exhibited less initial aggregation than the other fields, perhaps due to a different source of primary inoculum. Aerial photography coupled with spatial analyses of late blight-infected plants was an effective technique to quantitatively assess disease patterns in relatively large fields and was useful in quantifying an intensification of aggregation during the epidemic process on a large scale.

scholarly journals Assessment of the soil loss caused by riverbank erosion in Serbia

2021 ◽  
Vol 101 (1) ◽  
pp. 31-47
Author(s):  
Marko Langovic ◽  
Slavoljub Dragicevic ◽  
Ivan Novkovic ◽  
Nenad Zivkovic ◽  
Radislav Tosic ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Loss ◽  
Large Scale ◽  
Temporal Dynamics ◽  
Land Use Changes ◽  
Arable Land ◽  
Aerial Photographs ◽  
Lateral Migration ◽  
Channel Migration ◽  
Riverbank Erosion

Riverbank erosion and lateral channel migration are important geomorphological processes which cause various landscape, socio-economic, and environmental consequences. Although those processes are present on the territory of Serbia, there is no available data about the soil loss caused by riverbank erosion for the entire country. In this study, the spatial and temporal dynamics of the riverbank erosion for the largest internal rivers in Serbia (Velika Morava, Zapadna Morava, Juzna Morava, Pek, Mlava, Veliki Timok, Kolubara) was assessed using remote sensing and GIS. The aim of this paper is to determine the total and average soil loss over large-scale periods (1923-2020), comparing data from the available sources (aerial photographs, satellite images, and different scale paper maps). Results indicated that lateral migration caused significant problems through land loss (approximately 2,561 ha), especially arable land, and land use changes in river basins, but also economic loss due to the reduction of agricultural production. Total and average soil loss was calculated for five most representative meanders on all studied rivers, and on the basis of the obtained values, certain regularities about further development and dynamics of riverbank movement are presented. A better understanding of river channel migration in this area will be of a great importance for practical issues such as predicting channel migration rates for river engineering and planning purposes, soil and water management and land use changes, environment protection.

Efficacy of fungicides in controlling late blight of potato

2015 ◽  
Vol 26 (2) ◽  
pp. 103-108
Author(s):  
MM Anwar ◽  
A Parveen ◽  
MM Hossain ◽  
NU Mahamud ◽  
RK Roy
Keyword(s):  
Late Blight ◽  
Tuber Yield ◽  
Cultural Practices ◽  
Disease Incidence ◽  
Integrated Approach ◽  
Control Treatment ◽  
Commercial Potato ◽  
Late Blight Disease ◽  
Blight Disease ◽  
Late Blight Of Potato

Potato cultivars grown in Bangladesh have low levels of general resistance to late blight. As such, most commercial potato farmers rely on fungicide applications for control of Phytophthora infestans, the causal agent of late blight. Management of late blight of potato requires an integrated approach that includes rotation with non-hosts, resistant cultivars, cultural practices, and fungicides. The study on efficacy of some new fungicides against late blight disease of potato was conducted at ARS, Alamnagar Rangpur during rabi season 2010-2011 to select suitable fungicides against late blight of potato. Thirteen different fungicides were tested and all the tested fungicides showed significantly better performance over control. Considering percentage disease incidence T4,T6 and T12 showed better performance than all other treatment. In case of T4,T6 and T12 treatment disease reduction was more than 80 % over control. Significantly the highest tuber yield 25.5 t ha-1was obtained from T3  which was statistically similar to the yield of T2,T5 , T6, T9, T10, T11and T12  treatment whereas the lowest tuber  yield 14.5 t ha-1 was obtained from control treatment. Field experiment was conducted from 2010 to 2011 to investigate the comparative efficacy of the fungicides. In the field, applications of fungicide that preceded the largest incremental increase in disease incidence provided the best control of disease or increased yield.Progressive Agriculture 26 (2): 103-108, 2015

Detection of root disease in coastal Douglas-fir stands using large scale 70-mm aerial photography

1984 ◽  
Vol 14 (4) ◽  
pp. 523-527 ◽  
Author(s):  
G. W. Wallis ◽  
Y. J. Lee
Keyword(s):  
Aerial Photography ◽  
Large Scale ◽  
Douglas Fir ◽  
Root Disease ◽  
Aerial Photographs ◽  
Stand Age ◽  
Adequate Information ◽  
Disease Occurrence ◽  
Mature Stands

Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stands 15, 40, and 100 years of age containing root disease openings of various sizes were photographed using 70-mm Aerochrome color and color-infrared film at scales of 1:1 500 to 1:15 000. Success in detecting disease centers varied with scale relative to stand age and disease symptomatology. Scales of 1:6 000 provided adequate information for young stands 15–20 years of age whereas scales of up to 1:15 000 proved satisfactory for locating most centers in 100-year-old stands. The large variation in symptomatology among stands in the midage class made accurate assessment of disease occurrence difficult at all scales used. Measurement of area within most disease centers in a stand using aerial photographs is probably feasible only in mature stands. Color photographs were superior to color-infrared for detecting early foliage discoloration; the reverse was true when characterization of ground features and downed trees was desired.

scholarly journals Application of GIS Technologies and Aerial Photography for Geoinformation Mapping and Modelling of Relief of Agroland Landscapes

2020 ◽  
Vol 34 ◽  
pp. 82-95
Author(s):  
S. V. Pashkov ◽  
◽  
G. Z. Mazhitova ◽  
Keyword(s):  
Precision Agriculture ◽  
Aerial Photography ◽  
Crop Production ◽  
Large Scale ◽  
Local Level ◽  
Field Studies ◽  
Aerial Photographs ◽  
Visible Range ◽  
Gis Technologies ◽  
Gis Environment

The article is devoted to one of the topical applied areas of agrarian landscape research – geoinformation mapping, the development of maps and models of the topography of agricultural areas. The authors demonstrate results of works on large-scale geoinformation mapping and modeling of the topography of the oldest region of bogharic agriculture of Kazakhstan – North Kazakhstan region using methods and materials of remote sensing data and GIS technologies. The main source material in the study was a series of aerial photographs obtained from an unmanned aerial vehicle (UAV). The site of photographing was carried out by GEOSCAN-Kazakhstan LLP with using the Geoscan-201M Agro/Geodesy aerial photography complex. Characteristics of photographing: height – 280 m, visible range – 5 cm/pixel, multispectral – 13 cm/pixel. Geoinformation data on the nature of the relief were obtained during field studies in 2018-2020. Studies were carried out at the local level on the example of agricultural area located in the north of the region within the forest and steppe arable small-circuit agrarian landscape. Based on the results of the study, an electronic vector basis and specialized attribute data of the key area in the GIS environment, a digital relief model were prepared, spatial analysis and modeling of the geomorphological device of the arable surface were performed. The importance of the work is given by a significant agrogenic transformation of the relief of the definite locality during the almost 270-year history of agriculture. A series of maps of the main characteristics and morphometric indicators of the relief, significant from the point of view of crop production intensification and the development of accurate (precision) agriculture of the region, has been worked out. As a result of the study, the methodology of large-scale geoinformation mapping and modeling of the terrain of agrolandscapes in the GIS environment based on aerial photographs from UAVs was developed and tested. The algorithm of work has been compiled, starting from field studies, completing with the development of thematic maps and morphometric analysis of the relief and nature of the surface structure of the studied area.

Identification of former shallow coal mining from aerial photographs: an example from West Yorkshire

1987 ◽  
Vol 4 (1) ◽  
pp. 133-136
Author(s):  
J. R. A. Giles
Keyword(s):  
Coal Mining ◽  
Aerial Photography ◽  
Large Scale ◽  
Geological Mapping ◽  
Aerial Photographs ◽  
Major Constraint ◽  
Scale Cover ◽  
Mine Workings

AbstractSystematic, large-scale, aerial photography is now available for many areas of the exposed coalfields. In West Yorkshire 1:10000 or 1:10 560 scale cover is generally available, supplemented by 1:5000 and 1:3000 cover in more limited areas. Examination of aerial photographs, in conjunction with detailed geological mapping, has identified characteristic ground patterns associated with the existence of former shallow workings. These patterns are interpreted in terms of changes of style of mining with increasing depth.The presence of shallow mine workings is a major constraint on planning in areas of exposed coalfield. The examination of large scale aerial photographs offers a rapid reconnaissance method of identifying such workings.

scholarly journals A semi-automated workflow for processing historic aerial photography

2019 ◽  
Vol 1 ◽  
pp. 1-1
Author(s):  
Nathan Piekielek
Keyword(s):  
Satellite Imagery ◽  
Aerial Photography ◽  
Large Scale ◽  
Geographic Information ◽  
Structured Data ◽  
Geospatial Data ◽  
Aerial Photographs ◽  
Web Mapping ◽  
Technical Specifications ◽  
The U.S

<p><strong>Abstract.</strong> Libraries, museums and archives were the original big geospatial information repositories that to this day house thousands to millions of resources containing research-quality geographic information. However, these print resources (and their digital surrogates), are not easily incorporated into the contemporary research process because they are not structured data that is required of web-mapping and geographic information system tools. Fortunately, contemporary big data tools and methods can help with the large-scale conversion of historic resources into structured datasets for mapping and spatial analysis.</p><p>Single frame historic aerial photographs captured originally on film (hereafter “photographs”), are some of the most ubiquitous and information-rich geographic information resources housed in libraries, museums and archives. Photographs authentically encoded information about past places and time-periods without the thematic focus and cartographic generalization of historic print maps. As such, they contain important information in nearly every category of base mapping (i.e. transportation networks, populated places etc.), that is useful to a broad spectrum of research projects and other applications. Photographs are also some of the most frustrating historic resources to use due to their very large map-scale (i.e. small geographic area), lack of reference information and often unknown metadata (i.e. index map, flight altitude, direction etc.).</p><p>The capture of aerial photographs in the contiguous United States (U.S.) became common in the 1920s and was formalized in government programs to systematically photograph the nation at regular time intervals beginning in the 1930s. Many of these photography programs continued until the 1990s meaning that there are approximately 70 years of “data” available for the U.S. that is currently underutilized due to inaccessibility and the challenges of converting photographs to structured data. Large collections of photographs include government (e.g. the U.S. Department of Agriculture Aerial Photography Field Office “The Vault” – over 10 million photographs), educational (e.g. the University of California Santa Barbara Library – approximately 2.5 million photographs), and an unknown number non-governmental organizations (e.g. numerous regional planning commissions and watershed conservation groups). Collectively these photography resources constitute an untapped big geospatial data resource.</p><p>U.S. government photography programs such as the National Agricultural Imagery Program continued and expanded in the digital age (i.e. post early 2000s), so that not only is there opportunity to extend spatial analyses back in time, but also to create seamless datasets that integrate with current and expected future government aerial photography campaigns. What is more, satellite imagery sensors have improved to the point that there is now overlap between satellite imagery and aerial photography in terms of many of their technical specifications (i.e. spatial resolution etc.). The remote capture of land surface imagery is expanding rapidly and with it are new opportunities to explore long-term land-change analyses that require historical datasets.</p><p>Manual methods to process photographs are well-known, but are too labour intensive to apply to entire photography collections. Academic research on methods to increase the discoverability of photographs and convert them to geospatial data at large-scale has to date been limited (although see the work of W. Karel et al.). This presentation details a semi-automated workflow to process historic aerial photographs from U.S. government sources and compares the workflow and results to existing methods and datasets. In a pilot test area of 94 photographs in the U.S. state of Pennsylvania, the workflow was found to be nearly 100-times more efficient than commonly employed alternatives while achieving greater horizontal positional accuracy. Results compared favourably to contemporary digital aerial photography data products, suggesting that they are well-suited for integration with contemporary datasets. Finally, initial results of the workflow were incorporated into several existing online discovery and sharing platforms that will be highlighted in this presentation. Early online usage statistics as well as direct interaction with users demonstrates the broad interest and high-impact of photographs and their derived products (i.e. structured geospatial data).</p>

scholarly journals REQUIREMENTS FOR AERIAL PHOTOGRAPHY

2012 ◽  
Vol 30 (3) ◽  
pp. 75-79 ◽  
Author(s):  
Birutė Ruzgienė
Keyword(s):  
European Union ◽  
Aerial Photography ◽  
Large Scale ◽  
Digital Camera ◽  
Aerial Photographs ◽  
Flying Height ◽  
The European Union ◽  
Flight Planning ◽  
Mapping Process ◽  
Urban Territories

The photogrammetric mapping process at the first stage requires planning of aerial photography. Aerial photographs quality depends on the successfull photographic mission specified by requirements that meet not only Lithuanian needs, but also the requirements of the European Union. For such a purpose the detailed specifications for aerial photographic mission for mapping urban territories at a large scale are investigated. The aerial photography parameters and requirements for flight planning, photographic strips, overlaps, aerial camera and film are outlined. The scale of photography, flying height and method for photogrammetric mapping is foreseen as well as tolerances of photographs tilt and swings round (yaw) are presented. Digital camera based on CCD sensors and on-board GPS is greatly appreciated in present-day technologies undertaking aerial mission.

scholarly journals Spatial and Temporal Analyses of Bacterial Blight of Onion Caused by Xanthomonas axonopodis pv. allii

2004 ◽  
Vol 94 (2) ◽  
pp. 138-146 ◽  
Author(s):  
P. Roumagnac ◽  
O. Pruvost ◽  
F. Chiroleu ◽  
G. Hughes
Keyword(s):  
Bacterial Blight ◽  
Disease Incidence ◽  
Severe Disease ◽  
Spatial Dynamics ◽  
Seed Transmission ◽  
Contamination Rate ◽  
Xanthomonas Axonopodis ◽  
Initial Inoculum ◽  
Incidence Data ◽  
Disease Patterns

Bacterial blight of onion is a severe disease, which emerged over the past decade in several onion-producing areas. This disease currently is observed in both the Old and New Worlds. Although the causative agent, Xanthomonas axonopodis pv. allii, is potentially seedborne, seed transmission and significance of seedborne initial inoculum for the development of bacterial blight of onion previously has not been assessed. This article describes experimental work designed to evaluate the biological importance of seedborne X. axonopodis pv. allii as an initial inoculum source, and examine the temporal and spatial dynamics of the disease. Over 3 years, outbreaks of bacterial blight of onion always were induced in experimental plots sown with naturally contaminated seed lots, with a contamination rate determined as 0.04%. Analyses of disease patterns indicated a likely seedborne origin for the inoculum associated with the early stages of epidemics. Spatial analyses performed with several statistical methods indicated aggregated patterns of disease incidence data. Primary foci enlarged over time, and a few distinct secondary foci sometimes were established after occurrence of wind-driven rains (with gusts up to 15 m s-1). Distances between primary and secondary foci ranged from less than 1 m (satellite foci) to 25 m. It remains possible that longdistance dispersal of inoculum was at least partly involved in the later stages of epidemics.

Classification of vegetation in Cucphuong National Park with the aim of large-scale mapping, Vietnam

1996 ◽  
pp. 64-67 ◽  
Author(s):  
Nguen Nghia Thin ◽  
Nguen Ba Thu ◽  
Tran Van Thuy
Keyword(s):  
National Park ◽  
Large Scale ◽  
Satellite Images ◽  
Field Work ◽  
Aerial Photographs ◽  
Vegetation Map ◽  
Dense Forest ◽  
Broad Leaved Forest ◽  
Leaved Forest

The tropical seasonal rainy evergreen broad-leaved forest vegetation of the Cucphoung National Park has been classified and the distribution of plant communities has been shown on the map using the relations of vegetation to geology, geomorphology and pedology. The method of vegetation mapping includes: 1) the identifying of vegetation types in the remote-sensed materials (aerial photographs and satellite images); 2) field work to compile the interpretation keys and to characterize all the communities of a study area; 3) compilation of the final vegetation map using the combined information. In the classification presented a number of different level vegetation units have been identified: formation classes (3), formation sub-classes (3), formation groups (3), formations (4), subformations (10) and communities (19). Communities have been taken as mapping units. So in the vegetation map of the National Park 19 vegetation categories has been shown altogether, among them 13 are natural primary communities, and 6 are the secondary, anthropogenic ones. The secondary succession goes through 3 main stages: grassland herbaceous xerophytic vegetation, xerophytic scrub, dense forest.

Sign in / Sign up

Export Citation Format

Share Document