scholarly journals From Archived Historical Aerial Imagery to Informative Orthophotos: A Framework for Retrieving the Past in Long-Term Socioecological Research

2019 ◽  
Vol 11 (11) ◽  
pp. 1388 ◽  
Author(s):  
Ana Teresa Pinto ◽  
José A. Gonçalves ◽  
Pedro Beja ◽  
João Pradinho Honrado
Keyword(s):  
Land Cover ◽  
Aerial Imagery ◽  
Aerial Photographs ◽  
Ground Control ◽  
High Definition ◽  
The Past ◽  
Control Information ◽  
Image Orientation ◽  
Land Cover Maps

Aerial photographs have been systematically collected from as early as the 1930s, providing a unique resource to describe changes in vegetation and land cover over extended periods of time. However, their use is often limited by technical constraints, such as the lack of ground control information and precise camera parameters, which hamper an accurate orthorectification of the raw imagery. Here, we describe the historical aerial photographs orthorectification (HAPO) workflow, based on a conventional photogrammetric procedure (the direct linear transformation (DLT) Method), integrated as a geographic information systems (GIS) procedure, in order to perform the image orientation and orthorectification, thereby converting historical aerial imagery into high-definition historical orthoimages. HAPO implementation is illustrated with an application to a rugged landscape in Portugal, where we aimed to produce land-cover maps using an aerial photograph coverage from 1947, as part of a study on long-term socioecological dynamics. We show that HAPO produces highly accurate orthoimages and discuss the wider usefulness of our framework in long-term socioecological research.

scholarly journals Spatially explicit statistical modeling of random and systematic land cover transitions in the main grassland plain of Nech Sar National Park, Ethiopia

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Kiros Tsegay Deribew
Keyword(s):  
Land Cover ◽  
Land Cover Change ◽  
Statistical Modeling ◽  
National Park ◽  
Spatial Extent ◽  
Aerial Photographs ◽  
Woody Vegetation ◽  
Spatially Explicit ◽  
Strong Signal ◽  
The Past

AbstractThe main grassland plain of Nech Sar National Park (NSNP) is a federally managed protected area in Ethiopia designated to protect endemic and endangered species. However, like other national parks in Ethiopia, the park has experienced significant land cover change over the past few decades. Indeed, the livelihoods of local populations in such developing countries are entirely dependent upon natural resources and, as a result, both direct and indirect anthropogenic pressures have been placed on natural parks. While previous research has looked at land cover change in the region, these studies have not been spatially explicit and, as a result, knowledge gaps in identifying systematic transitions continue to exist. This study seeks to quantify the spatial extent and land cover change trends in NSNP, identify the strong signal transitions, and identify and quantify the location of determinants of change. To this end, the author classifies panchromatic aerial photographs in 1986, multispectral SPOT imagery in 2005, and Sentinel imagery in 2019. The spatial extent and trends of land cover change analysis between these time periods were conducted. The strong signal transitions were systematically identified and quantified. Then, the basic driving forces of the change were identified. The locations of these transitions were also identified and quantified using the spatially explicit statistical model. The analysis revealed that over the past three decades (1986–2019), nearly 52% of the study area experienced clear landscape change, out of which the net change and swap change attributed to 39% and 13%, respectively. The conversion of woody vegetation to grassland (~ 5%), subsequently grassland-to-open-overgrazed land (28.26%), and restoration of woody vegetation (0.76%) and grassland (0.72%) from riverine forest and open-overgrazed land, respectively, were found to be the fully systematic transitions whereas the rest transitions were recorded either partly systematic or random transitions. The location of these most systematic land cover transitions identified through the spatially explicit statistical modeling showed drivers due to biophysical conditions, accessibility, and urban/market expansions, coupled with successive government policies for biodiversity management, geo-politics, demographic, and socioeconomic factors. These findings provide important insights into biodiversity loss, land degradation, and ecosystem disruption. Therefore, the model for predicted probability generally suggests a 0.75 km and 0.72 km buffers which are likely to protect forest and grassland from conversion to grassland and open-overgrazed land, respectively.

scholarly journals AUTOMATED MAPPING WITH LiDAR AND SPECTRAL CHARACTERIZATION IN MEDITERRANEAN FOREST AGROECOSYSTEMS

AGROFOR ◽  
2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Ricardo MARTÍNEZ ◽  
César VICENTE ◽  
Nuria SÁNCHEZ-LÓPEZ ◽  
Javier MONTALVO
Keyword(s):  
Land Cover ◽  
Aerial Photographs ◽  
Woody Vegetation ◽  
Simple Method ◽  
Automated Mapping ◽  
Oak Tree ◽  
Standardized Practice ◽  
Open Woodland ◽  
Remote Sensing Methods ◽  
Land Cover Maps

Mapping with LiDAR data is not a standardized practice, though LiDAR databasesare increasing in all countries in Europe. We develop and test a simple method forautomated land-cover mapping. The study area was a farm located at a natural parkof southern Spain. It comprises 502 ha covered by Mediterranean forestagroecosystems, like dehesa (a very open woodland of scattered evergreen treesused by grazing animals), woodland and scrubland, and transitions among them,composing a heterogeneous landscape. This heterogeneity is caused by variationsin holm and cork oak tree density and a sclerophyllous shrub cover, i.e., 3Dstructure of woody vegetation. Using aerial photographs digitization, Landsatimage classification, and image segmentation of tree crowns, land-cover maps weregenerated. Besides, other maps were produced from LiDAR-derived canopy coverand height of tree vegetation and shrub stratum. These 3D variables allowed to awall-to-wall characterization of woody vegetation land-cover classes in the studyarea, that was completed with a NDVI assessment. The results show that automatedmapping with LiDAR is reliable and accurate enough in comparison with othermapping techniques. It outperforms them because its higher spatial resolution, andcan be combined with other remote sensing methods to provides an improvedunderstanding of forest landscapes.

scholarly journals Opening the Woods: Towards a Quantification of Neolithic Clearance Around the Somerset Levels and Moors

2019 ◽  
Vol 27 (2) ◽  
pp. 271-301
Author(s):  
Michelle Farrell ◽  
M. Jane Bunting ◽  
Fraser Sturt ◽  
Michael Grant ◽  
Gerard Aalbersberg ◽  
...  
Keyword(s):  
Land Cover ◽  
Palynological Data ◽  
New Interpretation ◽  
Nuanced Understanding ◽  
Land Cover Maps ◽  
Wooden Structures ◽  
Pollen Records ◽  
Scenario Approach

Abstract Environmental reconstructions from pollen records collected within archaeological landscapes have traditionally taken a broadly narrative approach, with few attempts made at hypothesis testing or formal assessment of uncertainty. This disjuncture between the traditional interpretive approach to palynological data and the requirement for detailed, locally specific reconstructions of the landscapes in which people lived has arguably hindered closer integration of palaeoecological and archaeological datasets in recent decades. Here we implement a fundamentally different method for reconstructing past land cover from pollen records to the landscapes of and around the Somerset Levels and Moors—the Multiple Scenario Approach (MSA)—to reconstruct land cover for a series of 200-year timeslices covering the period 4200–2000 cal BC. Modelling of both archaeological and sediment chronologies enables the integration of reconstructed changes in land cover with archaeological evidence of contemporary Neolithic human activity. The MSA reconstructions are presented as a series of land cover maps and as graphs of quantitative measures of woodland clearance tracked over time. Our reconstructions provide a more nuanced understanding of the scale and timing of Neolithic clearance than has previously been available from narrative-based interpretations of pollen data. While the archaeological record tends to promote a view of long-term continuity in terms of the persistent building of wooden structures in the wetlands, our new interpretation of the palynological data contributes a more dynamic and varying narrative. Our case study demonstrates the potential for further integration of archaeological and palynological datasets, enabling us to get closer to the landscapes in which people lived.

scholarly journals Perhitungan Erosi Kualitatif Dengan Analisis Citra Satelit Di Sub DAS Tulis, Daerah Tangkapan Waduk Mrica

2019 ◽  
Vol 15 (1) ◽  
pp. 10
Author(s):  
Beny Harjadi ◽  
Pranata Dyah Susanti
Keyword(s):  
Soil Erosion ◽  
Land Cover ◽  
Satellite Imagery ◽  
Satellite Images ◽  
Light Level ◽  
Shuttle Radar Topography Mission ◽  
Digital Analysis ◽  
Land Unit ◽  
Land Cover Maps

The purpose of this study is to calculate qualitative erosion with digital analysis of satellite imagery in Subwatershed Tulis. Planning for a watershed for the long term requires the calculation of qualitative erosion values that are accurate and spread evenly to each land unit. This study uses digital analysis methods by relying on the digital value of each pixel that can be performed mathematically. Satellite images used are Landsat TM 8 images on October 31, 2016, and a radar image is SRTM (Shuttle Radar Topography Mission). The analysis was carried out by calculating each of the factors causing erosion in the form of drainage maps, aspect maps, slope maps, texture maps, and land cover maps. Each factor was given a score or score from 1 to 3, namely low (1), medium (2) and high (3), so that after being calculated by the method of SES (Soil Erosion Status) it became light level erosion (1) <50, medium (2 ) = 50-100 and weight (3)> 100 tons/ha/ year. The results of the calculation of qualitative erosion in Sub-watershed Tulis which has an area of 12,750 ha, obtained light erosion 4% (529 ha), medium 85% (10,781 ha), and weight 11% (1,440 ha).

scholarly journals Human Neural Stem Cells in Space Proliferate more than Ground Control Cells: Implications for Long-Term Space Travel

2021 ◽  
Vol 7 (2) ◽  
pp. 1-10
Author(s):  
Araceli Espinosa-Jeffrey ◽  
Keyword(s):  
Stem Cells ◽  
Outer Space ◽  
Ground Control ◽  
Extreme Conditions ◽  
Space Travel ◽  
Human Neural Stem Cells ◽  
The Past ◽  
Long Duration ◽  
Fluid Shifts

Long-term travel and lengthy stays for astronauts in outer space are imminent. To date, more than 500 astronauts have experienced the extreme conditions of space flight including microgravity and radiation. For the past decade, many studies associated with long-duration spaceflight have shown the recurring occurrence of ophthalmic abnormalities. The reasons of the observed changes in some astronauts remained unclear. However, factors such as the increase in intracranial pressure and fluid shifts are among the top potential contributing elements.

scholarly journals Land Cover Changes Implications in Energy Flow and Water Cycle in São Francisco Basin, Brazil, over the Past Seven Decades

2021 ◽  
Author(s):  
Vitor Juste dos Santos ◽  
Maria Lúcia Calijuri ◽  
Leonardo Campos de Assis
Keyword(s):  
Land Cover ◽  
Energy Flow ◽  
Water Cycle ◽  
Water Infiltration ◽  
Native Vegetation ◽  
Land Cover Changes ◽  
The Past ◽  
Energy Flows ◽  
Basin Area

Abstract This research aimed to quantify and qualify alterations in land cover and verify the implications of these modifications for variables related to energy flows and water cycle in São Francisco basin (SFB), located entirely in Brazilian territory, in the second half of the 20th century and beginning of the 21st. For this, statistical analyzes (descriptive, trends, seasonal and correlations) were used to quantify changes in the variables of land cover and energy/water flows, in addition to relating them. As a result, it was found that the SFB lost 65,680 km² of native vegetation (10.4% of basin area) to crops and pastures, reducing water infiltration (-52%) while the rains remained stable (-2%). Water loss increased through evapotranspiration (+5%) and surface runoff (+225%). Such changes in the water cycle have entailed an 11% reduction in São Francisco river long term flow rate (Q95), comparing pre and post-1990s period. In SFB, the activities that required water, such as farming activities, are those that promote hydric loss.

scholarly journals Influences of Environmental Drivers on Land Cover Structure and its Long-Term Changes: a Case Study of the Villages of Malachov and Podkonice in Slovakia / Vliv Environmentálních Podmínek Na Strukturu Krajinného Pokryvu A Její Dlouhodobé Změny: Případová Studie Obcí Malachov A Podkonice Na Slovensku

2014 ◽  
Vol 22 (3) ◽  
pp. 29-41 ◽  
Author(s):  
Michal Druga ◽  
Vladimír Falťan
Keyword(s):  
Land Cover ◽  
Land Cover Change ◽  
Linear Models ◽  
Arable Land ◽  
Aerial Photographs ◽  
Environmental Drivers ◽  
Cadastral Maps ◽  
Cover Class

Abstract The influence of environmental drivers on long-term land cover changes in two mountainous villages in Central Slovakia is assessed in this paper using generalized linear models (GLM). Historical cadastral maps and aerial photographs were analyzed to describe the land cover change over five time horizons ranging from 1860 to the present, using the CORINE Land Cover classification. The hypothesis that higher slope, elevation and distance to settlement strongly influence lower intensities of land use was mostly confirmed, but geology was also identified as an important factor. The category of ‘forests’ was the most accounted for land cover class, while arable land and grassland were only considerably affected by the drivers in some periods. On the other hand, shrubs were almost completely unrelated to the investigated drivers. The areas of land cover change were not so well explained by the GLMs.

scholarly journals Spatiotemporal Analysis of Land Cover Changes in the Chemoga Basin, Ethiopia, Using Landsat and Google Earth Images

2020 ◽  
Vol 12 (9) ◽  
pp. 3607 ◽  
Author(s):  
Wubeshet Damtea ◽  
Dongyeob Kim ◽  
Sangjun Im
Keyword(s):  
Land Cover ◽  
Agricultural Land ◽  
Environmental Concern ◽  
Kappa Statistic ◽  
Spatiotemporal Analysis ◽  
Google Earth ◽  
Agricultural Lands ◽  
Landsat Images ◽  
The Past ◽  
Land Cover Maps

Land cover change is a major environmental concern in the northwestern highlands of Ethiopia. This study detected land cover transitions over the past 30 years in the Chemoga basin (total area = 118,359 ha). Land cover maps were generated via the supervised classification of Landsat images with the help of the Google Earth (GE) images. A total of 218 unchanged land features sampled from GE images were used as the training datasets. Classification accuracy was evaluated by comparing classified images with 165 field observations during the 2017 field visit. The overall accuracy was 85.4% and the kappa statistic was 0.81, implying that the land classification was satisfactory. Agricultural land is the dominant land cover in the study basin, and increased in extent by 2,337 ha from 1987 to 2017. The second and third most dominant land cover types, grassland and woodland, decreased by 1.9% and 3.6%, respectively, over the past 30 years. The increase in agricultural lands was mostly due to the conversion of grasslands and woodlands, although some agricultural lands changed to Eucalyptus plantations and human settlements. The results revealed that the expansion of built-up space and agricultural lands was the major driver of fragmentation of the landscape, and degradation of natural resources in the Chemoga basin, Ethiopia.

scholarly journals Structure-From-Motion Photogrammetry of Antarctic Historical Aerial Photographs in Conjunction with Ground Control Derived from Satellite Data

2020 ◽  
Vol 13 (1) ◽  
pp. 21
Author(s):  
Sarah F. Child ◽  
Leigh A. Stearns ◽  
Luc Girod ◽  
Henry H. Brecher
Keyword(s):  
Data Collection ◽  
Structure From Motion ◽  
Temporal Scale ◽  
Aerial Imagery ◽  
Aerial Photographs ◽  
Aerial Image ◽  
Ground Control ◽  
In Situ Data ◽  
Glacier Dynamics

A longer temporal scale of Antarctic observations is vital to better understanding glacier dynamics and improving ice sheet model projections. One underutilized data source that expands the temporal scale is aerial photography, specifically imagery collected prior to 1990. However, processing Antarctic historical aerial imagery using modern photogrammetry software is difficult, as it requires precise information about the data collection process and extensive in situ ground control is required. Often, the necessary orientation metadata for older aerial imagery is lost and in situ data collection in regions like Antarctica is extremely difficult to obtain, limiting the use of traditional photogrammetric methods. Here, we test an alternative methodology to generate elevations from historical Antarctic aerial imagery. Instead of relying on pre-existing ground control, we use structure-from-motion photogrammetry techniques to process the imagery with manually derived ground control from high-resolution satellite imagery. This case study is based on vertical aerial image sets collected over Byrd Glacier, East Antarctica in December 1978 and January 1979. Our results are the oldest, highest resolution digital elevation models (DEMs) ever generated for an Antarctic glacier. We use these DEMs to estimate glacier dynamics and show that surface elevation of Byrd Glacier has been constant for the past ∼40 years.

scholarly journals Fire hazard modulation by long-term dynamics in land cover and dominant forest type in eastern and central Europe

2020 ◽  
Vol 17 (5) ◽  
pp. 1213-1230 ◽  
Author(s):  
Angelica Feurdean ◽  
Boris Vannière ◽  
Walter Finsinger ◽  
Dan Warren ◽  
Simon C. Connor ◽  
...  
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Biomass Burning ◽  
Forest Type ◽  
Fire Hazard ◽  
Fire Regimes ◽  
Early Holocene ◽  
Tree Cover ◽  
The Past

Abstract. Wildfire occurrence is influenced by climate, vegetation and human activities. A key challenge for understanding the risk of fires is quantifying the mediating effect of vegetation on fire regimes. Here, we explore the relative importance of Holocene land cover, land use, dominant functional forest type, and climate dynamics on biomass burning in temperate and boreo-nemoral regions of central and eastern Europe over the past 12 kyr. We used an extensive data set of Holocene pollen and sedimentary charcoal records, in combination with climate simulations and statistical modelling. Biomass burning was highest during the early Holocene and lowest during the mid-Holocene in all three ecoregions (Atlantic, continental and boreo-nemoral) but was more spatially variable over the past 3–4 kyr. Although climate explained a significant variance in biomass burning during the early Holocene, tree cover was consistently the highest predictor of past biomass burning over the past 8 kyr. In temperate forests, biomass burning was high at ∼45 % tree cover and decreased to a minimum at between 60 % and 70 % tree cover. In needleleaf-dominated forests, biomass burning was highest at ∼ 60 %–65 % tree cover and steeply declined at >65 % tree cover. Biomass burning also increased when arable lands and grasslands reached ∼ 15 %–20 %, although this relationship was variable depending on land use practice via ignition sources, fuel type and quantities. Higher tree cover reduced the amount of solar radiation reaching the forest floor and could provide moister, more wind-protected microclimates underneath canopies, thereby decreasing fuel flammability. Tree cover at which biomass burning increased appears to be driven by warmer and drier summer conditions during the early Holocene and by increasing human influence on land cover during the late Holocene. We suggest that long-term fire hazard may be effectively reduced through land cover management, given that land cover has controlled fire regimes under the dynamic climates of the Holocene.

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