scholarly journals LANDSAT-BASED WOODY VEGETATION COVER MONITORING IN SOUTHERN AFRICAN SAVANNAHS

2016 ◽  
Vol XLI-B7 ◽  
pp. 563-567 ◽  
Author(s):  
E. Symeonakis ◽  
K. Petroulaki ◽  
T. Higginbottom
Keyword(s):  
Vegetation Cover ◽  
Urban Areas ◽  
Agricultural Land ◽  
Remote Sensing Data ◽  
Earth Observation ◽  
Mitigation Measures ◽  
Management Tool ◽  
Woody Vegetation ◽  
Steady Increase ◽  
Vegetation Types

Mapping woody cover over large areas can only be effectively achieved using remote sensing data and techniques. The longest continuously operating Earth-observation program, the Landsat series, is now freely-available as an atmospherically corrected, cloud masked surface reflectance product. The availability and length of the Landsat archive is thus an unparalleled Earth-observation resource, particularly for long-term change detection and monitoring. Here, we map and monitor woody vegetation cover in the Northwest Province of South Africa, an area of more than 100,000 km<sup>2</sup> covered by 11 Landsat scenes. We employ a multi-temporal approach with dry-season data from 7 epochs between 1990 to 2015. We use 0.5 m-pixel colour aerial photography to collect > 15,000 point samples for training and validating Random Forest classifications of (i) woody vegetation cover, (ii) other vegetation types (including grasses and agricultural land), and (iii) non-vegetated areas (i.e. urban areas and bare land). Overall accuracies for all years are around 80 % and overall kappa between 0.45 and 0.66. Woody vegetation covers a quarter of the Province and is the most accurately mapped class (balanced accuracies between 0.74-0.84 for the 7 epochs). There is a steady increase in woody vegetation cover over the 25-year-long period of study in the expense of the other vegetation types. We identify potential woody vegetation encroachment 'hot-spots' where mitigation measures might be required and thus provide a management tool for the prioritisation of such measures in degraded and food-insecure areas.

scholarly journals LANDSAT-BASED WOODY VEGETATION COVER MONITORING IN SOUTHERN AFRICAN SAVANNAHS

2016 ◽  
Vol XLI-B7 ◽  
pp. 563-567
Author(s):  
E. Symeonakis ◽  
K. Petroulaki ◽  
T. Higginbottom
Keyword(s):  
Vegetation Cover ◽  
Urban Areas ◽  
Agricultural Land ◽  
Remote Sensing Data ◽  
Earth Observation ◽  
Mitigation Measures ◽  
Management Tool ◽  
Woody Vegetation ◽  
Steady Increase ◽  
Vegetation Types

Mapping woody cover over large areas can only be effectively achieved using remote sensing data and techniques. The longest continuously operating Earth-observation program, the Landsat series, is now freely-available as an atmospherically corrected, cloud masked surface reflectance product. The availability and length of the Landsat archive is thus an unparalleled Earth-observation resource, particularly for long-term change detection and monitoring. Here, we map and monitor woody vegetation cover in the Northwest Province of South Africa, an area of more than 100,000&thinsp;km<sup>2</sup> covered by 11 Landsat scenes. We employ a multi-temporal approach with dry-season data from 7 epochs between 1990 to 2015. We use 0.5&thinsp;m-pixel colour aerial photography to collect >&thinsp;15,000 point samples for training and validating Random Forest classifications of (i) woody vegetation cover, (ii) other vegetation types (including grasses and agricultural land), and (iii) non-vegetated areas (i.e. urban areas and bare land). Overall accuracies for all years are around 80&thinsp;% and overall kappa between 0.45 and 0.66. Woody vegetation covers a quarter of the Province and is the most accurately mapped class (balanced accuracies between 0.74-0.84 for the 7 epochs). There is a steady increase in woody vegetation cover over the 25-year-long period of study in the expense of the other vegetation types. We identify potential woody vegetation encroachment 'hot-spots' where mitigation measures might be required and thus provide a management tool for the prioritisation of such measures in degraded and food-insecure areas.

scholarly journals Spectral properties of Antarctic and Alpine vegetation monitored by multispectral camera: Case studies from James Ross Island and Jeseníky Mts.

2020 ◽  
Vol 10 (2) ◽  
pp. 297-312
Author(s):  
Peter Váczi ◽  
Miloš Barták ◽  
Michaela Bednaříková ◽  
Filip Hrbáček ◽  
Josef Hájek
Keyword(s):  
Vegetation Cover ◽  
Remote Sensing Data ◽  
Field Research ◽  
Alpine Tundra ◽  
Vegetation Types ◽  
Nostoc Commune ◽  
James Ross Island ◽  
Bryum Pseudotriquetrum ◽  
Reflectance Indices ◽  
Multispectral Camera

In this study, we investigated the utility of spectral remote sensing data gathered by a multispectral camera for estimating of vegetation cover in Antarctic vegetation oasis and Arcto-Alpine tundra. The surveys exploiting unmanned aerial vehicles (UAV) and multispectral camera were done in an Antarctic vegetation oasis located at the Northern shore of James Ross Island (Antarctica), and arcto-alpine tundra located in the Jeseníky Mts. (NE Czech Republic, 1 420 m a.s.l.). For the two locations, false colour images of spectral indices (VARI, NGRDI, GLI, RGVI, ExG, NDVI, PRI) were taken and analysis of vegetation types and components of vegetation cover done. Additionally, field research was performed by handheld instruments measuring NDVI, PRI and of selected vegetation components: Bryum pseudotriquetrum, Nostoc commune colonies (Antarctica), lichens grown on flat stones and boulders (the Jeseníky Mts.). The results show UAV photo surveys and imaging of spectral reflectance indices can be used to monitor vegetation types forming Antarctic vegetation oases and arcto-alpine tundra.

scholarly journals Defining Deforestation Patterns Using Satellite Images from 2000 and 2017: Assessment of Forest Management in Miombo Forests—A Case Study of Huambo Province in Angola

2018 ◽  
Vol 11 (1) ◽  
pp. 98 ◽  
Author(s):  
Vasco Chiteculo ◽  
Azadeh Abdollahnejad ◽  
Dimitrios Panagiotidis ◽  
Peter Surový ◽  
Ram Sharma
Keyword(s):  
Forest Management ◽  
Urban Areas ◽  
Agricultural Land ◽  
Bare Soil ◽  
Vegetation Types ◽  
Forest Protection ◽  
Management Zones ◽  
Management Zone ◽  
The Impact

A few studies have recently been published on changes in land use/land cover (LU/LC) of Angolan Miombo forests, however, none have attempted to offer forest management solutions for degraded Miombo forests. Landscapes are witness to past and present natural and social processes influencing the environment, where each period in the past leaves footprints on the landscape’s development, which can be described by a continual decrease in forest area over time. The expansion of degraded areas from 2000 to 20017 began near urban areas where many Miombo forests have been eliminated or highly degraded, particularly in the southwest and northeast of the Huambo province. Large areas of degraded forests were observed along the Benguela railway (Caminho de ferro de Benguela). Our detailed analysis of the landcover map suggests that the impact has been devastating and there is no form of forest protection, which leads to unregulated exploitation. Descriptions of the Miombo forest dynamics are explained using height–diameter curves developed for different vegetation types that provide important insights about forest structures in the management zones. The height–diameter models differed for all vegetation types, and four management zones (MZ) were created based on a set of particular attributes. The vegetation types differed in each management zone, which included agricultural land and bare soil (MZ–E), grassland or savanna (MZ–C), open Miombo forests (MZ–B), and closed Miombo forests (Miombo forests). The four management zones were easily identified on the available maps and the height–diameter models developed represent a fundamental tool for future studies on forest planning.

The Study Air temperature Annual Rates Effect for Urban of Baghdad City by Using Remote Sensing Data Techniques

2020 ◽  
Vol 38 (2B) ◽  
pp. 66-73
Author(s):  
Ali K. Mohammed Ali ◽  
Fouad K. Mashee Al Ramahi
Keyword(s):  
Air Temperature ◽  
Urban Areas ◽  
Agricultural Land ◽  
Remote Sensing Data ◽  
Inverse Correlation ◽  
Economic Factor ◽  
Human Beings ◽  
Local Climate ◽  
Negative Results ◽  
The Impact

Within a short amount of years, urban land in Baghdad governorate increased as a result of the improvement of the economic factor of human beings, the speedy enlargement Buildings method brought many negative climate issues, for instance, the violent modification of land use and the growth UHI, which led to a decrease in vegetation cover, where influenced the temperature averages, Accordingly, we conducted the following study to find solutions, From 2008 to 2018, Landsat Information 5 and 8 were adopted in this analysis, show that urbanization is increasing rapidly as well as the impact of degrees Temperature in this change, was the source of temperature data (ECMWF) for the province of the study, and the results of the method (IDW) used for temperature mapping showed a change in the rates of temperature in urban areas, where the decline of vegetation impact on temperature rates, As well as commercial activities developed by people, which occupied some agricultural land, which led to negative results ,Several previous kinds of research show that the developed lands by humans will affect the local climate. The satellites used were Landsat 5 and 8, where the images of the study area were taken by these satellites during the study period and were entered into a program (ArcGIS) for the objective of modification and clear output. From the information obtained from the results, there is an inverse correlation between increasing urbanization and air temperature rates and positive correlation with solar radiation and wind speed. We conclude from this...

scholarly journals AVALIAÇÃO E MAPEAMENTO DA COBERTURA VEGETAL DA REGIÃO CENTRAL DA CIDADE DE JUIZ DE FORA – MG - EVALUATION AND MAPPING OF REGION CENTRAL VEGETATION COVER OF JUIZ DE FORA – MG

2017 ◽  
Vol 39 ◽  
pp. 146
Author(s):  
Isabela Fernanda Moraes de Paula ◽  
Cássia Castro Martins Ferreira
Keyword(s):  
Spatial Distribution ◽  
Population Density ◽  
Vegetation Cover ◽  
Urban Areas ◽  
Central Area ◽  
Important Variable ◽  
Woody Vegetation ◽  
Environmental Balance ◽  
The Many ◽  
The City

A presença da cobertura vegetal nas cidades tem sido considerada por diversos pesquisadores uma variável importante, devido aos diversos benefícios que proporcionam ao homem e ao equilíbrio ambiental. Nesse contexto este artigo objetiva contribuir para o conhecimento do verde urbano da área central do município de Juiz de Fora, calculando índices de cobertura vegetal e aplicando a metodologia proposta por Jim (1989), na análise da forma e espacialização da cobertura vegetal. Nesse sentido, os resultados alcançados demonstram que grande parte das regiões da área central da cidade de Juiz de Fora encontram-se abaixo do desejável em cobertura vegetal, necessitando de investimentos, principalmente, nos espaços de integração urbana, cujo percentual de áreas cobertas por vegetação em relação à totalidade abrange apenas 2%. Destaca-se que quanto maior a densidade demográfica, menor foi o percentual de cobertura vegetal, pode-se afirmar que a cobertura vegetal da área central da cidade de Juiz de Fora é fragmentada, descontínua e apresenta muitos “espaços vazios”. No mapeamento realizado foi encontrado 15,401% de áreas cobertas por vegetação arbórea, cerca de 1,694% de vegetação arbustiva e 8,59% de vegetação rasteira. As maiores extensões de manchas verdes encontram-se dispersas no meio, espalhadas por toda a área e desconectas uma com as outras. Logo, sua mensuração, classificação e distribuição espacial são de suma importância, pois tornam-se base essenciais para melhorias e planejamentos, no contexto das áreas urbanas.ABSTRACTThe presence of vegetation cover in the cities has been considered by many researchers an important variable, due to the many benefits they provide to humans and the environmental balance. In this context, this article aims to contribute to the knowledge of green urban central area of the city of Juiz de Fora, calculating vegetation cover ratios and applying the methodology proposed by Jim (1989), in the analysis of the shape and spatial distribution of vegetation cover. In this sense, the results achieved show that most regions of the central area of the city of Juiz de Fora are less than desirable in vegetation cover, requiring investments, mainly in the areas of urban integration, whose percentage of areas covered by vegetation in respect of all covers only 2%. It is noteworthy that the higher the population density, the lower the percentage of vegetation cover, it can be said that the vegetation cover in the central area of the city of Juiz de Fora is fragmented, discontinuous and presents many "empty spaces". In the mapping carried out was found 15.401% of areas covered by woody vegetation, about 1.694% of shrub and 8.59% of undergrowth. The largest expanses of green spots are scattered in between, scattered throughout the area and disconnect with each other. Therefore, its measurement, classification and spatial distribution are of paramount importance as it become essential basis for improvements and planning in the context of urban areas.

Effect of photoscale, interpreter bias and land type on woody crown-cover estimates from aerial photography

2007 ◽  
Vol 55 (4) ◽  
pp. 457 ◽  
Author(s):  
R. J. Fensham ◽  
R. J. Fairfax
Keyword(s):  
Aerial Photography ◽  
Vegetation Cover ◽  
Field Measurements ◽  
Woody Vegetation ◽  
Vegetation Types ◽  
Land Type ◽  
Crown Cover ◽  
Woody Cover ◽  
Land Types ◽  
Residual Deviance

Woody vegetation cover interpreted from aerial photography requires assessment against field data as the signature of woody vegetation cover may differ between photoscales, vegetation types and photo-interpreters. Measurements of aerial woody cover taken from aerial photography of four different photoscales were compared with a field dataset from Eucalyptus- and Acacia-dominated landscapes of semi-arid Queensland. Two interpreters employed a method that utilises a stereoscope and sample-point graticule for manual quantified measurements of aerial woody cover. Both interpreters generated highly significant models accounting for 77 and 78% of deviance. Photoscale appears to have a consistent effect whereby the signature of woody cover increases as the photoscale decreases from 1 : 25 000 to 1 : 80 000, although the magnitude of this effect was different between interpreters. The results suggest no substantial differences in the shape of models predicting crown cover between Acacia- and Eucalyptus-dominated land types, although the precision of the models was greater for the Acacia (90–91% of residual deviance) than for the Eucalyptus (50–56% of residual deviance) land type. The reduced accuracy in the Eucalyptus land type probably reflects the relatively diffuse crowns of the dominant trees. The models generated for this dataset are within the range of those from other calibration studies employing photography of a range of scales and methodologies. The effect of photoscale is verified between the available studies, but there may also be variations arising from methodological differences or image properties. The present study highlights the influence of photoscale and interpreter bias for assessing woody crown cover from aerial photography. Studies that employ aerial photography should carefully consider potential biases and cater for them by calibrating assessments with field measurements.

Political Economy of Land Tax in Pakistan

1986 ◽  
Vol 25 (4) ◽  
pp. 839-853
Author(s):  
Sarfraz Khan Qureshi
Keyword(s):  
Urban Areas ◽  
Agricultural Development ◽  
Agricultural Sector ◽  
Agricultural Land ◽  
Poor Countries ◽  
Scarce Resources ◽  
Agricultural Produce ◽  
Finance Development ◽  
Equity And Efficiency ◽  
Formed Part

Taxation of the agricultural sector is a major instrument for mobilization of the surplus to finance development projects within the agricultural sector and/or the rest of the economy. For many years, the need for a heavier taxation of agricultural land has formed part of the conventional wisdom regarding the ways of extracting agricultural surplus and increasing the tempo of agricultural development in poor countries. Land taxes have both equity and efficiency properties that gladden the hearts of both economists and vocal politicians belonging to urban areas. Taxes on land promote efficiency in the allocation of scarce resources by creating incentives for farmers to increase their effort and reduce their consumption, thus expanding the amount of agricultural produce available to the non-agricultural sectors of the economy. A tax on land has an important redistributive function because its incidence falls squarely on the landlord and is shifted neither forward to consumers nor backwards to suppliers of agricultural inputs; nor does it introduce distortions in the allocation of productive resources.

STUDYING OF TERSKO-SULAKSKAYA LOWLAND VEGETATION UNDER THE RESULTS OF GROUND-BASED RESEARCH AND AUTOMATED INTERPRETATION

1970 ◽  
pp. 29-32
Author(s):  
M. I. Dzhalalova ◽  
A. B. Biarslanov ◽  
D. B. Asgerova
Keyword(s):  
Plant Communities ◽  
Satellite Imagery ◽  
Vegetation Cover ◽  
Anthropogenic Impacts ◽  
Species Abundance ◽  
Remote Sensing Data ◽  
Indigenous Communities ◽  
The State ◽  
Anthropogenic Factors ◽  
Internet Resource

The state of plant communities in areas located in the Tersko-Sulak lowland was studied by assessing phytocenotic indicators: the structure of vegetation cover, projective cover, species diversity, species abundance and elevated production, as well as automated decoding methods. There are almost no virgin soils and natural phytocenoses here; all of them have been transformed into agrocenoses (irrigated arable lands and hayfields, rice-trees and pastures). The long-term impact on pasture ecosystems of natural and anthropogenic factors leads to significant changes in the indigenous communities of this region. Phytocenoses are formed mainly by dry-steppe types of cereals with the participation of feather grass, forbs and ephemera, a semi-desert haloxerophytic shrub - Taurida wormwood. At the base of the grass stand is common coastal wormwood and Taurida wormwood - species resistant to anthropogenic influences. Anthropogenic impacts have led to a decrease in the number of species of feed-rich grain crops and a decrease in the overall productivity of pastures. Plant communities in all areas are littered with ruderal species. The seasonal dynamics of the land cover of the sites was estimated by the methods of automatic decoding of satellite images of the Landsat8 OLI series satellite for 2015, dated by the periods: spring - May 20, summer - July 23, autumn - October 20. Satellite imagery data obtained by Landsat satellite with a resolution in the multispectral image of 30 m per pixel, and in the panchromatic image - 10 m per pixel, which correspond to the requirements for satellite imagery to assess the dynamics of soil and vegetation cover. Lower resolution data, for example, NDVI MODIS, does not provide a reliable reflection of the state of soil and vegetation cover under arid conditions. In this regard, remote sensing data obtained from the Internet resource https://earthexplorer.usgs.gov/ was used.

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