Approaches to fractional land cover and continuous field mapping: A comparative assessment over the BOREAS study region

Abstract. Scotty Creek, Northwest Territories (NWT), Canada, has been the focus of hydrological research for nearly three decades. Over this period, field and modelling studies have generated new insights into the thermal and physical mechanisms governing the flux and storage of water in the wetland-dominated regions of discontinuous permafrost that characterises much of the Canadian and circumpolar subarctic. Research at Scotty Creek has coincided with a period of unprecedented climate warming, permafrost thaw, and resulting land cover transformations including the expansion of wetland areas and loss of forests. This paper (1) synthesises field and modelling studies at Scotty Creek, (2) highlights the key insights of these studies on the major water flux and storage processes operating within and between the major land cover types, and (3) provides insights into the rate and pattern of the permafrost-thaw-induced land cover change and how such changes will affect the hydrology and water resources of the study region.

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Land and Forest Management by Land Use/ Land Cover Analysis and Change Detection Using Remote Sensing and GIS

Journal of Landscape Ecology ◽

10.1515/jlecol-2016-0005 ◽

2016 ◽

Vol 9 (1) ◽

pp. 63-77 ◽

Cited By ~ 4

Author(s):

Keyword(s):

Remote Sensing ◽

Land Use ◽

Forest Management ◽

Land Cover ◽

Spatial Data ◽

Management Strategies ◽

Geographical Information ◽

Spatial Data Analysis ◽

Study Region ◽

Rugged Terrain

Abstract Remote sensing and Geographical Information System (GIS) are the most effective tools in spatial data analysis. Natural resources like land, forest and water, these techniques have proved a valuable source of information generation as well as in the management and planning purposes. This study aims to suggest possible land and forest management strategies in Chakia tahsil based on land use and land cover analysis and the changing pattern observed during the last ten years. The population of Chakia tahsil is mainly rural in nature. The study has revealed that the northern part of the region, which offers for the settlement and all the agricultural practices constitutes nearly 23.48% and is a dead level plain, whereas the southern part, which constitute nearly 76.6% of the region is characterized by plateau and is covered with forest. The southern plateau rises abruptly from the northern alluvial plain with a number of escarpments. The contour line of 100 m mainly demarcates the boundary between plateau and plain. The plateau zone is deeply dissected and highly rugged terrain. The resultant topography comprises of a number of mesas and isolated hillocks showing elevation differences from 150 m to 385 m above mean sea level. Being rugged terrain in the southern part, nowadays human encroachment are taking place for more land for the cultivation. The changes were well observed in the land use and land cover in the study region. A large part of fallow land and open forest were converted into cultivated land.

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Using SCS-CN and Earth Observation for the Comparative Assessment of the Hydrological Effect of Gradual and Abrupt Spatiotemporal Land Cover Changes

Water ◽

10.3390/w12051386 ◽

2020 ◽

Vol 12 (5) ◽

pp. 1386 ◽

Cited By ~ 6

Author(s):

Emmanouil Psomiadis ◽

Konstantinos X. Soulis ◽

Nikolaos Efthimiou

Keyword(s):

Land Cover ◽

Forest Fires ◽

Earth Observation ◽

Comparative Assessment ◽

Combined Effect ◽

Population Increase ◽

Urbanization Process ◽

Direct Runoff ◽

The Impact ◽

Scs Cn

In this study a comparative assessment of the impacts of urbanization and of forest fires as well as their combined effect on runoff response is investigated using earth observation and the Soil Conservation Service Curve Number (SCS-CN) direct runoff estimation method in a Mediterranean peri-urban watershed in Attica, Greece. The study area underwent a significant population increase and a rapid increase of urban land uses, especially from the 1980s to the early 2000s. The urbanization process in the studied watershed caused a considerable increase of direct runoff response. A key observation of this study is that the impact of forest fires is much more prominent in rural watersheds than in urbanized watersheds. However, the increments of runoff response are important during the postfire conditions in all cases. Generally, runoff increments due to urbanization seem to be higher than runoff increments due to forest fires affecting the associated hydrological risks. It should also be considered that the effect of urbanization is lasting, and therefore, the possibility of an intense storm to take place is higher than in the case of forest fires that have an abrupt but temporal impact on runoff response. It should be noted though that the combined effect of urbanization and forest fires results in even higher runoff responses. The SCS-CN method, proved to be a valuable tool in this study, allowing the determination of the direct runoff response for each soil, land cover and land management complex in a simple but efficient way. The analysis of the evolution of the urbanization process and the runoff response in the studied watershed may provide a better insight for the design and implementation of flood risk management plans.

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Comparative assessment of CORINE2000 and GLC2000: Spatial analysis of land cover data for Europe

International Journal of Applied Earth Observation and Geoinformation ◽

10.1016/j.jag.2007.02.004 ◽

2007 ◽

Vol 9 (4) ◽

pp. 425-437 ◽

Cited By ~ 61

Author(s):

K. Neumann ◽

M. Herold ◽

A. Hartley ◽

C. Schmullius

Keyword(s):

Spatial Analysis ◽

Land Cover ◽

Comparative Assessment ◽

Land Cover Data

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Simulating the atmospheric CO<sub>2</sub> concentration across the heterogeneous landscape of Denmark using a coupled atmosphere–biosphere mesoscale model system

Biogeosciences ◽

10.5194/bg-16-1505-2019 ◽

2019 ◽

Vol 16 (7) ◽

pp. 1505-1524

Author(s):

Anne Sofie Lansø ◽

Thomas Luke Smallman ◽

Jesper Heile Christensen ◽

Mathew Williams ◽

Kim Pilegaard ◽

...

Keyword(s):

Land Cover ◽

Mesoscale Model ◽

Co2 Exchange ◽

Surface Fluxes ◽

Atmospheric Co2 ◽

Atmospheric Concentration ◽

Study Region ◽

The North ◽

Modelling Framework ◽

Atmospheric Co2 Concentrations

Abstract. Although coastal regions only amount to 7 % of the global oceans, their contribution to the global oceanic air–sea CO2 exchange is proportionally larger, with fluxes in some estuaries being similar in magnitude to terrestrial surface fluxes of CO2. Across a heterogeneous surface consisting of a coastal marginal sea with estuarine properties and varied land mosaics, the surface fluxes of CO2 from both marine areas and terrestrial surfaces were investigated in this study together with their impact in atmospheric CO2 concentrations by the usage of a high-resolution modelling framework. The simulated terrestrial fluxes across the study region of Denmark experienced an east–west gradient corresponding to the distribution of the land cover classification, their biological activity and the urbanised areas. Annually, the Danish terrestrial surface had an uptake of approximately −7000 GgC yr−1. While the marine fluxes from the North Sea and the Danish inner waters were smaller annually, with about −1800 and 1300 GgC yr−1, their sizes are comparable to annual terrestrial fluxes from individual land cover classifications in the study region and hence are not negligible. The contribution of terrestrial surfaces fluxes was easily detectable in both simulated and measured concentrations of atmospheric CO2 at the only tall tower site in the study region. Although, the tower is positioned next to Roskilde Fjord, the local marine impact was not distinguishable in the simulated concentrations. But the regional impact from the Danish inner waters and the Baltic Sea increased the atmospheric concentration by up to 0.5 ppm during the winter months.

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Defining spring foraging habitat and prioritization of conservation sites for Tricolored Blackbirds in California, USA

The Condor ◽

10.1093/condor/duz054 ◽

2019 ◽

Vol 121 (4) ◽

Cited By ~ 1

Author(s):

Chad B Wilsey ◽

Nicole L Michel ◽

Katie Krieger ◽

Lotem Taylor ◽

Liling Lee ◽

...

Keyword(s):

Surface Water ◽

Land Cover ◽

Landscape Connectivity ◽

Percent Cover ◽

Private Land ◽

Foraging Habitat ◽

Critical Feature ◽

Study Region ◽

Colonial Nesting ◽

Surrounding Landscape

Abstract The Tricolored Blackbird (Agelaius tricolor) is a range-restricted, colonial-nesting species in decline. Colonies include tens of thousands of individuals that forage in the surrounding landscape, at times commuting miles between nesting and foraging grounds. We explored the role of landscape composition on colony occupancy and mapped core and potential spring foraging habitat in California, USA. We used observations of spring Tricolored Blackbird nesting colonies from 2008, 2011, and 2014 and characterized changes in the surrounding landscape during an extended drought. Then, we constructed occurrence and abundance models in order to map core foraging habitat across 4 ecoregions in California. Finally, we used simulated land cover changes to identify potential habitat under restoration scenarios. Across the 3 survey years, surface water declined over time at unoccupied colony locations but remained stable at occupied colony locations, confirming that permanent surface water was a critical feature of persistent Tricolored Blackbird colonies. Average percent cover of nearly all land cover types suitable for foraging, as well as frequency of dairies and median NDVI, were all higher in current or historical colony sites than elsewhere. The proportion of surrounding alfalfa, grasslands, and surface water were the elements of foraging habitat best able to predict Tricolored Blackbird early breeding season colony presence and colony size. Core foraging habitat covered over 6 million acres in the study region, but only 18% was occupied in 2014. This result suggests a need to study additional factors determining colony occurrence and persistence, such as landscape connectivity, distributions of nesting substrates, and risk from predators. The vast majority (93.1%) of Tricolored Blackbird core habitat occurred on private land; therefore, saving the species will require engagement and partnership with private landowners.

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The Influence of Near-field Fluxes on Seasonal Carbon Dioxide Enhancements: Results From the Indianapolis Flux Experiment (INFLUX)

10.21203/rs.3.rs-66160/v1 ◽

2020 ◽

Author(s):

NATASHA MILES ◽

Kenneth J. Davis ◽

Scott J. Richardson ◽

Thomas Lauvaux ◽

Douglas K. Martins ◽

...

Keyword(s):

Land Cover ◽

Near Field ◽

Growing Season ◽

Model Data ◽

Study Region ◽

Sources And Sinks ◽

Dormant Season ◽

Time Of Year ◽

Local Emissions ◽

Biogenic Fluxes

Abstract BackgroundNetworks of tower-based CO2 mole fraction sensors have been deployed in and around cities across the world to quantify anthropogenic CO2 emissions from metropolitan areas. A critical aspect in these approaches is the separation of atmospheric signatures from distant sources and sinks (i.e., the background) from local emissions and biogenic fluxes. We examined CO2 enhancements compared to forested and agricultural background towers in Indianapolis, Indiana, USA, as a function of season and compared them to modeled results, as a part of the Indianapolis Flux (INFLUX) project.ResultsAt the INFLUX urban tower sites, daytime growing season enhancement on a monthly timescale was up to 4.3 – 6.5 ppm, 2.6 times as large as those in the dormant season, on average. The enhancement differed significantly depending on choice of background and time of year, being 2.8 ppm higher in June and 1.8 ppm lower in August using a forested background tower compared to an agricultural background tower. A prediction based on land cover and observed CO2 fluxes showed that differences in phenology and drawdown intensities drove measured differences in enhancements. Forward modelled CO2 enhancements using fossil fuel and biogenic fluxes indicated growing season model-data mismatch of 1.1 ± 1.7 ppm for the agricultural background and 2.1 ± 0.5 ppm for the forested background, corresponding to 25 – 29 % of the modelled CO2 enhancements. The model-data total CO2 mismatch during the dormant season was low, – 0.1 ± 0.5 ppm. ConclusionsBecause growing season biogenic fluxes at the background towers are large, the urban enhancements must be disentangled from the biogenic signal, and growing season increases in CO2 enhancement could be misinterpreted as increased anthropogenic fluxes if the background ecosystem CO2 drawdown is not considered. The magnitude and timing of enhancements depend on the land cover type and net fluxes surrounding each background tower, so a simple box model is not appropriate for interpretation of these data. Quantification of the seasonality and magnitude of the biological fluxes in the study region using high-resolution and detailed biogenic models is necessary for the interpretation of tower-based urban CO2 networks for cities with significant vegetation.

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Comparison of Simple Averaging and Latent Class Modeling to Estimate the Area of Land Cover in the Presence of Reference Data Variability

Land ◽

10.3390/land10010035 ◽

2021 ◽

Vol 10 (1) ◽

pp. 35

Author(s):

Dingfan Xing ◽

Stephen V. Stehman ◽

Giles M. Foody ◽

Bruce W. Pengra

Keyword(s):

Land Cover ◽

Latent Class ◽

Reference Data ◽

Land Cover Class ◽

Reference Class ◽

Study Region ◽

Latent Class Modeling ◽

Class Labels ◽

Cover Class ◽

Percent Area

Estimates of the area or percent area of the land cover classes within a study region are often based on the reference land cover class labels assigned by analysts interpreting satellite imagery and other ancillary spatial data. Different analysts interpreting the same spatial unit will not always agree on the land cover class label that should be assigned. Two approaches for accommodating interpreter variability when estimating the area are simple averaging (SA) and latent class modeling (LCM). This study compares agreement between area estimates obtained from SA and LCM using reference data obtained by seven trained, professional interpreters who independently interpreted an annual time series of land cover reference class labels for 300 sampled Landsat pixels. We also compare the variability of the LCM and SA area estimates over different numbers of interpreters and different subsets of interpreters within each interpreter group size, and examine area estimates of three land cover classes (forest, developed, and wetland) and three change types (forest gain, forest loss, and developed gain). Differences between the area estimates obtained from SA and LCM are most pronounced for the estimates of wetland and the three change types. The percent area estimates of these rare classes were usually greater for LCM compared to SA, with the differences between LCM and SA increasing as the number of interpreters providing the reference data increased. The LCM area estimates generally had larger standard deviations and greater ranges over different subsets of interpreters, indicating greater sensitivity to the selection of the individual interpreters who carried out the reference class labeling.

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