Spatio-temporal dynamics of normalized differential vegetation index and its driving factors in Xilin Gol, China

Land use planners require a time series land resources information and changing pattern for future management. Therefore, it is essential to assess changes in land cover. This study was to quantify the spatio-temporal dynamics of land use change over North and West Africa between 1985 and 2015 using the Normalized Difference Vegetation Index (NDVI) from the Very High Resolution Radiometer (AVHRR). The total investigated area was determined by 17,328,557.16 km2. The class of Urban and Built-up, Barren or sparsely vegetated, Savannas and Deciduous Broadleaf Forests increases considerably during the last three decades. In contrast, the class of Open Shrublands, Woody Savannas and water decrease notably during the three decades. The class of croplands decreases from 1985 to 1995 and increased from 1995 to 2015. The class of grasslands recorded a first increase from 1985 to 1995, and then decreased from 1995 to 2015. The class of permanent wetlands first decrease from 1985 to 1995, then increase from 1995 to 2005, followed by a decreasing trend during the last decade. The class of evergreen broadleaf forests decreased in the first two decades, from 1985 to 2005, and increased over the last decade.

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Burned Area Mapping Using Multi-Temporal Sentinel-2 Data by Applying the Relative Differenced Aerosol-Free Vegetation Index (RdAFRI)

Remote Sensing ◽

10.3390/rs12172753 ◽

2020 ◽

Vol 12 (17) ◽

pp. 2753

Author(s):

Manuel Salvoldi ◽

Gil Siaki ◽

Michael Sprintsin ◽

Arnon Karnieli

Keyword(s):

Biomass Burning ◽

Vegetation Index ◽

Normalized Difference Vegetation Index ◽

Temporal Dynamics ◽

Gaza Strip ◽

Threshold Level ◽

Burned Area ◽

Spatio Temporal ◽

The Gaza Strip ◽

Sentinel 2

Assessing the development of wildfire scars during a period of consecutive active fires and smoke overcast is a challenge. The study was conducted during nine months when Israel experienced massive pyro-terrorism attacks of more than 1100 fires from the Gaza Strip. The current project strives at developing and using an advanced Earth observation approach for accurate post-fire spatial and temporal assessment shortly after the event ends while eliminating the influence of biomass burning smoke on the ground signal. For fulfilling this goal, the Aerosol-Free Vegetation Index (AFRI), which has a meaningful advantage in penetrating an opaque atmosphere influenced by biomass burning smoke, was used. On top of it, under clear sky conditions, the AFRI closely resembles the widely used Normalized Difference Vegetation Index (NDVI), and it retains the same level of index values under smoke. The relative differenced AFRI (RdAFRI) set of algorithms was implemented at the same procedure commonly used with the Relative differenced Normalized Burn Ratio (RdBRN). The algorithm was applied to 24 Sentinel-2 Level-2A images throughout the study period. While validating with ground observations, the RdAFRI-based algorithms produced an overall accuracy of 90%. Furthermore, the RdAFRI maps were smoother than the equivalent RdNBR, with noise levels two orders of magnitude lower than the latter. Consequently, applying the RdAFRI, it is possible to distinguish among four severity categories. However, due to different cloud cover on the two consecutive dates, an automatic determination of a threshold level was not possible. Therefore, two threshold levels were considered through visual inspection and manually assigned to each imaging date. The novel procedure enables calculating the spatio-temporal dynamics of the fire scars along with the statistics of the burned vegetation species within the study area.

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Mapping spatio-temporal dynamics of main water parameters and understanding their relationships with driving factors using GF-1 images in a clear reservoir

Environmental Science and Pollution Research ◽

10.1007/s11356-020-09687-z ◽

2020 ◽

Vol 27 (27) ◽

pp. 33929-33950

Author(s):

Shuai Zeng ◽

Yunmei Li ◽

Heng Lyu ◽

Jiafeng Xu ◽

Xianzhang Dong ◽

...

Keyword(s):

Temporal Dynamics ◽

Driving Factors ◽

Water Parameters ◽

Spatio Temporal

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Spatio-temporal dynamics of vegetation cover in North-West Algeria using remote sensing data

Polish Cartographical Review ◽

10.2478/pcr-2019-0009 ◽

2019 ◽

Vol 51 (3) ◽

pp. 117-127

Author(s):

Si Tayeb Tayeb ◽

Benabdeli Kheloufi

Keyword(s):

Remote Sensing ◽

Land Cover ◽

Human Activities ◽

Vegetation Cover ◽

Vegetation Index ◽

Temporal Dynamics ◽

Anthropogenic Impacts ◽

Regional Scale ◽

Anthropogenic Factors ◽

Spatio Temporal

Abstract Land cover change is the result of complex interactions between social and environmental systems which change over time. While climatic and biophysics phenomena were for a long time the principal factor of land transformations, human activities are today the origin of the major part of land transformation which affects natural ecosystems. Quantification of natural and anthropogenic impacts on vegetation cover is often hampered by logistical issues, including (1) the difficulty of systematically monitoring the effects over large areas and (2) the lack of comparison sites needed to evaluate the effect of the factors. The effective procedure for measuring the degree of environmental change due to natural factors and human activities is the multitemporal study of vegetation cover. For this purpose, the aim of this work is the analysis of the evolution of land cover using remote sensing techniques, in order to better understand the respective role of natural and anthropogenic factors controlling this evolution. A spatio-temporal land cover dynamics study on a regional scale in Oranie, using Landsat data for two periods (1984–2000) and (2000–2011) was conducted. The images of the vegetation index were classified into three classes based on Normalized Difference Vegetation Index (NDVI) values and analysed using image difference approach. The result shows that the vegetation cover was changed. An intensive regression of the woody vegetation and forest land resulted in -22.5% of the area being lost between 1984 and 2000, 1,271 km2 was converted into scrub formations and 306 km2 into bare soil. On the other hand, this class increased by around 45% between 2000 and 2011, these evolutions resulting from the development of scrub groups with an area of 1,875.7 km2.

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Nonlinear Spatio-Temporal Dynamics and Chaos in Semiconductors

10.1017/cbo9780511524615 ◽

2001 ◽

Cited By ~ 136

Author(s):

Eckehard Schöll

Keyword(s):

Temporal Dynamics ◽

Spatio Temporal

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Spatio-temporal dynamics of ascidian larval recruitment and colony abundance in a non-indigenous Newfoundland population

Marine Ecology Progress Series ◽

10.3354/meps12437 ◽

2017 ◽

Vol 585 ◽

pp. 99-112 ◽

Cited By ~ 2

Author(s):

KCK Ma ◽

D Deibel ◽

JB Lowen ◽

CH McKenzie

Keyword(s):

Temporal Dynamics ◽

Larval Recruitment ◽

Spatio Temporal

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Spatial and temporal dynamics of Pacific capelin Mallotus catervarius in the Gulf of Alaska: implications for ecosystem-based fisheries management

Marine Ecology Progress Series ◽

10.3354/meps13211 ◽

2020 ◽

Vol 637 ◽

pp. 117-140 ◽

Cited By ~ 1

Author(s):

DW McGowan ◽

ED Goldstein ◽

ML Arimitsu ◽

AL Deary ◽

O Ormseth ◽

...

Keyword(s):

Temporal Dynamics ◽

Marine Ecosystem ◽

Gulf Of Alaska ◽

Data Series ◽

Limited Information ◽

Important Species ◽

Multiple Data ◽

Spatial And Temporal Dynamics ◽

Spawning Areas ◽

Spatio Temporal

Pacific capelin Mallotus catervarius are planktivorous small pelagic fish that serve an intermediate trophic role in marine food webs. Due to the lack of a directed fishery or monitoring of capelin in the Northeast Pacific, limited information is available on their distribution and abundance, and how spatio-temporal fluctuations in capelin density affect their availability as prey. To provide information on life history, spatial patterns, and population dynamics of capelin in the Gulf of Alaska (GOA), we modeled distributions of spawning habitat and larval dispersal, and synthesized spatially indexed data from multiple independent sources from 1996 to 2016. Potential capelin spawning areas were broadly distributed across the GOA. Models of larval drift show the GOA’s advective circulation patterns disperse capelin larvae over the continental shelf and upper slope, indicating potential connections between spawning areas and observed offshore distributions that are influenced by the location and timing of spawning. Spatial overlap in composite distributions of larval and age-1+ fish was used to identify core areas where capelin consistently occur and concentrate. Capelin primarily occupy shelf waters near the Kodiak Archipelago, and are patchily distributed across the GOA shelf and inshore waters. Interannual variations in abundance along with spatio-temporal differences in density indicate that the availability of capelin to predators and monitoring surveys is highly variable in the GOA. We demonstrate that the limitations of individual data series can be compensated for by integrating multiple data sources to monitor fluctuations in distributions and abundance trends of an ecologically important species across a large marine ecosystem.

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