Fire Recurrence and the Dynamics of the Enhanced Vegetation Index in a Mediterranean Ecosystem

2015 ◽  
Vol 6 (2) ◽  
pp. 18-35 ◽  
Author(s):  
Dania Abdul Malak ◽  
Juli G. Pausas ◽  
Josep E. Pardo-Pascual ◽  
Luis A. Ruiz
Keyword(s):  
Forest Fires ◽  
Vegetation Index ◽  
Land Use Changes ◽  
Extended Period ◽  
Mediterranean Ecosystem ◽  
Climatic Effects ◽  
Enhanced Vegetation Index ◽  
Mediterranean Landscapes ◽  
The Impact ◽  
Vegetation Regeneration

This study area is located in the eastern littoral of the Iberian Peninsula; its importance resides in its Mediterranean ecosystem, complex topography, extensive land use changes, and intensive forest fires history. The study is done at the landscape level, covering a wide area for an extended period of time. This work uses Geographic Information Systems (GIS) and Satellite Remote Sensing (SRS) techniques to evaluate the impact of spatio-temporal parameters on shaping Mediterranean landscapes. Interacting ecological parameters are analysed and correlated to post-fire vegetation regeneration in an attempt to understand its dynamics. The results provide evidence that the number of fires separated by short time intervals influence vegetation growth negatively measured as Enhanced Vegetation Index (EVI). During this period, micro-climatic effects (soil and environmental humidity) are major factors influencing EVI-measured vegetation regeneration. The conclusions expect shifts in Mediterranean plant communities in heavily burned ecosystems stressing the importance of their correct short and long term post-fire management.

Fire Recurrence and the Dynamics of the Enhanced Vegetation Index in a Mediterranean Ecosystem

2019 ◽  
pp. 1690-1708
Author(s):  
Dania Abdul Malak ◽  
Juli G. Pausas ◽  
Josep E. Pardo-Pascual ◽  
Luis A. Ruiz
Keyword(s):  
Forest Fires ◽  
Vegetation Index ◽  
Mediterranean Ecosystem ◽  
Climatic Effects ◽  
Vegetation Growth ◽  
Enhanced Vegetation Index ◽  
Spatio Temporal ◽  
Major Factors ◽  
Ecosystem Complex ◽  
Vegetation Regeneration

This study area is located in the eastern littoral of the Iberian Peninsula; its importance resides in its Mediterranean ecosystem, complex topography, extensive land use changes, and intensive forest fires history. The study is done at the landscape level, covering a wide area for an extended period of time. This work uses Geographic Information Systems (GIS) and Satellite Remote Sensing (SRS) techniques to evaluate the impact of spatio-temporal parameters on shaping Mediterranean landscapes. Interacting ecological parameters are analysed and correlated to post-fire vegetation regeneration in an attempt to understand its dynamics. The results provide evidence that the number of fires separated by short time intervals influence vegetation growth negatively measured as Enhanced Vegetation Index (EVI). During this period, micro-climatic effects (soil and environmental humidity) are major factors influencing EVI-measured vegetation regeneration. The conclusions expect shifts in Mediterranean plant communities in heavily burned ecosystems stressing the importance of their correct short and long term post-fire management.

scholarly journals Analysis of the Impact of Land Use and Occupation on the Biophysical Variables of the Cerrado Biome in Southwest Goiano, Brazil

2018 ◽  
Vol 11 (1) ◽  
pp. 399
Author(s):  
Victor H. Moraes ◽  
Pedro R. Giongo ◽  
Marcio Mesquita ◽  
Thomas J. Cavalcante ◽  
Matheus V. A. Ventura ◽  
...  
Keyword(s):  
Land Use ◽  
Surface Temperature ◽  
Urban Areas ◽  
Vegetation Index ◽  
Land Use Changes ◽  
Weighted Average ◽  
Natural Vegetation ◽  
Agricultural Crops ◽  
Quantitative Classification ◽  
The Impact

The change in the use of natural vegetation by annual or perennial crops, sugarcane and fast-growing forests causes changes in the biophysical variables, and these changes can be monitored by remote sensing. The objective of this work was to evaluate, on a temporal scale, the impacts of land use changes on biophysical variables in the county of Santa Helena de Goias-Goias/Brazil. Between the years of 2000 to 2015 areas were identified for agricultural crops 1 (annual crops), water, agricultural crops 2 (sugarcane), natural vegetation, pasture and urban areas. The MODIS (Moderate Resolution Spectroradiometer) sensor products were selected for study: MOD11A2-Surface temperature; MOD16A2-Real evapotranspiration, MOD13Q1-Enhanced Vegetation Index and rainfall data from TRMM (Tropical Rainfall Measuring Mission). The geographic coordinates referring to the land uses were inserted in the LAPIG platform, searching the information of the biophysical variables referring to the selected pixel. The impact of land use change was evaluated by calculating the weighted average through the quantitative classification of the areas. It is concluded for the period of study that the index of average vegetation of the county had increase. There was an increase in the evapotranspiration volume of the county from 28% from 2000 to 2013 and the average surface temperature of the county showed a reduction of 2 °C in the period from 2000 to 2015.

scholarly journals Increasing wild boar density explains the decline of a Montagu’s harrier population on a protected coastal wetland

2021 ◽  
pp. 229-239
Author(s):  
J. Crespo ◽  
J. Jiménez ◽  
A. Martínez–Abraín
Keyword(s):  
Wild Boar ◽  
Forest Fires ◽  
Coastal Wetland ◽  
Land Use Changes ◽  
Annual Number ◽  
Rapid Decline ◽  
Wetland Birds ◽  
Montagu’S Harrier ◽  
The Impact ◽  
Montagu's Harrier

We studied the rapid decline in the number of breeding pairs (geometric growth rate λ = 0.86; 14 % annual decrease) of a semi–colonial ground–nesting bird of prey, the Montagu’s harrier (Circus pygargus), after twelve years of rapid population growth (λ = 1.15; 15 % rate of annual increase) in a protected coastal wetland in Eastern Spain. The study was conducted from 1992–2017, and the range of values in population size was: 2–37 breeding pairs. We contrasted 20 biologically–sound hypotheses (including local and regional factors) to explain the trend over time in the annual number of pairs. The most parsimonious model included a surrogate of wild boar (Sus scrofa) density in the region during the previous year and the annual number of Montagu’s harrier pairs breeding inland in the study province during the focal year. Syntopic western marsh harriers (C. aeruginosus) were not found to have any effect on the numbers of Montagu’s harriers either in our modelling or when we performed a quantitative and qualitative study both for years t and t–1. Our final ‘best’ models did not include spring rainfall, regional forest fires or local land use changes. The impact of wild boars on breeding success, together with conspecific attraction, could have resulted in the dispersal of coastal wetland birds to larger populations in dense inland shrub lands where levels of wild boar nest predation were more likely lower

Fire danger estimation from MODIS Enhanced Vegetation Index data: application to Galicia region (north-west Spain)

2011 ◽  
Vol 20 (3) ◽  
pp. 465 ◽  
Author(s):  
M. M. Bisquert ◽  
J. M. Sánchez ◽  
V. Caselles
Keyword(s):  
Forest Fires ◽  
Vegetation Index ◽  
Estimation Error ◽  
Fire Danger ◽  
Enhanced Vegetation Index ◽  
North West ◽  
Remote Sensing Technique ◽  
Moderate Resolution ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Terra Satellite

Galicia, in north-west Spain, is a region especially affected by devastating forest fires. The development of a fire danger prediction model adapted to this particular region is required. In this paper, we focus on changes in the condition of vegetation as an indicator of fire danger. The potential of the Enhanced Vegetation Index (EVI) together with period-of-year to monitor vegetation changes in Galicia is shown. The Moderate Resolution Imaging Spectroradiometer (MODIS), onboard the Terra satellite, was chosen for this study. A 6-year dataset of EVI images, from the product MOD13Q1 (16-day composites), together with fire data in a 10 × 10-km grid basis, were used. Logistic regression was used to assess the relationship between the percentage of fire activity and EVI variations together with period-of-year. The results show the ability of the model obtained to discriminate different levels of fire occurrence danger, with an estimation error of ~5%. This remote sensing technique may contribute to improving the efficiency of the currently used fire prevention systems.

scholarly journals Capturing the Impact of the 2018 European Drought and Heat across Different Vegetation Types Using OCO-2 Solar-Induced Fluorescence

2020 ◽  
Vol 12 (19) ◽  
pp. 3249
Author(s):  
Ankit Shekhar ◽  
Jia Chen ◽  
Shrutilipi Bhattacharjee ◽  
Allan Buras ◽  
Antony Oswaldo Castro ◽  
...  
Keyword(s):  
Forest Fires ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Coniferous Forest ◽  
Mixed Forest ◽  
Terrestrial Ecosystem ◽  
Added Value ◽  
Summer Drought ◽  
Vegetation Types ◽  
The Impact

The European heatwave of 2018 led to record-breaking temperatures and extremely dry conditions in many parts of the continent, resulting in widespread decrease in agricultural yield, early tree-leaf senescence, and increase in forest fires in Northern Europe. Our study aims to capture the impact of the 2018 European heatwave on the terrestrial ecosystem through the lens of a high-resolution solar-induced fluorescence (SIF) data acquired from the Orbiting Carbon Observatory-2 (OCO-2) satellite. SIF is proposed to be a direct proxy for gross primary productivity (GPP) and thus can be used to draw inferences about changes in photosynthetic activity in vegetation due to extreme events. We explore spatial and temporal SIF variation and anomaly in the spring and summer months across different vegetation types (agriculture, broadleaved forest, coniferous forest, and mixed forest) during the European heatwave of 2018 and compare it to non-drought conditions (most of Southern Europe). About one-third of Europe’s land area experienced a consecutive spring and summer drought in 2018. Comparing 2018 to mean conditions (i.e., those in 2015–2017), we found a change in the intra-spring season SIF dynamics for all vegetation types, with lower SIF during the start of spring, followed by an increase in fluorescence from mid-April. Summer, however, showed a significant decrease in SIF. Our results show that particularly agricultural areas were severely affected by the hotter drought of 2018. Furthermore, the intense heat wave in Central Europe showed about a 31% decrease in SIF values during July and August as compared to the mean over the previous three years. Furthermore, our MODIS (Moderate Resolution Imaging Spectroradiometer) and OCO-2 comparative results indicate that especially for coniferous and mixed forests, OCO-2 SIF has a quicker response and a possible higher sensitivity to drought in comparison to MODIS’s fPAR (fraction of absorbed photosynthetically active radiation) and the Normalized Difference Vegetation Index (NDVI) when considering shorter reference periods, which highlights the added value of remotely sensed solar-induced fluorescence for studying the impact of drought on vegetation.

Climate-forced changes of bio-productivity of Belorussian terrestrial ecosystems

2019 ◽  
pp. 77-88
Author(s):  
S. A. Lysenko
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Vegetation Index ◽  
Precipitation Amount ◽  
Terrestrial Ecosystems ◽  
Vegetation Period ◽  
Climatic Trend ◽  
Vegetation Growth ◽  
Current Century ◽  
The Impact

The spatial and temporal particularities of Normalized Differential Vegetation Index (NDVI) changes over territory of Belarus in the current century and their relationship with climate change were investigated. The rise of NDVI is observed at approximately 84% of the Belarus area. The statistically significant growth of NDVI has exhibited at nearly 35% of the studied area (t-test at 95% confidence interval), which are mainly forests and undeveloped areas. Croplands vegetation index is largely descending. The main factor of croplands bio-productivity interannual variability is precipitation amount in vegetation period. This factor determines more than 60% of the croplands NDVI dispersion. The long-term changes of NDVI could be explained by combination of two factors: photosynthesis intensifying action of carbon dioxide and vegetation growth suppressing action of air warming with almost unchanged precipitation amount. If the observed climatic trend continues the croplands bio-productivity in many Belarus regions could be decreased at more than 20% in comparison with 2000 year. The impact of climate change on the bio-productivity of undeveloped lands is only slightly noticed on the background of its growth in conditions of rising level of carbon dioxide in the atmosphere.

(Preprint)

2018 ◽  
Author(s):  
Natalia Banasik ◽  
Dariusz Jemielniak ◽  
Wojciech P?dzich
Keyword(s):  
Medical Condition ◽  
Extended Period ◽  
Well Being ◽  
Marginal Effect ◽  
Life Duration ◽  
Significant Difference ◽  
The Mean ◽  
Academic Teachers ◽  
Length Of Life ◽  
The Impact

BACKGROUND There have been mixed results of the studies checking whether prayers do actually extend the life duration of the people prayed for. Most studies on the topic included a small number of prayers and most of them focused on people already struggling with a medical condition. Intercessory prayer’s influence on health is of scholarly interest, yet it is unclear if its effect may be dependent on the number of prayers for a named individual received per annum. OBJECTIVE We sought to examine if there is a noticeable increased longevity effect of intercessory prayer for a named individual’s well-being, if he receives a very high number of prayers per annum for an extended period. METHODS We retrieved and conducted a statistical analysis of the data about the length of life for 857 Roman Catholic bishops, 500 Catholic priests, and 3038 male academics from the US, France, Italy, Poland, Brazil, and Mexico. We obtained information for these individuals who died between 1988 and 2018 from Wikidata, and conducted an observational cohort study. Bishops were chosen for the study, as they receive millions of individual prayers for well being, according to conservative estimates. RESULTS There was a main effect for occupation F(2, 4391) = 4.07, p = .017, ηp 2 = .002, with pairwise comparisons indicating significant differences between the mean life duration of bishops (M=30489) and of priests (M=29894), but none between the academic teachers (M=30147) and either of the other groups. A comparison analysis between bishops from the largest and the smallest dioceses showed no significant difference t(67.31)=1.61, p = .11. Our main outcome measure is covariance of the mean length of life in each of the categories: bishops, priests, academic teachers, controlled for nationality. CONCLUSIONS The first analysis proved that bishops live longer than priests, but due to a marginal effect size this result should be treated with caution. No difference was found between the mean length of life of bishops from the largest and the smallest dioceses. We found no difference between bishops and male academics. These results show that the impact of intercessory prayers on longevity is not observable.

scholarly journals Evaluating the Relationship Between Initial Injury, Referral to A Pain Clinic, and Medical Retirement from the Army: A Retrospective Analysis

2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 502-505
Author(s):  
Justin J Stewart ◽  
Diane Flynn ◽  
Alana D Steffen ◽  
Dale Langford ◽  
Honor McQuinn ◽  
...  
Keyword(s):  
Chronic Pain ◽  
Retrospective Analysis ◽  
Extended Period ◽  
Pain Clinic ◽  
Outcome Variable ◽  
Future Research ◽  
Curvilinear Relationship ◽  
The Impact ◽  
Pain Care ◽  
The Relationship

ABSTRACT Introduction Soldiers are expected to deploy worldwide and must be medically ready in order to accomplish their mission. Soldiers unable to deploy for an extended period of time because of chronic pain or other conditions undergo an evaluation for medical retirement. A retrospective analysis of existing longitudinal data from an Interdisciplinary Pain Management Center (IPMC) was used to evaluate the temporal relationship between the time of initial duty restriction and referral for comprehensive pain care to being evaluated for medical retirement. Methods Patients were adults (>18 years old) and were cared for in an IPMC at least once between May 1, 2014 and February 28, 2018. A total of 1,764 patients were included in the final analysis. Logistic regression was used to evaluate the impact of duration between date of first duty restriction documentation and IPMC referral to the outcome variable of establishment of a permanent 3 (P3) profile. Results The duration between date of first duty restriction and IPMC referral showed a curvilinear relationship to probability of a P3 profile. According to our model, a longer duration before referral is associated with an increased probability of a subsequent P3 profile with the highest probability peaking at 19 months. The probability of P3 declines gradually for those who were referred later. Discussion This is the first time the relationship between time of initial duty restriction, referral to an IPMC, and subsequent P3 or higher profile has been tested. Future research is needed to examine medical conditions listed on the profile to see how they might contribute to the cause of referral to the IPMC. Conclusion A longer duration between initial duty restriction and referral to IPMC was associated with higher odds of subsequent P3 status for up to 19 months. Referral to an IPMC for comprehensive pain care early in the course of chronic pain conditions may reduce the likelihood of P3 profile and eventual medical retirement of soldiers.

scholarly journals Urban Fire Severity and Vegetation Dynamics in Southern California

2020 ◽  
Vol 13 (1) ◽  
pp. 19
Author(s):  
Lauren E. H. Mathews ◽  
Alicia M. Kinoshita
Keyword(s):  
Vegetation Cover ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Current Knowledge ◽  
Fire Severity ◽  
Satellite Image ◽  
Burn Severity ◽  
Native Vegetation ◽  
Riparian Areas ◽  
The Impact

A combination of satellite image indices and in-field observations was used to investigate the impact of fuel conditions, fire behavior, and vegetation regrowth patterns, altered by invasive riparian vegetation. Satellite image metrics, differenced normalized burn severity (dNBR) and differenced normalized difference vegetation index (dNDVI), were approximated for non-native, riparian, or upland vegetation for traditional timeframes (0-, 1-, and 3-years) after eleven urban fires across a spectrum of invasive vegetation cover. Larger burn severity and loss of green canopy (NDVI) was detected for riparian areas compared to the uplands. The presence of invasive vegetation affected the distribution of burn severity and canopy loss detected within each fire. Fires with native vegetation cover had a higher severity and resulted in larger immediate loss of canopy than fires with substantial amounts of non-native vegetation. The lower burn severity observed 1–3 years after the fires with non-native vegetation suggests a rapid regrowth of non-native grasses, resulting in a smaller measured canopy loss relative to native vegetation immediately after fire. This observed fire pattern favors the life cycle and perpetuation of many opportunistic grasses within urban riparian areas. This research builds upon our current knowledge of wildfire recovery processes and highlights the unique challenges of remotely assessing vegetation biophysical status within urban Mediterranean riverine systems.

scholarly journals A Model-Based Tool for Assessing the Impact of Land Use Change Scenarios on Flood Risk in Small-Scale River Systems—Part 1: Pre-Processing of Scenario Based Flood Characteristics for the Current State of Land Use

Hydrology ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 102
Author(s):  
Frauke Kachholz ◽  
Jens Tränckner
Keyword(s):  
Land Use ◽  
River Flow ◽  
Land Use Changes ◽  
Small Rivers ◽  
Small Scale ◽  
Model Parameters ◽  
Ungauged Catchments ◽  
Model Based ◽  
Current State ◽  
The Impact

Land use changes influence the water balance and often increase surface runoff. The resulting impacts on river flow, water level, and flood should be identified beforehand in the phase of spatial planning. In two consecutive papers, we develop a model-based decision support system for quantifying the hydrological and stream hydraulic impacts of land use changes. Part 1 presents the semi-automatic set-up of physically based hydrological and hydraulic models on the basis of geodata analysis for the current state. Appropriate hydrological model parameters for ungauged catchments are derived by a transfer from a calibrated model. In the regarded lowland river basins, parameters of surface and groundwater inflow turned out to be particularly important. While the calibration delivers very good to good model results for flow (Evol =2.4%, R = 0.84, NSE = 0.84), the model performance is good to satisfactory (Evol = −9.6%, R = 0.88, NSE = 0.59) in a different river system parametrized with the transfer procedure. After transferring the concept to a larger area with various small rivers, the current state is analyzed by running simulations based on statistical rainfall scenarios. Results include watercourse section-specific capacities and excess volumes in case of flooding. The developed approach can relatively quickly generate physically reliable and spatially high-resolution results. Part 2 builds on the data generated in part 1 and presents the subsequent approach to assess hydrologic/hydrodynamic impacts of potential land use changes.

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