scholarly journals The Extent of Infrastructure Causing Fragmentation in the Hydrocarbon Basin in the Arid and Semi-Arid Zones of Patagonia (Argentina)

2019 ◽  
Vol 11 (21) ◽  
pp. 5956
Author(s):  
Buzzi ◽  
Rueter ◽  
Ghermandi ◽  
Lasaponara
Keyword(s):  
Principal Component ◽  
Mesh Size ◽  
Oil Production ◽  
Landscape Fragmentation ◽  
Arid Zones ◽  
Effective Mesh Size ◽  
The Mean ◽  
Patch Density ◽  
Landscape Units ◽  
Semi Arid

Fragmentation is a disruption in the connectivity of landscapes. The aims of this paper are (i) to quantitatively assess the fragmentation rates in three landscape units located in a hydrocarbon basin, and (ii) to model their behavior between 2001 and 2013 using landscape metrics at different scales of resolution. The following metrics were selected using principal component analysis (PCA): The Clumpiness Index (CLUMPY), patch density (PD), perimeter-area fractal dimension (PAFRAC) and effective mesh size (MESH). Results from our investigations pointed out that hydrocarbon activity increased the fragmentation at the sites. In particular, the CLUMPY index increased in all three landscape units, the average of PD decreased from 60 to 14 patches per 100 hectares, whereas the mean of MESH was quite constant, however, due to oil production, it decreased mainly in the coastal valleys. Finally, the PAFRAC also decreased at sites with oil production, being more evident in the plateau and coastal canyons. As a whole, outputs from our analyses clearly pointed out that the monitoring of landscape fragmentation trends in arid and semi-arid zones can be successfully achieved using metrics derived from satellite spectral information.

Modification of the effective mesh size for measuring landscape fragmentation to solve the boundary problem

2006 ◽  
Vol 22 (3) ◽  
pp. 447-459 ◽  
Author(s):  
Brigitte Moser ◽  
Jochen A. G. Jaeger ◽  
Ulrike Tappeiner ◽  
Erich Tasser ◽  
Beatrice Eiselt
Keyword(s):  
Boundary Problem ◽  
Mesh Size ◽  
Landscape Fragmentation ◽  
Effective Mesh Size

scholarly journals Recent Shrinkage and Fragmentation of Bluegrass Landscape in Kentucky

2020 ◽  
Vol 12 (11) ◽  
pp. 1815
Author(s):  
Bo Tao ◽  
Yanjun Yang ◽  
Jia Yang ◽  
Ray Smith ◽  
James Fox ◽  
...  
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Mesh Size ◽  
Landscape Fragmentation ◽  
Climate Mitigation ◽  
Fragmentation Model ◽  
Cultural Significance ◽  
Effective Mesh Size ◽  
Grassland Conversion ◽  
Bluegrass Region

The Bluegrass Region is an area in north-central Kentucky with unique natural and cultural significance, which possesses some of the most fertile soils in the world. Over recent decades, land use and land cover changes have threatened the protection of the unique natural, scenic, and historic resources in this region. In this study, we applied a fragmentation model and a set of landscape metrics together with the satellite-derived USDA Cropland Data Layer to examine the shrinkage and fragmentation of grassland in the Bluegrass Region, Kentucky during 2008–2018. Our results showed that recent land use change across the Bluegrass Region is characterized by grassland decline, cropland expansion, forest spread, and suburban sprawl. The grassland area decreased by 14.4%, with an interior (or intact) grassland shrinkage of 5%, during the study period. Land conversion from grassland to other land cover types has been widespread, with major grassland shrinkage occurring in the west and northeast of the Outer Bluegrass Region and relatively minor grassland conversion in the Inner Bluegrass Region. The number of patches increased from 108,338 to 126,874. The effective mesh size, which represents the degree of landscape fragmentation in a system, decreased from 6629.84 to 1816.58 for the entire Bluegrass Region. This study is the first attempt to quantify recent grassland shrinkage and fragmentation in the Bluegrass Region. Therefore, we call for more intensive monitoring and further conservation efforts to preserve the ecosystem services provided by the Bluegrass Region, which has both local and regional implications for climate mitigation, carbon sequestration, diversity conservation, and culture protection.

scholarly journals Assessing Landscape Sensitivity Based on Fragmentation Caused by the Artificial Barriers in Hungary

2013 ◽  
Vol 6 (1-2) ◽  
pp. 37-47 ◽  
Author(s):  
Teodóra Bata ◽  
Gábor Mezősi
Keyword(s):  
Landscape Metrics ◽  
Patch Size ◽  
Mesh Size ◽  
Landscape Fragmentation ◽  
Effective Population ◽  
Landscape Unit ◽  
Landscape Sensitivity ◽  
The Stability ◽  
Landscape Units ◽  
Degree Of Fragmentation

Abstract Artificial barriers significantly disturb the landscape unit. Roads split the contiguous landscape units, thus basically modi fying their ecological characters. The more artificial barriers are constructed in the landscape, the more fragmented it is. Theref ore, the contiguous landscape unit is divided into two or more patches, weakening resilience and stability of ecological systems. During decrease in patch size, the stability reduces until the patch size is at its minimum viable or effective population size. In current study analysing the degree of fragmentation caused by artificial barriers in meso-scale landscape units (meso-regions) we can get an overall picture about changes in their stability and sensitivity. The major aims of this study is to investigate the fragmentation of landscape units caused by three types of artificial barriers (roads, railways and settlements) in micro-regions, and to measure the degree of fragmentation and its spatial-temporal (1990, 2011 and future scenario to 2027) changes using mathemat ical/ statistical analysis and landscape metrics (Number of Patches, Division, Landscape Splitting Index and Effective Mesh Size). By calculating landscape fragmentation metrics, the micro-regions are identified, which must be protected with high priority in the future. In the planning processes, type and position of artificial barriers could be more properly determined by calculation of these landscape metrics.

scholarly journals Influencia de la actividad petrolera y la ganadería ovina en la cubierta del suelo en una región árida y semiárida de la Patagonia Argentina

2019 ◽  
Vol 45 (2) ◽  
pp. 661
Author(s):  
M.A. Buzzi ◽  
B.L. Rueter ◽  
L. Ghermandi ◽  
F. Maldonado
Keyword(s):  
Plant Communities ◽  
Mesh Size ◽  
Ground Cover ◽  
Bare Soil ◽  
Edge Density ◽  
Oil Exploitation ◽  
Multi Temporal ◽  
Effective Mesh Size ◽  
Landscape Units ◽  
Geographical Space

The Geography has provided the greatest theoretical body for the study of the configurations that occur over the geographical space. The generation of cartography that represents ground cover is one of the most important uses of remote sensing. Polygons were selected, with oil and livestock activity, in the landscape units: coastal canyons, plateaus and western valleys. The polygons were used to evaluate multi-temporal changes in land cover and plant communities over a period of 15 years. Supervised classifications and analysis of landscape metrics were made to examine the possible causes of these changes by comparing: i) polygons without oil or livestock activity (control), ii) polygons with oil and livestock activity, iii) polygons with oil activity and without livestock activity, and iv) polygons without oil activity and livestock activity. The results obtained indicated that the density of patches, the total edge, the edge density and the division index of the fragments increased in the three landscape units, between 2001 and 2016. The contagion index, however, decreased. An increase in bare soil was observed in the plateaus and in the western valleys, with a regression of the dominant plant communities. The density of patches in the sites without disturbance was the lowest, and in the sites with both disturbances acting simultaneously was maximum. In the sites without disturbance the effective mesh size was maximum, while in the sites with some disturbance it was smaller. When analyzing the effect of the disturbance on the elements of the landscape it was observed that the presence of the disturbance generates the highest density of patches and the minimum connectivity. The results show that there was a process of fragmentation in the coverage of the soil directed by the oil exploitation and sheep farming, which decrease the size of the patches and, therefore, the density of the same per unit area.

Multivariate Analysis, Genetic Diversity and Phenotypic Correlation of Nineteen Exotic Groundnut Accessions

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
YPJ AMARASINGHE ◽  
G . WIJESINGHE ◽  
R W PUSHPAKUMARA
Keyword(s):  
Genetic Diversity ◽  
Principal Component Analysis ◽  
Growth Parameters ◽  
Principal Component ◽  
Phenotypic Correlation ◽  
Clustering Method ◽  
Yield Parameters ◽  
Arachis Hypogaea L ◽  
Semi Arid ◽  
Number Of Branches

19 Groundnut ( Arachis hypogaea L. ) genotypes receiv ed from International Crops Research Institute for Semi Arid T ropics (ICRISA T) India w ere ev aluated in a non replicated trial and the characters w ere subjected to multiv ariate analysis to study the v ariability within the genotypes. The first 5 axes of the principal component analysis captured 78% of the total v ariability and identified yield parameters such as number of pods per plant, pod w eight per plant and growth parameters such as number of branches per plant, plant spread, and pod characteristics as the characters contributing most to total v ariation. Phenotypic correlation analysis rev ealed that the yield has positiv e correlation with the characters such as number of pods per plant and number of branches per plant. W ards clustering method has grouped the genotypes into 3 distinct clusters. The results can be applied in order to strengthen the breeding program

scholarly journals To Weight or Not to Weight, That Is the Question: The Design of a Composite Indicator of Landscape Fragmentation

2021 ◽  
Vol 11 (7) ◽  
pp. 3208
Author(s):  
Andrea De Montis ◽  
Vittorio Serra ◽  
Giovanna Calia ◽  
Daniele Trogu ◽  
Antonio Ledda
Keyword(s):  
Principal Component Analysis ◽  
Geometric Mean ◽  
Composite Index ◽  
Weighted Average ◽  
Principal Component ◽  
Expert Judgment ◽  
Landscape Fragmentation ◽  
Composite Indicator ◽  
Per Se ◽  
Higher Sensitivity

Composite indicators (CIs), i.e., combinations of many indicators in a unique synthetizing measure, are useful for disentangling multisector phenomena. Prominent questions concern indicators’ weighting, which implies time-consuming activities and should be properly justified. Landscape fragmentation (LF), the subdivision of habitats in smaller and more isolated patches, has been studied through the composite index of landscape fragmentation (CILF). It was originally proposed by us as an unweighted combination of three LF indicators for the study of the phenomenon in Sardinia, Italy. In this paper, we aim at presenting a weighted release of the CILF and at developing the Hamletian question of whether weighting is worthwhile or not. We focus on the sensitivity of the composite to different algorithms combining three weighting patterns (equalization, extraction by principal component analysis, and expert judgment) and three indicators aggregation rules (weighted average mean, weighted geometric mean, and weighted generalized geometric mean). The exercise provides the reader with meaningful results. Higher sensitivity values signal that the effort of weighting leads to more informative composites. Otherwise, high robustness does not mean that weighting was not worthwhile. Weighting per se can be beneficial for more acceptable and viable decisional processes.

scholarly journals Towards Understanding Variability in Droughts in Response to Extreme Climate Conditions over the Different Agro-Ecological Zones of Pakistan

2021 ◽  
Vol 13 (12) ◽  
pp. 6910
Author(s):  
Adil Dilawar ◽  
Baozhang Chen ◽  
Arfan Arshad ◽  
Lifeng Guo ◽  
Muhammad Irfan Ehsan ◽  
...  
Keyword(s):  
Pearson Correlation ◽  
Principal Component ◽  
Mitigation Strategies ◽  
Precipitation Extremes ◽  
Climate Mitigation ◽  
Mean Annual Temperature ◽  
Climate Extreme ◽  
Ecological Zones ◽  
The Mean ◽  
Agro Ecological Zones

Here, we provided a comprehensive analysis of long-term drought and climate extreme patterns in the agro ecological zones (AEZs) of Pakistan during 1980–2019. Drought trends were investigated using the standardized precipitation evapotranspiration index (SPEI) at various timescales (SPEI-1, SPEI-3, SPEI-6, and SPEI-12). The results showed that droughts (seasonal and annual) were more persistent and severe in the southern, southwestern, southeastern, and central parts of the region. Drought exacerbated with slopes of −0.02, −0.07, −0.08, −0.01, and −0.02 per year. Drought prevailed in all AEZs in the spring season. The majority of AEZs in Pakistan’s southern, middle, and southwestern regions had experienced substantial warming. The mean annual temperature minimum (Tmin) increased faster than the mean annual temperature maximum (Tmax) in all zones. Precipitation decreased in the southern, northern, central, and southwestern parts of the region. Principal component analysis (PCA) revealed a robust increase in temperature extremes with a variance of 76% and a decrease in precipitation extremes with a variance of 91% in the region. Temperature and precipitation extremes indices had a strong Pearson correlation with drought events. Higher temperatures resulted in extreme drought (dry conditions), while higher precipitation levels resulted in wetting conditions (no drought) in different AEZs. In most AEZs, drought occurrences were more responsive to precipitation. The current findings are helpful for climate mitigation strategies and specific zonal efforts are needed to alleviate the environmental and societal impacts of drought.

Sign in / Sign up

Export Citation Format

Share Document