CHARACTERIZATION NDVI SPACE-TIME AND SURFACE AND ANALYSIS PHYTOSOCIOLOGIC ALBEDO FOR SÃO JOÃO DO CARIRI

Virginia Mirtes de Alcântara Silva

Abstract


Advances in research on desertification processes were acquired through remote sensing, especially in the analysis of the dynamics between surface and atmosphere. The techniques in remote sensing for its intrinsic spatial and multi-temporal approach allow the evaluation process trends by identifying changes in vegetation and surface soil by monitoring multiple parameters including the Vegetation Index Difference standardized and surface albedo. The main objective of the study was to determine the evolution spatiotemporal two indicators of desertification obtained through remote sensing: the albedo surface and NDVI based on spectral bands of TM - Landsat 5, thus contributing to the establishment plans to combat desertification in action for the municipality of São João do Cariri, Paraiba semi-arid, presenting severe levels of land degradation (84%). Satellite images were used Landsat - 5 TM, orbit 215 point 065 between the years 1990 and 2005 acquired the site of the United States Geological Survey - USGS. Use of ArcGIS software 9.3 and ERDAS Imagine 9.3 GIS lab meteorological department of the Federal University of Campina Grande - UFCG. The images were validated with field research and conducting this survey vegetation in the area (7 26'57.12 "S and 36º30'25.85" O). The structure of vegetation was carried out in two plots of 10 x 20 m, lying 50 cm between plots with a total area of ​​0,04ha. Were used for analysis only, the shrubby-arboreal extracts with (CAP) ≥ 3.5, Phytosociological using the following parameters: absolute density (DA), the relative density (RD), absolute frequency (AF), on rate (RR) absolute dominance (DoA), relative dominance (DoR) and importance value (VI). found that there is a strong inverse linear relationship between NDVI and surface albedo and according to the results obtained for the city of São João do Cariri, in the period between 1990 and 2005.Verificou It is this temporal analysis of biophysical parameters that when the value of albedo declined in class 0.10-0.15 there was an increase in classes 0.4- 0.6 and> 0.6 NDVI, conversely the 0.15-0.20 and 20-30 albedo classes showed an expansion in these areas and hence a decrease in the area corresponding to 0.2 to 0 class 4 NDVI.O increase in albedo values ​​can be explained by the influence of meteorological factors (rain irregularity, energy balance etc.) and by human activities responsible for landscape change over time. The Phytosociological results for the two installments selected 30 individuals were found belonging to 9 species contained in 5 families. The families with the highest number of species were: Mimosaceae, with 12 individuals, Cactaceae with 8 individuals and Fabaceae with 4 individuals, they are typical of anthropogenic environments showing enough tolerance to high levels of disturbance.

Keywords


vegetation, desertification, human actions, semiarid region

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DOI: https://doi.org/10.29150/jhrs.v6i6.22745

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