Use of remote sensing to identify areas at risk of degradation in the semi-arid region

Aquino, Deodato do Nascimento; Neto, Odílio Coimbra da Rocha; Moreira, Maurício Alves; Teixeira, Adunias dos Santos; Andrade, Eunice Maia de

doi:10.5935/1806-6690.20180047

Cited by 24 publications

(20 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Nevertheless, an NDVI value higher than 0 depicts of vegetative cover. The main goal of this step is to isolate the non-vegetated areas, such as the built-up area, paved roads, bare soil, and only keep the vegetative [23].…”

Section: = − + (1)mentioning

confidence: 99%

Identifying Drought Status in Duhok Governorate (Iraqi Kurdistan Region) from 1998 through 2012 using Landsat Time Series Dataset

Gaznayee

Al-Quraishi²

2020

JASTT

View full text Add to dashboard Cite

Drought is a natural hazard that has a significant impact on the various aspects (i.e., economic, agricultural, environmental, and social). This study was carried out to evaluate drought severity and frequency during the growing season (April month) in Duhok Governorate (DUG), the Iraqi Kurdistan Region (IKR), for the period from 1998 through 2012 based on Landsat-based spectral indices. In this study, 15 mosaics assembled for 15 years consist of two scenes of Landsat time series, in a total of 30 TM and ETM+ images (WRS2: 170/34 & 170/35) acquired in 1998 to 2012. Annual precipitation data were collected from 18 meteorological stations distributed in the (DUG) for the study period. Drought status was investigated using the Normalized Difference Vegetation Index (NDVI), Modified Soil Adjusted Vegetation Index (MSAVI2), and Normalized Difference Water Index (NDWI). The study results showed an increase in drought severity and frequency in the (DUG) during the fifty years, particularly in 2000 and 2008. Whereas, the NDVI-based vegetation cover area has been reduced by 21.5% and 50.2% in 2000 and 2008, respectively. Additionally, the lowest values of the MSAVI2 (0.012 and 0.266) occurred in 2000 and 2008. As a result, the percentage of the vegetation cover reduction was 14.0% and 23.9%, respectively. Moreover, drop-in precipitation averages have occurred in those two drought years 2000 and 2008, as well as a significant reduction in the vegetation cover. On the other side, the most significant shrinkage in Duhok Dam (DUD) was by 1.13, 1.44, and 1.36 km2 in 2007, 2008, and 2009. It can be concluded that there are increasing drought episodes in the last two decades, declining in the water body surface area, and decreasing the precipitation averages in DUG from 1998 through 2012.

show abstract

Section: = − + (1)mentioning

confidence: 99%

Identifying Drought Status in Duhok Governorate (Iraqi Kurdistan Region) from 1998 through 2012 using Landsat Time Series Dataset

Gaznayee

Al-Quraishi²

2020

JASTT

View full text Add to dashboard Cite

show abstract

“…Other studies (Grohs et al, 2009) have indicated the potential of this equipment to validate and generate algorithms that are able to determine the nutritional status, grain yield, and productivity of agricultural crops such as wheat, barley, and corn. Aquino et al (2018) demonstrated that remote sensing (RS) has been an important tool worldwide to identify locations with some type of manipulation, and it has been essential in the planning of the developed activity. Therefore, the use of NDVI in the pasture management process can be an important tool.…”

Section: Resultsmentioning

confidence: 99%

Prediction of Brachiaria decumbens forage biomass using structural characteristics

Conrado

Lopes

Cândido

et al. 2021

Chil. j. agric. res.

View full text Add to dashboard Cite

Tools that generate models with good biomass predictive capacity are essential to maintain the sustainability of production systems. The objective was to analyze the relationship between forage biomass and structural variables and generate models to predict total forage biomass (TFB) and green leaf blade biomass (GLB). Irrigated pastures of Brachiaria decumbens Stapf 'Basilisk' were kept under rotational stocking with sheep (Ovis aries L.) The TFB, GLB, leaf area index (LAI), height (cm), and normalized difference vegetation index (NDVI) were evaluated. The experimental design was completely randomized with four replicates: ten and five cycles of defoliation management, respectively, were used to generate and validate the stages of the models. The best goodness of fit was obtained by nonlinear models for both TFB and GLB, which can be confirmed by high Spearman's correlations and significance (P < 0.0001). The path analysis showed low collinearity (42.60) between NDVI, LAI, and height; the high determination coefficient (R²) with values of 0.8421 and 0.7767 demonstrated their associations with TFB and GLB, respectively. Among the studied models to predict TFB and GLB, only exponentials using NDVI and power using LAI and height showed the best fit. In the validation stage, the models related to height exhibited the highest performance with 0.9531 (TFB) and 0.9638 (GLB) d-index, -2.3 (TFB) and -7.20 (GLB) bias, and 0.8532 (TFB) and 0.8932 (GLB) R². Only nonlinear models using height (cm) to predict TFB and GLB had the best practical application potential, thus ensuring efficiency in data collection.

show abstract

“…A Figura 4, traz uma informação complementar à Figura 2, quanto a modificação do uso e ocupação do solo, explanando que entre os anos de 1987 e 1997 houve um aumento da cobertura vegetal em todo município. Essa alteração ocorre devido aos índices pluviométricos mais elevados, uma vez que valores elevados de NDVI no semiárido refletem a maiores precipitações devido ao aumento da atividade fotossintética (BARBOSA et al, 2017;AQUINO et al, 2018). Por conseguinte, essas novas áreas verdes em 1997, ano que não existia mais o crédito agrícola da política do feijão, podem ser atribuídas a regeneração da caatinga e áreas abandonadas de cultivo, além de áreas cultivadas corroborando com Aquino et al (2018) que relatam sobre a contribuição da estiagem para o aumento do abandono de terras, elevando os valores de NDVI.…”

Section: Resultsunclassified

Análise do uso e ocupação do solo no interior baiano através das geotecnologias: estudo de caso no município de São Gabriel

Neto¹,

Filho²,

Lacerda³

et al. 2020

RICA

View full text Add to dashboard Cite

A ação antrópica vem causando mudanças significativas no uso e ocupação do solo, trazendo com si, muitos impactos ambientais negativos que causam a degradação dos recursos naturais principalmente devido a agricultura e ao manejo inadequado do solo, como no município de São Gabriel. Esse trabalho objetivou analisar a variação do uso e ocupação do solo entre os anos de 1987 a 2018 através das geotecnologias. As classificações obtiveram precisões acima de 95% pelo método Kappa. De acordo com os resultados, as políticas de crédito rural realizadas na década de 1960 na região influenciaram diretamente na dinâmica espacial do município, uma vez que incentivou a supressão vegetal para o cultivo do feijão, milho e mamona. No ano de 1987 a área destinada a agricultura ocupava 52,8% do município. Passados 31 anos e o fim da política de crédito rural, em 2018 ainda havia a permanência do manejo inadequado do solo. A área destinada a agricultura aumentou para 9,7%, porém houve a diminuição da produção ao longo dos anos com crescente áreas de solo exposto, correspondendo a 40% do município, que estão em processos de degradação, destacando a perca de produtividade, assoreamento de corpos d‘água e processos de erosões aceleradas, apontando ainda para algumas áreas em processo de desertificação e fragmentação do Bioma Caatinga.

show abstract

Use of remote sensing to identify areas at risk of degradation in the semi-arid region

Cited by 24 publications

References 2 publications

Identifying Drought Status in Duhok Governorate (Iraqi Kurdistan Region) from 1998 through 2012 using Landsat Time Series Dataset

Identifying Drought Status in Duhok Governorate (Iraqi Kurdistan Region) from 1998 through 2012 using Landsat Time Series Dataset

Prediction of Brachiaria decumbens forage biomass using structural characteristics

Análise do uso e ocupação do solo no interior baiano através das geotecnologias: estudo de caso no município de São Gabriel

Contact Info

Product

Resources

About