Monitoring spatio-temporal drought dynamics using multiple indices in the dry land of the upper Tekeze Basin, Ethiopia

Fentaw, Alemu Eshetu; Yimer, Assefa Abegaz; Zeleke, Gebeyehu Abebe

doi:10.1016/j.envc.2023.100781

Cited by 9 publications

(3 citation statements)

References 55 publications

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“…The Kolla agroecological zone (warm, semiarid lowlands; covering 17.5 %), followed by Weyna-dega (cool, humid highlands; covering 68 %), and Dega (temperate cool sub-humid highlands; covering 14.5 % of the study area). Most of the study area is semi-arid and arid according to the United Nations Environment Programme (UNEP) aridity classification [ 51 ]. While the northern and northeastern part of the basin is dry sub-humid and non-dryland, the central and northern holds semi-arid and arid land characteristics.…”

Section: Methods and Datasetsmentioning

confidence: 99%

“…However, rainfall distribution of the lowland part extends from early July to mid of August. About 63 % of the annual rainfall is in July and August [ 51 ]. The area's annual minimum and maximum temperatures are 12.8 °C and 29 °C, respectively ( Fig.…”

Section: Methods and Datasetsmentioning

confidence: 99%

“…GEE offers cutting-edge technologies and unrestricted access to various remote sensing data, fostering the formation of transformative research issues. GEE has been used for a variety of applications, such as drought assessment [ 50 , 51 ] and land use-land cover change (LULCC) and vegetation mapping [ [52] , [53] , [54] ]. However, there are very few attempts to estimate soil loss estimation through the RUSLE-GIS-GEE framework by integrating ArcGIS and GEE interface [ 55 ], for example, studies by Elnashar et al [ 56 ] and Wang and Zhao [ 57 ].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Soil erosion assessment and identification of erosion hotspot areas in the upper Tekeze Basin, Northern Ethiopia

Fentaw,

Abegaz

2024

Heliyon

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Section: Methods and Datasetsmentioning

confidence: 99%

Section: Methods and Datasetsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Soil erosion assessment and identification of erosion hotspot areas in the upper Tekeze Basin, Northern Ethiopia

Fentaw,

Abegaz

2024

Heliyon

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Drought Dynamics: Enhanced Characterization Through Hyper‐Temporal Satellite Observations

Kundu,

Dutta,

Patel

et al. 2024

Hydrological Processes

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Drought is a multifaceted hazard, influenced directly or indirectly by factors such as precipitation, evapo‐transpiration, soil moisture content and groundwater levels. Drought dynamics is fundamentally linked to hydrological processes, as droughts directly impact water availability, soil moisture and overall hydrological balance. Given the global climate change and consequent increasing frequency of extreme events, assessing the vulnerability to drought stress in underprivileged areas has become highly relevant. In this context, drought characterization has become crucial for understanding the complex patterns of droughts and its impacts on agriculture, ecosystems and communities, thereby contributing to food security, environmental sustainability and disaster preparedness. The major goal of this study was to evaluate the onset, duration, frequency and extent of agricultural drought using satellite‐based datasets. The hyper‐temporal Système Pour l'Observation de la Terre (SPOT) VEGETATION (VGT) Normalized Difference Vegetation Index (NDVI) data were used in this study to quantify the drought related stress on vegetation cover. The spatial extent of drought and its pattern were estimated using the long‐term Vegetation Condition Index (VCI) derived from hyper‐temporal SPOT‐VGT NDVI datasets. Notably, strong agreement was found between the estimations of onset and duration, particularly during severe drought years such as 2002 and 2008. The study reveals that more over 95% of the total area encountered severe crop stress before the second week of July in 1999, 2002 and 2008, which are identified as severe drought years in the region. The frequency maps effectively captured the occurrence of drought events over a sixteen‐year span, highlighting distinct drought episodes in the study area and underscoring the significant prevalence of drought stress across a considerable area. The high r2 (0.61) value indicates a significant level of shared variability between VCI and yield of major crops, demonstrating their consistent alignment in capturing vegetation health and crop yield anomalies. The comprehensive delineation of drought patterns in the Bundelkhand region revealed by this study is potential for future preparedness efforts, enabling strategic planning and facilitating the implementation of sustainable policy interventions.

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Analyzing spatiotemporal variations and dynamics of vegetation over Amathole district municipality in South Africa

Afuye,

Kalumba,

Owolabi

et al. 2024

Environ Dev Sustain

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Global biodiversity loss and ecosystem services are significantly impacted by vegetation stress and environmental degradation. The study evaluates vegetation dynamics and long-term meteorological variables in Amathole District Municipality, South Africa, using satellite-derived vegetation indices from 2001 to 2022. The study utilised Terra MODIS and Landsat time series data to evaluate vegetation cover variation using the seasonal Vegetation Condition Index (VCI) and Landsat Normalized Difference Vegetation Index (NDVI). A MODIS-specific compositing algorithm was used to acquire and extract data from the Application for Extracting and Exploring Analysis Ready Samples (AppEEARS) using the study area extent. Pearson correlation and non-parametric trend analysis were used to assess the long-term vegetation cover characteristics and the influence of temperature, precipitation, and potential evapotranspiration (ETo) on vegetation cover. The results reveal a significant decline (<10%) in the quality of green vegetation condition index from moderate to low due to prolonged dryness in autumn and winter, affecting seasonal VCI trends. In certain years, the western region has experienced browning trends and increased vegetation. Spring and summer months experienced high vegetation greenness (50-100%), with inter-annual and decadal NDVI trends shifting, causing high drought sensitivity in the east. The study found a significant positive correlation (P < 0.001) between precipitation and simulated evapotranspiration anomalies with vegetation dynamics, contrasting with inter-annual and decadal changes in NDVI trends. The changes were primarily observed in small areas, with a greening trend resulting from an increased rate of ETo, which in turn affects temperature change. The approach is suitable for semi-arid environments and can be adopted by stakeholders due to its geospatial implications for vegetation monitoring and evaluation.

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Monitoring spatio-temporal drought dynamics using multiple indices in the dry land of the upper Tekeze Basin, Ethiopia

Cited by 9 publications

References 55 publications

Soil erosion assessment and identification of erosion hotspot areas in the upper Tekeze Basin, Northern Ethiopia

Soil erosion assessment and identification of erosion hotspot areas in the upper Tekeze Basin, Northern Ethiopia

Drought Dynamics: Enhanced Characterization Through Hyper‐Temporal Satellite Observations

Analyzing spatiotemporal variations and dynamics of vegetation over Amathole district municipality in South Africa

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