Impacts of Drought on Vegetation Assessed by Vegetation Indices and Meteorological Factors in Afghanistan

Remote Sensing, Journal Year: 2020, Volume and Issue: 12(15), P. 2433 - 2433

Published: July 29, 2020

Drought has severe impacts on human society and ecosystems. In this study, we used data acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) Tropical Rainfall Measuring Mission (TRMM) sensors to examine drought effects vegetation in Afghanistan from 2001 2018. The MODIS included 16-day 250-m composites of Normalized Difference Vegetation Index (NDVI) Condition (VCI) with Land Surface Temperature (LST) images 1 km resolution. TRMM were monthly rainfalls 0.1-degree relationship between index-defined variation was examined using time series, regression analysis, anomaly calculation. results showed that coverage for whole country, reaching lowest levels 6.2% 5.5% observed years 2008, respectively. However, there is a huge inter-regional study period significant rising trend Helmand Watershed R = 0.66 (p value 0.05). Based VCI same two (2001 2008), 84% 72% country subject conditions, Coherently, confirm 2008 least rainfall 108 251 mm, On other hand, 2009 2010 registered largest 16.3% mainly due lower annual LST than average 14 degrees partially their slightly higher 378 425 respectively, historical 327 mm. derived VCI, 28% 21% area experienced conditions 2010, It also found correlations are relatively high NDVI (r 0.77, p 0.0002), but precipitation 0.51, 0.03). addition, played key role influencing NDVI. both must be considered together order properly capture correlation

Language: Английский

---

Remote Sensing Indices for Spatial Monitoring of Agricultural Drought in South Asian Countries

Remote Sensing, Journal Year: 2021, Volume and Issue: 13(11), P. 2059 - 2059

Published: May 23, 2021

Drought is an intricate atmospheric phenomenon with the greatest impacts on food security and agriculture in South Asia. Timely appropriate forecasting of drought vital reducing its negative impacts. This study intended to explore performance evaporative stress index (ESI), vegetation health (VHI), enhanced (EVI), standardized anomaly (SAI) based satellite remote sensing data from 2002–2019 for agricultural assessment Afghanistan, Pakistan, India, Bangladesh. The spatial maps were generated against each index, which indicated a severe during year 2002, compared other years. results showed that southeast region north, northwest, southwest regions India Afghanistan significantly affected by drought. However, Bangladesh faced substantial northeast northwest (2002). longest period seven months was observed followed Pakistan six months, while, only three perceived correlation between indices climate variables such as soil moisture has remained significant drought-initiating variable. Furthermore, this confirmed (ESI) good indicator, being quick greater sensitivity, thus advantageous VHI, EVI, SAI indices.

Language: Английский

---

Drought Monitoring Using Landsat Derived Indices and Google Earth Engine Platform: A Case Study from Al-Lith Watershed, Kingdom of Saudi Arabia

Remote Sensing, Journal Year: 2023, Volume and Issue: 15(4), P. 984 - 984

Published: Feb. 10, 2023

Precise assessment of drought and its impact on the natural ecosystem is an arduous task in regions with limited climatic observations due to sparsely distributed situ stations, especially hyper-arid region Kingdom Saudi Arabia (KSA). Therefore, this study investigates application remote sensing techniques monitor compare sensing-retrieved indices (RSDIs) standardized meteorological index (Standardized Precipitation Evapotranspiration Index, SPEI) during 2001–2020. The computed RSDIs include Vegetation Condition Index (VCI), Temperature (TCI), Health (VHI), which are derived using multi-temporal Landsat 7 ETM+, 8 OLI/TIRS satellites, Google Earth Engine (GEE) platform. Pearson correlation coefficient (CC) used find extent agreement between SPEI RSDIs. comparison showed CC values 0.74, 0.67, 0.57, 0.47 observed for VHI/SPEI-12, VHI/SPEI-6, VHI/SPEI-3, VHI/SPEI-1, respectively. Comparatively low was TCI 0.60, 0.61, 0.42, 0.37 TCI/SPEI-12, TCI/SPEI-6, TCI/SPEI-3, TCI/SPEI-1. A lower 0.53, 0.45, 0.33 0.24 VCI/SPEI-12, VCI/SPEI-6, VCI/SPEI-3, VCI/SPEI-1, Overall, results suggest that VHI better correlated suitable monitoring data-scarce regions. This research will help improve our understanding relationships indices.

Language: Английский

---

Spatio-temporal assessment of agricultural drought using remote sensing and ground-based data indices in the Northern Ethiopian Highland

Journal of Hydrology Regional Studies, Journal Year: 2024, Volume and Issue: 52, P. 101700 - 101700

Published: Feb. 12, 2024

Northern Ethiopian highland, North Wollo, Ethiopia Drought is one of the most serious environmental and socioeconomic problems Sub-Sahara Africa's countries. The study aims to assess evaluate agricultural drought occurrence its severity by using remote sensing-based multivariate indices provide real-time spatial-temporal information for monitoring. Satellite datasets from Landsat images with a spatial resolution 30 m were processed rescaled compute vegetation temperature derive status indices. temporal variability detected mapped satellite-based validated available in-situ data. revealed that area was exposed extreme in 1984, 2009, 2014. On contrary, no longer dominated 1989, 1994, 1999, 2004. Moreover, relationships between various have been examined linear regression model. It has there significant strong relationship NDVI LST (R2 /p = 0.93/0.00), VCI TCI 0.71/0.00), VHI SPI (R2/p 0.85/0.00). Therefore, extent assessment drought-related are important decision-making field agriculture.

Language: Английский

---

Monitoring agricultural drought using geospatial technologies: the case of Menna Watershed, northwestern Ethiopia

Theoretical and Applied Climatology, Journal Year: 2025, Volume and Issue: 156(2)

Published: Jan. 10, 2025

Language: Английский

---

The spatio-temporal trend of climate and characterization of drought in Borana Zone, Ethiopia

Scientific Reports, Journal Year: 2025, Volume and Issue: 15(1)

Published: Feb. 8, 2025

This research assessed the Borana Zone's climate trends and drought characteristics from 1991 to 2050. Using Innovative Trend Analysis (ITA), we quantified changes. The standard Precipitation Evaporation index (SPEI) self calibrated Palmer's Droguht Severity Index (scPDSI) were selected compute drought's magnitude. significantly decreased 2020, with a variation 2021 Drought indices generally showed decreasing trend. short-term (SPEI3) in Mid-Moist (MM) category experienced greatest decline, slope of − 0.055/year during reference period. Under RCP4.5 scenarios, SPEI3 for Extremely-Most (EM) class steepest decline at 1.827/year. For RCP8.5, MM categories displayed significant reductions, annual slopes 0.073, 0.021, 0.14 SPEI3, SPEI12, scPDSI, respectively. moisture intensity also diminishing trend, scPDSI projected decrease by 40.47% 20.77% under two emission scenarios. During period, Near Normal (NN) frequency varied 71.39% 82.81%, but is expected 12% 8% adverse impacts can be mitigated building capacity drought-vulnerable community.

Language: Английский

---

Causes for the Changes in Reference Crop Evapotranspiration Over Ethiopia During 1980–2021

International Journal of Climatology, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 24, 2025

ABSTRACT Considering the great significance of reference crop evapotranspiration (ET o ) for various sectors (i.e., biodiversity, agriculture, forestry development and water resources), this study comprehensively investigated its changes during 1980–2021 based on Food Agriculture Organisation‐56 Penman‐Monteith equation five popular meteorological datasets. As whole Ethiopia, both annual monthly ET significantly increased, but increasing trends varied among months with larger values January–April September–December. Spatially, exhibited evident differences, characterised by increases over more than 88% areas, especially September–December, an area percentage exceeding 78%. Attribution analyses a joint‐solution method multiple sensitivity experiments suggested that were determined increased mean temperature ( T ). However, dominant factors spatially. On scale, net radiation R n , accounting 21.2% 78.8% respectively, mainly in northwestern, southwestern southeastern Ethiopia remaining regions. Although different spatial distributions existed months, factor always had most extensive (> 47%), followed 18%) January–April, June, August, October November, wind speed at 2 m 19%) May, July, September December. This complete analysis related physical mechanisms can partly fill research gap Ethiopia. Moreover, provides essential information better understanding climate change, protecting biodiversity sustaining regional (e.g., agriculture resources).

Language: Английский

---

Application of Artificial Neural Networks in Forecasting a Standardized Precipitation Evapotranspiration Index for the Upper Blue Nile Basin

Water, Journal Year: 2020, Volume and Issue: 12(3), P. 643 - 643

Published: Feb. 27, 2020

The occurrence frequency of drought has intensified with the unprecedented effect global warming. Knowledge about spatiotemporal distributions droughts and their trends is crucial for risk management developing mitigation strategies. In this study, we developed seven artificial neural network (ANN) predictive models incorporating hydro-meteorological, climate, sea surface temperatures, topographic attributes to forecast standardized precipitation evapotranspiration index (SPEI) stations in Upper Blue Nile basin (UBN) Ethiopia from 1986 2015. main aim was analyze sensitivity drought-trigger input parameters measure ability by comparing predicted values observed values. Statistical comparisons different showed that accurate results predicting SPEI could be achieved including large-scale climate indices. Furthermore, it found coefficient determination root-mean-square error best architecture ranged 0.820 0.949 0.263 0.428, respectively. terms statistical achievement, concluded ANNs offer an alternative framework forecasting index.

Language: Английский

---

Quantitative assessment of the effects of climate, vegetation, soil and groundwater on soil moisture spatiotemporal variability in the Mongolian Plateau

The Science of The Total Environment, Journal Year: 2021, Volume and Issue: 809, P. 152198 - 152198

Published: Dec. 7, 2021

Language: Английский

---

Assessment of land use/land cover changes and their impacts on land surface temperature in Bangui (the capital of Central African Republic)

Environmental Challenges, Journal Year: 2021, Volume and Issue: 4, P. 100114 - 100114

Published: April 29, 2021

Extreme land-use and land-cover (LULC) as the result of rapid urbanization has been raising land surface temperature core city areas its surrounding. Therefore, investigation on is very vital to analyze variations minimize effect. This research aims impacts LULC changes LST in Bangui city, Central African Republic using combined techniques remote sensing GIS. The this study indicates that there was a significant change between 1986 2017 particularly expanded vegetation built-up declined bare soil. For instance, increased by + 130.29 % with rate 137.06; 8.44% or 17.2. Whereas soil sharply −35.33% for −155.83. mean firstly decreased from 26.24 °C 23.37 1999 27.23 2017. also stated 26.21 27.59 Besides, raised 26.51 27.33 respectively. These indicate built up experienced high than water body. found positive correlation NDBI whereas negative correlations NDVI NDLI. City planners should be implemented urban green belts roof mitigate effect heat islands (SUHI) surooundings.

Language: Английский

---