Mapping and Assessing Riparian Vegetation Response to Drought along the Buffalo River Catchment in the Eastern Cape Province, South Africa

Climate, Journal Year: 2024, Volume and Issue: 12(1), P. 7 - 7

Published: Jan. 11, 2024

The increasing drought frequency poses a significant threat to global and regional river systems ecosystem functioning, especially in the complex topographical Buffalo River catchment area of Eastern Cape Province, South Africa. This study explored impact on riparian vegetation dynamics using Normalize Difference Vegetation Index (NDVI), Transformed (TDVI) Modified Normalized Water (MNDWI) from satellite-derived Landsat data 1990 2020. least-squares linear regression Pearson’s correlation coefficient were used evaluate long-term cover role precipitation streamflow. results revealed moderate positive (r = 0.77) between streamflow with p-value 0.04 suggesting consequences health. Concurrent precipitation, trends showed that increased insignificantly less an influence while reverse was case long term. show NDVI TDVI indices for detecting water-stressed dynamics. Much these changes reflected MNDWI dry areas higher accuracy (87.47%) dense upper areas. standardized index (SPI) inter-annual inter-seasonal variations drought-stressed years 1991–1996, 2000–2004, 2009–2010, 2015, 2018–2019, 2020 exhibited slight sensitivity drought. findings this underscore need heightened efforts catchment-scale awareness policy development, programs, practices towards ecosystem-based adaptation.

Language: Английский

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Response of Vegetation Productivity to Greening and Drought in the Loess Plateau Based on VIs and SIF

Forests, Journal Year: 2024, Volume and Issue: 15(2), P. 339 - 339

Published: Feb. 9, 2024

In the context of global warming, frequent occurrence drought has become one main reasons affecting loss gross primary productivity (GPP) terrestrial ecosystems. Under influence human activities, vegetation greening trend Loess Plateau increased significantly. Therefore, it is great significance to study response GPP in under trend. Here, we comprehensively assessed ability indices (VIs) and solar-induced chlorophyll fluorescence (SIF) capture changes at different seasonal scales during drought. Specifically, utilized three indices: normalized difference index (NDVI), near-infrared reflectance (NIRV), kernel NDVI (kNDVI), determined period 2001 based on standardized precipitation evapotranspiration (SPEI) soil moisture (SSMI). Moreover, anomalies VIs SIF relationship with were compared. The results showed that both able as well normal years. Overall, captured better due water heat stress compared VIs. Across time scales, strongest (meanR2 = 0.85), followed by NIRV 0.84), 0.76), kNDVI 0.74), suggesting more sensitive physiological vegetation. Notably, performed best sparse 0.85). drought, less productive land classes; superior use class increased. addition, correlated 0.50) than other anomalies. future, efforts integrate respective strengths SIF, NIRV, will improve our understanding changes.

Language: Английский

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Drought-Related Spatiotemporal Cumulative and Time-Lag Effects on Terrestrial Vegetation across China

Remote Sensing, Journal Year: 2023, Volume and Issue: 15(18), P. 4362 - 4362

Published: Sept. 5, 2023

Vegetation is one of the most important indicators climate change, as it can show regional change in environment. health affected by various factors, including drought, which has cumulative and time-lag effects on vegetation response. However, drought different terrestrial China are still unclear. To address this issue, study examined from 2001 to 2020 using Standardized Precipitation Evapotranspiration Index (SPEI) Global SPEI database Normalized Difference (NDVI) MOD13A3. Based Sen-Median trend analysis Mann–Kendall test, significance NDVI were explored. The Pearson correlation coefficient was used analyze between at each scale further vegetation. results following: (1) value increased a rate 0.019/10 years, area accounted for 80.53% mainland China, with spatial low values west high east. (2) average time relevant 7.3 months, effect demonstrated 9–12 months revealed distributions areas. widely distributed 9-month scale, followed 12-month scale. coefficients cropland, woodland grassland peaked 9 months. (3) 6.9 had highest 7-month strongest cropland seen 7 while 6 Woodland lower than scales. research significant their use aiding scientific response disasters making decisions precautions.

Language: Английский

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Spatial and Temporal Evolution Patterns of Droughts in China over the Past 61 Years Based on the Standardized Precipitation Evapotranspiration Index

Water, Journal Year: 2024, Volume and Issue: 16(7), P. 1012 - 1012

Published: March 31, 2024

Based on the data of 2254 daily meteorological stations in China from 1961 to 2021, this study calculated standardized precipitation evapotranspiration index (SPEI) national multi-time scale by using FAO Penman–Monteith model quantify changes dry and wet conditions. The Mann–Kendall mutation test, wavelet analysis, other methods were used spatial pattern temporal evolution drought. results showed: (1) In past 61 years, there obvious differences drought China, interannual variation severity SPEI-1, SPEI-3, SPEI-12 gradually decreased at a rate 0.005/10a, 0.021/10a, 0.092/10a, respectively. (2) time point was 1989 according MK mutagenicity test. (3) Wavelet analysis showed that cycle annual seasonal consistent, main period about 30 years. (4) intensity different degrees has shown weakening trend, reached highest value years 1978, 1836.42. 2020, lowest, 261.55. (5) proportion decreasing trend. drought-free fluctuated greatly, ranging 42.12% 89.25%, with 2020 being highest. This provides scientific basis for further research causes coping strategies is great significance strengthening China’s monitoring, early warning ,and adaptation capabilities.

Language: Английский

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Vegetation Greening and Its Response to a Warmer and Wetter Climate in the Yellow River Basin from 2000 to 2020

Remote Sensing, Journal Year: 2024, Volume and Issue: 16(5), P. 790 - 790

Published: Feb. 24, 2024

Vegetation greening is time-dependent and region-specific. The uncertainty of vegetation under global warming has been highlighted. Thus, it crucial to investigate its response climate change at the regional scale. Yellow River Basin (YRB) a vital ecological barrier in China with high vulnerability climatic sensitivity. relationship between YRB relative contribution remain be explored. Using Enhanced Index (EVI) meteorological observation data, spatiotemporal patterns across basin sub-regional scales from 2000 2020 were analyzed. impact human activities on was further quantified. Results showed that approximately 92% had experienced greening, average annual growing season rates 0.0024 0.0034 year–1, respectively. Greening particularly prominent central eastern YRB. Browning more prevalent urban areas intensity activities, occupying less than 6.3% total basin, but this proportion increased significantly seasonal scales, especially spring. Regional positively correlated overall warmer wetter climate, partial correlation coefficients EVI precipitation higher those temperature. However, varied among different sub-regions. combined effects conducive 84.5% during season, while stronger change. contributions browning 65.15% 70.30%, respectively, mainly due promotion rehabilitation programs inhibition urbanization construction projects.

Language: Английский

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Response of Vegetation to Drought in the Source Region of the Yangtze and Yellow Rivers Based on Causal Analysis

Remote Sensing, Journal Year: 2024, Volume and Issue: 16(4), P. 630 - 630

Published: Feb. 8, 2024

The vegetation and ecosystem in the source region of Yangtze River Yellow (SRYY) are fragile. Affected by climate change, extreme droughts frequent permafrost degradation is serious this area. It very important to quantify drought–vegetation interaction area under influence climate–permafrost coupling. In study, based on saturated vapor pressure deficit (VPD) soil moisture (SM) that characterize atmospheric drought, as well Normalized Differential Vegetation Index (NDVI) solar-induced fluorescence (SIF) greenness function, evolution regional productivity drought were systematically identified. On basis, technical advantages causal discovery algorithm Peter–Clark Momentary Conditional Independence (PCMCI) applied distinguish response VPD SM. Furthermore, study delves into mechanisms NDVI SIF considering different types areas. findings indicated low SM high limiting factors for growth. positive negative effects accounted 47.88% 52.12% total area, respectively. Shrubs most sensitive SM, speed grassland was faster than forest land. impact SRYY stronger VPD, effect frozen more obvious. average 0.21 0.41, respectively, which twice those whole dominated changes 62.87% (76.60%) research results can provide scientific basis theoretical support assessment adaptation permafrost, vegetation, change reference ecological protection regions.

Language: Английский

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A CMIP6 Multi-Model Analysis of the Impact of Climate Change on Severe Meteorological Droughts through Multiple Drought Indices—Case Study of Iran’s Metropolises

Water, Journal Year: 2024, Volume and Issue: 16(5), P. 711 - 711

Published: Feb. 28, 2024

This study extensively explores the impact of climate change on meteorological droughts within metropolises in Iran. Focused Tehran, Mashhad, Isfahan, Karaj, Shiraz, and Tabriz, this research employed CMIP6 models under varying scenarios (SSPs) to forecast severe spanning period from 2025 2100. The investigation utilized a diverse set drought indices (SPI, DI, PN, CZI, MCZI, RAI, ZSI) assess severity each city. is crucial as it addresses pressing concerns rapidly decreasing water levels Iran’s dams, serious declines underground aquifers, compounding issues land subsidence soil erosion due excessive groundwater withdrawal face droughts. culminated generation box plots heatmaps based results. These visual representations elucidated distribution values different provided depiction probability occurrences until end century for resulting findings serve invaluable tools, furnishing policymakers with informed insights proactively manage fortify metropolitan resilience against evolving challenges posed by changing climate.

Language: Английский

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Temporal and Spatial Characteristics of Agricultural Drought Based on the TVDI in Henan Province, China

Water, Journal Year: 2024, Volume and Issue: 16(7), P. 1010 - 1010

Published: March 30, 2024

As a major grain-producing province in China’s Central Plains, Henan Province is severely impacted by drought, making the study of agricultural drought characteristics region crucial. Theil–Sen (Sen) trend analysis, Mann–Kendall (M-K) test and Hurst index method were used to systematically analyze spatial variation based on Temperature Vegetation Dryness Index (TVDI). The results show that: (1) occurs central, northwestern southern an annual scale. situation will continue increase northern, eastern northeastern central Henan. (2) spring, summer winter showed increasing trend, but opposite was observed autumn. each season mainly distributed (3) January, February, April, July, September December while other 6 months decreasing trend. during July August not pronounced, remained largely unchanged. distribution across exhibited varying patterns different regions. Overall, rise, displaying distinct seasonal regional its temporal distribution. can provide reference for formulate effective measures resistance disaster reduction ensure grain production.

Language: Английский

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From pixels to riverscapes: How remote sensing and geospatial tools can prioritize riverscape restoration at multiple scales

Wiley Interdisciplinary Reviews Water, Journal Year: 2024, Volume and Issue: 11(3)

Published: Feb. 1, 2024

Abstract Prioritizing restoration opportunities effectively across entire riverscape networks (i.e., riverine landscape including floodplain and stream channel networks) can be difficult when relying on in‐channel, reach‐scale monitoring data, or watershed‐level summaries that fail to capture heterogeneity the information necessary implement actions. Leveraging remote sensing geospatial tools develop spatially continuous nested hierarchical scales may support increased understanding of local reaches in their broader network context. Using riparian (vegetation) geomorphic (elevation) indicators assess status health, along with a measure capacity (valley bottom area), could adapted fit specific management goals related restoration. Frameworks using remotely sensed vegetation elevation data prioritize continuously riverscapes at restoration‐relevant, reach‐scales uphold ecosystem services provided by riverscapes. By incorporating knowledge identifying caveats for these datasets, inferences applied (watershed regional extent resolution) over wide variety ecoregions. This article is categorized under: Water Life > Conservation, Management, Awareness Methods Stresses Pressures Ecosystems

Language: Английский

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Assessing the Accuracy of 50 Temperature-Based Models for Estimating Potential Evapotranspiration (PET) in a Mediterranean Mountainous Forest Environment

Atmosphere, Journal Year: 2024, Volume and Issue: 15(6), P. 662 - 662

Published: May 30, 2024

Potential evapotranspiration (PET) is a crucial parameter for forest development, having an important role in ecological, biometeorological, and hydrological assessments. Accurate estimations of PET using the FAO–56 Penman–Monteith (FAO–56 PM) benchmark method require wide range data parameters, which are not typically available at meteorological stations installed environments. The aim this study to investigate accuracy various methods with low requirements assessing Mediterranean environment propose appropriate alternatives accurate estimation. Specifically, 50 temperature-based were evaluated against PM sub-humid northern Greece, high-quality daily data. outcomes indicate that offer viable alternative estimation when availability limited, considerable number (22) presenting deviations (up 10%) compared method. Temperature-based models outperformed those incorporating water-related parameters (as relative humidity or precipitation) top performing site, based on several statistical indices, equations Ravazzani et al., proposed 2012, followed by Hargreaves–Samani 1985 Heydari 2014.

Language: Английский

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