Impact Of Recent Climate Change Research Articles

The Impact of Recent Climate Change on the Global Ocean Carbon Sink

AbstractIn recent decades, the ocean CO2 uptake has increased in response to rising atmospheric CO2. Yet, physical climate change also affects the ocean CO2 uptake, but magnitude and driving processes are poorly understood. Using a global ocean biogeochemistry model, we find that without climate change, the mean carbon uptake 2000–2019 would have been 13% higher and the trend 1958–2019 would have been 27% higher. Changes in wind are the dominant driver of the climate effect on CO2 uptake as they affect advective carbon transport and mixing, but the effect of warming increases over time. Roughly half of the globally integrated wind‐driven trend stems from the subpolar Southern Ocean and polar oceans in both hemispheres. Warming reduces the solubility of CO2 and acts rather homogeneously over the world oceans. However, the warming effect on pCO2 is dampened by limited exchange of surface and deep waters.

The Impact of Recent Climate Change on Plants

Climatic conditions play a key role in the basic plants processes (photosynthesis, respiration, growth and development), their seasonal cycle, and in determining the limits of their distribution. Climate has a great impact on plant individuals, populations and species, as well as on their communities, ecosystems and biomes. As a result, concerns have grown in recent decades about the possible effects of global climate change on flora. The paper gives an overview of the observed climate change, primarily changes in the atmospheric concentration of greenhouse gases, air temperature (global warming), precipitation regime and extreme weather and climate events. Then, the observed effects of recent climate change on the plants are analyzed, primarily the effects on the physiology, phenology and distribution of plant species, as well as the effects on plant communities and ecosystems. The results of numerous studies in the world proved that recent climate change has led to significant changes in the plants distribution ‒ range (shifts to higher latitudes and higher altitudes), physiology (improving the rate of photosynthesis and water use efficiency, decreasing stomatal conductivity and increasing net primary production) and the seasonal cycle ‒ phenology (earlier onset of growing season and earlier occurrence of phenophases in spring and summer and delay of autumn phenophases ending the growing season, and as a consequence of these changes prolongation of growing season in many regions) as well as that changed climatic conditions have already led to changes in plant communities (through changes in composition and altered interactions between species such as pollination, competition, predation, parasitism, mutualism, disease transmission, food chains, etc.) and local extinction of certain plant species.

Impacts of recent climate change on crop yield can depend on local conditions in climatically diverse regions of Norway

Globally, climate change greatly impacts the production of major crops, and there have been many attempts to model future yields under warming scenarios in recent years. However, projections of future yields may not be generalisable to all crop growing regions, particularly those with diverse topography and bioclimates. In this study, we demonstrate this by evaluating the links between changes in temperature and precipitation and changes in wheat, barley, and potato yields at the county-level during 1980–2019 in Norway, a Nordic country with a range of climates across a relatively small spatial scale. The results show that the impacts of climate variables on yield vary widely by county, and that for some crops, the strength and direction of the link depends on underlying local bioclimate. In addition, our analysis demonstrates the need for some counties to focus on weather changes during specific crucial months corresponding with certain crop growth stages. Furthermore, due to the local climatic conditions and varying projected climate changes, different production opportunities are likely to occur in each county.

Impact of recent climate change on corn, rice, and wheat in southeastern USA

Climate change and its impact on agriculture productivity vary among crops and regions. The southeastern United States (SE-US) is agro-ecologically diversified, economically dependent on agriculture, and mostly overlooked by agroclimatic researchers. The objective of this study was to compute the effect of climatic variables; daily maximum temperature (Tmax), daily minimum temperature (Tmin), and rainfall on the yield of major cereal crops i.e., corn (Zea mays L.), rice (Oryza sativa L.), and wheat (Triticum aestivum L.) in SE-US. A fixed-effect model (panel data approach) was used by applying the production function on panel data from 1980 to 2020 from 11 SE-US states. An asymmetrical warming pattern was observed, where nocturnal warming was 105.90%, 106.30%, and 32.14%, higher than the diurnal warming during corn, rice, and wheat growing seasons, respectively. Additionally, a shift in rainfall was noticed ranging from 19.2 to 37.2 mm over different growing seasons. Rainfall significantly reduced wheat yield, while, it had no effect on corn and rice yields. The Tmax and Tmin had no significant effect on wheat yield. A 1 °C rise in Tmax significantly decreased corn (− 34%) and rice (− 8.30%) yield which was offset by a 1 °C increase in Tmin increasing corn (47%) and rice (22.40%) yield. Conclusively, overall temperature change of 1 °C in the SE-US significantly improved corn yield by 13%, rice yield by 14.10%, and had no effect on wheat yield.

Impact of recent climate change on cotton and soybean yields in the southeastern United States

The Southeastern region of the United States (SE-US) is agroecologically diverse, economically agriculture reliant, and distinct from the twentieth-century warming trend. Considering the inextricable link between climate and agricultural production, it is necessary to quantify future environmental implications on economically important crops of cotton ( Gossypium hirsutum L.) and soybean [ Glycine max (L.) Merr.] in the SE-US. The current study used the fixed-effect model (panel data approach) for climate and yield studies, to assess the impact of climatic variables from 1980 to 2020 such as daily maximum temperature (T max ), minimum temperatures (T min ), and rainfall on cotton and soybean yields. The data from 11 states were averaged per growing season and results revealed significant variability in temperature and rainfall during the last four decades. The T max , T min , and rainfall shifted in the range of 0.46–0.50 °C, 1.30–1.45 °C, and 3.74–3.95 cm, respectively, during the cotton growing season (CGS) and soybean growing seasons (SGS). However, the annual rate of change in T max , T min , and rainfall from 1980 to 2020 was in the range of 0.011–0.012 °C, 0.031–0.034 °C, and 0.089–0.094 cm, respectively, during the CGS and SGS. Rainfall had no significant effect on cotton and soybean yields. A 1 °C rise in T min increased cotton yield by 20.8% while decreasing soybean yield by 31.6%. Alternatively, a 1 °C rise in T max decreased cotton and soybean yield by 10.3% and 25.6%, respectively. • The nocturnal temperature explained the overall heating trend for both Soybean and Cotton over the 41-years. • Rainfall had a positive effect on cotton yield but a non-significant negative effect on soybean yield. • The 1 °C incremental T min boosted the cotton yield while reducing the soybean yield. • The 1 °C rise in the T max decreased the cotton yield and reduced the soybean yield.

Mapping the impact of recent climate change on viticultural potential in Romania

Mapping the impact of recent climate change on viticultural potential in Romania

Effects of Recent Climate Change on Maize Yield in Southwest Ecuador

In recent years, evidence of recent climate change has been identified in South America, affecting agricultural production negatively. In response to this, our study employs a crop modelling approach to estimate the effects of recent climate change on maize yield in four provinces of Ecuador. One of them belongs to a semi-arid area. The trend analysis of maximum temperature, minimum temperature, precipitation, wind speed, and solar radiation was done for 36 years (from 1984 to 2019) using the Mann–Kendall test. Furthermore, we simulated (using the LINTUL5 model) the counterfactual maize yield under current crop management in the same time-span. During the crop growing period, results show an increasing trend in the temperature in all the four studied provinces. Los Rios and Manabi showed a decreasing trend in radiation, whereas the semi-arid Loja depicted a decreasing precipitation trend. Regarding the effects of climate change on maize yield, the semi-arid province Loja showed a more significant negative impact, followed by Manabi. The yield losses were roughly 40 kg ha−1 and 10 kg ha−1 per year, respectively, when 250 kg N ha−1 is applied. The simulation results showed no effect in Guayas and Los Rios. The length of the crop growing period was significantly different in the period before and after 2002 in all provinces. In conclusion, the recent climate change impact on maize yield differs spatially and is more significant in the semi-arid regions.

Impacts of Recent Climate Change on Potato Yields at a Provincial Scale in Northwest China

Understanding the effects of climate change on potato yield is vital for food security in northwest China. Based on the long-term data of yields and meteorology, this study analysed the impacts of recent climate change on potato yields at a provincial scale in northwest China. The first difference method was used to disentangle the contributions of climate change from the changes in potato yield in two consecutive years. The moving average method was used to decouple the climate-induced yield of potato. The results showed that the yield and planting area of potato from the period 1982 to 2015 increased markedly, with inter-annual fluctuations. The temperature increased significantly during the potato growing period in northwest China, while other climatic factors did not change significantly. Specifically, the changing trends in climatic factors varied among different provinces. The key meteorological factors limiting potato yield were temperature, precipitation and diurnal temperature range, varying in the different provinces. Potato yields in Gansu, Shaanxi, Ningxia and Xinjiang decreased by 127, 289, 199 and 339 kg ha−1, respectively, for every 1 °C increase in daily maximum temperature. The potato yield in Xinjiang decreased by 583 kg ha−1 for every 1 °C increase in daily minimum temperature. For every 100 mm increase in precipitation, the potato yields in Gansu, Qinghai and Ningxia increased by 250, 375 and 182 kg ha−1, respectively. Combining the first difference method and the moving average method, precipitation was the dominant climatic factor affecting potato yield in rain-fed areas (Gansu, Qinghai and Ningxia). For areas with irrigation (Xinjiang) or relatively high rainfall (Shaanxi), maximum temperature was the deciding climatic factor affecting potato yield. Appropriate adaptation to climate change in the different regions will help to ensure potato production in northwest China.

Snow line elevation variability under the effect of climate variations in the Zagros Mountains: case study of Oshtorankooh

The Zagros Mountains are one of the key water sources for Iran and recession of the snow line would have an impact on regional water resources. In this study, we used Moderate Resolution Imaging Spectro radiometer (MODIS) data obtained from 2000 to 2016 to investigate the upward retreat of the Temporary Snow Line Elevation (TSLE) for the months with the greatest snowfall and highest snow lines (December, January, and February) in the Oshtorankooh region. In addition, to gain a better insight into the impact of recent climate change on the snow cover in Oshtorankooh and its TSLE variations, the Mann–Kendall and TSA non-parametric tests were used for the time period 2000–2016. The results showed an upward retreat of the TSLE. The ground surface temperature observations analyzed using the MODIS data show a temperature increase of 0.52–0.99 °C (Aqua MODIS) and 0.82–1.12 °C (Terra MODIS) in the same time period. According to the Mann–Kendall and TSA methods, climatic parameters have changed during recent years in most of the studied stations and climate change is responsible for Oshtorankooh TSLE variation, so that the TSLE during the studied statistical period demonstrated an upward movement in four orientations (North, South, East, West).The largest variation between December and the other months (January and February) was observed between 2004 and 2016 247.18 km2, 76.05 km2, and 249.64 km2, respectively.

Assessing the provision of carbon-related ecosystem services across a range of temperate grassland systems in western Canada

Reliable data on the provision of ecosystem services (ES) is essential to the design and implementation of policies that incorporate ES into grassland conservation and restoration. We developed and applied an innovative approach for regional parameterization, and calibration of the CENTURY ecosystem model. We quantified spatiotemporal variation of soil organic carbon stock (SOC) and aboveground plant biomass production (AGB) and examined their responses to the recent climate change across a diverse range of native grassland systems in Alberta, western Canada. The simultaneous integration of SOC and AGB into calibration and analysis accounted for most of the spatiotemporal variability in the SOC and AGB measurements and resulted in reduced simulation uncertainty across nine grassland regions. These findings suggest the importance of the systematic parameterization and calibration for the reliable assessment of carbon-related ES across a wide geographic area with heterogeneous ecological conditions. Simulation results showed a pronounced variation in the spatial distribution of SOC and AGB and their associated uncertainty across grassland regions. Under baseline grazing intensity regime, an overall negative effect of recent climatic changes on the SOC, and a less consistent effect on the AGB were found. While, an overall positive or slightly negative impact of recent climate change on the SOC and AGB was found under a proposed 10% lower grazing intensity regime. These heterogeneities in the magnitude and direction of climate change effects under different grazing regimes suggest needs for a range of climate change adaptation strategies to maintain carbon-related ES in Alberta's grasslands. The modeling framework developed in this study can be used to improve the spatially explicit assessment of carbon-related ES in other geographically vast grassland areas and examine the effectiveness of alternative management scenarios to ensure the long-term provision of carbon-related ES in grassland systems.

Role of recent climate change on carbon sequestration in peatland systems

This paper provides information on the impact of recent climate change on carbon sequestration in peatland systems in South West England. This is important because peatlands have the potential to sequester and hold large quantities of anthropogenically released CO2. This paper investigates whether there has been a reduction in the strength of carbon sinks in a valley mire and blanket bog, which occur on the limits of the biogeographical envelop for peatlands in Britain. Past rates of carbon accumulation were calculated from peat depth and the sequential analysis of peat age, bulk density and carbon content from cores taken from valley mire and blanket bog. At the valley mire site contemporary net ecosystem carbon balance (NECB) was calculated by measuring inputs to the peat body, via net primary productivity (NPP), of Sphagna. Losses of C from the peat body were calculated by measuring CH4, and aquatic carbon, calculated from catchment export of particulate and dissolved organic carbon. The study found similar mean rates of carbon accumulation since 1850 of 11.26 t ± 0.68 t CO2e ha−1 yr−1 (307 g C m−2 yr−1) in valley mire and 11.77 t ± 0.88 t CO2e ha−1 yr−1 (321 g C m−2 yr−1) in blanket bog. The mean present-day CO2 sequestration rate for Sphagna on valley mire was calculated to be 9.13 t ± 0.98 t CO2e ha−1 yr−1 (249 g C m−2 yr−1). Both past and contemporary rates of CO2 sequestration were found to be at the maxima of those reported for temperate peatlands. NPP was found to vary according to microform with higher rates of carbon sequestration found in lawn and hummock microforms compared with pools. Our work suggests that recent changes in the climate appear to have had limited impact on the strength of peatland carbon sinks in South West England.

Impacts of recent climate change on terrestrial flora and fauna: Some emerging Australian examples

AbstractThe effects of anthropogenic climate change on biodiversity are well known for some high‐profile Australian marine systems, including coral bleaching and kelp forest devastation. Less well‐published are the impacts of climate change being observed in terrestrial ecosystems, although ecological models have predicted substantial changes are likely. Detecting and attributing terrestrial changes to anthropogenic factors is difficult due to the ecological importance of extreme conditions, the noisy nature of short‐term data collected with limited resources, and complexities introduced by biotic interactions. Here, we provide a suite of case studies that have considered possible impacts of anthropogenic climate change on Australian terrestrial systems. Our intention is to provide a diverse collection of stories illustrating how Australian flora and fauna are likely responding to direct and indirect effects of anthropogenic climate change. We aim to raise awareness rather than be comprehensive. We include case studies covering canopy dieback in forests, compositional shifts in vegetation, positive feedbacks between climate, vegetation and disturbance regimes, local extinctions in plants, size changes in birds, phenological shifts in reproduction and shifting biotic interactions that threaten communities and endangered species. Some of these changes are direct and clear cut, others are indirect and less clearly connected to climate change; however, all are important in providing insights into the future state of terrestrial ecosystems. We also highlight some of the management issues relevant to conserving terrestrial communities and ecosystems in the face of anthropogenic climate change.

Chemical characterisation and source identification of atmospheric aerosols in the Snowy Mountains, south-eastern Australia

Characterisation of atmospheric aerosols is of major importance for: climate, the hydrological cycle, human health and policymaking, biogeochemical and palaeo-climatological studies. In this study, the chemical composition and source apportionment of PM2.5 (particulate matter with aerodynamic diameters less than 2.5μm) at Yarrangobilly, in the Snowy Mountains, SE Australia are examined and quantified. A new aerosol monitoring network was deployed in June 2013 and aerosol samples collected during the period July 2013 to July 2017 were analysed for 22 trace elements and black carbon by ion beam analysis techniques. Positive matrix factorisation and back trajectory analysis and trajectory clustering methods were employed for source apportionment and to isolate source areas and air mass travel pathways, respectively. This study identified the mean atmospheric PM2.5 mass concentration for the study period was (3.3±2.5)μgm−3. It is shown that automobile (44.9±0.8)%, secondary sulfate (21.4±0.9)%, smoke (12.3±0.6)%, soil (11.3±0.5)% and aged sea salt (10.1±0.4)% were the five PM2.5 source types, each with its own distinctive trends. The automobile and smoke sources were ascribed to a significant local influence from the road network and bushfire and hazard reduction burns, respectively. Long-range transport are the dominant sources for secondary sulfate from coal-fired power stations, windblown soil from the inland saline regions of the Lake Eyre and Murray-Darling Basins, and aged sea salt from the Southern Ocean to the remote alpine study site. The impact of recent climate change was recognised, as elevated smoke and windblown soil events correlated with drought and El Niño periods. Finally, the overall implications including potential aerosol derived proxies for interpreting palaeo-archives are discussed. To our knowledge, this is the first long-term detailed temporal and spatial characterisation of PM2.5 aerosols for the region and provides a crucial dataset for a range of multidisciplinary research.

Impact of recent climate change on Lake Kanas, Altai Mountains (N.W. China) inferred from diatom and geochemical evidence

Glacier shrinkage and melting of snow patches caused by the current phase of warming is having a profound impact on lake ecosystems located in glacierized environments at high altitude and/or latitude because it alters the hydrology and the physico-chemistry of the river discharges and catchment runoff. These changes, in turn, have a major impact on the biota of these lakes. In this study, we combined geochemical and diatom analyses of a sediment core retrieved from Lake Kanas (N.W. China) to assess how climate change has affected this ecosystem over the past ~ 100 years. Our results show that the aquatic ecosystem of Lake Kanas was sensitive to changes in the regional climate over that period of time. The lake has been affected by change in hydrology (e.g. influx of glacier meltwater, variations in precipitation) and change in hydrodynamics (water column stability). The variations in abundance and composition of the diatom assemblages observed in the sedimentary record have been subtle and are complex to interpret. The principal changes in the diatom community were: (1) a rise in diatom accumulation rates starting in the AD 1970s that is coeval with changes observed in temperate lakes of the Northern Hemisphere and (2) an increase in species diversity and assemblage turnover and a faster rate-of-change since ~ AD 2000. The diatom community is expected to change further with the projected melting of the Kanas glacier throughout the twenty-first century.

High carbon dioxide concentration and elevated temperature impact the growth of weeds but do not change the efficacy of glyphosate.

Global climate changes may impact the growth and management of weed species. The aim of this work was to evaluate the impact of recent climate changes on the growth of weeds and herbicide efficacy. The effects of temperature, carbon dioxide (CO2 ), and herbicide on growth and control of Bromus tectorum L., Hordeum murinum L., and Lactuca serriola L. were studied. Treatments included: control or ambient environment (CO2 concentration 400-450 ppm; temperature 20/10 °C day/night); elevated temperature (CO2 concentration 400-450 ppm; temperature 25/15 °C day/night); high CO2 and elevated temperature (CO2 concentration 800-900 ppm; temperature 25/15 °C day/night); high CO2 (CO2 concentration 800-900 ppm; temperature 20/10 °C day/night). Glyphosate rates (active ingredient) used in the experiment were: 0 g ha-1 (untreated control); 360 g ha-1 ; 720 g ha-1 ; 1080 g ha-1 ; 1440 g ha-1 (recommended rate), and 2880 g ha-1 . High CO2 concentration and high CO2 concentration plus high temperature improved the biomass and growth parameters of weeds in the studies. In general, high temperature had a neutral, negative or slightly positive effect on the growth of weed species. Climatic conditions did not affect the activity of glyphosate; its application provided equal and effective weed control under both CO2 and temperature levels and their combinations. The positive effect of high CO2 concentration on the growth of weeds does not impact the activity of glyphosate. © 2017 Society of Chemical Industry.

Peer review report 1 on “Impacts of recent climate change on the hydrology in the source region of the Yellow River basin”

Peer review report 1 on “Impacts of recent climate change on the hydrology in the source region of the Yellow River basin”

Influence of disturbances and climate on high-mountain Norway spruce forests in the Low Tatra Mts., Slovakia

Survival and growth of trees in high-mountain regions is limited by harsh environmental conditions, and is therefore sensitive to climate change. The main aims of this study were to develop the regional boundary line for high-mountain spruce forests of the Low Tatra Mts., to reconstruct and compare the disturbance regime of investigated localities, and to present the impact of recent climate change on release potential of Norway spruce. The study area included three localities with forest stands dominated by Norway spruce that were selected to represent the altitudinal zone 1200–1500m a.s.l., excluding the tree line and extreme sites. In order to determine the most important climate characteristics driving tree growth, site chronologies were computed from the sample cores of dominant and co-dominant trees, and correlations between chronologies and monthly climate variables from the previous May to the current September were computed for the period 1901–2008. Analysis of release potential and disturbance histories was performed using the boundary line method. Uniform macro-climate and site conditions in the selected region enabled to construct the regional boundary line for Norway spruce in the Low Tatra. The comparison between boundary lines developed for Norway spruce in the Low Tatra and the other regions showed considerable differences. Therefore, in the high-mountain conditions, the transfer of boundary lines from other regions cannot be recommended. In investigated localities, we identified different disturbance regimes that resulted in variable stand structures and modified the growth responsiveness of Norway spruce to climate. A higher sensitivity to previous October temperature was observed in the most disturbed locality, whereas the growth of Norway spruce on the site with the lowest disturbance rates showed the highest correlation with current June–July temperature. After 1990, we registered enhanced release potential of Norway spruce accompanied by the increase of disturbance rates. Increased release potential was detected even for the trees older than 150years.

Propagation of forcing and model uncertainties on to hydrological drought characteristics in a multi-model century-long experiment in large river basins

Recent climate change impact studies studies have presented conflicting results regarding the largest source of uncertainty in essential hydrological variables, especially streamflow and derived characteristics that describe the evolution of drought events. Part of the problem arises from the lack of a consistent framework to address compatible initial conditions for the impact models and a set of standardized historical and future forcings. The ISI-MIP2 project provides a good opportunity to advance our understanding of the propagation of forcing and model uncertainties on to century-long time series of drought characteristics using an ensemble of hydrological model (HM) projections across a broad range of climate scenarios and regions. To achieve this goal, we used six regional preconditioned hydrological models set up in seven large river basins: Upper-Amazon, Blue-Nile, Ganges, Upper-Niger, Upper-Mississippi, Rhine, and Upper-Yellow. These models were forced with bias-corrected outputs from five CMIP5 general circulation models (GCMs) under two extreme representative concentration pathway scenarios (i.e., RCP2.6 and RCP8.5) for the period 1971-2099. The simulated streamflow was transformed into a monthly runoff index (RI) to analyze the attributions of the GCM and HM uncertainties on to drought magnitudes and durations over time. The results indicated that GCM uncertainty mostly dominated over HM uncertainty for the projections of runoff drought characteristics, irrespective of the selected RCP and region. In general, the overall uncertainty increased with time. The uncertainty in the drought characteristics increased as the radiative forcing of the RCP increased, but the propagation of the GCM uncertainty on to a drought characteristic depended largely upon the hydro-climatic regime. Although our study emphasizes the need for multi-model ensembles for the assessment of future drought projections, the agreement between the GCM forcings was still too weak to draw conclusive recommendations.

Impacts of recent climate change on trends in baseflow and stormflow in United States watersheds

AbstractCharacterizing the impacts of climatic change on hydrologic processes is critical for managing freshwater systems. Specifically, there is a need to evaluate how the two major components of streamflow, baseflow and stormflow, have responded to recent trends in climate. We derive baseflow and stormflow for 674 sites throughout the United States from 1980 to 2010 to examine their associations with precipitation, potential evapotranspiration, and maximum/minimum temperature. The northeastern (NE) and southwestern (SW) United States display consistent trends in baseflow and stormflow: increasing during fall and winter in the NE and decreasing during all seasons in the SW. Trends elsewhere and at other times of the year are more variable but still associated with changes in climate. Counter to expectations, baseflow and stormflow trends throughout the United States tend to change concurrently. These trends are primarily associated with precipitation trends, but increases in PET are influential and likely to become important in the future.

Impacts of recent climate change on the hydrology in the source region of the Yellow River basin

Abstract Study region The source region of the Yellow River (SRYE) in the northeastern Tibetan Plateau. Study focus The spatial-temporal changes of hydrological and meteorological variables and their linkages over the SRYE were investigated for 1961⿿2013. Meanwhile, we quantified the impacts of precipitation and evapotranspiration on hydrological changes through climate elasticity by applying a land surface hydrological model. Furthermore, the impacts of warming climate on the seasonal snow cover and spring flow over the SRYE were examined. New hydrological insights for the region Decreased precipitation and lightly increased evapotranspiration both contributed to reduced runoff in the 1990s, with the decreased precipitation playing a more important role (70%) than the increased evapotranspiration (30%). In the 2000s, precipitation contributed 3% to the runoff reduction, while the increased evapotranspiration accounted for 97%. Along with rapid warming, evapotranspiration is playing an increasingly important role in affecting runoff changes in the SRYE. During 2001⿿2012, snow cover in May decreased over the region. Spring peak flow mainly caused by snowmelt occurred earlier for about 15 days at the Jimai hydrological station due to an earlier snow melt associated with the climate warming in the past 3 decades.