Current and future patterns of forest fire occurrence in China

2020 ◽  
Vol 29 (2) ◽  
pp. 104 ◽  
Author(s):  
Zhiwei Wu ◽  
Hong S. He ◽  
Robert E. Keane ◽  
Zhiliang Zhu ◽  
Yeqiao Wang ◽  
...  
Keyword(s):  
Forest Fire ◽  
General Circulation ◽  
Southern China ◽  
Northern China ◽  
General Circulation Models ◽  
Boosted Regression Trees ◽  
Fire Occurrence ◽  
Representative Concentration Pathways ◽  
Fire Patterns ◽  
In Fire

Forest fire patterns are likely to be altered by climate change. We used boosted regression trees modelling and the MODIS Global Fire Atlas dataset (2003–15) to characterise relative influences of nine natural and human variables on fire patterns across five forest zones in China. The same modelling approach was used to project fire patterns for 2041–60 and 2061–80 based on two general circulation models for two representative concentration pathways scenarios. The results showed that, for the baseline period (2003–15) and across the five forest zones, climate variables explained 37.4–43.5% of the variability in fire occurrence and human activities were responsible for explaining an additional 27.0–36.5% of variability. The fire frequency was highest in the subtropical evergreen broadleaf forests zone in southern China, and lowest in the warm temperate deciduous broadleaved mixed-forests zone in northern China. Projection results showed an increasing trend in fire occurrence probability ranging from 43.3 to 99.9% and 41.4 to 99.3% across forest zones under the two climate models and two representative concentration pathways scenarios relative to the current climate (2003–15). Increased fire occurrence is projected to shift from southern to central-northern China for both 2041–60 and 2061–80.

Forest fire occurrence and climate change in Canada

2010 ◽  
Vol 19 (3) ◽  
pp. 253 ◽  
Author(s):  
B. M. Wotton ◽  
C. A. Nock ◽  
M. D. Flannigan
Keyword(s):  
Climate Change ◽  
Boreal Forest ◽  
Forest Fire ◽  
Forest Fires ◽  
General Circulation ◽  
Fire Regime ◽  
General Circulation Models ◽  
Fire Occurrence ◽  
Fire Activity ◽  
In Fire

The structure and function of the boreal forest are significantly influenced by forest fires. The ignition and growth of fires depend quite strongly on weather; thus, climate change can be expected to have a considerable impact on forest fire activity and hence the structure of the boreal forest. Forest fire occurrence is an extremely important element of fire activity as it defines the load on suppression resources a fire management agency will face. We used two general circulation models (GCMs) to develop projections of future fire occurrence across Canada. While fire numbers are projected to increase across all forested regions studied, the relative increase in number of fires varies regionally. Overall across Canada, our results from the Canadian Climate Centre GCM scenarios suggest an increase in fire occurrence of 25% by 2030 and 75% by the end of the 21st century. Results projected from fire climate scenarios derived from the Hadley Centre GCM suggest fire occurrence will increase by 140% by the end of this century. These general increases in fire occurrence across Canada agree with other regional and national studies of the impacts of climate change on fire activity. Thus, in the absence of large changes to current climatic trends, significant fire regime induced changes in the boreal forest ecosystem are likely.

scholarly journals Spatiotemporal Trends and Attribution of Drought across China from 1901–2100

2020 ◽  
Vol 12 (2) ◽  
pp. 477
Author(s):  
Yongxia Ding ◽  
Shouzhang Peng
Keyword(s):  
Adverse Effects ◽  
General Circulation ◽  
Potential Evapotranspiration ◽  
Northern China ◽  
General Circulation Models ◽  
Research Unit ◽  
Mitigation Strategies ◽  
Climatic Research Unit ◽  
The Past ◽  
Spatiotemporal Trends

Investigating long-term drought trends is of great importance in coping with the adverse effects of global warming. However, little attention has been focused on studying the detailed spatial variability and attribution of drought variation in China. In this study, we first generated a 1 km resolution monthly climate dataset for the period 1901–2100 across China using the delta spatial downscaling method to assess the variability of the Standardized Precipitation Evaporation Index (SPEI). We then developed a simple approach to quantifying the contributions of water supply (precipitation) and demand (potential evapotranspiration, PET) on SPEI variability, according to the meaning of the differentiating SPEI equation. The results indicated that the delta framework could accurately downscale and correct low-spatial-resolution monthly temperatures and precipitation from the Climatic Research Unit and general circulation models (GCMs). Of the 27 GCMs analyzed, the BNU-ESM, CESM1-CAM5, and GFDL-ESM2M were found to be the most accurate in modeling future temperatures and precipitation. We also found that, compared with the past (1901–2017), the climate in the future (2018–2100) will tend toward significant droughts, although both periods showed a high spatial heterogeneity across China. Moreover, the proportion of areas with significantly decreasing SPEI trends was far greater than the proportion of those with increasing trends in most cases, especially for northwestern and northern China. Finally, the proposed approach to quantifying precipitation and PET contributions performed well according to logical evaluations. The percentage contributions of precipitation and PET on SPEI variability varied with study periods, representative concentration pathway scenarios, trend directions, and geographic spaces. In the past, PET contributions for significant downward trends and precipitation contributions for significantly upward trends accounted for 95% and 72%, while their future contributions were 57 ± 22%–149 ± 20% and 95 ± 27%–190 ± 58%, respectively. Overall, our results provide detailed insights for planning flexible adaptation and mitigation strategies to cope with the adverse effects of climate drought across China.

scholarly journals Investigating Future Changes in Southern China Precipitation Characteristics Based on Dynamically Downscaled CMIP5 Climate Projections

2021 ◽  
Author(s):  
Ying Lung Liu ◽  
Chi-yung Tam ◽  
Hang Wai Tong ◽  
Kevin Cheung ◽  
Zhongfeng Xu
Keyword(s):  
General Circulation ◽  
Climate Model ◽  
Hydrological Cycle ◽  
Southern China ◽  
Coupled Model ◽  
General Circulation Models ◽  
Horizontal Resolution ◽  
Annual Number ◽  
Climate Projections ◽  
Budget Analysis

Abstract The Regional Climate Model version 4 (RegCM4) has been used to dynamically downscale outputs from four different general circulation models (GCM) participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5) to the horizontal resolution of 25 km × 25km, in order to study 2050-to-2099 changes in the Southern China hydrological cycle according to Representative Concentration Pathway (RCP) 8.5, relative to the period of 1979 to 2003. The mean summertime precipitation is projected to increase by 0.5 – 1.5 mm/day over coastal Southern China, and with significantly enhanced interannual variability. In boreal spring, similar increase in both the seasonal mean and its year-to-year variation north of 25°N is also found. A novel moisture budget analysis shows that changes in mean background humidity (anomalous wind convergence) dominates the increase in the interannual precipitation variability in spring (summer). Extreme daily precipitation (based on the 95 th percentile) is projected to become more intense, roughly following the Clausius–Clapeyron relation for the aforementioned seasons. On the other hand, autumn mean rainfall rate will be reduced over a broad area in Southern China (although this might be subjected to models’ ability in capturing tropical cyclone activities). The annual number of maximum consecutive dry days (CDD) is found to increase by about 3 to 5 days over locations south of 32°N. Analyses of GCM raw outputs indicate that strengthened northerlies over coastal East Asia , which is likely associated with the so-called tropical expansion, are responsible for the drier autumn.

scholarly journals Projected impacts of climate change on hydropower potential in China

2016 ◽  
Author(s):  
Xingcai Liu ◽  
Qiuhong Tang ◽  
Nathalie Voisin ◽  
Huijuan Cui
Keyword(s):  
Climate Change ◽  
General Circulation ◽  
River Flow ◽  
Southern China ◽  
Eastern China ◽  
General Circulation Models ◽  
Central China ◽  
Climate Data ◽  
South Central ◽  
Hydropower Potential

Abstract. Hydropower is an important renewable energy source in China, but it is sensitive to climate change, because the changing climate may alter hydrological conditions (e.g., river flow and reservoir storage). Future changes and associated uncertainties in China's gross hydropower potential (GHP) and developed hydropower potential (DHP) are projected using simulations from eight global hydrological models (GHMs) forced by five general circulation models (GCMs) with climate data under two representative concentration pathways (RCP2.6 and RCP8.5). Results show that the estimation of the present GHP of China is comparable to other studies; overall, the annual GHP is projected to change by −1.7 to 2% in the near future (2020–2050) and increase by 3 to 6 % in the late 21st century (2070–2099). The annual DHP is projected to change by −2.2 to −5.4 % (0.7–1.7 % of the total installed hydropower capacity [IHC]) and −1.3 to −4% (0.4–1.3 % of total IHC) for 2020–2050 and 2070–2099, respectively. Regional variations emerge: GHP will increase in northern China, but decrease in southern China – mostly in South-Central China and Eastern China – where numerous reservoirs and large IHCs currently are located. The area with the highest GHP in Southwest China will have more GHP, while DHP will reduce in the regions with high IHC (e.g., Sichuan and Hubei) in the future. The largest decrease in DHP (in %) will occur in autumn or winter, when streamflow is relatively low and water use is competitive. Large ranges in hydropower estimates across GHMs and GCMs highlight the necessity of using multi-model assessments under climate change conditions. This study prompts the consideration of climate change in planning for hydropower development and operations in China.

scholarly journals Modeling the Impacts of Future Climate Change on Irrigation over China: Sensitivity to Adjusted Projections

2014 ◽  
Vol 15 (5) ◽  
pp. 2085-2103 ◽  
Author(s):  
Guoyong Leng ◽  
Qiuhong Tang
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
General Circulation ◽  
Southern China ◽  
Climate Change Impacts ◽  
General Circulation Models ◽  
Future Climate ◽  
Future Climate Change ◽  
Community Land Model ◽  
The Impact

Abstract Because of the limitations of coarse-resolution general circulation models (GCMs), delta change (DC) methods are generally used to derive scenarios of future climate as inputs into impact models. In this paper, the impact of future climate change on irrigation was investigated over China using the Community Land Model, version 4 (CLM4), which was calibrated against observed irrigation water demand (IWD) at the provincial level. The results show large differences in projected changes of IWD variability, extremes, timing, and regional responses between the DC and bias-corrected (BC) methods. For example, 95th-percentile IWD increased by 62% in the BC method compared to only a 28% increase in the DC method. In addition, a shift of seasonal IWD peaks (averaged over the country) to one month later in the year was projected when using the BC method, whereas no evident changes were predicted when using the DC method. Furthermore, low-percentile runoff has larger impacts in the BC method compared with proportional changes in the DC method, indicating that hydrological droughts seem to be exacerbated by increased climate variability. The discrepancies between the two methods were potentially due to the inability of the DC method to capture the changes in precipitation variability. Therefore, the authors highlight the potential effects of climate variability and the sensitivity to the choice of particular strategy-adjusting climate projection in assessing climate change impacts on irrigation. Some caveats, however, should be placed around interpretation of simulated percentage changes for all of China since a large model bias was found in southern China.

scholarly journals Projection of rainfall under representative concentration pathways scenarios in a data scarce region of Iraq

2020 ◽  
pp. 32-37
Author(s):  
Saleem A. Salman ◽  
Mohamad Rajab Houmsi ◽  
Ghaith Falah Ziarh ◽  
Tarmizi Ismail
Keyword(s):  
General Circulation ◽  
Research University ◽  
Coupled Model ◽  
General Circulation Models ◽  
Support Vector ◽  
Rcp Scenarios ◽  
Representative Concentration Pathways ◽  
Statistical Measures ◽  
Simulated Precipitation ◽  
Grid Points

A study has been conducted for projection of monthly rainfall in Baghdad of Iraq using a General Circulation Models (GCM) of Coupled Model Intercomparison Project Phase 5 (CMIP5) under four representative concentration pathways (RCP) scenarios namely RCP2.6, RCP4.5, RCP6.0 and RCP8.5. For this purpose, monthly gridded precipitation datasets produced by the centre for climatic research, University of Delaware (UDel) and GCM BCC-CSM1-1 simulated precipitation data at 46 grid points surrounding Baghdad were used. The statistical downscaling models were developed using Support Vector Machine (SVM) and Random Forest (RF). The performance of downscaling model assessed using different statistical measures showed that SVM could simulate historical rainfall in the region very well. Projection of rainfall using SVM revealed that rainfall at Baghdad will change in the range of 3.5% to -6.2% in the end of this century.

Successive Modulation of ENSO to the Future Greenhouse Warming

2008 ◽  
Vol 21 (1) ◽  
pp. 3-21 ◽  
Author(s):  
Soon-Il An ◽  
Jong-Seong Kug ◽  
Yoo-Geun Ham ◽  
In-Sik Kang
Keyword(s):  
General Circulation ◽  
Southern Oscillation ◽  
General Circulation Models ◽  
Tropical Pacific ◽  
Greenhouse Warming ◽  
Delayed Response ◽  
Subsurface Temperature ◽  
Climate System Model ◽  
The Mean ◽  
The Tropical Pacific

Abstract The multidecadal modulation of the El Niño–Southern Oscillation (ENSO) due to greenhouse warming has been analyzed herein by means of diagnostics of Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) coupled general circulation models (CGCMs) and the eigenanalysis of a simplified version of an intermediate ENSO model. The response of the global-mean troposphere temperature to increasing greenhouse gases is more likely linear, while the amplitude and period of ENSO fluctuates in a multidecadal time scale. The climate system model outputs suggest that the multidecadal modulation of ENSO is related to the delayed response of the subsurface temperature in the tropical Pacific compared to the response time of the sea surface temperature (SST), which would lead a modulation of the vertical temperature gradient. Furthermore, an eigenanalysis considering only two parameters, the changes in the zonal contrast of the mean background SST and the changes in the vertical contrast between the mean surface and subsurface temperatures in the tropical Pacific, exhibits a good agreement with the CGCM outputs in terms of the multidecadal modulations of the ENSO amplitude and period. In particular, the change in the vertical contrast, that is, change in difference between the subsurface temperature and SST, turns out to be more influential on the ENSO modulation than changes in the mean SST itself.

Spatial variation of East Asian winter monsoon evolution between northern and southern China since the last glacial maximum

2021 ◽  
pp. 1-14
Author(s):  
Qin Li ◽  
Haibin Wu ◽  
Jun Cheng ◽  
Shuya Zhu ◽  
Chunxia Zhang ◽  
...  
Keyword(s):  
East Asian Winter Monsoon ◽  
Southern China ◽  
Ice Sheets ◽  
Northern China ◽  
Winter Monsoon ◽  
Asian Winter Monsoon ◽  
Spatial Differences ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Abstract The East Asian winter monsoon (EAWM) is one of the most dynamic components of the global climate system. Although poorly understood, knowledge of long-term spatial differences in EAWM variability during the glacial–interglacial cycles is important for understanding the dynamic processes of the EAWM. We reconstructed the spatiotemporal characteristics of the EAWM since the last glacial maximum (LGM) using a comparison of proxy records and long-term transient simulations. A loess grain-size record from northern China (a sensitive EAWM proxy) and the sea surface temperature gradient of an EAWM index in sediments of the southern South China Sea were compared. The data–model comparison indicates pronounced spatial differences in EAWM evolution, with a weakened EAWM since the LGM in northern China but a strengthened EAWM from the LGM to the early Holocene, followed by a weakening trend, in southern China. The model results suggest that variations in the EAWM in northern China were driven mainly by changes in atmospheric carbon dioxide (CO2) concentration and Northern Hemisphere ice sheets, whereas orbital insolation and ice sheets were important drivers in southern China. We propose that the relative importance of insolation, ice sheets, and atmospheric CO2 for EAWM evolution varied spatially within East Asia.

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