scholarly journals Impact of bushfire and climate variability on streamflow from forested catchments in southeast Australia

2013 ◽  
Vol 10 (4) ◽  
pp. 4397-4437 ◽  
Author(s):  
Y. Zhou ◽  
Y. Zhang ◽  
J. Vaze ◽  
P. Lane ◽  
S. Xu
Keyword(s):  
Climate Variability ◽  
Forest Disturbance ◽  
Natural Disturbance ◽  
Climatic Conditions ◽  
Climate Impacts ◽  
Water Yield ◽  
Hydrological Models ◽  
Forested Catchments ◽  
Southeast Australia ◽  
The Impact

Abstract. Most of the surface water for natural environmental and human water uses in southeast Australia is sourced from forested catchments located in the higher rainfall areas. Water yield of these catchments is mainly affected by climatic conditions, but it is also greatly affected by vegetation cover change. Bushfires are a major natural disturbance in forested catchments and potentially modify the water yield of the catchments through changes to evapotranspiration (ET), interception and soil moisture storage. This paper quantifies the impacts of bushfire and climate variability on streamflow from three southeast Australian catchments where Ash Wednesday bushfires occurred in February 1983. The hydrological models used here include AWRA-L, Xinanjiang and GR4J. The three models are first calibrated against streamflow data from the pre-bushfire period and they are used to simulate runoff for the post-bushfire period with the calibrated parameters. The difference between the observed and model simulated runoff for the post-bushfire period provides an estimate of the impact of bushfire on streamflow. The hydrological modelling results for the three catchments indicate that there is a substantial increase in streamflow in the first 15 yr after the 1983 bushfires. The increase in streamflow is attributed to initial decreases in ET and interception resulting from the fires, followed by logging activity. After 15 yr, streamflow dynamics are more heavily influenced by climate effects, although some impact from fire and logging regeneration may still occur. It is shown that hydrological models provide reasonable consistent estimates of forest disturbance and climate impacts on streamflow for the three catchments. The results might be used by forest managers to understand the relationship between forest disturbance and climate variability impacts on water yield in the context of climate change.

scholarly journals Impact of bushfire and climate variability on streamflow from forested catchments in southeast Australia

2015 ◽  
Vol 60 (7-8) ◽  
pp. 1340-1360 ◽  
Author(s):  
Yanchun Zhou ◽  
Yongqiang Zhang ◽  
Jai Vaze ◽  
Patrick Lane ◽  
Shiguo Xu
Keyword(s):  
Climate Variability ◽  
Forested Catchments ◽  
Southeast Australia

scholarly journals Multi-model climate impact assessment and intercomparison for three large-scale river basins on three continents

2014 ◽  
Vol 5 (2) ◽  
pp. 849-900 ◽  
Author(s):  
T. Vetter ◽  
S. Huang ◽  
V. Aich ◽  
T. Yang ◽  
X. Wang ◽  
...  
Keyword(s):  
Impact Assessment ◽  
Climate Models ◽  
Water Discharge ◽  
River Basins ◽  
Climate Impact ◽  
Climate Impacts ◽  
Hydrological Models ◽  
Climate Scenarios ◽  
Climate Impact Assessment ◽  
The Impact

Abstract. Climate change impacts on hydrological processes should be simulated for river basins using validated models and multiple climate scenarios in order to provide reliable results for stakeholders. In the last 10–15 years climate impact assessment was performed for many river basins worldwide using different climate scenarios and models. Nevertheless, the results are hardly comparable and do not allow to create a full picture of impacts and uncertainties. Therefore, a systematic intercomparison of impacts is suggested, which should be done for representative regions using state-of-the-art models. Our study is intended as a step in this direction. The impact assessment presented here was performed for three river basins on three continents: Rhine in Europe, Upper Niger in Africa and Upper Yellow in Asia. For that, climate scenarios from five GCMs and three hydrological models: HBV, SWIM and VIC, were used. Four "Representative Concentration Pathways" (RCPs) covering a range of emissions and land-use change projections were included. The objectives were to analyze and compare climate impacts on future trends considering three runoff quantiles: Q90, Q50 and Q10 and on seasonal water discharge, and to evaluate uncertainties from different sources. The results allow drawing some robust conclusions, but uncertainties are large and shared differently between sources in the studied basins. The robust results in terms of trend direction and slope and changes in seasonal dynamics could be found for the Rhine basin regardless which hydrological model or forcing GCM is used. For the Niger River scenarios from climate models are the largest uncertainty source, providing large discrepancies in precipitation, and therefore clear projections are difficult to do. For the Upper Yellow basin, both the hydrological models and climate models contribute to uncertainty in the impacts, though an increase in high flows in future is a robust outcome assured by all three hydrological models.

scholarly journals ANALYSIS OF CLIMATE VARIABILITY AND ITS INFLUENCES ON SEASONAL RAINFALL PATTERNS ON THE BATEKE PLATEAUS IN THE REPUBLIC OF CONGO-BRAZZAVILLE

2021 ◽  
Vol 9 (01) ◽  
pp. 327-337
Author(s):  
Harmel Obami-Ondon ◽  
◽  
Medard Ngouala Mabonzo ◽  
Ngoma Mvoundou Christian ◽  
Bernard Mabiala ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Climate Variability ◽  
Principal Component ◽  
Climatic Conditions ◽  
Seasonal Rainfall ◽  
Republic Of Congo ◽  
Rainfall Patterns ◽  
The Republic ◽  
Congo Brazzaville ◽  
The Impact

Climate variability, in Africa in general and in the Republic of Congo-Brazzaville in particular, has been widely documented over the past 20 years. However, variables related to rainfall, such as the nine-month rainy seasons, have been very little studied in the Bateke Plateaux zone, which play a major role in regional hydrology. The objective of this study is to investigate the influence of climatic events on seasonal rainfall patterns on the Plateaux Bateke. On the one hand, it involves monitoring the evolution of climatic parameters through the analysis of temperature, relative humidity and rainfall variation. On the other hand, it was a question of comparing the monthly rainfall normals over the period 1987-2016 in order to determine the behaviour of seasonal rainfall patterns in the context of climate variability. The principal component analysis, based on nine (09) variables, highlighted the impact of climate variability on seasonal rainfall patterns. The first principal component (F1) is associated with the factors defining the climatic conditions of the Plateau Bateke. The second main component (F2) does not express clear correlations. Generally speaking, the temperature and relative humidity of the air are factors in the temporal variability of seasonal rainfall regimes on the Plateaux Bateke.

Effect of climate variability on pasture-based dairy feeding systems in south-east Australia

2015 ◽  
Vol 55 (9) ◽  
pp. 1106 ◽  
Author(s):  
Şeyda Özkan ◽  
Julian Hill ◽  
Brendan Cullen
Keyword(s):  
Climate Variability ◽  
Perennial Ryegrass ◽  
Cropping Systems ◽  
Climatic Conditions ◽  
Feeding System ◽  
Pasture Production ◽  
Double Cropping ◽  
The Impact ◽  
Better Than ◽  
Feeding Systems

The Australian dairy industry relies primarily on pasture for its feed supply. However, the variability in climate affects plant growth, leading to uncertainty in dryland pasture supply. This paper models the impact of climate variability on pasture production and examines the potential of two pasture-based dairy feeding systems: (1) to experience winter deficits; (2) to carry forward the conserved pasture surpluses as silage for future use; and (3) to conserve pasture surpluses as hay. The two dairy feeding systems examined were a traditional perennial ryegrass-based feeding system (ryegrass max. – RM) and a system that incorporated double cropping into the perennial ryegrass pasture base (complementary forage – CF). The conditional probability of the RM and CF systems to generate pasture deficits in winter were 94% and 96%, respectively. Both systems could carry forward the surplus silage into the following lactation almost once in every 4–5 years with the RM system performing slightly better than the CF system. The proportions of the grain-based concentrates fed in the two systems were 25% and 27% for the RM and CF systems, respectively. This study suggests that double-cropping systems have the potential to provide high-quality feed to support the feed gaps when pasture is not available due to increased variability in climatic conditions.

scholarly journals Multi-model climate impact assessment and intercomparison for three large-scale river basins on three continents

2015 ◽  
Vol 6 (1) ◽  
pp. 17-43 ◽  
Author(s):  
T. Vetter ◽  
S. Huang ◽  
V. Aich ◽  
T. Yang ◽  
X. Wang ◽  
...  
Keyword(s):  
Impact Assessment ◽  
General Circulation ◽  
Climate Models ◽  
River Basins ◽  
Climate Impact ◽  
Climate Impacts ◽  
Hydrological Models ◽  
Climate Scenarios ◽  
Climate Impact Assessment ◽  
The Impact

Abstract. Climate change impacts on hydrological processes should be simulated for river basins using validated models and multiple climate scenarios in order to provide reliable results for stakeholders. In the last 10–15 years, climate impact assessment has been performed for many river basins worldwide using different climate scenarios and models. However, their results are hardly comparable, and do not allow one to create a full picture of impacts and uncertainties. Therefore, a systematic intercomparison of impacts is suggested, which should be done for representative regions using state-of-the-art models. Only a few such studies have been available until now with the global-scale hydrological models, and our study is intended as a step in this direction by applying the regional-scale models. The impact assessment presented here was performed for three river basins on three continents: the Rhine in Europe, the Upper Niger in Africa and the Upper Yellow in Asia. For that, climate scenarios from five general circulation models (GCMs) and three hydrological models, HBV, SWIM and VIC, were used. Four representative concentration pathways (RCPs) covering a range of emissions and land-use change projections were included. The objectives were to analyze and compare climate impacts on future river discharge and to evaluate uncertainties from different sources. The results allow one to draw some robust conclusions, but uncertainties are large and shared differently between sources in the studied basins. Robust results in terms of trend direction and slope and changes in seasonal dynamics could be found for the Rhine basin regardless of which hydrological model or forcing GCM is used. For the Niger River, scenarios from climate models are the largest uncertainty source, providing large discrepancies in precipitation, and therefore clear projections are difficult to do. For the Upper Yellow basin, both the hydrological models and climate models contribute to uncertainty in the impacts, though an increase in high flows in the future is a robust outcome ensured by all three hydrological models.

scholarly journals Assessing the impact of climate variability and human activities on streamflow variation

2016 ◽  
Vol 20 (4) ◽  
pp. 1547-1560 ◽  
Author(s):  
Jianxia Chang ◽  
Hongxue Zhang ◽  
Yimin Wang ◽  
Yuelu Zhu
Keyword(s):  
Climate Variability ◽  
Water Conservation ◽  
Human Activities ◽  
Water Resource Management ◽  
Water Withdrawal ◽  
Shaanxi Province ◽  
Hydrological Models ◽  
Moisture Index ◽  
Model Parameter ◽  
The Impact

Abstract. Water resources in river systems have been changing under the impact of both climate variability and human activities. Assessing the respective impact on decadal streamflow variation is important for water resource management. By using an elasticity-based method and calibrated TOPMODEL and VIC hydrological models, we quantitatively isolated the relative contributions that human activities and climate variability made to decadal streamflow changes in the Jinghe basin, located in the northwest of China. This is an important watershed of the Shaanxi province that supplies drinking water for a population of over 6 million people. The results showed that the maximum value of the moisture index (E0∕P) was 1.91 and appeared in 1991–2000, and the decreased speed of streamflow was higher since 1990 compared with 1960–1990. The average annual streamflow from 1990 to 2010 was reduced by 26.96 % compared with the multiyear average value (from 1960 to 2010). The estimates of the impacts of climate variability and human activities on streamflow decreases from the hydrological models were similar to those from the elasticity-based method. The maximum contribution value of human activities was 99 % when averaged over the three methods, and appeared in 1981–1990 due to the effects of soil and water conservation measures and irrigation water withdrawal. Climate variability made the greatest contribution to streamflow reduction in 1991–2000, the values of which was 40.4 %. We emphasized various source of errors and uncertainties that may occur in the hydrological model (parameter and structural uncertainty) and elasticity-based method (model parameter) in climate change impact studies.

Forest disturbance effects on snow and water yield in interior British Columbia

2014 ◽  
Vol 46 (4) ◽  
pp. 521-532 ◽  
Author(s):  
Rita Winkler ◽  
Dave Spittlehouse ◽  
Sarah Boon ◽  
Barbara Zimonick
Keyword(s):  
Mountain Pine Beetle ◽  
Snow Water Equivalent ◽  
Forest Disturbance ◽  
Natural Disturbance ◽  
High Elevation ◽  
Snow Accumulation ◽  
Water Yield ◽  
Hydrologic Response ◽  
Salvage Logging ◽  
Snow Water

Long-term studies at Mayson Lake (ML) and Upper Penticton Creek (UPC) in British Columbia's southern interior quantify snow-dominated hydrologic response to natural disturbances and logging. Following natural disturbance at ML, changes in snow accumulation related directly to mountain pine beetle attack were measurable by the fifth year following attack, when canopy transmittance had increased 24% due to needlefall. In year 1, April 1 snow water equivalent (SWE) was 48% higher in the clearcut than in the pine forest. This difference was reduced to 23% by year 8. A 3-year lag in snow response was also observed in a nearby burned stand where SWE was on average 27 and 59% higher in the clearcut than in the burn and forest, respectively. At UPC, April 1 SWE averaged 12% more and 12% less in a low and high elevation clearcut than forest, respectively, and snow disappeared ∼10 days earlier in both clearcuts. Partially as a result of snowmelt synchronization from higher with lower elevations after 50% of the treatment watersheds had been clearcut, April water yield increased and June to July yield decreased. Research results improve evaluation of hydrologic response to forest disturbance, including retention of beetle-killed stands versus salvage logging.

scholarly journals Multimodel assessments of human and climate impacts on mean annual streamflow in China

2019 ◽  
Vol 23 (3) ◽  
pp. 1245-1261 ◽  
Author(s):  
Xingcai Liu ◽  
Wenfeng Liu ◽  
Hong Yang ◽  
Qiuhong Tang ◽  
Martina Flörke ◽  
...  
Keyword(s):  
Climate Variability ◽  
Quantitative Assessment ◽  
Climate Impact ◽  
Climate Impacts ◽  
Future Climate Change ◽  
Hydrological Models ◽  
Annual Streamflow ◽  
Water Withdrawals ◽  
Over Time ◽  
Quantitative Assessments

Abstract. Human activities, as well as climate variability, have had increasing impacts on natural hydrological systems, particularly streamflow. However, quantitative assessments of these impacts are lacking on large scales. In this study, we use the simulations from six global hydrological models driven by three meteorological forcings to investigate direct human impact (DHI) and climate impact on streamflow in China. Results show that, in the sub-periods of 1971–1990 and 1991–2010, one-fifth to one-third of mean annual streamflow (MAF) was reduced due to DHI in northern basins, and much smaller (<4 %) MAF was reduced in southern basins. From 1971–1990 to 1991–2010, total MAF changes range from −13 % to 10 % across basins wherein the relative contributions of DHI change and climate variability show distinct spatial patterns. DHI change caused decreases in MAF in 70 % of river segments, but climate variability dominated the total MAF changes in 88 % of river segments of China. In most northern basins, climate variability results in changes of −9 % to 18 % in MAF, while DHI change results in decreases of 2 % to 8 % in MAF. In contrast with the climate variability that may increase or decrease streamflow, DHI change almost always contributes to decreases in MAF over time, with water withdrawals supposedly being the major impact on streamflow. This quantitative assessment can be a reference for attribution of streamflow changes at large scales, despite remaining uncertainty. We highlight the significant DHI in northern basins and the necessity to modulate DHI through improved water management towards a better adaptation to future climate change.

Influence of potential climate change on forest landscape dynamics of west-central Alberta

2000 ◽  
Vol 30 (12) ◽  
pp. 1905-1912 ◽  
Author(s):  
C Li ◽  
M D Flannigan ◽  
I GW Corns
Keyword(s):  
Climate Model ◽  
Global Climate Model ◽  
Natural Disturbance ◽  
Biomass Accumulation ◽  
Climatic Conditions ◽  
Landscape Dynamics ◽  
Fire Disturbance ◽  
Disturbance Regimes ◽  
Simulation Results ◽  
The Impact

Changes in climatic conditions may influence both forest biomass accumulation rates and natural disturbance regimes. While changes in biomass accumulation of forests under various climatic conditions have been described by yield equations, large uncertainties exist with regard to disturbance regimes. Under the doubling carbon dioxide scenario, global warming impacts have been predicted from simulation results of the first generation of coupled global climate model (CGCMI). The calculated fine fuel moisture code (FFMC) distribution from the simulation results showed a one-point increase compared with the distribution under current climate conditions. The impact of predicted changes in FFMC distributions on fire disturbance patterns, forest volume, and landscape structure was investigated by using the spatially explicit model for landscape dynamics (SEM-LAND). The simulation results showed increases in fire disturbance frequency and decreases in forest volume. The simulations also showed decreases in landscape fragmentation and landscape diversity, whereas total availability of core habitat for wildlife increased.

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