Impact of Climate and Land Use Changes on the Flood Hazard of the Middle Brahmaputra Reach, India

2012 ◽  
Vol 7 (5) ◽  
pp. 573-581 ◽  
Author(s):  
Subashisa Dutta ◽  
◽  
Shyamal Ghosh
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Change ◽  
Land Cover ◽  
Climate Change Scenario ◽  
Hydrological Model ◽  
Flood Hazard ◽  
Baseline Period ◽  
Change Scenario ◽  
Flood Characteristics

Being the highest specific discharge river in the world, the Brahmaputra has a large floodplain area of 700 km in length in its middle reaches falling in the high flood vulnerability category. Floods generated in upland Himalayan catchments are mainly controlled by land use and land cover, storm characteristics, and vegetation dynamics. Floods propagate through a floodplain region consisting of wetlands, paddy agriculture, and wide braided river reaches with natural constraint points (nodals) that make the reaches more vulnerable to flood hazards. In this study, a macroscale distributed hydrological model was used to obtain the flood characteristics of the reaches. A hydrological model with spatially distributed input parameters and meteorological data was simulated at (1 km × 1 km) spatial grids to estimate flood hydrographs at the main river and itsmajor tributaries. Aftermodel validation, “best guess” land use change scenarios were used to estimate potential changes in flood characteristics. Results show that at the middle reaches of the Brahmaputra, peak discharge increases by a maximum of 9% for land use change scenarios. The same model with bias-corrected climatological data from a regional climate model (RCM) simulation (PRECIS) was used to obtain future changes in flood generation and its propagation through the basin in the projected climatological scenario. Changes in flood characteristics with reference to the baseline period show that the average duration of flood waves will increase from 15.2 days in the baseline period (1961-1990) to 19.3 days in the future (2071-2100). Peak discharge will increase by an average of 21% in the future in the projected climate change scenario. After statistics on changes of flood characteristics in the projected climate change scenario (2071-2100) were obtained, a 2-dimensional hydrodynamic model was used to obtain flood inundation and velocity distribution on the floodplain. Distribution of velocity and inundation depth was spatially analyzed to obtain flood hazard zones in the projected climate change scenario. Results show that spatial variation in flood hazard zones will be significantly altered in the projected climate change scenario compared to land use/land cover changes.

scholarly journals Modelling of the Discharge Response to Climate Change under RCP8.5 Scenario in the Alata River Basin (Mersin, SE Turkey)

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 483
Author(s):  
Ümit Yıldırım ◽  
Cüneyt Güler ◽  
Barış Önol ◽  
Michael Rode ◽  
Seifeddine Jomaa
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Hydrological Model ◽  
Baseline Period ◽  
Change Scenario ◽  
Climate Projections ◽  
Worst Case ◽  
Distributed Process ◽  
In The Beginning ◽  
Se Turkey

This study investigates the impacts of climate change on the hydrological response of a Mediterranean mesoscale catchment using a hydrological model. The effect of climate change on the discharge of the Alata River Basin in Mersin province (Turkey) was assessed under the worst-case climate change scenario (i.e., RCP8.5), using the semi-distributed, process-based hydrological model Hydrological Predictions for the Environment (HYPE). First, the model was evaluated temporally and spatially and has been shown to reproduce the measured discharge consistently. Second, the discharge was predicted under climate projections in three distinct future periods (i.e., 2021–2040, 2046–2065 and 2081–2100, reflecting the beginning, middle and end of the century, respectively). Climate change projections showed that the annual mean temperature in the Alata River Basin rises for the beginning, middle and end of the century, with about 1.35, 2.13 and 4.11 °C, respectively. Besides, the highest discharge timing seems to occur one month earlier (February instead of March) compared to the baseline period (2000–2011) in the beginning and middle of the century. The results show a decrease in precipitation and an increase in temperature in all future projections, resulting in more snowmelt and higher discharge generation in the beginning and middle of the century scenarios. However, at the end of the century, the discharge significantly decreased due to increased evapotranspiration and reduced snow depth in the upstream area. The findings of this study can help develop efficient climate change adaptation options in the Levant’s coastal areas.

scholarly journals Influence of future climate and cropland expansion on isoprene emissions and tropospheric ozone

2014 ◽  
Vol 14 (2) ◽  
pp. 1011-1024 ◽  
Author(s):  
O. J. Squire ◽  
A. T. Archibald ◽  
N. L. Abraham ◽  
D. J. Beerling ◽  
C. N. Hewitt ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Change ◽  
21St Century ◽  
Tropospheric Ozone ◽  
Climate Model ◽  
Anthropogenic Emissions ◽  
Change Scenario ◽  
Dynamic Global Vegetation Model ◽  
The Tropics

Abstract. Over the 21st century, changes in CO2 levels, climate and land use are expected to alter the global distribution of vegetation, leading to changes in trace gas emissions from plants, including, importantly, the emissions of isoprene. This, combined with changes in anthropogenic emissions, has the potential to impact tropospheric ozone levels, which above a certain level are harmful to animals and vegetation. In this study we use a biogenic emissions model following the empirical parameterisation of the MEGAN model, with vegetation distributions calculated by the Sheffield Dynamic Global Vegetation Model (SDGVM) to explore a range of potential future (2095) changes in isoprene emissions caused by changes in climate (including natural land use changes), land use, and the inhibition of isoprene emissions by CO2. From the present-day (2000) value of 467 Tg C yr−1, we find that the combined impact of these factors could cause a net decrease in isoprene emissions of 259 Tg C yr−1 (55%) with individual contributions of +78 Tg C yr−1 (climate change), −190 Tg C yr−1 (land use) and −147 Tg C yr−1 (CO2 inhibition). Using these isoprene emissions and changes in anthropogenic emissions, a series of integrations is conducted with the UM-UKCA chemistry-climate model with the aim of examining changes in ozone over the 21st century. Globally, all combined future changes cause a decrease in the tropospheric ozone burden of 27 Tg (7%) from 379 Tg in the present-day. At the surface, decreases in ozone of 6–10 ppb are calculated over the oceans and developed northern hemispheric regions, due to reduced NOx transport by PAN and reductions in NOx emissions in these areas respectively. Increases of 4–6 ppb are calculated in the continental tropics due to cropland expansion in these regions, increased CO2 inhibition of isoprene emissions, and higher temperatures due to climate change. These effects outweigh the decreases in tropical ozone caused by increased tropical isoprene emissions with climate change. Our land use change scenario consists of cropland expansion, which is most pronounced in the tropics. The tropics are also where land use change causes the greatest increases in ozone. As such there is potential for increased crop exposure to harmful levels of ozone. However, we find that these ozone increases are still not large enough to raise ozone to such damaging levels.

scholarly journals Modeling the Impacts of Urbanization on Regional Climate Change: A Case Study in the Beijing-Tianjin-Tangshan Metropolitan Area

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Jinyan Zhan ◽  
Juan Huang ◽  
Tao Zhao ◽  
Xiaoli Geng ◽  
Yihui Xiong
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Change ◽  
Land Cover ◽  
Metropolitan Area ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Urban Land Use ◽  
Sufficient Evidence ◽  
Temperature And Precipitation

China has experienced rapid urbanization since 1978, and the dramatic change in land cover is expected to have significant impacts on the climate change. Some models have been used to simulate the relationship between land use and land cover change and climate change; however, there is still no sufficient evidence for the impacts of urbanization on the regional climate. This study aims to identify the impact of urban land use change on regional temperature and precipitation in summer in the Beijing-Tianjin-Tangshan Metropolitan area during 2030–2040 based on the analysis of the simulation results of WRF model. Firstly, we analyzed the land use change and climate change during 1995–2005 in the study area. The impacts of future urbanization on regional climate change were then simulated. The results indicate that urbanization in this area has affected the regional climate and has the potential to increase temperature and precipitation in the summer of 2030–2040. These research results can offer decision-making support information related to future planning strategies in urban environments in consideration of regional climate change.

Modeling the changing sediment yield of the Amazon under climate change and deforestation scenarios and the possible impacts on the Guiana coast

2020 ◽  
Author(s):  
Safaa Naffaa ◽  
L.P.H. (Rens) van Beek ◽  
Frances E.Dunn ◽  
Steven de Jong
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Change ◽  
Land Cover ◽  
Sediment Yield ◽  
Coastal Erosion ◽  
Sediment Supply ◽  
Trapping Efficiency ◽  
Amazon River ◽  
Land Cover Changes

<p>The Amazon River is an important source of the sediment that is transported and accumulated along the coast of Suriname. As such it is an important factor in maintaining the coastline as this sediment is deposited in mud banks that move towards the shore and coalesce with it, thus preventing coastal erosion. Accordingly, a steady and adequate supply of sediment from the Amazon river is required especially considering increased coastal erosion rates that may occur as a result of rising sea levels due to climate change. Yet at the same time, climate change may alter the hydrological regime of the Amazon and influence its transport capacity, affecting sediment transport to the mouth and coast. Furthermore, the sediment supply to the river may be altered as a result of land cover changes and other anthropogenic activities, including deforestation and sediment trapping in existing and future planned reservoirs.<br>Studying the transport of sediment from source to sink and quantifying how future changes affect the mean rate of sediment supply to the Surinam coast and its variability will lead to a better understanding of the intricacies involved. We use a spatial-temporal process-based model together with a set of plausible scenarios of future change based on combinations of the Shared Socioeconomic Pathways (SSP) and the Representative Concentration Pathways (RCP). In this study, we used two models: PCRGLOB-Set and PCRGLOB-WB. PCRGLOB-SET is based on the RUSLE equation and is used to assess the local sediment supply including the effects of land cover changes. PCRGLOB-WB simulates hydrological responses and changes under climate and land-use change. Moreover, PCRGLOB-WB is used to determine the trapping efficiency of reservoirs. The PCRGLOB-WB model was applied to a business-as-usual scenario for the 21st century (SSP 2 with RCP 6.0) and we considered uncertainty in the projected climate by using 5 Global Climate Models (GCMs). We apply the model to different future scenarios considering climate, socioeconomic and land-use change. For validation, the observations of six stations along the Amazon river were compared to the estimations of the models for the historical period (1971-2010), which also serves as a reference run to evaluate changes in sediment production and sediment yield. </p>

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