scholarly journals Impact of climate change on sediment yield in the Mekong River Basin: a case study of the Nam Ou Basin, Lao PDR

2012 ◽  
Vol 9 (3) ◽  
pp. 3339-3384
Author(s):  
B. Shrestha ◽  
M. S. Babel ◽  
S. Maskey ◽  
A. van Griensven ◽  
S. Uhlenbrook ◽  
...  

Abstract. This paper evaluates the impact of climate change on sediment yield in the Nam Ou Basin located in Northern Laos. The Soil and Water Assessment Tool (SWAT) is used to assess future changes in sediment flux attributable to climate change. Future precipitation and temperature series are constructed through a delta change approach. As per the results, in general, temperature as well as precipitation show increasing trends in both scenarios, A2 and B2. However, monthly precipitation shows both increasing and decreasing trends. The simulation results exhibit that the wet and dry seasonal and annual stream discharges are likely to increase (by up to 15, 17 and 14% under scenario A2; and 11, 5 and 10% under scenario B2 respectively) in the future, which will lead to increased wet and dry seasonal and annual sediment yields (by up to 39, 28 and 36% under scenario A2; and 23, 12 and 22% under scenario B2 respectively). A higher discharge and more sediment flux are expected during the wet seasons, although the changes, percentage-wise, are observed to be higher during the dry months. In conclusion, the sediment yield from the Nam Ou Basin is likely to increase with climate change, which strongly suggests the need for basin-wide sediment management strategies in order to reduce the negative impact of this change.

2013 ◽  
Vol 17 (1) ◽  
pp. 1-20 ◽  
Author(s):  
B. Shrestha ◽  
M. S. Babel ◽  
S. Maskey ◽  
A. van Griensven ◽  
S. Uhlenbrook ◽  
...  

Abstract. This paper evaluates the impact of climate change on sediment yield in the Nam Ou basin located in northern Laos. Future climate (temperature and precipitation) from four general circulation models (GCMs) that are found to perform well in the Mekong region and a regional circulation model (PRECIS) are downscaled using a delta change approach. The Soil and Water Assessment Tool (SWAT) is used to assess future changes in sediment flux attributable to climate change. Results indicate up to 3.0 °C shift in seasonal temperature and 27% (decrease) to 41% (increase) in seasonal precipitation. The largest increase in temperature is observed in the dry season while the largest change in precipitation is observed in the wet season. In general, temperature shows increasing trends but changes in precipitation are not unidirectional and vary depending on the greenhouse gas emission scenarios (GHGES), climate models, prediction period and season. The simulation results show that the changes in annual stream discharges are likely to range from a 17% decrease to 66% increase in the future, which will lead to predicted changes in annual sediment yield ranging from a 27% decrease to about 160% increase. Changes in intra-annual (monthly) discharge as well as sediment yield are even greater (−62 to 105% in discharge and −88 to 243% in sediment yield). A higher discharge and sediment flux are expected during the wet seasons, although the highest relative changes are observed during the dry months. The results indicate high uncertainties in the direction and magnitude of changes of discharge as well as sediment yields due to climate change. As the projected climate change impact on sediment varies remarkably between the different climate models, the uncertainty should be taken into account in both sediment management and climate change adaptation.


2020 ◽  
Vol 38 (2A) ◽  
pp. 265-276
Author(s):  
Mahmoud S. Al- Khafaji ◽  
Rana D. Al- Chalabi

The impact of climate change on stream flow and sediment yield in Darbandikhan Watershed is an important challenge facing the water resources in Diyala River, Iraq. This impact was investigated using five Global Circulation Models (GCM) based climate change projection models from the A1B scenario of medium emission. The Soil and Water Assessment Tool (SWAT) was used to compute the temporal and spatial distribution of streamflow and sediment yield of the study area for the period 1984 to 2050. The daily-observed flow recorded in Darbandikhan Dam for the period from 1984 to 2013 was used as a base period for future projection. The initial results of SWAT were calibrated and validated using SUFI-2 of the SWAT-CUP program in daily time step considering the values of the Nash-Sutcliffe Efficiency (NSE) coefficient of determination (R2) as a Dual objective function. Results of NSE and R2 during the calibration (validation) periods were equal to 0.61 and 0.62(0.53 and 0.68), respectively. In addition, the average future prediction for the five climate models indicated that the average yearly flow and sediment yield in the watershed would decrease by about 49% and 44%, respectively, until the year 2050 compared with these of the base period from 1984 to 2013. Moreover, spatial analysis shows that 89.6 % and 90 % of stream flow and sediment come from the Iranian part of Darbandikhan watershed while the remaining small percent comes from Iraq, respectively. However, the middle and southern parts of Darbandikhan Watershed contribute by most of the stream...


2021 ◽  
Vol 4 (1) ◽  
pp. 106-119
Author(s):  
Mira Giri ◽  
Dhundi Raj Dahal

 This study aims to assist the impact of climate change on agriculture in Banepa municipality, as a case study to the local climatic trends and its impacts, vulnerability, and adaptation. The study was conducted among the household of ward no. one to eleven except two and six in the municipality. A questionnaire survey, field observation, in-depth interview, and focus group discussion, methods were adopted for the information collection, cross-validation with verification, and using the secondary source of the information. Monthly precipitation and monthly minimum and maximum air temperatures data of Dhulikhel station were used to study their annual and seasonal trends.Agriculture is one of the vulnerable sectors of the impact of climate change. Trend analysis of temperature and precipitation over 27 years indicates that this region is facing various weather variability. The annual mean of the minimum temperature was showing the highest (13.530C) in 2014 and the lowest (7.860C) in 2001. The trend analysis shows that the annual average minimum temperature has also been increasing per year. Drought, delay in monsoon, hailstorm,and heavy rainfall are major challenges in agriculture.The study concluded that climate change affected the negative impact on agriculture in the Banepa Municipality of Kavre. The existing local and institutional strategies are not sufficient and sustainable to cope with climatic vagaries. There is a proactive need for climate change adaptation measures to address the negative impact of climate change in agriculture to sustain the food and nutrition security in the community through institutional support and long-term agricultural policy and strategic plan.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anna Åkesson ◽  
Alva Curtsdotter ◽  
Anna Eklöf ◽  
Bo Ebenman ◽  
Jon Norberg ◽  
...  

AbstractEco-evolutionary dynamics are essential in shaping the biological response of communities to ongoing climate change. Here we develop a spatially explicit eco-evolutionary framework which features more detailed species interactions, integrating evolution and dispersal. We include species interactions within and between trophic levels, and additionally, we incorporate the feature that species’ interspecific competition might change due to increasing temperatures and affect the impact of climate change on ecological communities. Our modeling framework captures previously reported ecological responses to climate change, and also reveals two key results. First, interactions between trophic levels as well as temperature-dependent competition within a trophic level mitigate the negative impact of climate change on biodiversity, emphasizing the importance of understanding biotic interactions in shaping climate change impact. Second, our trait-based perspective reveals a strong positive relationship between the within-community variation in preferred temperatures and the capacity to respond to climate change. Temperature-dependent competition consistently results both in higher trait variation and more responsive communities to altered climatic conditions. Our study demonstrates the importance of species interactions in an eco-evolutionary setting, further expanding our knowledge of the interplay between ecological and evolutionary processes.


2021 ◽  
Vol 7 (4) ◽  
pp. 19-27
Author(s):  
Saifuddin Soz ◽  
Dhananjay Mankar

Climate change is already bringing tremendous influence on people’s lives, particularly the underprivileged. It’s already visible in a variety of ways. In recent decades, Asia and the Pacific have seen consistent warming trends as well as more frequent and powerful extreme weather events such as droughts, cyclones, floods, and hailstorms. This study was done in Ajmer District of Rajasthan, to find out the climate variation in the last 10 years. The study describes the effects due to climate change on the livelihoods of the people, so a descriptive research design was used for the study to find out the impact of climate change on rural livelihood in central Rajasthan. The study is based on a large representative of sample, quantitative data was collected to gain an idea of the impact on the livelihoods due to climate change at the household level. It shows the negative impact of climate change on rural livelihood which forced the people to change their livelihood directly or indirectly. It was found that climate change had an impact on people’s lives and people do understand the variation in climate change in terms of changes in the weather, unseasonal rain, and drought.


Author(s):  
Nwakor Flora Ngozi ◽  
Amadi C. Okey ◽  
Okwusi Moses Chukwunwike ◽  
Adiele Ezekiel Chinyere

Climate change is a global problem affecting agricultural production, a good adaptation strategy for this phenomena should be sought for increase agricultural production. The study was conducted in Nigeria to assess the Impact of Climate Change on root and tuber crops production among farmers in Nigeria. Secondary data were used for the study, they were collected from NRCRI Umudike and other individual publications. The result shows that climate change had negative impact on root and tubers crops production including potato. Adaptation of Agriculture to climate change in the areas of crop and animal production, post harvest activities and capacity building, divers friction of livelihood sources through the use of different farming methods and improved agricultural practices will help to reduce the impact of climate change. Examples are establishment of forestry, generation of improved and disease resistance crop varieties addition of value into agricultural products and post harvest activities for climate change adaptation and sustainable development.


Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2141 ◽  
Author(s):  
Saddique ◽  
Usman ◽  
Bernhofer

Projected climate changes for the 21st century may cause great uncertainties on the hydrology of a river basin. This study explored the impacts of climate change on the water balance and hydrological regime of the Jhelum River Basin using the Soil and Water Assessment Tool (SWAT). Two downscaling methods (SDSM, Statistical Downscaling Model and LARS-WG, Long Ashton Research Station Weather Generator), three Global Circulation Models (GCMs), and two representative concentration pathways (RCP4.5 and RCP8.5) for three future periods (2030s, 2050s, and 2090s) were used to assess the climate change impacts on flow regimes. The results exhibited that both downscaling methods suggested an increase in annual streamflow over the river basin. There is generally an increasing trend of winter and autumn discharge, whereas it is complicated for summer and spring to conclude if the trend is increasing or decreasing depending on the downscaling methods. Therefore, the uncertainty associated with the downscaling of climate simulation needs to consider, for the best estimate, the impact of climate change, with its uncertainty, on a particular basin. The study also resulted that water yield and evapotranspiration in the eastern part of the basin (sub-basins at high elevation) would be most affected by climate change. The outcomes of this study would be useful for providing guidance in water management and planning for the river basin under climate change.


2020 ◽  
pp. 002190962094034
Author(s):  
Hong Hiep Hoang ◽  
Cong Minh Huynh

Using the Feasible Generalized Least Squares econometric method, the paper analyzes the impact of climate change on economic growth in Vietnam’s coastal South Central region over the period of 2006–2015. The results indicate that, after controlling for the main determinants in the growth model, the climate change with various proxies has a significantly negative impact on provinces’ economic growth in the region. In particular, local institutions not only increase economic growth, but also reduce the negative impact of climate change on economic growth as well. These results suggest some policy implications aimed at boosting the process of transforming the economic growth model for the coastal region adapting to climate change. JEL codes: F21, F23, E22


Author(s):  
K. Nivedita Priyadarshini ◽  
S. A. Rahaman ◽  
S. Nithesh Nirmal ◽  
R. Jegankumar ◽  
P. Masilamani

<p><strong>Abstract.</strong> Climate change impacts on watershed ecosystems and hydrologic processes are complex. The key significant parameters responsible for balancing the watershed ecosystems are temperature and rainfall. Though these parameters are uncertain, they play a prime role in the projections of dimensional climate change studies. The impact of climate change is more dependent on temperature and precipitation which contributes at a larger magnitude for characterising global warming issues. This paper aims to forecast the variations of temperature and precipitation during the period of 2020&amp;ndash;2050 for the northern part of Thenpennar sub basin. This study is modelled using SWAT (Soil and Water Assessment Tool) &amp;ndash; a scale model developed to predict the impact of changes that occurs in land, soil and water over a period of time. This study is validated using the base period from 1980&amp;ndash;2000 which shows the distribution of rainfall and temperature among 38 watersheds. The results from this study show that there is a decrease in the rainfall for a maximum of about 20% in the month of December during the predicted period of 2020 and 2050. This study assesses the possible adverse impact of climate change on temperature and precipitation of Thenpennai sub-basin. This kind of predictions will help the government agencies, rulers and decision makers in policy making and implementing the adaptation strategies for the changing climatic conditions.</p>


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