scholarly journals Multi-Model Assessment of Streamflow Simulations under Climate and Anthropogenic Changes Exemplified in Two Indian River Basins

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 194
Author(s):  
Anusha Somisetty ◽  
Akshay Pachore ◽  
Renji Remesan ◽  
Rohini Kumar
Keyword(s):  
Climate Change ◽  
Monsoon Season ◽  
River Basins ◽  
Low Flows ◽  
Post Monsoon ◽  
Post Monsoon Season ◽  
Rcp 8.5 ◽  
Induced Changes ◽  
The Ganges ◽  
Near Future

This study aims to evaluate the climate- and human-induced impacts on two contrasting river basins in India, specifically, the Ganges and the Godavari. Monthly discharge simulations from global hydrological models (GHMs), run with and without human influence using CMIP5 projections under the framework of the Inter-Sectoral Impact Model Intercomparison Project, are utilized to address the scientific questions related to the quantification of the future impacts of climate change and the historical impacts of human activities on these river basins. The five state-of-the-art GHMs were considered and subsequently used to evaluate the human and climate change impacts on river discharges (seasonal mean discharge and extreme flows) during the pre-monsoon, monsoon, and post-monsoon seasons under the RCP2.6 and RCP8.5 emission scenarios. Results showed that human impacts during the baseline period on long-term seasonal discharge in the Ganges and Godavari River basins for the pre-monsoon season are around 40% and 23%, respectively, and these impacts are stronger than the future climate change impact in the pre-monsoon season for the Ganges basin, whereas, for the Godavari basin, the same pattern is observed with some exceptions. The human impact in the course of the historical period on the pre-monsoon flows of both the Ganges and the Godavari are more significant than on the monsoon and post-monsoon flows. In the near future (2010–39) time slice, the impact of climate change on the streamflow of the Ganges is highest for the post-monsoon season (13.4%) under RCP 8.5 as compared to other seasons. For Godavari, in the near-future period, this impact is highest for the pre-monsoon season (18.2%) under RCP 2.6. Climate-induced changes in both of the basins during both the monsoon and post-monsoon seasons is observed to have a higher impact on future flows than direct human impact-induced changes to flow during the current period. High flows (31.4% and 19.9%) and low flows (51.2% and 36.8%) gain greater influence due to anthropogenic actions in the time of the pre-monsoon season compared to other times of year for the Ganges and Godavari basins, respectively. High flows for the Ganges during the near future time slice are most affected in the monsoon season (15.8%) under RCP 8.5 and, in the case of the Godavari, in the pre-monsoon season (18.4%) under the RCP 2.6 scenario. Low flows of the Ganges during the near-future period are most affected during the monsoon season (22.3%) and for the Godavari, low flows are affected most for the post-monsoon season (22.1%) under RCP 2.6. Uncertainty in the streamflow estimates is more pronounced for the Godavari basin compared to the Ganges basin. The findings of this study enhance our understanding of the natural and human-influenced flow regimes in these river basins, which helps the formation of future strategies, especially for inter-state and transboundary river management.

scholarly journals Projection of Hydro-Climatic Extreme Events under Climate Change in Yom and Nan River Basins, Thailand

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 665
Author(s):  
Chanchai Petpongpan ◽  
Chaiwat Ekkawatpanit ◽  
Supattra Visessri ◽  
Duangrudee Kositgittiwong
Keyword(s):  
Climate Change ◽  
Air Temperature ◽  
Extreme Events ◽  
River Basins ◽  
Annual Rainfall ◽  
Extreme Floods ◽  
Extreme Flood ◽  
Rcp 8.5 ◽  
Near Future ◽  
Far Future

Due to a continuous increase in global temperature, the climate has been changing without sign of alleviation. An increase in the air temperature has caused changes in the hydrologic cycle, which have been followed by several emergencies of natural extreme events around the world. Thailand is one of the countries that has incurred a huge loss in assets and lives from the extreme flood and drought events, especially in the northern part. Therefore, the purpose of this study was to assess the hydrological regime in the Yom and Nan River basins, affected by climate change as well as the possibility of extreme floods and droughts. The hydrological processes of the study areas were generated via the physically-based hydrological model, namely the Soil and Water Assessment Tool (SWAT) model. The projected climate conditions were dependent on the outputs of the Global Climate Models (GCMs) as the Representative Concentration Pathways (RCPs) 2.6 and 8.5 between 2021 and 2095. Results show that the average air temperature, annual rainfall, and annual runoff will be significantly increased in the intermediate future (2046–2070) onwards, especially under RCP 8.5. According to the Flow Duration Curve and return period of peak discharge, there are fluctuating trends in the occurrence of extreme floods and drought events under RCP 2.6 from the future (2021–2045) to the far future (2071–2095). However, under RCP 8.5, the extreme flood and drought events seem to be more severe. The probability of extreme flood remains constant from the reference period to the near future, then rises dramatically in the intermediate and the far future. The intensity of extreme droughts will be increased in the near future and decreased in the intermediate future due to high annual rainfall, then tending to have an upward trend in the far future.

scholarly journals Future Projection of Mean Temperature of Post-Monsoon Season Over Bangladesh Using Statistical Downscaling of Global Climate Models

2020 ◽  
Vol 11 (2) ◽  
pp. 27-35
Author(s):  
Md Bazlur Rashid ◽  
Syed Shahadat Hossain
Keyword(s):  
Statistical Downscaling ◽  
Climate Models ◽  
Monsoon Season ◽  
Future Climate ◽  
Climate Projections ◽  
Post Monsoon ◽  
Mean Temperature ◽  
Post Monsoon Season ◽  
Near Future ◽  
Far Future

In statistical downscaling technique, regional or local information are derived by determining a statistical model which relates large-scale climate variables or predictors generated by Global Climate Models (GCMs) to regional and local variables or predictands. In this paper, the results of GCMs were statistically downscaled to produce future climate projections of mean temperature in the post-monsoon season (October and November), for the time periods 2021-2050 and 2071-2100 for Bangladesh. The future climate projections are based on the three emission scenarios RCP2.6, RCP4.5 and RCP8.5 provided by the fifth Coupled Model Intercomparison Project (CMIP5). This paper established a method to analyze GCMs for use in statistical downscaling and utilized fifteen GCMs. The GCMs were assessed based upon their performance in simulated past climate in Bangladesh and adjoining areas. Downscaling was undertaken by linking large scale climate variables, taken from the ERA-Interim (resolution 79 km) reanalysis temperature, a gridded data set incorporating observations and climate models, to local scale observations. Overall, all fifteen GCMs, via statistical downscaling, show that mean temperature of the post-monsoon season in Bangladesh will increase under future climate scenarios. Comparing the ensemble of future projections with the reference period (1981- 2010), the mean post-monsoon temperature in Bangladesh is projected for RCP8.5 showing warming by 0.310C in near future and 1.790C in far future. On the other hand, estimated warming is 0.390C in near future and 1.140C is far future for RCP4.5. Low emission scenarios RCP2.6, near future temperature is nearly same the far future temperature. Journal of Engineering Science 11(2), 2020, 27-35

scholarly journals Trend analysis of annual and seasonal rainfall to climate variability in North-East region of India

2014 ◽  
Vol 6 (2) ◽  
pp. 480-483 ◽  
Author(s):  
G. T. Patle ◽  
A. Libang
Keyword(s):  
Climate Change ◽  
Trend Analysis ◽  
Monsoon Season ◽  
Kendall Test ◽  
Seasonal Rainfall ◽  
Arunachal Pradesh ◽  
Post Monsoon ◽  
North East ◽  
East Region ◽  
Post Monsoon Season

Global warming, climate change and its consequences are major threat for the global agriculture. The agriculture in the North-East region of India is supposed to more in danger due to its topographic features. Agriculture in the state of Arunachal Pradesh is dependent on rainfall and variability in rainfall due to climate change is expected to threaten the food production in future. This study examines the impact of climate change on rainfall using the trend analysis technique for the four districts of Arunachal Pradesh. For this purpose temporal trends in annual and seasonal rainfall were detected using nonparametric Mann-Kendall test at 5% significance level. The daily time series rainfall data for the period 1971-2007 were analyzed statistically for each district separately. The results of Mann Kendall test showed decreasing trend in annual mean rainfall in east Siang, upper Siang and lowers Dibang valley and no trend in the west Siang district over the period of 1971-2007. In case of east Siang, upper Siang and lower Dibang valley districts, decreasing trend of rainfall was observed in the post monsoon season with slope magnitude of 3.01 mm/yr, 3.32 mm/yr and 3.95 mm/yr respectively. Decreasing pattern of rainfall in post monsoon season may affect the vegetable and fruit production in the winter season.

scholarly journals Assessment of Trophic Responses of a Reservoir to Seasonal and Annual Variations in Monsoon

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2117
Author(s):  
Su-mi Kim ◽  
Hyun-su Kim
Keyword(s):  
Water Quality ◽  
Trophic State ◽  
Monsoon Season ◽  
Phytoplankton Growth ◽  
Phosphorus Loading ◽  
Nutrient Concentrations ◽  
Trophic State Index ◽  
Post Monsoon ◽  
Post Monsoon Season ◽  
State Index

The variations in water quality parameters and trophic status of a multipurpose reservoir in response to changing intensity of monsoon rain was investigated by applying a trophic state index deviation (TSID) analysis and an empirical regression model to the data collected in two periods from 2014 to 2017. The reservoir in general maintained mesotrophic conditions, and Carlson’s trophic state index (TSIc) was affected most by TSITP. Nutrient concentrations, particularly phosphorus, did not show strong correlations with precipitation, particularly in the period with weak monsoon, and a significant increase in total phosphorus (TP) was observed in Spring 2015, indicating the possibility of internal phosphorus loading under decreased depth and stability of water body due to a lack of precipitation. TSIChl was higher than TSISD in most data in period 1 when a negligible increase in precipitation was observed in the monsoon season while a significant fraction in period 2 showed the opposite trend. Phytoplankton growth was not limited by nutrient limitation although nutrient ratios (N/P) of most samples were significantly higher than 20, indicating phosphorus-limited condition. TSID and regression analysis indicated that phytoplankton growth was limited by zooplankton grazing in the Spring, and that cell concentrations and community structure in the monsoon and post-monsoon season were controlled by the changing intensity of the monsoon, as evidenced by the positive and negative relationships between community size and cyanobacterial population with the amount of precipitation in the Summer, respectively. The possibility of contribution from internal loading and an increase in cyanobacterial population associated with weak monsoon, in addition to potential for nutrient enrichment in the post-monsoon season, implies a need for the application of more stringent water quality management in the reservoir that can handle all potential scenarios of eutrophication.

A Study on Prevalence and Seasonal Distribution of Dengue at a Tertiary Care Centre of North India

Healthline ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 100-107
Author(s):  
Arti Agrawal ◽  
Vikas Kumar ◽  
Sanjeev Kumar ◽  
Neha K Mani
Keyword(s):  
Monsoon Season ◽  
Dengue Infection ◽  
Tertiary Care ◽  
Seasonal Distribution ◽  
North India ◽  
Care Centre ◽  
Tertiary Care Centre ◽  
Post Monsoon ◽  
Post Monsoon Season ◽  
Male Preponderance

Introduction: Dengue virus infection is a major public health issue prevalent in tropical and sub-tropical countries all over the world mostly in urban and semi-urban areas. WHO estimates about 50-100 million dengue infections worldwide every year. The present study is aimed to assess the prevalence and seasonal distribution of dengue disease during three consecutive years from 2016-2018 at a tertiary care centre of North India. Method: This is an observational retrospective study conducted on total 6,481 clinical suspected cases referred from indoor and outdoor departments of Medicine and Pediatrics of one of the medical colleges of Agra during the period from 1st January 2016 to 31st December 2018. Results: The maximum positivity was recorded in the year 2016 (16.66%), followed by 2017 (14.07%) and 2018(13.56%).Our study shows male preponderance with maximum cases in the year 2018 was recorded in the month of October (22.75%) whereas the lowest in the month of May (1.96%). Most of the cases were in the age group 0-30 years with a male preponderance. The outbreak occurred during the months of August to November indicating vector transmission in the monsoon and post-monsoon season. Conclusion: From the analysis, this study reflects that the numbers of dengue cases in 2016 were maximum and outnumbered the dengue cases among three consecutive years from 2016 to 2018. The peak in dengue positivity was observed during September to October. As this disease affects the population in the monsoon and post monsoon months therefore continuous monitoring of dengue infection is important during the post-monsoon season.

scholarly journals Seasonal Nature and Trends of Tropical Cyclone Frequency and Intensity over the North Indian Ocean

2020 ◽  
Vol 15 (3) ◽  
pp. 526-534
Author(s):  
Abhisek Pal ◽  
Soumendu Chatterjee
Keyword(s):  
Time Series ◽  
Tropical Cyclone ◽  
Indian Ocean ◽  
Monsoon Season ◽  
North Indian Ocean ◽  
Post Monsoon ◽  
The North ◽  
Increasing Trend ◽  
Post Monsoon Season ◽  
Cyclone Frequency

Tropical cyclone (TC) genesis over the North Indian Ocean (NIO) region showed significant amount of both spatial and temporal variability.It was observed that the TC genesis was significantly suppressed during the monsoon (June-September) compared to pre-monsoon (March-May) and post-monsoon (October-December) season specifically in terms of severe cyclonic storms (SCS) frequency. The Bay of Bengal (BoB) was characterized by higher TC frequency but lower intensity compared to the Arabian Sea (AS). It was also observed that the TC genesis locations were shifted significantly seasonally.The movement of the TCs also portrayed some significant seasonal differences. The pre-monsoon and post-monsoon season was responsible for generating TCs with higher values of accumulated cyclone energy (ACE) compared to the monsoon. The time series of TC frequency showed a statistically significant decreasing trend whereas the time series of ACE showed astatistically significant increasing trend over the NIO.

scholarly journals Dragonflies and damselflies (Insecta: Odonata) of the Kole Wetlands, central Kerala, India

2021 ◽  
Vol 13 (3) ◽  
pp. 17963-17971
Author(s):  
A. Vivek Chandran ◽  
Subin K. Jose ◽  
Sujith V. Gopalan
Keyword(s):  
Species Richness ◽  
Monsoon Season ◽  
Survey Method ◽  
Ramsar Site ◽  
Post Monsoon ◽  
Post Monsoon Season

A year-long study was conducted at the Kole Wetlands, a Ramsar site in central Kerala to document the diversity of dragonflies and damselflies and understand their seasonality.  Checklist survey method was used to sample adult odonates in 30 randomly chosen locations.  A total of 44 species (30 dragonflies and 14 damselflies) belonging to 33 genera and eight families were recorded in the study area.  Species richness showed a peak in the post-monsoon season and a dip in the summer.  The observations support the value of the Kole Wetlands in providing valuable resources for Odonata.

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