PG Thesis

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Subject: search.filters.subject.Climate Change

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    Climate change impact on irrigation water requirement and crop water productivity of rice
    (Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Food Technology, Tavanur, 2025-02-19) Midhula, B N.; Asha Joseph
    The study evaluated the impact of climate change on the irrigation water requirement (IWR) and crop water productivity (CWP) of rice in Pattambi, Kerala, using observed climate data from 1991-2022 and projected data for 2025-2095. Climate projections were based on four Global Climate Models (GCMs), MPI-ESM 1-2-HR, ACCESS-ESM 1-5, MPI-ESM 1-2-LR, and INM-CM-5-0 under SSP2 4.5 and SSP5 8.5 scenarios. GCM data was bias-corrected using linear scaling for temperature and power transformation for precipitation. The AquaCrop model, calibrated and validated with RMSE (0.3527-0.3728) and NSE (0.97-0.99), simulated rice yields and CWP, while CROPWAT 8.0 estimated ETo, ETc, and IWR for the baseline and future periods (2025-2049 (2035s), 2050- 2074 (2055s) and 2075- 2095 (2085s)). The climate model INM-CM 5-0 exhibited strong agreement between observed and model-derived data with RMSE (1.5-4.80) and R² (0.5-0.85) in acceptable range. Future projections for the period 2025-2095 indicated that maximum temperatures could rise by +0.6, +0.84, and +0.89°C, minimum temperatures by +0.57, +0.85, and +1.2°C, and precipitation by +96.19, +122, and +214.23 cm during 2035s, 2055s and 2085s respectively under the SSP2 4.5. Under SSP5 8.5, the maximum temperature could rise by +0.66, +1.33, and +1.97°C, minimum temperatures by +0.67, +1.48, and +2.46°C, and precipitation by +159.3, +699.9, and +415.57 cm for the same time horizons. The AquaCrop model was calibrated and validated with RMSE (0.3527-0.3728) and NSE (0.99- 0.97) in the acceptable range for simulating rice yield. Future projections of IWR indicated a remarkable rise in water demand both in Virippu (1st crop) and Mundakan (2nd crop) seasons. During Virippu, IWR is expected to increase by up to +42.63% and +37.97% under SSP2 4.5 and SSP5 8.5, respectively, while the same for Mundakan was found to be +4.20% and +11.65% respectively. This reflected higher water requirements for rice production under future climate change scenarios. Future yield projections showed a reduction in yield both in Mundakan (-51.72% and -42.12%) and Virippu season (-77.38% and -81.97%) under SSP2 4.5 and SSP5 8.5, respectively. However, the Virippu season showed a more prominent reduction in yield than Mundakan. This significantly impacted CWP during Virippu, which showed a sharp reduction of -87.92% and - 90.82%, and Mundakan showed a reduction of -66.36% and -46.36% under SSP2 4.5 and SSP5 8.5, respectively. Adopting early transplanting dates, particularly on April 21st, will help to increase yields (+26.2%) and reduce irrigation water requirements (-1.97%), while late transplanting should be avoided due to significant yield reduction in Virippu. But during the Mundakan season, transplanting dates on Oct 12th (in 2035s), Nov 11th (in 2055s), and Nov 21st (in 2085s) were found optimal due to increased yield (+2 - 9.8%). Adopting drip irrigation reduced water use by 20% and improved rice yields by +2.5%. Hence, it is concluded that, rising temperatures and rainfall under future climate scenarios are projected to increase IWR, reduce rice yields, and significantly lower CWP. Hence, adaptation measures are recommended to combat the effect of climate change and enhances CWP.
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    Analysis of gender dimensions of climate variability and adaptation process in the fishermen households of Thrissur district
    (Academy of Climate Change Education and Research, Vellanikkara, 2021-01-07) Sreya, P S; Chitra Parayil
    The nature of work and the geographical location cause the fisher community to be economically marginalized and highly vulnerable to climate variability and extreme weather events with women enduring most of this wrath. Though research on the linkages between a changing climate and vulnerability has been increasing, only few studies inspect the gender dimensions of vulnerability. In this regard the present study attempts to evaluate the factors contributing to the economic vulnerability of the fisher households due to the extreme weather events with respect to the gender of the household head and the adaptation strategies preferred by the households. The study assessed the livelihood vulnerability of 120 male headed and 30 female headed fisher households of two coastal taluks of Thrissur, Kerala using the LVI (Livelihood Vulnerability Index) methodology. The LVI estimates the overall vulnerability score of both categories of households based on 7 major components and their subcomponents. The economic vulnerability is quantified based on the major component -economic status. The factors affecting the economic vulnerability of the households are selected based on LVI subcomponents. The statistical significance of the selected factors are estimated based on the logistic regression. The lone income from fisheries was revealed to be the factor affecting the economic vulnerability of both the households. Kendall’s concordance test is performed to determine the extent of agreement for the adaptation options among the households. The test was found to have a concordance value of 0.836 with the disaster preparedness measures to be the most preferred option among the households.
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    Impact of climate change on the distribution of montane shola species (Ficus drupacea) in the southern ghats
    (College of Climate Change and Environmental Science ,Vellanikkara, 2021) Swathy Krishna, G; Nameer, P O
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    Larval connectivity among the coral reefs of the Andaman sea
    (College of Climate Change and Environmental Science ,Vellanikkara, 2021) Vimuktha Viswanath; Sreenath, K R
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    Spatio-temporal variation of tropical cyclones in northern Indiam ocean and its impact on marine fisheries
    (College of Climate Change and Environmental Science,Vellanikkara, 2021) Gopika Gopi; Shelton Padua
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    Seasonal and monthly rainfall variability over Kerala in a warming climate
    (Academy of Climate Change Education and Research , Vellanikkara, 2021) Suja Mary; Sam; Abhilash, S
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    Species richness and carbon stock of Sharngakavu sacred grove, Chengannur Kerala
    (Academy of Climate Change Education and Research,Vellanikkara, 2019) Kavya Jeevan; Gopakumar, S
    Global warming and biodiversity loss are the major environmental issues faced by the planet today. The “sacred groves” are repositories of woody vegetation that successfully and efficiently conserve these “trees outside the forests”. Documentation of the species present in such C sinks will help to document the native species that are conserved here. Estimation of carbon locked up in these vegetated areas will help to further understand the potential of these sacred natural sites in mitigating climate change. With this background, a study titled “Species richness and carbon stock of Sharngakavu sacred grove, Chengannur, Kerala” was attempted on Sharngakavu sacred grove, Aalapuzha during 2018- 2019. The objectives of the study were to document the floristic wealth of the grove, enumerate the carbon stock of the grove and to understand the people’s perception on the role of conservation of this sacred grove in combating climate change. The grove was delineated into core zone and buffer zone for detailed vegetation analysis and estimation of carbon stock. Fifty three plant species were recorded from the core zone of the grove, while from the buffer zone, 37 species could be identified. Actinodaphne malabarica and Xanthophyllum arnottianum which is endemic to Western Ghats were observed in the core region. Other species identified, included some major evergreen and semi- evergreen species such as, Aphanamixis polystachya, Ardisia pauciflora, Carallia brachiata, Cinnamomum malabatrum, Cinnamomum verum, Lagerstroemia microcarpa, Morinda citrifolia, Pongamia pinnata and Strebles asper. Some deciduous tree species such as Alangium salvifolium, Grewia tillifolia and Boswellia serrata were also found. The Shannon Weiner index value of the core was about 1.9, which suggests the grove inhabits a fairly good number of species. The core zone was dominated by Xanthophyllum arnottianum while the buffer was dominated by Caryota urens. The carbon stock of the soil was found to be decreasing with depth. The carbon stock of the standing vegetation was found to be the highest in the core which could be attributed to the species richness. The total carbon stock was also found to be the highest in the core zone (456.71 Mg ha-1), while 344.36 Mg ha-1was recorded total C of the buffer zone, even though in terms of area, this constituted the major portion of the grove. Perception studies revealed that majority of the respondents are strongly interested in the conservation of the grove. They also considered deforestation and exploitation of nature as the major causes of climate change. It was also clear that the people’s perception on the causes and impacts of climate change was highly influenced by their age, gender, education and occupation. Among the local residents, people’s interest to conserve the grove was influenced by their age, while among non-resident devotees, education levels was observed to influence their attitude. Traditional beliefs certainly had an influence on the existence of the grove. Even though the grove has been conserved as a part of cultural belief, its role in biodiversity conservation was well understood by the people. Strengthening the people’s knowledge on the importance of value of the grove in both biodiversity conservation and climate change mitigation will help to conserve this Important Plant Area (IPA).
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    Impact of heat stress on different toll like receptors gene expression in Malabari goats
    (Academy of Climate Change Education and Research, Vellanikkara, 2018) Vandana Gokul Das; Sejian, V
    Research efforts are needed to quantify immune responses to environmental stresses in different indigenous goats and these efforts will be of practical relevance to identify an animal with better immune potential in the changing climate scenario. Hence, a study was conducted to establish the impact of heat stress on different toll-like-receptors (TLR) genes expression in lymph node of Malabari goats. The study was conducted with the primary objective of establishing the impact of heat stress on the expression pattern of different toll like-receptors (TLRs) in Malabari goats. The study was conducted for a period of 45 days using twelve Malabari goats. The goats were randomly allocated into two groups: MC (n=6; Malabari control) and MHS (n=6; Malabari heat stress). At the end of study, all 12 animals were slaughtered and their mesenteric lymph node (MLN) tissues were collected for gene expression. Heat stress significantly (P<0.05) down regulated TLR1, TLR4, and TLR6 and significantly increased (P<0.05) TLR2 expression pattern. A negative correlation (P<0.01) was also established between THI and different TLRs except TLR3, TLR7 and TLRIO. Further a strong positive correlation was obtained between THI and TLR2. The results from the study established that Malabari goat breed showed extreme resilience to cope with heat stress in terms of maintaining the innate immune response and this was evident from the non-significant influence of heat stress on the expression patterns of TLR3, TLR5, TLR7, TLR8, TLR9 and TLR10 genes. Further, the study also indicated that TLR1, TLR4 and TLR6 genes were sensitive to the heat stress effects and the significantly lower expression of these genes in MHS group as compared to MC group indicates the partly compromised immune status in this breed. In addition, the significantly higher expression of TLR2 in the beat stress group indicates the reliability of this gene in assessing the immune status of this breed during heat stress exposure.
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    Effect of heat stress on the expression patterns of different reproduction related genes in Malabari goats
    (Academy of Climate Change Education and Research, Vellanikkara, 2018) Amitha J Pai; Krishnan, G
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    Heat shock protein 70 expression in different vital organs of heat stressed Malabari goats
    (Academy of Climate Change Education and Research, Vellanikkara, 2018) Afsal, A; Sejian, V