http://localhost:8080/xmlui/handle/123456789/30 2026-07-14T00:18:36Z 2026-07-14T00:18:36Z Midhula B N Asha Joseph, (Guide) http://localhost:8080/xmlui/handle/123456789/2036 2025-11-27T08:29:17Z 2025-01-01T00:00:00Z

Climate change impact on irrigation water requirement and crop water productivity of rice Midhula B N; Asha Joseph, (Guide) 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.

2025-01-01T00:00:00Z Revathi, N Sajeena, S (Guide) http://localhost:8080/xmlui/handle/123456789/2034 2025-11-27T08:30:14Z 2025-01-01T00:00:00Z

Impact of soil and water conservation measures on LULC and groundwater in Olanthichira watershed, Malappuram Revathi, N; Sajeena, S (Guide)

2025-01-01T00:00:00Z Arjun Prakash, K V Suseela, P (Giude) http://localhost:8080/xmlui/handle/123456789/1985 2025-11-27T08:34:18Z 2024-01-01T00:00:00Z

Refinement and performace evaluation of media bed aquaponic system Arjun Prakash, K V; Suseela, P (Giude) In Kerala, the production of fish and vegetables is much less than that of the daily requirement. In this study, an attempt was made to design and develop an aquaponics system to achieve an efficient, less energy-consuming, problem-free operational system working in a sustainable manner at the Hi-tech Research and Training Unit (HTR&TU), Instructional Farm (IF), KAU, Vellanikkara. The study was also made for selection of suitable media (20 mm gravel/ 8-20 mm broken tiles/ 8-15 mm hydroton/ 8-10 mm gravel), performance evaluation of the two aquaponics systems (S1- Aquaponic system fitted with a conventional siphon system and S2- Aquaponic system fitted with feeder cum operation regulation system) with fruiting plant (Tomato) and leafy vegetable (Lettuce) and developing and evaluating a system for automatic recording of temperature and dissolved oxygen level of water in the fish pond. At all stages, the growth and yield of tomato, lettuce and fish in the S2 system were comparatively higher than that of S1 system. Lettuce crop (Cherokee RZ and Starfighter RZ) have given maximum yield in broken tile and minimum yield in hydroton in both S1 and S2 systems during the first and second seasons. 8-10mm gravel was found to be more favorable for the growth and yield of tomato (Yakamoz RZ and Manulakshmi) than all other media selected for the study. In all the cases, the plants grown in the dutch buckets filled with 75 % portion of gravel and wick inserted buckets filled with 75 % portion of gravel showed better performance than the buckets filled with 50 % portion of gravel. The performance of the plants grown in dutch buckets and wick-inserted buckets of S2 system was superior to S1 system. The overall result showed that tomato grown in 8- 10mm gravel and lettuce grown in broken tiles of S2 system showed better performance than all other media of S1 and S2 systems. The macro and micro nutrient level in the water of S2 system was found to be higher than that of S1 system during the study period. The benefit cost ratio obtained while cultivating tomato and lettuce in S2 system was more than that of S1 system. Considering the economic benefits, trouble free and easy operation, S2 system can be recommended for the aquaponics farmers of Kerala.

2024-01-01T00:00:00Z L, AISWARYA K.P, Rema (Guide) http://localhost:8080/xmlui/handle/123456789/1902 2026-07-07T09:41:13Z 2024-01-01T00:00:00Z

LANDSLIDE HAZARD VULNERABILITY AND RISK ASSESSMENT FOR CHALIYAR RIVER BASIN L, AISWARYA; K.P, Rema (Guide)

2024-01-01T00:00:00Z