1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Impact of projected climate change on cropping pattern of different agro ecological units of southern Kerala(Academy of Climate Change Education and Research Vellanikkara, 2017) Sukanya, K S; Sunil, K MClimate change poses an emerging threat to sustainability of social and economic development, livelihoods, and environmental management across the globe. Characterization of the ecosystems using the AEZ concept is a good decision making approach for variety of farming activities performed by the farmers and is a useful tool for the studying the impact of climate change. The objectives of this study are (1) to study rainfall variability and to determine water availability periods of Agro ecological units of southern Kerala under different climate change scenarios. (2) To study the impact of projected climate change on cropping pattern, crop calendar and the possible changes in the water requirements of major cropping systems prevailed in the various Agro ecological Units of southern Kerala. Daily rainfall data for the period 1991-2014 were collected from the India Meteorological Department, Thiruvananthapurm. Weather cock v.1.5 was used for converting the daily weather data into standard week, month and seasonal formats. It is also used to compute PET and Thornthwaite water balances. CROPWAT model was used for the calculations of crop evapotranspiration, crop water requirements and irrigation requirements for the development of irrigation schedules under various management conditions and scheme water supply. The annual rainfall availability in most of the AEUs of Thiruvananthapuram, Kollam and Pathanamthitta districts show a decreasing trend in the projected climate and an increasing trend in Idukki, Kottayam and Alappuzha. The number of annual rainy days generally shows a decreasing trend. The seasonal rainfall of southwest and summer monsoon will show an increase from the current situation where as northeast monsoon and winter will have a decreasing trend. In projected climate of both RCP 4.5 and 8.5 there will be high probability of having reduction in the number of months having the surplus and an increase in the number of deficit. The crop evapotranspiration values of rice based cropping system will show a tendency to increase. In perennial cropping systems of coconut based and rubber the projected crop evapotranspiration will have a reduction from the present situation whereas in coffee based cropping system the ETc will have an increasing trend. The irrigation requirement of all the major cropping systems will increase from the present situation except in the case of rice-fallow-fallow. The length of growing period of the cropping season in the major rice growing areas of different AEUs are getting shorter with slight differences among various agro-ecological units, implying a higher risk of operating under projected climate as per RCP 4.5. The sowing date will be delayed up to three to five weeks. It can be also observed that the crops will have to suffer water stress during the grain filling stage and will be under heavy rains at time of harvest in almost all the considered cases.Item Land use pattern and regional water balance in relation to climate change - a case study of Kanthallor panchayath, Idukki, Kerala(Academy of Climate Change Education and Research Vellanikkara, 2018) Vishnumaya, A P; Jalaja S MenonItem Impact of climate change on water balance of agro ecological units of Kerala(Academy of Climate Change Education and Research Vellanikkara, 2016) Athul Krishna, K S; Sunil, K MThe research project entitled “Impact of climate change on water balance of agro ecological units (AEUs) of Kerala” was carried out in RARS Pattambi and the daily rainfall data for the period 1991-2014 were collected from 60 stations of Kerala state from the India Meteorological Department, Thiruvananthapurm. Agro Ecological Unit wise information on area and production of various crops were collected fiom Agro Ecology of Kerala, Published by NBSS & LUP and Kerala State Planning Board, 2012. Kerala state, which depends to a great extent on its agriculture for its welfare a detailed knowledge of the Agricultural potential of the region in relation to the climatology of the area is an essential requirement in agricultural planning. In recent decades the increasing population and the resultant higher demands for food have necessitated for optimal exploitation of the available natural resources, in particular, land and water. As the eastern boundary of Kerala is fully bordered by the Western Ghats, the entire state is under the dominant influence of its orography. This results in heavy monsoon rains and large water surplus during a part of the year. This feature combined with the variety of soil types, vegetation classes and geomorphological features result in a diversity of land use patterns. This study assessed the potential impacts of climate change on rainfall and its variations across different agro ecological units as per the projected climate change. To project future climate conditions, the simulation outputs for 2030s, 2050s, and 2080s from seventeen general circulation models (GCMs) were extracted under Intergovernmental Panel on Climate Change (IPCC) greenhouse gases emissions scenario RCP 4.5 to consider the range of uncertainty. Thornthwaite water balance model was estimated to the observed and predicted climate data and this was used to estimate different components of water balance for different agro ecological conditions. This project also studied the impact of climate change on drought, length of growing period and intensity of high rainfall events in the future. The results suggest that future precipitation for the 2030s, 2050s and 2080s are expected to increase based on the multi ensemble GCM outputs. The temporarily and spatial distribution of rainfall like to change significantly throughout Kerala. In nutshell the amount of precipitation during summer and SW monsoon season will expect an increase whereas NE monsoon season and winter season anticipated a decrease in rainfall activity. But the trend is reverse in most of the coastal and high ranges. The total length of growing period is likely to increase in the future due to increased precipitation during summer months. But it can be also noticed that the length of continuous growing period which is a necessity for successful crop production anticipated a decrease. The most interesting observations are the present rain shadow regions of Kerala will going to have a favourable agricultural environment in the future. Studies on impact of climatic change on water balance over the state show that the moisture regime of different AEUs of the state undergo wild fluctuations both in the drier and wetter directions. In general the state is going to witness a hike in evapotranspiration due to increase in temperature as a part of global warming. There is high possibility of flood and drought occurrence in the same calendar year. It can also be inferred that the continuous water surplus period over the state is in a declining trend. It is expected that the results of the present investigation would help in the formulation of climate change adaptive strategies at agro ecological unit level by the judicious management of the available natural resources of land, water and atmosphere. Pointless to say this would enable effective planning for sustainable development of Kerala state.