13 resultados para Irrigation.

em Cochin University of Science


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The present investigation on the Muvattupuzha river basin is an integrated approach based on hydrogeological, geophysical, hydrogeochemical parameters and the results are interpreted using satellite data. GIS also been used to combine the various spatial and non-spatial data. The salient finding of the present study are accounted below to provide a holistic picture on the groundwaters of the Muvattupuzha river basin. In the Muvattupuzha river basin the groundwaters are drawn from the weathered and fractured zones. The groundwater level fluctuations of the basin from 1992 to 2001 reveal that the water level varies between a minimum of 0.003 m and a maximum of 3.45 m. The groundwater fluctuation is affected by rainfall. Various aquifer parameters like transmissivity, storage coefficient, optimum yield, time for full recovery and specific capacity indices are analyzed. The depth to the bedrock of the basin varies widely from 1.5 to 17 mbgl. A ground water prospective map of phreatic aquifer has been prepared based on thickness of the weathered zone and low resistivity values (<500 ohm-m) and accordingly the basin is classified in three phreatic potential zones as good, moderate and poor. The groundwater of the Muvattupuzha river basin, the pH value ranges from 5.5 to 8.1, in acidic nature. Hydrochemical facies diagram reveals that most of the samples in both the seasons fall in mixing and dissolution facies and a few in static and dynamic natures. Further study is needed on impact of dykes on the occurrence and movement of groundwater, impact of seapages from irrigation canals on the groundwater quality and resources of this basin, and influence of inter-basin transfer of surface water on groundwater.

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Mann–Kendall non-parametric test was employed for observational trend detection of monthly, seasonal and annual precipitation of five meteorological subdivisions of Central Northeast India (CNE India) for different 30-year normal periods (NP) viz. 1889–1918 (NP1), 1919–1948 (NP2), 1949–1978 (NP3) and 1979–2008 (NP4). The trends of maximum and minimum temperatures were also investigated. The slopes of the trend lines were determined using the method of least square linear fitting. An application of Morelet wavelet analysis was done with monthly rainfall during June– September, total rainfall during monsoon season and annual rainfall to know the periodicity and to test the significance of periodicity using the power spectrum method. The inferences figure out from the analyses will be helpful to the policy managers, planners and agricultural scientists to work out irrigation and water management options under various possible climatic eventualities for the region. The long-term (1889–2008) mean annual rainfall of CNE India is 1,195.1 mm with a standard deviation of 134.1 mm and coefficient of variation of 11%. There is a significant decreasing trend of 4.6 mm/year for Jharkhand and 3.2 mm/day for CNE India. Since rice crop is the important kharif crop (May– October) in this region, the decreasing trend of rainfall during themonth of July may delay/affect the transplanting/vegetative phase of the crop, and assured irrigation is very much needed to tackle the drought situation. During themonth of December, all the meteorological subdivisions except Jharkhand show a significant decreasing trend of rainfall during recent normal period NP4. The decrease of rainfall during December may hamper sowing of wheat, which is the important rabi crop (November–March) in most parts of this region. Maximum temperature shows significant rising trend of 0.008°C/year (at 0.01 level) during monsoon season and 0.014°C/year (at 0.01 level) during post-monsoon season during the period 1914– 2003. The annual maximum temperature also shows significant increasing trend of 0.008°C/year (at 0.01 level) during the same period. Minimum temperature shows significant rising trend of 0.012°C/year (at 0.01 level) during postmonsoon season and significant falling trend of 0.002°C/year (at 0.05 level) during monsoon season. A significant 4– 8 years peak periodicity band has been noticed during September over Western UP, and 30–34 years periodicity has been observed during July over Bihar subdivision. However, as far as CNE India is concerned, no significant periodicity has been noticed in any of the time series.

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Soil moisture plays a cardinal role in sustaining eclological balance and agricultural development – virtually the very existence of life on earth. Because of the growing shortage of water resources, we have to use the available water most efficiently by proper management. Better utilization of rainfall or irrigation management depends largely on the water retention characteristics of the soil.Soil water retention is essential to life and it provides an ongoing supply of water to plants between periods of irrigation so as to allow their continued growth and survival.It is essential to maintain readily available water in the soil if crops are to sustain satisfactory growth. The plant growth may be retarded if the soil moisture is either deficient or excessive. The optimum moisture content is that moisture which leads to optimum growth of plant. When watering is done, the amount of water supplied should be such that the water content is equal to the field capacity that is the water remained in the saturated soil after gravitational drainage. Water will gradually be utilized consumptively by plants after the water application, and the soil moisture will start falling. When the water content in the soil reaches the value known as permanent wilting point (when the plant starts wilting) fresh dose of irrigation may be done so that water content is again raised to the field capacity of soil.Soil differ themselves in some or all the properties depending on the difference in the geotechnical and environmental factors. Soils serve as a reservoir of the nutrients and water required for crops.Study of soil and its water holding capacity is essential for the efficient utilization of irrigation water. Hence the identification of the geotechnical parameters which influence the water retention capacity, chemical properties which influence the nutrients and the method to improve these properties have vital importance in irrigation / agricultural engineering. An attempt in this direction has been made in this study by conducting the required tests on different types of soil samples collected from various locations in Trivandrum district Kerala, with and without admixtures like coir pith, coir pith compost and vermi compost. Evaluation of the results are presented and a design procedure has been proposed for a better irrigation scheduling and management.

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The present investigation on “Coconut Phenology and Yield Response to Climate Variability and Change” was undertaken at the experimental site, at the Regional Station, Coconut Development Board, KAU Campus, Vellanikkara. Ten palms each of eight-year-old coconut cultivars viz., Tiptur Tall, Kuttiadi (WCT), Kasaragod (WCT) and Komadan (WCT) were randomly selected.The study therefore, reinforces our traditional knowledge that the coconut palm is sensitive to changing weather conditions during the period from primordium initiation to harvest of nuts (about 44 months). Absence of rainfall from December to May due to early withdrawal of northeast monsoon, lack of pre monsoon showers and late onset of southwest monsoon adversely affect the coconut productivity to a considerable extent in the following year under rainfed conditions. The productivity can be increased by irrigating the coconut palm during the dry periods.Increase in temperature, aridity index, number of severe summer droughts and decline in rainfall and moisture index were the major factors for a marginal decline or stagnation in coconut productivity over a period of time, though various developmental schemes were in operation for sustenance of coconut production in the State of Kerala. It can be attributed to global warming and climate change. Therefore, there is a threat to coconut productivity in the ensuing decades due to climate variability and change. In view of the above, there is an urgent need for proactive measures as a part of climate change adaptation to sustain coconut productivity in the State of Kerala.The coconut productivity is more vulnerable to climate variability such as summer droughts rather than climate change in terms of increase in temperature and decline in rainfall, though there was a marginal decrease (1.6%) in the decade of 1981-2009 when compared to that of 1951-80. This aspect needs to be examined in detail by coconut development agencies such as Coconut Development Board and State Agriculture Department for remedial measures. Otherwise, the premier position of Kerala in terms of coconut production is likely to be lost in the ensuing years under the projected climate change scenario. Among the four cultivars studied, Tiptur Tall appears to be superior in terms of reproduction phase and nut yield. This needs to be examined by the coconut breeders in their crop improvement programme as a part of stress tolerant under rainfed conditions. Crop mix and integrated farming are supposed to be the best combination to sustain development in the long run under the projected climate change scenarios. Increase in coconut area under irrigation during summer with better crop management and protection measures also are necessary measures to increase coconut productivity since the frequency of intensity of summer droughts is likely to increase under projected global warming scenario.

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This thesis Entitled Post-Environmental Evaluation of The Rajjaprabha Dam In Thailand. This post evaluation of environmental consequences of Rajjaprabha dam IS conducted ten years after its commencement. The Rajjaprabha dam project was planned and implemented as a multipurpose project, mainly for hydropower production, flood protection, fisheries, recreation and irrigation. The project includes the dam and reservoir with a 240 MW hydropower plant located about 90 km upstream from Surat Thani province, and irrigation systems covering the coastal plain in Surat Thani. The upstream storage reservoir (with about 5,639 mcm storage) and the hydropower plant had already been implemented. The first phase of irrigation system covers an area of 23,100 hectares. The second phase is envisaged to cover about 50,000 hectares. This study was conducted with the following objectives: (I) to assess all existing environmental resources and their values with the help of input-output analysis (2) to findout the beneficial impacts of the project (3) to evaluate the actual positive effects vis-a-vis the estimated effects before the project was implemented and (4) to identify all significant changes in relatives to the impacts previously assessed. The study area includes the Phum Duang river basin of about 4,668 km2 (placed on the areas that are upstream and downstream to the damsite), The duration of study is limited to 10 years after the dam has become operational i.e. from 1987-1997. The results of the study reveal that there is no significant changes in climatic and ground water resources, with respect to the study area inspte of the fact that the physical and chemical properties of the soil have slightly changed. Sedimentation in the reservoir does not have much effect on the function of the dam.

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There is no baseline data available at present on the nature of various diseases that occur in a orchid population, under cultivation, in any commercial orchid farm maintained by small scale entrepreneurs who invest considerable amount of money, effort and time. The available data on type of disease symptoms, causative agent, , nature of pathogens, as to bacteria or ftmgi or any other biological agents, and their source, appropriate and effective control measures could not be devised, for large scale implementation and effective management, although arbitrary methods are being practiced by very few farms. Further influence of seasonal variations and environmental factors on disease outbreak is also not scientifically documented and statistically verified as to their authenticity. In this context, the primary objective of the present study was to create a data bank on the following aspects 1. Occurrence of different disease symptoms in Dendrobium hybrid over a period of one year covering all seasons 2. Variations in the environmental parameters at the orchid farms 3. Variations in the characteristics of water used for irrigation in the selected orchid farm 4. Microbial population associated with the various disease symptoms 5. Isolation and identification of bacteria isolated from diseased plants 6. Statistical treatment of the quantitative data and evolving statistical model

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Nitrification is the biological oxidation of ammonium, first to nitrite and then to nitrate by two groups of aerobic, chemolithotrophic bacteria belonging to the family Nitrobacteriaceae. The biological nitrification in municipal wastewater treatment is important in those cases were ammonia removal requirement specially exist. In a trickling filter or in an activated sludge system nitrification is rate limiting and thus necessitates longer detention time. The combined carbon oxidation-nitrification processes generally have low population of nitrifiers due to a high ratio of BOD to total nitrogen in the effluent. This necessitates, separate carbon and nitrogen oxidation processes, which thus minimizes wash out ofthe nitrifiers. Therefore, a separate stage nitrification has become essential to achieve faster and efficient removal of ammonia from the wastewater. The present work deals with the development of bio reactor for nitrifying of sewage as the tertiary process so that the treated wastewater can be used for irrigation, algal culture or fish culture

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NABARD has completed 14 years of operation.ln the light of its experiences and achievements, the performance ev.ilu.ilion of the National Bank need to be looked into.This could provide certain criteria for its strength and weakness which may help in consolidating the institution for better utilisation of its potentialities. It is also noteworthy that no evaluative study on the National Bank has been conducted in Kerala. The Major objective of this study is to evaluate the role of NABARD in catering to the long-term agricultural requirements of Kerala for 1982 to 1992.This is done by analysing the quantum and quality of NABARD's schematic refinance. The qualitative indices like (1) the efficiency of loan recovery, (2) the impact or financial viability of NABARD refinanced schemes, (3) the credit gap, (4) the commitment-disbursement gap, and (5) the imbalances in the NABARD refinance form the core of the study.Hypotheses were formulated inorder to study and analyse these qualitative indices. The study is presented in eight chapters

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The present study deals with the different hydrogeological characteristics of the coastal region of central Kerala and a comparative analysis with corresponding hard rock terrain. The coastal regions lie in areas where the aquifer systems discharge groundwater ultimately into the sea. Groundwater development in such regions will require a precise understanding of the complex mechanism of the saline and fresh water relationship, so that the withdrawals are so regulated as to avoid situations leading to upcoming of the saline groundwater bodies as also to prevent migration of sea water ingress further inland. Coastal tracts of Kerala are formed by several drainage systems. Thick pile of semi-consolidated and consolidated sediments from Tertiary to Recent age underlies it. These sediments comprise phreatic and confined aquifer systems. The corresponding hard rock terrain is encountered with laterites and underlined by the Precambrian metamorphic rocks. Supply of water from hard rock terrain is rather limited. This may be due to the small pore size, low degree of interconnectivity and low extent of weathering of the country rocks. The groundwater storage is mostly controlled by the thickness and hydrological properties of the weathered zone and the aquifer geometry. The over exploitation of groundwater, beyond the ‘safe yield’ limit, cause undesirable effects like continuous reduction in groundwater levels, reduction in river flows, reduction in wetland surface, degradation of groundwater quality and many other environmental problems like drought, famine etc.

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The evolution of wireless sensor network technology has enabled us to develop advanced systems for real time monitoring. In the present scenario wireless sensor networks are increasingly being used for precision agriculture. The advantages of using wireless sensor networks in agriculture are distributed data collection and monitoring, monitor and control of climate, irrigation and nutrient supply. Hence decreasing the cost of production and increasing the efficiency of production.This paper describes the application of wireless sensor network for crop monitoring in the paddy fields of kuttand, a region of Kerala, the southern state of India.

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The evolution of wireless sensor network technology has enabled us to develop advanced systems for real time monitoring. In the present scenario wireless sensor networks are increasingly being used for precision agriculture. The advantages of using wireless sensor networks in agriculture are distributed data collection and monitoring, monitor and control of climate, irrigation and nutrient supply. Hence decreasing the cost of production and increasing the efficiency of production. This paper describes the development and deployment of wireless sensor network for crop monitoring in the paddy fields of Kuttanad, a region of Kerala, the southern state of India.

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The evolution of wireless sensor network technology has enabled us to develop advanced systems for real time monitoring. In the present scenario wireless sensor networks are increasingly being used for precision agriculture. The advantages of using wireless sensor networks in agriculture are distributed data collection and monitoring, monitor and control of climate, irrigation and nutrient supply. Hence decreasing the cost of production and increasing the efficiency of production. This paper describes the security issues related to wireless sensor networks and suggests some techniques for achieving system security. This paper also discusses a protocol that can be adopted for increasing the security of the transmitted data