DSpace Community:http://localhost:8081/xmlui/handle/123456789/182023-12-27T21:28:09Z2023-12-27T21:28:09ZHYDROLOGICAL MODELLING OF A TROPICAL WATERSHED UNDER LAND USE AND CLIMATE CHANGE SCENARIOSChandrakar, Ayushhttp://localhost:8081/xmlui/handle/123456789/154912023-06-16T12:45:10Z2019-12-01T00:00:00ZTitle: HYDROLOGICAL MODELLING OF A TROPICAL WATERSHED UNDER LAND USE AND CLIMATE CHANGE SCENARIOS
Authors: Chandrakar, Ayush
Abstract: Water is one of the essential components of our environment. Therefore, proper planning and
management are essential to achieve sustainable utilization. Changes in climate and land use have
significantly altered the hydrological cycle which in turn has affected the water resources. Due to
increased uncertainty in both climate and land-use change projections, improved knowledge of
watershed hydrology and resource availability are indispensable for current and future policy
formulation and sustainable development of the water sector.
The present study has been carried out to ascertain the availability of water and its distribution under
the impact of climate change projection and anthropogenic intervention in the Kharun watershed,
India. This study investigated the changes in water balance components under varied land use and
climate change projections over the Kharun watershed. Kharun watershed lies in the tropical region
of central India. Trend changes in meteorological parameters of the past and the future constituted
the climate change aspect of the study. The land use land cover (LULC) change dynamics constituted
the anthropogenic intervention aspect of the study. Keeping into account the changes in climatic
conditions and land change patterns, a hydrological impact assessment was carried out over the study
area.
Trend analysis is one of the most significant tools to analyze the global warming problem as it
quantifies the past and future changes in meteorological and hydro-climatological parameters. In the
present study, trend detection was carried out for two metrological parameters namely, long term
temperature (maximum, minimum and mean) and precipitation using regression analysis and
Modified Mann-Kendall (MMK) test. The magnitude of change was estimated using the Sen’s slope
estimator over 22 grids in and around the study area. Cumulative sum (Cusum) and sequential
Mann-Kendall (SQMK) test was used to identify the climatic shift (change per year) over the
meteorological time series. Significant findings of the study stated an increase in average maximum
temperature during summer (0.19⁰C), post-monsoon (0.21⁰C), and winter (0.61⁰C) seasons. A
significant reduction in average yearly minimum temperature (-0.68⁰C) was also observed. The
annual precipitation decreased by almost 210 mm over 115 years.
Similar statistics were computed over 23 indices of meteorological extremes derived from long term
precipitation and temperature time series. Out of these 23 indices, five were proposed in the study
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based on the precipitation intensity indices suggested by India Meteorological Department (IMD).
Long term trend changes in these indices were computed for both historical as well as future periods.
For reproduction of meteorological parameters in order to study changes in extreme value indices in
the future, regional climate model (RCMs) were evaluated. Four RCMs were identified as the most
suitable models to determine future times series data of precipitation and temperature (maximum
and minimum) for the study viz. CCCma, CSIRO, MIROC5 and NorESM. The distribution mapping
technique was used to remove systematic biases present in the data. MMK test statistic was used to
evaluate the presence of any trend while the magnitude of the trend was quantified using Sen’s slope
estimator over the entire period (2011-2100) and for three climate periods, namely CC1 (2011-2041),
CC2 (2041-2070) and CC3 (2071-2100). These tests were applied over two scenarios viz. RCP 4.5
and RCP 8.5.
After the computation of long term variation in meteorological extremes, it can be inferred that the
gap between the minimum and maximum temperature is increasing over the study period at an
average rate of 0.09⁰C/decade (4.6%), which explains the increasing trend in Diurnal Temperature
Range (DTR). This precisely precedes the fact that the days are getting hotter, and the nights are
getting colder and its effects can be seen over the rainfall intensities in the region. As per the results
obtained, there is a reduction observed in the number of light rainy days (-10.2%), moderate rainy
days (-17.8%) in contrast to heavy and heavy rainy days (-25.5 and -18.4%). The number of
cumulative dry days in the study area has also increased by 19.5%, which explains the reduction in
rainy days. The overall result indicates an increase in DTR in the future along with an increase in
days with heavy rainfalls in the case of both scenarios for the study area.
Evaluation of land use land cover is critical and must be monitored to assess the impact on the
environment. For this purpose, LULC mapping was carried out for the region using satellite
imageries (LANDSAT 5, 7, and 8), remote sensing (RS), and geographical information system (GIS)
tools. The LULC maps were classified into six different classes namely water bodies, urban areas,
agricultural land, barren land, mixed forest, and sand/open rocks. Significant findings in the study
state a decrease in vegetation (agricultural land and mixed forest) in the region due to the rise in the
urban area and barren land. After the analysis of historical trend patterns in LULC, the land use land
cover map for the near future (2030) was projected using the CA-Markov model. The model was
validated and simulated with the classified LULC map of 2015. The projected LULC map of 2030
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indicated the continuation of the same trend of the past. These future projections indicate the
expected changes in the near future. Therefore, the LULC changes concerning different classes in
the near future will help in cautioning the concerned authorities for proper planning and management
of the study area.
In order to investigate the effect of land use land cover change and historical and future climate
variability on water availability of Kharun watershed, Soil and Water Assessment Tool (SWAT), a
semi-distributed hydrological model was calibrated and validated for the area. Parameters namely
Baseflow Alpha Factor (ALPHA_BF), Plant uptake compensation factor (EPCO), and Deep aquifer
percolation fraction (RCHRG_DP), were found to be the most sensitive parameters for the Kharun
watershed. For monthly simulations, the values of Coefficient of determination (R2), Nash-Sutcliffe
efficiency (NSE), and Percent bias (PBIAS) were found to be 0.84, 0.8, and -9.4% during calibration,
and 0.85, 0.79 and -9.2% during validation respectively. The results indicated a very good model
performance for Kharun watershed. Based on these results, it is concluded that the SWAT model
can be successfully employed for the hydrological simulation purposes over Kharun watershed. In
order to compute the hydrological components under the dynamics of land use land cover and
climate change, 29 simulations were carried out under different variations of land use and climate
parameters. Results indicated that the increase in settlement (urban and barren land) for real estate
development, accompanied by a decrease in vegetation (agricultural land and mixed forest), has
resulted in an increased water yield but the evapotranspiration (ET) reduced due to reduction of
vegetation. It is observed that ET reduced with time due to a decrease in vegetation, earlier it used
to be 326.71 mm in 1990 but it declined to 298.39 mm during the projected the year of 2030. Due
to an increase in overland flow, the water yield increased from 781.58 mm in 1990 to 881.84 mm in
the projected the year of 2030. During the last two decades (2010-2030), LULC change increased
water yield by 45.88 mm and accounted for 5.48% of the total change (881.84 mm).
Moreover, ET decreased by 4.19% in the same duration. Reduction in precipitation was observed
for both RCP scenarios in the period CC1 (2011-2040) by -16.83% for NorESM and by -16.29% for
MIROC5. The simulation result suggests that the evapotranspiration (ET) in the region is going to
increase between 2011 and 2100 but when compared to IMD simulation as a reference, it was
observed that the ET has decreased. The maximum change in ET was obtained in CC3. For RCP
4.5, it was 3.99% (MIROC5) and for RCP 8.5, it was 7.26% (MIROC5). While the minimum change
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in ET was observed in CC1. The maximum increase in water yield was observed in CC3, 37.36%
for CSIRO (RCP 4.5), and 77.10% for CCCma (RCP 8.5).
In summary, the study provided a scientifically essential and practically relevant approach towards
identifying the historical climate variability and hydrological assessment under land use and climate
change scenarios considering representative climate models output, in contributing to water
resources planning and management in the context of a small tropical watershed.2019-12-01T00:00:00ZPERFORMANCE EVALUATION OF SALIA IRRIGATION PROJECT IN CHANGING CLIMATESethi, Rabindranathhttp://localhost:8081/xmlui/handle/123456789/154352022-06-03T07:25:14Z2013-06-01T00:00:00ZTitle: PERFORMANCE EVALUATION OF SALIA IRRIGATION PROJECT IN CHANGING CLIMATE
Authors: Sethi, Rabindranath
Abstract: Under climate change conditions, many water systems are projected to be less reliable
and more vulnerable in meeting users' demands, exacerbating existing competition for
water resources. At the global scale, water demand will grow in the next decades due
to population growth, and substantial changes in irrigation water demand due to
impact of climate change. National Water Mission was set up by Govt. of India
recommended to study impact of climate change on water resources. The present
research work aims at evaluating performance of reservoir by implementing
hydrological model with climate change implication to optimize the efficiency of
existing irrigation systems, expand irrigation, where feasible, with a special effort to
increase storage capacity. In the current study, performance of Salia reservoir in
Odisha is analyzed under climate change conditions.
The thesis is focused on the following heuristics: (I) trend analysis for identification of
temporal changes in hydrological parameters such as precipitation and inflows time
series due to potential impacts of climate change, (ii) quantification of inflows to
reservoir using ARNO model with changing climate, and (iii) reservoir performance
evaluation using WEAP model and scenarios development.
From the trend analysis using Mann-Kendall test, no significant trend noticed for
annual, seasonal and for any monthly rainfall. Variation of precipitation shows that
number of rainy days is decreasing and number of intense rainy days (more than 100
mm) is increasing. As a result flash floods and dry spells are creating havoc. A
significant rising trend with the test statistic value of +3.18 is observed for daily inflow
series at 95% confidence level. ARNO result shows that the simulated flow
increase/decrease is directly proportional to the change in the rainfall decrease/increase.
It is observed that, a change of 25% decrease or increase in rainfall amount resulted in
equal amount of decrease or increase in the inflow. The performance of WEAP model
shows that if inflows reduced by 20% there would be a decrease in supply reliability,
and it would not be possible to increase supplies. Reducing live storage by 10%
* influence supply delivered in May and June, but again has little impact on the rest of the
year.2013-06-01T00:00:00ZDSS (DECISION SUPPORT SYSTEM) FOR URBAN WATER MANAGEMENT WITH CLIMATE CONSIDERATIONKumar, Praveenhttp://localhost:8081/xmlui/handle/123456789/153942022-04-26T07:31:56Z2013-05-01T00:00:00ZTitle: DSS (DECISION SUPPORT SYSTEM) FOR URBAN WATER MANAGEMENT WITH CLIMATE CONSIDERATION
Authors: Kumar, Praveen
Abstract: To find out the water demand and problems in supplying that in the near future is a big problem, as in the urban areas like Dehradun, which is a decade old state capital, the change in Landuse/ Landcover pattern has been very rapid. The built up area is increasing day by day which is effecting the hydrological cycle of the district. Change in climate is also becoming a major factor to effect the hydrological cycle of the district. In the present study a scientific approach is used to propose the coming problems regarding water in the city and probable places where it will most likely to happen in the city. Different thematic layers required to study the city and nearby area of the city, such as landuse/ landcover, past and present population density, have been prepared in a Geographic Information System enviroment using high resolution digital data of LAN DSAT satellite amalgamated with field data. By studying these maps one can propose the high water demand area in the near future by considering some factors, such as distance from the city, topographic slopes, landuse/lancover, present population density, existing water supply etc. Population of the city is also forecasted as per last three decades census data to have an idea of the demand of water in the near future and problems which will arise to compete that challenge. In addition a trend is made using the precipitation and temperature data of 1901 to 2002 years data from indian Meteorological Department(IMD). Auto Regressive Integrated Moving Average(ARIMA) model is used to predict a trend between precipitation and temperature with graphical approach and analytical approach both. To assemble all the data at one place and to make it easy to use, Visual Basic 6.0 is used to make a model which is an user friendly platform. Analytical data, graphical data of precipitation and temperature, thematic maps, forecasted population and demand data is placed in the model so that one can see all the things at one place to make out decision regarding the future water problems2013-05-01T00:00:00ZEXPERIMENTAL STUDY ON EFFECT OF MODERN METHODS FOR DEWAXING CERAMIC SHELL FOR INVESTMENT CASTING PROCESSRani, Dolihttp://localhost:8081/xmlui/handle/123456789/153932022-04-26T07:28:47Z2013-06-01T00:00:00ZTitle: EXPERIMENTAL STUDY ON EFFECT OF MODERN METHODS FOR DEWAXING CERAMIC SHELL FOR INVESTMENT CASTING PROCESS
Authors: Rani, Doli
Abstract: investment casting is the process well known for achieving excellent finishing of surface,
accuracy of dimensions and intricate shapes development. The process parameters behind the
preparation of wax blends and ceramic slurry make the investment casting process laborious
and troublesome. Due to the thermal expansion, shrinkage of material of pattern, material of
mould and solidification of alloy being casted, there are changes that occur between pattern
and its corresponding part of casting. Composition of the wax plays a vital role to optimization
of the expansion, shrinkage and maximization of hardness of pattern. The ceramic slurry,
composition also plays an important role to improve and stabilize the ceramic slurry. The most
crucial step in investment casting is the 'dewaxing' of investment shells. It describes the
nature of casting because the surface and dimensional traits of the wax are transferred to the
shell of ceramic and it leads to the final stage of casting. In the present work, experiments
were conducted with different type of waxes namely paraffin wax, microcrystalline wax and
carnauba wax, varying their proportion.
The dewaxing of wax from shell was done in microwave and infrared ovens. Using the data
obtained from the experiments an attempt has been made to find out the set of input
parameters, which could offer a set of ideal properties of wax blend and ceramic slurry.
Taguchi method was used to optimize the process parameters. The Orthogonal Array which
represents the matrix of number of parameters those are to be varied gives the number of tests
to be conducted. Taguchi method has successfully suggested the set of input parameters which
could offer the desired properties. The changes in properties like linear shrinkage, volumetric
shrinkage, surface roughness and hardness have been calculated by dewaxing the shell in
microwave and infrared ovens2013-06-01T00:00:00Z