Faculty Publications
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Item Forest Vulnerability to Climate Change: A Review for Future Research Framework(MDPI, 2022) Roshani; Sajjad, H.; Kumar, P.; Masroor, M.; Rahaman, M.H.; Rehman, S.; Ahmed, R.; Sahana, M.Climate change has caused vulnerability not only to the forest ecosystem but also to forest-dependent communities. Therefore, its management is essential to increase forest ecosystem services and reduce vulnerability to climate change using an integrated approach. Although many scientific studies examined climate change impact on forest ecosystems, forest vulnerability assessment, including forest sensitivity, adaptability, sustainability and effective management was found to be scant in the existing literature. Through a systematic review from 1990 to 2019, this paper examined forest vulnerability to climate change and its management practices. In this paper, descriptive, mechanism and thematic analyses were carried out to analyze the state of existing research, in order to understand the concept of vulnerability arising from climate change and forest management issues. The present study proposed a framework for integrated forest assessment and management for addressing such issues in future research. The conversion of forest land into other land uses, forest fragmentation, forest disturbance and the effects of climate change on the forest ecosystem are the existing problems. Forest vulnerability, effective adaptation to forest ecosystems and long-term sustainability are priority areas for future research. This study also calls for undertaking researchers at a local scale to involve communities for the effective management of forest ecosystems. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Item Effect of climate change on Netravathi riverflow(2010) Shetkar, R.V.; Mahesha, A.The adequacy of freshwater resources for future is difficult to assess due to complex and rapidly changing environmental and social parameters. There is uncertainty with respect to the prediction of climate change and its effect on planning and management of water resources. Higher temperature and reduced precipitation would lead to larger deficiencies in the supply and demand for water. This might cause deterioration in the quality of freshwater adding strain on the already fragile balance between supply and demand. Although the effect of climate change on water resources is uncertain and site specific, the perception is that it will result into increased extreme events and hence increased risk of flooding and droughts. This paper aims at assessing the trends of temperature, precipitation and river flow for the Netravathi river, a tropical river of south India. The river water utilization at present is less than 1% of the average annual flow. The river flow is neither controlled nor altered due to manmade structures hence may be considered as natural flow. From the analysis, it is important to note that the temperature is rising and there is declining trend in precipitation and stream flow during the study period of 30 years (1971 to 2001). Also, the low flow frequency analysis shows an upward trend. Similar analyses carried out for the number of days of flow peaks above a threshold value indicate that the high flow frequency trend is declining and the magnitude of these high flow events is also decreasing. The outcome of the present study indicates a definitive, decreasing trend in the river flow due to climate change and a forecasting mechanism may be essential in the future for the sustainable development of the available water resources. © 2010 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.Item Coastal erosion and mitigation methods - global state of art(2010) Hegde, A.V.Coastal erosion is assuming large proportions these days. Global climate change coupled with local attributes is eroding the coasts of the world in alarming proportions. Most of the conventional protection methods are hard, short lived, expensive and not eco-friendly. Trend in coastal erosion mitigation and protection has been shifting these days towards soft but novel, eco-friendly methods. Pro-active methods are being developed and used which are eco-friendly, construction-friendly, cheaper and which also reasonably address the root cause of the problem without much 'side effects'. Many non-traditional ways to armor, stabilize or restore beaches, including the use of patented precast concrete units, geotextile sand-filled bags, green belts, bio-engineering, sand fencing, beach-face dewatering systems, integrated costal protection methods are being used. Retreat from the coast is also thought about, in many circles. Present study consists the global coastal erosion scenario and also some of the state of the art soft and pro-active erosion mitigation methods.Item Tropical, Seasonal River Basin Development: Hydrogeological Analysis(2011) Shetkar, R.V.; Mahesha, A.This study presents a hydrogeological analysis of a humid tropical, seasonal river in the context of climate change, increasing demand for water, and uneven distribution of rainfall. We investigate the Netravathi basin, a tropical river basin of south India. The climate change effect on the basin was evident in terms of increasing trend in temperature by about 0.7°C/100 years and decreasing trend in the river flow during the monsoon by about 0.8% of average annual flow per year using the Mann-Kendall trend test. Even though rainfall was found to be decreasing, no significant trend could be established. From the trend analysis of the river flow, it was found that there is an overall declining trend with longer scarcity periods. In addition, the trends of magnitude and frequency of high flows are declining. Even though the region receives an average annual rainfall of about 3,930 mm, it has nonuniform distribution with most of the rainfall confining to a few months of a year. In view of this, the region suffers from a prolonged dry period during February to May. The projected domestic water demand of the region for the next 25 years is estimated to be increasing from the present 0.09 mm3 to 0.25 mm3 per day because of rapid urbanization and industrialization. The purpose of this investigation is to highlight the effects of climate change and uneven distribution of rainfall in the river basin. This may assist in proper planning of the basin through strategies such as river water harvesting, which is investigated in the companion paper. Because the Netravathi River is a seasonal and tidal river, and saltwater intrusion along the river during the summer months is affecting the development of the basin. It was found that the river water is affected up to distance of about 22,000 m from the Arabian sea and the wells on the banks of the river are found to be highly vulnerable to saltwater intrusion during the summer period (March to May). © 2011 American Society of Civil Engineers.Item Parameter estimation and vulnerability assessment of coastal unconfined aquifer to saltwater intrusion(2012) Mahesha, A.; Vyshali; Lathashri, U.A.; Ramesh, H.The focus of the present work is to characterize a tropical, coastal aquifer and to carry out its vulnerability to saltwater intrusion using hydrogeological parameters. The characterization of the aquifer involves pumping tests, vertical electrical sounding, and water quality analysis carried out at 41 monitoring wells. The area under investigation lies between two tropical, seasonal, tidal rivers, i.e., Pavanje and Gurpur rivers, joining the Arabian on the west coast of India. The aquifer is predominantly shallow and unconfined, having moderate to good groundwater potential with transimissivity and specific yield ranging from 49.2 to 461:4 m2/day and 0.00058 to 0.2805, respectively. The electrical resistivity tests indicated that the thickness of the aquifer ranges from 18 to 30 m. The study also investigates the saltwater affected areas in the region the vertical electrical sounding and water quality analysis. The resistivity results revealed several probable isolated saltwater intruded pockets in the region with resistivity less than 70 Om. From the salinity analysis of water, the locations that are affected during February to May (summer) and throughout the year are identified. The wells that are located close to the coast (< 350 m) and at lower elevations (well bottom < +1 m) were found to be saline throughout the year. Also, wells along the banks of the river show considerable salinity (> 200 ppm) during the summer period from tidal inflow along the rivers. The water samples were also analyzed for chloride to bicarbonate ratios during December to May at all the monitoring wells and were found to be exceeding the allowable limit at several locations. The saltwater vulnerability maps are derived for the area by the index-based method using the hydrogeological parameters. The method was found to be effective while compared to the field observations. The results from the analysis indicate that the aquifer is medium to highly vulnerable to saltwater intrusion at majority of the locations. The impact of projected sea level rise by 0.25 and 0.50 m from the climate change is also assessed on the vulnerability of the region to saltwater intrusion. © 2012 American Society of Civil Engineers.Item El nino effect(CAFET INNOVA Technical Society cafetinnova@gmail.com 1-2-18/103, Mohini Mansion, Gagan Mahal Road, Domalguda, Hyderabad 500029, 2014) Reddy, P.R.; Venkat Reddy, D.V.[No abstract available]Item Analysis of variability and trends in rainfall over northern Ethiopia(Springer Verlag service@springer.de, 2016) Kiros, G.; Shetty, A.; Nandagiri, L.Rainfall is a key component of the hydrological cycle, and its spatiotemporal variability is essential from the both scientific and practical perspectives. This study is focused on analysis of temporal variability and trends in historical rainfall records for stations in the Geba River basin. The Geba catchment is surrounded by the Danakil basin in the east, by the Tekeze River basin in the south, and the Werie River basin in the west which is located in the northern Ethiopia regional state of Tigray between 38° 38? E and 39° 48? E and 13° 18? N and 14° 15? N. The climate over the basin is semi-arid and has large elevation differences varying from 926 to 3301 m above mean sea level. Daily rainfall data of 43 years measured at seven stations in the basin for the period of 1971 to 2013 for annual and seasonal rainfall trends have been processed and used for the analysis. The non-parametric Mann–Kendall test and the Sen’s slope estimator have been used to identify the existence of trends and slope magnitude in rainfall. Results revealed that although there was a mix of positive and negative trends, they were no statistically significant except at one station which showed an increasing trend in annual rainfall. Considering rainfall in different seasons, an increase in rainfall was observed in two stations in the wet season which, however, was not statistically significant. For the remaining stations, a weak decline in wet season rainfall (not statistically significant at 95 % confidence level) for four stations and absence of trend for one station were noticed. Furthermore, no statistically significant trend (positive or negative) was evident for the dry season rainfall. Results of this study may prove useful in the preparation of climate change mitigation and adaptation strategies in rainfed agricultural and water supply systems in the region. © 2016, Saudi Society for Geosciences.Item Modelling the land use system process for a pre-industrial landscape in India(Springer Science and Business Media Deutschland GmbH, 2017) Ghosh, S.; Shetty, A.Land in India is changing in a rapid pace since the green revolution during 1960 and industrial policy reforms during 1990. Certainly land cover land use (LCLU) changes have huge impacts on countries overall ecological balance and climate change. The most intriguing fact is LCLU change is an interconnected phenomenon like a system. The understanding of local level LCLU dynamics are yet to get a momentum in India. The present study is an attempt: (1) to examine the land use change drivers active at the studied landscape of coastal Karnataka in India and (2) to model the LCLU changes in pre-industrialized period using Dyna-CLUE model. Binary logistic regression was used to categorize land change drivers and to estimate the probability of changes. Odd ratio from logistic regression indicates that the biophysical drivers are most prominent in determining location of LCLU. They being slope, relative relief, drainage density and availability of ground water are the most influential drivers for most of the land classes. The Dyna-CLUE model is successful to simulate the LCLU change at aggregate level but the spatial allocation needs improvement. © 2017, Springer International Publishing Switzerland.Item Impacts of climate change on varied River-Flow regimes of southern india(American Society of Civil Engineers (ASCE) onlinejls@asce.org, 2017) Mudbhatkal, A.; Raikar, R.V.; Venkatesh, B.; Mahesha, A.This paper assesses the possible impact of climate change on the hydrology of the subhumid and perhumid river regimes originating from the western mountain range (Western Ghats) of India. The modified Mann-Kendall test evaluates the trend of observed data (1975-2004) and RCP 4.5 data (2006-2070) of climatic variables. The results indicate a decreasing trend for annual rainfall over the Malaprabha River catchment (26 mm per year at the 5% significance level), whereas no trend is observed over the Netravathi River catchment at the 10% level. Indian southwestern monsoon rainfall shows a decreasing trend from 84 to 80% of total rainfall in the Malaprabha River catchment and from 80 to 77% in the Netravathi River catchment. Summer rains are found to be increasing in the Malaprabha River catchment (3-4.5% of total rainfall), whereas there is no significant trend for the Netravathi River catchment. Furthermore, the postmonsoon rainfall also shows a significant increase in the Malaprabha catchment (40 mm per decade at the 5% significance level) and the Netravathi catchment (30 mm per decade at the 10% significance level). The Netravathi River shows a decreasing trend for annual flow (0.22 Mm3 per year at the 10% significance level). However, for both catchments the temperature is found to be increasing by 0.2-0.8°C per decade. The soil and water assessment tool (SWAT) model is used to simulate the river catchments and exhibits a Nash-Sutcliffe efficiency of 0.831 and 0.857 for the Malaprabha and Netravathi River catchments, respectively. In addition, a decreasing trend in the high flow is estimated for Netravathi, whereas the trend is increasing for Malaprabha. Thus the impacts of climate change over the Western Ghats are very evident, but the flow of each river responds differently. © 2017 American Society of Civil Engineers.Item Analysis of climate trend and effect of land use land cover change on Harangi streamflow, South India: a case study(Springer Science and Business Media Deutschland GmbH, 2017) Anil, A.P.; Ramesh, H.Land use land cover (LULC) and climate change are considered to be driving factors contributing to the alteration of the hydrological regime. Therefore, an attempt has been made to study climate trend and the effect of LULC on streamflow in a basin covered predominantly by forest. The Harangi river basin is one of such basins located in the western ghats of South India. The LULC trend was carried out by considering temporal multispectral data for the years 1990, 2002 and 2008 obtained from Landsat-5TM and IRS 1C (Indian Remote Sensing Satellites). Climate parameters such as rainfall and temperatures were considered for the trend analysis in this study. The rainfall trend was studied using Man-Kendall and Sen’s slope method to understand the spatio-temporal variability. Rainfall shows the decrease trend at Suntikoppa rain gauge station in January and June months. Harangi and Madapura rain gauge stations also show a decrease of rainfall trend for only January month. Temperature trend show increase in maximum temperature for the month of April, May and November whereas increase in minimum temperature was observed in the month of November and December. Spatial extent of LULC found that 52.4% (220.014 km2) of the study area was covered with forest in 1990 which has considerably decreased to 43.9% (184.53 km2) in 2008. There was a rise in total area of plantation crops from 106.27 km2 (25.32%) to 138.20 km2 (32.9%) during this period. Soil and Water Assessment Tool (SWAT) was used to study the effect of LULC on streamflow. SWAT model was calibrated and validated using observed daily streamflow data. The coefficient of correlation (r2) was found to be 0.87 and 0.86 for calibration and validation, respectively. The results found the annual streamflow to increase by 0.77% from 1990 to 2008 whereas the mean monthly streamflow has increased by 9.46% during this period. This was mainly due to the reduction in forest area observed in LULC maps. © 2017, Springer International Publishing Switzerland.