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No description available.

Geodetic models suggest that much of the convergence across the Himalaya (~20 mm yr-1) is taken up on the Main Himalayan Thrust, the main decollement beneath the Himalayan orogenic wedge. In Central Nepal and the majority of Northwest India, several geomorphic, geophysical and seismological datasets indicate that this decollement has a mid-crustal ramp that continues uninterrupted for hundreds of kilometers along strike from Nepal in the east to Uttarakhand in the west. In this study, I use spatial analyses of elevation, relief, channel steepness indices, and basin-wide erosion rates from cosmogenic 10-Be concentrations to outline a potential large-scale change in the active fault configuration between the Main Himalayan Thrust and Main Boundary Thrust near longitude 77°E in the Northwestern Indian Himalaya. The physiography in the areas to the east of 77ºE appears similar to that observed along much of the Himalaya where topographic relief, erosion rates, and river channel steepness (ksn <200) remain relatively low in the areas to the south of a line known as the Physiographic Transition-2. North of the Physiographic Transition-2, these metrics increase sharply within a 30-km zone due to higher rock uplift rates above a mid-crustal ramp on the decollement or an unidentified out-of-sequence thrust fault that soles to the decollement. Either of these models are perceivable with a duplex growing by underplating of the Indian plate into the Himalayan orogenic wedge contributing to higher rock uplift rates north of the Physiographic Transition-2. To the west of 77ºE, however, the landscape morphology indicates the Main Boundary Thrust makes a northward bend coinciding with the along-strike termination of the Physiographic Transition-2 and an arc-perpendicular Bouguer gravity anomaly reflecting a trough on the Indian plate near longitude 77°E. These data suggest that the Main Boundary Thrust merges along strike with the ramp or with an emergent fault soling into the Main Himalayan Thrust at this location, potentially marking a significant change in tectonic configuration along the Himalayan arc. / Graduate

This thesis investigates the impact of two invasive ecosystem engineers on the river banks. Invasive species generate significant global environmental and economic costs and represent a particularly potent threat to freshwater ecosystems. Ecosystem engineers are organisms that modify their physical habitat. Therefore this thesis will explore the interaction of these two types of species and their impacts on the example of the impact of signal crayfish and Himalayan balsam The obtained results indicate that there are few avenues through which invasive ecosystem engineers can influence river bank processes. While many uncertainties remain, due to the intrinsic complexity of river ecosystems, a multitude of anthropogenic stressors that they are increasingly subjected to and a wide array of ecosystem services that rivers provide to people, it is important to consider the role of invasive ecosystem engineers in river management practices. on river banks. The work included analyses and development of conceptual models for the understanding of invasive ecosystem engineers, followed by four research chapters aimed at answering specific questions. A study of signal crayfish impact is primarily focused on the impact of burrows that crayfish dig as shelter and their influence on riverbank erosion. The interaction between habitat characteristics, the occurrence of burrows and erosion is analysed on three different levels of spatial scale: bank section in reach, reach in the catchment and bank section in the catchment. Bank section in reach survey (Chapter 4) focused on a reach heavily impacted by crayfish burrowing on the River Windrush, UK, in order to study the maximum effect of burrowing. Also, smaller spatial extent enabled detailed study of three sets of variables as well as an assessment of the impact that signal crayfish population density has on burrowing. Reach in catchment spatial scale expanded the survey to cover 103 river reaches in the Thames catchment and was based on a combination of habitat information from publicly available online data sets, primarily the River Habitat Survey database and rapid field surveys that recorded burrows and erosion. Bank section in catchment-scale was based on the same 103 sites, but the main focus of field observations were ten metres long bank sections for which habitat, burrows and erosion information were collected. Overall, burrowed banks were more likely to be characterised by cohesive bank material, steeper bank profiles with large areas of bare bank face, often on outer bend locations and were associated with bank profiles with signs of erosion. There were indications that signal crayfish burrowing is contributing to the river bank erosion, but no conclusive results have been made. Study of the impact of the Himalayan balsam was undertaken on eight sites at the River Brenta in Italy and it was focused on three main aspects. Firstly it was established that extent of Himalayan balsam domination over native vegetation varies widely depending on the habitat conditions and native plants encountered. Secondly, it was established that there are no conclusive differences in the extent of erosion and deposition on transects covered by native vegetation and Himalayan balsam. Thirdly, measurement of traits of individual plants showed significant differences in traits of individual plants that are known to have consequences for river bank erosion and deposition.

Mass balance records of glaciers help to understand long term climate change, yet there are very few in-situ measurements of mass balance in Himalayan glaciers. Mass balance of major glaciers in the Sagarmatha National Park was assessed using Digital Elevation Model prepared from ASTER images for period 2002 & 2005 and 2002 & 2008, employing geodetic model. Overall glacial mass balance during 2002-2005 was -2.978 plus/minus 0.89 and during 2002-2008 was -0.94 plus/minus 0.34 m.w.e per annum. Glacier melt could form glacial lakes in high Himalayas. One of the glacial lakes, Imja Lake in the study area increased its surface area by 268% from 1975 to 2010. Temperature analysis from MODIS data between 2000 and 2011 indicated increase in temperature in the study area. General loss of glacial mass in the Himalayan region indicated, and these loses if continue in the future will lead to catastrophic environmental and economic impacts.

Investigations were carried out into the allelopathic potential of the invasive alien annual Himalayan Balsam (Impatiens glandulifera Royle) using a series of bioassays, including ones developed or adapted for this study. They were evaluated for their suitability to detect three of the four main modes of allelochemical release, namely leaching, exudation and decomposition. Assays which involved the measurement of lettuce radicles and hypocotyls gave reliable results and allowed a range of different Impatiens material, both living and dead, to be assessed and ranked according to the allelopathic effects demonstrated. Attempts were made to isolate resource competition from allelopathy using separately grown but connected donor and receiver plants and a density dependent design where single I. glandulifera plants were grown in pots with variable numbers of receiver plants. Results proved inconclusive. Initial experiments showed that the allelopathic potential of I. glandulifera varied according to the organ from which the material was derived. Pods, leaves and stems produced the greatest inhibition of lettuce seedlings. Effects on germination were not significant at most of the concentrations tested. Live roots of I. glandulifera plants produced pronounced orange staining of the agar into which they were placed and showed clear evidence of distance dependent inhibition of lettuce radicles. Effects were limited to growth rather than germination of the test plants. Germinating I. glandulifera seeds caused a significant inhibition of lettuce radicle elongation when the two species were grown together in an agar medium. The inhibitory effects increased significantly with increasing exposure time. Increasing I. glandulifera seedling number also produced significant reductions in lettuce radicle length. Dormant seeds, by contrast, stimulated growth. Dead seeds did not produce significant changes to the growth of the test plants. When rhizosphere soil was gathered from pot grown I. glandulifera plants, the results were mixed. Initial samples inhibited growth, whereas those collected from dying plants over a period of weeks stimulated growth. Further experimentation is required before the indications of allelopathic interactions demonstrated here can be applied to the behaviour of wild populations of I. glandulifera.

Known as the Himalayan poppies or the blue poppies, Meconopsis is a genus with approximately 50 species distributed through the high altitude of the Himalaya and the Hengduan Mountains (SW China). This dissertation is a study of the systematics of Meconopsis primarily using molecular phylogenetic methods. DNA sequences of chloroplast matK, ndhF, trnL-trnF, rbcL, and nuclear ITS were collected to reconstruct the phylogenies of the genus. Results showed that traditional Meconopsis is a polyphyletic group and revealed extensive mismatches between the nuclear ITS tree and the chloroplast tree. Based on the phylogenies, the taxonomy of Meconopsis was revised, making Meconopsis monophyletic. Four new sections (sect. Meconopsis, sect. Aculeatae, sect. Primulinae, and sect. Grandes) were proposed as well as a species complex (M. horridula). The chloroplast phylogeny and a likelihood method (chromEvol) were applied to ancestral chromosome number estimation to reconstruct the polyploidy evolution history of the genus. The analysis recovered an ancient triploid ancestor shared by sect. Primulinae and sect. Grandes. A low-copy nuclear gene (GAPDH) network of Meconopsis was further reconstructed, which indicated that the ancient triploid ancestor was formed by hybridization. A hypothesis of reticulate history of Meconopsis was also proposed based on the GAPDH network. Using a reconstructed rbcL phylogeny of Ranunculales, the stem group of Meconopsis was estimated at ca. 22 Mya by molecular dating, which coincided with the time of Asian interior desertification and the onset of Asian monsoon. These climatic changes could possibly have been the impetus for the split between Meconopsis and its sister clade. Ancestral area reconstruction was further conducted using likelihood-based methods. The result indicated that Meconopsis originated in the Himalaya, most likely in the west Himalaya, followed by migration to the Hengduan Mountains. / text

In the Karnali valley of west Nepal, detailed mapping, thermobarometry, quartz-petrofabrics, vorticity analysis, and thermochronology delineate three tectonometamorphic domains separated by structural and metamorphic discontinuities. The lowest domain, the Lesser Himalayan sequence, is weakly metamorphosed and preserves evidence of primary sedimentary features and a polydeformational history. The Greater Himalayan sequence (GHS) is pervasively sheared and metamorphosed and overlies the Lesser Himalayan sequence along the Main Central thrust. The Greater Himalayan sequence is sub-divided into two tectonometamorphic domains that display contrasting metamorphic histories. The lower portion of the Greater Himalayan sequence contains garnet- to kyanite-grade rocks whose peak metamorphic assemblages developed during top-to-the-south directed shear and a metamorphic pressure gradient that increases up structural section. The upper portion of the Greater Himalayan sequence contains kyanite and sillimanite-grade migmatites that preserve polymetamorphic assemblages and a metamorphic pressure gradient that decreases up structural section. The upper and lower portions of the Greater Himalayan sequence are separated by a metamorphic discontinuity that roughly coincides with the bottom of the lowest migmatite unit. Vorticity estimates indicate roughly equal contributions of pure and simple shear during deformation of the upper and lower portions of the GHS. Quartz petrofabrics suggest deformation temperatures are equivalent to peak metamorphic temperatures in the lower Greater Himalayan sequence. These observations are consistent with channel flow tectonic models whereby the upper portion of the Greater Himalayan sequence is ductily extruded to the south while ductily accreting the subjacent lower portion of the Greater Himalayan sequence across a metamorphic discontinuity. 40Ar/39Ar thermochronology indicates Miocene homogeneous cooling of the Greater Himalayan sequence. Cooling rates of the GHS and the homogeneous cooling profile suggest east-west extensional exhumation followed peak-metamorphism and south-directed shearing and supports the hypothesis of the southeast propagation of the Gurla-Mandhata-Humla fault system into the Karnali valley. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2010-09-20 09:23:07.103

The Himalayan region of India is experiencing rapid development in tourism, agriculture, highway construction and hydroelectric development. This research describes and evaluates the role of public participation in tourism development projects in these high mountain environments, using the proposed Himalayan Ski Village (HSV) development in Manali as a case study. Qualitative data collected through semi-structured interviews, document reviews and participant observation revealed that there have been formal and informal opportunities for public participation in project development. The findings suggest that local people have been involved in project development activities, such as training for skiing, but not in the decision-making process related to the project. The majority of the participation activities were, in fact, instigated by the public including activities such as protests and court challenges. The findings also show that involvement in the participatory activities undertaken by the public and project proponent fostered instrumental and communicative learning outcomes.