FRESHWATER CONSERVATION, DRINKING WATER QUALITY AND CLIMATE CHANGE ADAPTATION: A CASE STUDY ON NEPAL

Our world today faces a myriad of unprecedented environmental challenges that transcends spatial and temporal reach. These problems involve interconnected ecological and social systems operating on multiple scales and include issues like climate disruption, water stress, food security, biodiversity loss, over-population and species declines and extinctions.These issues are more acute in rapidly growing nations like Nepal, where environmental protection is often considered a luxury. Such environmentally unsound development practices will not only create an imbalance in the ecological and the social functioning and dynamics, but it also threatens the future development of the country itself. In this dissertation, I investigate three major environmental challenges in Nepal: problems with freshwater conservation, issues with drinking water quality and availability, and concerns with climate change adaptation and mitigation. To approach these environmental challenges, chapter 2 employs a choice experiment method to assess the potential for a sustainable management of the Danda River system in Nepal. Using a Generalized Multinomial Logit model (GMNL) to account for households’ preference and scale heterogeneity, I find that respondents are willing to pay (WTP) about $17.06/year to improve the quality of the river water, and$13.46/year to introduce vegetation in theDanda riverbank. The results also suggest a presence of local spatial heterogeneity in the preference for the river ecosystem services. Households located in the central region in the urban town of Siddharthangar preferred the river ecosystem services to households located anywhere else. Further, I also find evidence for preference of local governance, with the households’ favoring a community-based management of the Danda river system. This finding highlights the need for policymakers to decentralize the management of local resources to communities to enhance interest in conservation of common pool resource like the Danda river system. In my third chapter, I investigate water averting behavior by placing a particular emphasis on the divergence between a household’s perception of their water quality and the objective water quality level. The findings indicate that the gap between perception and reality indeed plays a role in a household’s decision to adopt water treatment measures. Households with minimal divergence between subjective and objective water quality were more likely to engage in water averting behaviors than households otherwise. In my fourth chapter, I employ a hedonic model to investigate the impact of climate change on agricultural productivity in Nepal. Findings suggest that while the Nepalese farmlands are sensitive to increases in temperature and precipitation, the effects vary depending on whether the farmlands were irrigated or not

One-year observations of carbonaceous and nitrogenous components and major ions in the aerosols from subtropical Okinawa Island, an outflow region of Asian dusts

Ambient aerosol samples (TSP, <i>n</i> = 50) were collected for 12 months at subtropical Okinawa Island, Japan, an outflow region of Asian dusts in the western North Pacific and analysed for organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), water-soluble total nitrogen (WSTN), water-soluble organic nitrogen (WSON) and major ions to better understand the formation and transformation of East Asian aerosols during long-range atmospheric transport. Concentration ranges of these components are; OC: 0.76–7.1 μg m⁻³ (av. 1.7 ± 1.0 μg m⁻³), EC: 0.07–0.96 μg m⁻³ (0.28 ± 0.19 μg m⁻³), WSOC: 0.27–1.9 μg m⁻³ (0.73 ± 0.38 μg m⁻³), WSTN: 0.77 to 3.0 μg m⁻³ (0.58 ± 0.46 μg m⁻³) and WSON: 0.0–2.2 μg m⁻³ (0.12 ± 0.23 μg m⁻³). Higher OC concentrations were obtained in active biota seasons; spring (av. 2.4 μg m⁻³) and summer (1.8 μg m⁻³). EC and WSOC concentrations maximized in spring (av. 0.41 μg m⁻³ and 0.95 μg m⁻³, respectively) followed by winter (0. 70 and 0.90 μg m⁻³) whereas they became lowest in summer (0.19 and 0.52 μg m⁻³). In contrast, WSTN concentrations were highest in winter (0.86 μg m⁻³) and lowest in summer (0.37 μg m⁻³) and autumn (0.34 μg m⁻³). Concentrations of WSON are higher in early summer (av. 0.26 μg m⁻³) due to the emission from marine biota. The high ratios of OC / EC (av. 7.6) and WSOC / OC (44%) suggest a secondary formation of organic aerosols. Strong correlation between OC and MSA^- (0.81) in spring suggests that springtime aerosols are influenced by additional marine and terrestrial biogenic sources. The positive correlation of Ca²⁺ and TSP in spring (<i>r</i> = = 0.81) demonstrates a significant contribution of Asian dust whereas high abundances of NO₃^- and nss-SO₄^2- in winter suggest an important contribution from anthropogenic sources including biomass burning, vehicular emission and coal combustion. NH₄-N/WSTN ratios peaked in winter (0.56), indicating a significant contribution of biomass burning to WSTN in cold season. In contrast, higher NO₃-N/WSTN ratio in spring than winter suggests that the atmospheric transport of vehicular emissions maximizes in spring. Correlation analyses of major ions suggest that NH₄⁺ and Ca²⁺ play major role in the neutralization of acidic aerosols forming NH₄HSO₄, (NH₄)₂SO₄ and CaSO₄

Effects of non-universal large scales on conditional structure functions in turbulence

We report measurements of conditional Eulerian and Lagrangian structure functions in order to assess the effects of non-universal properties of the large scales on the small scales in turbulence. We study a 1m $\times$ 1m $\times$ 1.5m flow between oscillating grids which produces $R_\lambda=285$ while containing regions of nearly homogeneous and highly inhomogeneous turbulence. Large data sets of three-dimensional tracer particle velocities have been collected using stereoscopic high speed cameras with real-time image compression technology. Eulerian and Lagrangian structure functions are measured in both homogeneous and inhomogeneous regions of the flow. We condition the structure functions on the instantaneous large scale velocity or on the grid phase. At all scales, the structure functions depend strongly on the large scale velocity, but are independent of the grid phase. We see clear signatures of inhomogeneity near the oscillating grids, but even in the homogeneous region in the center we see a surprisingly strong dependence on the large scale velocity that remains at all scales. Previous work has shown that similar correlations extend to very high Reynolds numbers. Comprehensive measurements of these effects in a laboratory flow provide a powerful tool for assessing the effects of shear, inhomogeneity and intermittency of the large scales on the small scales in turbulence

Dynamic instability of microtubules: effect of catastrophe-suppressing drugs

Microtubules are stiff filamentary proteins that constitute an important component of the cytoskeleton of cells. These are known to exhibit a dynamic instability. A steadily growing microtubule can suddenly start depolymerizing very rapidly; this phenomenon is known as ``catastrophe''. However, often a shrinking microtubule is ``rescued'' and starts polymerizing again. Here we develope a model for the polymerization-depolymerization dynamics of microtubules in the presence of {\it catastrophe-suppressing drugs}. Solving the dynamical equations in the steady-state, we derive exact analytical expressions for the length distributions of the microtubules tipped with drug-bound tubulin subunits as well as those of the microtubules, in the growing and shrinking phases, tipped with drug-free pure tubulin subunits. We also examine the stability of the steady-state solutions.Comment: Minor corrections; final published versio

Competition of coarsening and shredding of clusters in a driven diffusive lattice gas

We investigate a driven diffusive lattice gas model with two oppositely moving species of particles. The model is motivated by bi-directional traffic of ants on a pre-existing trail. A third species, corresponding to pheromones used by the ants for communication, is not conserved and mediates interactions between the particles. Here we study the spatio-temporal organization of the particles. In the uni-directional variant of this model it is known to be determined by the formation and coarsening of ``loose clusters''. For our bi-directional model, we show that the interaction of oppositely moving clusters is essential. In the late stages of evolution the cluster size oscillates because of a competition between their `shredding' during encounters with oppositely moving counterparts and subsequent "coarsening" during collision-free evolution. We also establish a nontrivial dependence of the spatio-temporal organization on the system size

Solution of Integral Equation using Second and Third Order B-Spline Wavelets

It was proven that semi-orthogonal wavelets approximate the solution of integral equation very finely over the orthogonal wavelets Here we used the compactly supported semi-orthogonal B-spline wavelets generated in our paper Compactly Supported B-spline Wavelets with Orthonormal Scaling Functions satisfying the Daubechies conditions to solve the Fredholm integral equation The generated wavelets satisfies all the properties on the bounded interval The method is computationally easy which is illustrated with two examples whose solution closely resembles the exact solution as the order of wavelet increase

Grain Yield Stability of Early Maize Genotypes

The objective of this study was to estimate grain yield stability of early maize genotypes. Five early maize genotypes namely Pool-17, Arun1EV, Arun-4, Arun-2 and Farmer's variety were evaluated using Randomized Complete Block Design along with three replications at four different locations namely Rampur, Rajahar, Pakhribas and Kabre districts of Nepal during summer seasons of three consecutive years from 2010 to 2012 under farmer's fields. Genotype and genotype × environment (GGE) biplot was used to identify superior genotype for grain yield and stability pattern. The genotypes Arun-1 EV and Arun-4 were better adapted for Kabre and Pakhribas where as pool-17 for Rajahar environments. The overall findings showed that Arun-1EV was more stable followed by Arun-2 therefore these two varieties can be recommended to farmers for cultivation in both environments