A Three-Fold Approach to the Heat Equation: Data, Modeling, Numerics

This article describes our modeling approach to teaching the one-dimensional heat (diffusion) equation in a one-semester undergraduate partial differential equations course. We constructed the apparatus for a demonstration of heat diffusion through a long, thin metal rod with prescribed temperatures at each end. The students observed the physical phenomenon, collected temperature data along the rod, then referenced the demonstration for purposes in and out of the classroom. Here, we discuss the experimental setup, how the demonstration informed practices in the classroom and a project based on the collected data, including analytical and computational components

Is China’s Growth Sustainable?

A central pillar of the sustainability movement is the call to include environmental accounting in standard measures of economic performance. This increased transparency would, in principle, mitigate the temptation of economic managers and policy makers to increase growth in material consumption at the expense of the environment. Moreover, as Repetto (1989) and others have argued, deducting depreciation of produced capital from NNP but not deducting depreciation of natural capital is inconsistent and debases NNP as a possible indicator of welfare. Based on the evidence available, it appears that while GNNP is substantially less than NNP, these adjustments do not adversely compromise existing estimates of economic growth for China.sustainable development, China, genuine saving, SOx, NOx, TSP, resource depletion, natural capital, Environmental Kuznets Curve, green net national product

Delaying the Catastrophic Arrival of the Brown Tree Snake to Hawaii

This paper develops a two-stage model for the optimal management of a potential invasive species. The arrival of an invasive species is modeled as an irreversible event with an uncertain arrival time. The model is solved in two stages, beginning with the post-invasion stage. In this stage, we assume perfect certainty regarding population size and arrivals. The loss-minimizing paths of prevention and control are identified, resulting in a minimized present value penalty associated with the invasion. After calculating this penalty, we analyze the pre-invasion stage and solve for the level of prevention expenditures that will minimize expected total cost. For the case of the Brown Tree Snake potentially invading Hawaii, we find that under a regime of precommitment, pre-invasion expenditures on prevention should be approximately $3.2 million today, decreasing every year until invasion. However, if the planner is permitted to re-evaluate the threat following a non-event, prevention will be lower ($2.96 million a year) and constant until invasion. Once invasion occurs, optimal management requires lower annual expenditures on prevention ($3.1 million) but requires$1.6 million to be spent on control annually to keep the population at its steady state level.catastrophe, hazard function, invasive species, Brown Tree Snake, Boiga irregularis, prevention and control, Hawaii

Control of Invasive Species: Lessons from Miconia in Hawaii

Once established, invasive species can rapidly and irreversibly alter ecosystems and degrade the value of ecosystem services. Optimal control of an exotic pest solves for a trajectory of removals that minimizes the present value of removal costs and residual damages from the remaining pest population. The shrubby tree, Miconia calvescens, is used to illustrate dynamic policy options for a forest invader. Potential damages to Hawaii's forest ecosystems are related to decreased aquifer recharge, biodiversity, and other ecosystem values. We find that population reduction is the optimal management policy for the islands of Oahu, Maui, and Hawaii. On the island of Kauai, where tree density is lower and search costs higher, optimal policy calls for deferring removal expenditures until the steady state population is reached.

Environmental Policy Issues for Sustainable Economic Development in China

A central pillar of the sustainability movement is the call to include environmental accounting in standard measures of economic performance. This increased transparency would, in principle, mitigate the temptation of economic managers and policy makers to increase growth in material consumption at the expense of the environment. Moreover, as Repetto (1989) and others have argued, deducting depreciation of produced capital from NNP but not deducting depreciation of natural capital is inconsistent and debases NNP as a possible indicator of welfare. Based on the evidence available, it appears that while GNNP is substantially less than NNP, these adjustments do not adversely compromise existing estimates of economic growth for China.Environmental Economics and Policy,

Resource management for Sustainable Development of Island Economies

What is the role of resource management in sustaining competitiveness for island economies such as the Republic of the Philippines and Hawaii? We review the history of thought on sustainable resource management and sustainable development and then turn to the threats to sustainability from the resource curse and the parallel curse of paradise. We show how the resource curse undermines the pursuit of sustainability and describe innovations in governance that can transform the curse into a blessing.Resource curse, sustainable development, Dutch disease

Spatial Distribution of the Surface Geology and 1992 Land Use of the Buffalo River Watershed

The Buffalo River was established by Congress in 1972 as the first National River in the United States and is one of the few remaining free-flowing streams in Arkansas . The Buffalo River flows through the three major physiographic provinces of northern Arkansas, originating in the higher elevations of the Boston Mountains, and flowing generally northeastward to cut through the Springfield and Salem Plateaus. It drops from approximately 2000 feet in the headwaters to around 500 feet above sea level at its confluence with the White River in Marion County. The Buffalo River is considered to be one of Arkansas\u27 greatest natural treasures; thus there is strong interest in protecting it from undue anthropogenic influences. A general description of the area within the Buffalo River Watershed was given by Smith (1967)