Climate change: Pro-poor adaptation, risk management, and mitigation strategies

Poverty reduction, Hunger, Climate change, Pro-poor strategies, Development planning, Adaptation measures, Policies, Land use and agriculture, Risk management,

Climate Change and Asian Agriculture

Asian and global agriculture will be under significant pressure to meet the demands of rising populations, using finite and often degraded soil and water resources that are predicted to be further stressed by the impacts of climate change. In addition, agriculture and land use change are prominent sources of global greenhouse gas (GHG) emissions. Fertilizer application, livestock rearing, and land management affect levels of GHG in the atmosphere and the amount of carbon storage and sequestration potential. Therefore, while some impending climatic changes will have negative effects on agricultural production in parts of Asia, and especially on resource-poor farmers, the sector also presents opportunities for emission reductions. Warming across the Asian continent will be unevenly distributed, but will certainly lead to crop yield losses in much of the region and subsequent impacts on prices, trade, and food security—disproportionately affecting poor people. Most projections indicate that agriculture in South, Central, and West Asia will be hardest hit.

Energetics in Delaware Bay: Comparison of two box models with observations

A corrected version of an unstratified box model of potential energy anomaly , initially developed by Garvine and Whitney (2006), and a new two-layer box model that allows for stratified and well-mixed conditions are applied to Delaware Bay. The models are applied for the Garvine and Whitney (2006) 1988-1994 study period and in Spring 2003; however, only model results of potential energy anomaly from the latter period are compared to in situ observations obtained outside the bay mouth. Unstratified model results for the two study periods reveal that the river discharge (Ω1) is the largest potential energy anomaly contributor. This term is closely followed (but with opposite sign) by the coastal current efflux term (Ω2). For the two-layer model the largest contributor is the dense inflow term (Ω6). The wind term (Ω5) is the second largest, followed by the tide (Ω3), river discharge (Ω1) and coastal current terms. In both models the solar heat flux term (Ω4) makes the smallest contribution to ϕ. The available one-month comparison of model results to observations renders statistically insignificant correlation coefficients for both models. We speculate dynamical differences between conditions at the estuary mouth and the instrument location on the nearby shelf contribute to the model-observation mismatch. Other statistics, such as the root mean square error indicate that the unstratified model performs better than the two-layer model for the observation period. The latter model is, however, able to depict the importance of tides and winds in the computation of potential energy anomaly and is able to detect the response of ϕ due to strong wind events. While there is no clear model choice for the Delaware Bay, the unstratified model may be entirely inappropriate for highly stratified estuaries

A Study of the Long-Term Behavior of Hybrid Systems with Symmetries via Reduction and the Frobenius-Perron Operator

Hybrid dynamical systems are systems which undergo both continuous and discrete transitions. As typical in dynamical analysis, an essential goal is to study the long-term behavior of these systems. In this work, we present two different novel approaches for studying these systems. The first approach is based on constructing an analog of the Frobenius-Perron (transport) operator for hybrid systems. Rather than tracking the evolution of a single trajectory, this operator encodes the asymptotic nature of an ensemble of trajectories. The second approach presented applies to an important subclass of hybrid systems, mechanical impact systems. We develop an analog of Lie-Poisson(-Suslov) reduction for left-invariant impact systems on Lie groups. In addition to the Hamiltonian (and constraints) being left-invariant, the impact surface must also be a right coset of a normal subgroup. This procedure allows a reduction from a $2n$-dimensional system to an $(n+1)$-dimensional one. We conclude the paper by presenting numerical results on a diverse array of applications.Comment: 46 page