For centuries swidden was an important farming practice found across the girth of Southeast Asia. Today, however, these systems are changing and sometimes disappearing at a pace never before experienced. In order to explain the demise or transitioning of swidden we need to understand the rapid and massive changes that have and are occurring in the political and economic environment in which these farmers operate. Swidden farming has always been characterized by change, but since the onset of modern independent nation states, governments and markets in Southeast Asia have transformed the terms of swiddeners' everyday lives to a degree that is significantly different from that ever experienced before. In this paper we identified six factors that have contributed to the demise or transformation of swidden systems, and support these arguments with examples from China (Xishuangbanna), Laos, Thailand, Malaysia, and Indonesia. These trends include classifying swiddeners as ethnic minorities within nation-states, dividing the landscape into forest and permanent agriculture, expansion of forest departments and the rise of conservation, resettlement, privatization and commoditization of land and land-based production, and expansion of market infrastructure and the promotion of industrial agriculture. In addition we note a growing trend toward a transition from rural to urban livelihoods and expanding urban-labor markets.Keywords Policies . Political economy . Political ecology . Swidden . Southeast Asia Swidden farmers throughout Southeast Asia are rapidly transforming or abandoning traditional land-use practices (Padoch et al. 2007). In order to explain the demise of swidden we need to understand the political and economic changes that have occurred across the region, affecting the contexts in which these farmers operate. Of course, change has always characterized the milieu within which swiddeners function, and the intensities and rapidity of change in

Awareness of environmental services and land use change in Southeast Asia is high among scientists, policymakers, and society. In the case of transboundary smoke, the level of awareness and concern in the region is high, but subsides in between periods of 'crisis'. Although there is a rising level of awareness of habitat loss and associated loss of genetic diversity, the basic cause-effect relationships underlying the ecological roles of biodiversity are still debated. Degradation of watershed functions is the most mature of our three meso-scale environmental topics; indeed it shows signs of being 'fossilized' by vested interests in the present consensus. Land use planning and other regulatory approaches have had little success. Policy instruments for achieving meso-level environmental policy objectives through changing incentives such as payment schemes for environmental services, have not been tested widely in Southeast Asia (or anywhere else). Further research and experimentation needs to incorporate strategic consideration of processes and spatial scales of environmental impacts and resource governance.

Ethnic minority farmers in the infamous Golden Triangle were first incorporated into the nation states of China, Laos and Thailand, and later into the economic region called the Golden Economic Quadrangle. This article traces policies in each country for minorities, development and the environment, followed by an analysis of agrarian transitions under economic regionalization. Using the framework of powers of exclusion and racialization, our findings show the changes for ethnic minorities who, with the exception of those in the lowlands, face environmental enclosures that dispossess them from lands on which livelihoods are based. Ideological legacies from the Golden Triangle, including ‘backward’ minorities, the fight against drugs, and threats to national security, continue to inform policies and development projects. While some farmers have become entrepreneurs planting cash crops, most face increasing marginalization under deepening regional capitalism.

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District heating networks are a convenient, economic and environmental-friendly way to supply heat to buildings connected to a central heating plant. However, the control of such a system becomes challenging if the total length of the network reaches several kilometers because the travel time of the information into the system is over hours. One solution consists in instrumenting all the parts of the network and performing a closed loop control to optimize the temperature and the mass flow rate supplied to every single consumption point. However this solution is generally expensive and difficult to implement in existing networks. What is proposed in this paper is to dynamically model the heat waves in the network to determine the temperatures and mass flow rates at key locations considering the ambient losses and the pipe thermal inertia. A study is performed to check the possibility to use the one-dimensional finite volume method to simulate heat waves propagation. First, an adiabatic pipe is considered as a reference test case to determine the limitations of this method. The results are compared to a 2D computational fluid dynamic simulation and numerical diffusion is exhibited for low spatial discretization. Therefore, an improved alternative model is developed to overcome this problem.