Jean-Christophe Castella

Comparison of Three Maps at Multiple Resolutions: A Case Study of Land Change Simulation in Cho Don District, Vietnam

Geographic modelers frequently compare maps of observed land transitions to maps of simulated land transitions to relate the patterns in reference maps to the output from a simulation model. Pixel-by-pixel analysis of raster maps at a single resolution is useful for this task at a single scale, but scientists often need to consider additional scales. This article presents methods to satisfy this need by proposing a multiple-resolution method to compare land categories in three maps: a reference map of time 1, a reference map of time 2, and a simulation map of time 2. The method generates a three-dimensional table that gives the percentage of the study area for each combination of categories at the maps’ native resolution and at several nested sets of coarser squares. The method differentiates allocation disagreement within coarse squares, allocation disagreement among coarse squares, quantity disagreement, and agreement. We illustrate the method with output from a run of the SAMBA agent-based model from 1990 to 2001 using 32-m resolution pixels for Cho Don District, Vietnam. Results show that half of the overall disagreement is attributable to allocation disagreement within squares that are 506 m × 506 m, which is about the average size of a village. Much of the remaining disagreement is misallocation of forest and shrub between the northern and southern parts of the district, which is caused by differences between the data and the simulation concerning transitions from the crop and shrub categories.

Territorialising sustainable development: The politics of land-use planning in Laos

Abstract Since the emergence of the sustainable development paradigm in the late 1980s, land-use planning has become a key arena for political debates over society-environment interactions and, in practice, an important means for territorialisation projects. The paper reviews the main planning approaches that have been employed over the past three decades in the Lao Peoples Democratic Republic, a country that has long been viewed as a valuable policy testing ground for the proponents of sustainable development. It highlights three concurrent territorialisation projects that have shaped the history of land-use planning and have fuelled tensions between central and subnational governments and local actors, national and foreign institutions, and land suitability and sustainability approaches. The paper argues that the latter tensions reflect an important dynamism and reactivity in the planning arena. It concludes that the capacity of land-use planners to adapt to specific contexts and evolving socio-environmental challenges should be harnessed in order to reconcile conflicting approaches to planning and, perhaps, to achieve sustainable development.

Assessing the role of learning devices and geovisualisation tools for collective action in natural resource management: experiences from Vietnam.

In northern Vietnam uplands the successive policy reforms that accompanied agricultural decollectivisation triggered very rapid changes in land use in the 1990s. From a centralized system of natural resource management, a multitude of individual strategies emerged which contributed to new production interactions among farming households, changes in landscape structures, and conflicting strategies among local stakeholders. Within this context of agrarian transition, learning devices can help local communities to collectively design their own course of action towards sustainable natural resource management. This paper presents a collaborative approach combining a number of participatory methods and geovisualisation tools (e.g., spatially explicit multi-agent models and role-playing games) with the shared goal to analyse and represent the interactions between: (i) decision-making processes by individual farmers based on the resource profiles of their farms; (ii) the institutions which regulate resource access and usage; and (iii) the biophysical and socioeconomic environment. This methodological pathway is illustrated by a case study in Bac Kan Province where it successfully led to a communication platform on natural resource management. In a context of rapid socioeconomic changes, learning devices and geovisualisation tools helped embed the participatory approach within a process of community development. The combination of different tools, each with its own advantages and constraints, proved highly relevant for supporting collective natural resource management.

Constructing a Common Representation of Local Institutions and Land Use Systems through Simulation-Gaming and Multiagent Modeling in Rural Areas of Northern Vietnam: The SAMBA-Week Methodology

The authors propose to exploit the similitude and complementarity between simulation-gaming and multi-agent modeling through the development of a new methodology called SAMBA-Week, which is used for agricultural research and development. The need for such a new methodology came from the context of mountainous areas of Northern Vietnam characterized by a high social and natural diversity. As actions of research and development typically involve multiple actors, a precondition for communication is a mutual understanding of each others point of view. The authors thus used simulation-gaming, individual interviews, and multiagent modeling to enhance communication by constructing with the stakeholders a shared representation of their system as a basis for discussion.

A model of the science-practice-policy interface in participatory land-use planning: lessons from Laos

An essential task of participatory action-research is to help close the policy implementation gap that leads to large discrepancies between policy frameworks and local practices. Too often, official regulations, laws and decrees fail to translate into concrete action on the ground. Loose institutional linkages between research, extension and local communities are often blamed as the main culprits for this gap. In turn, many stakeholders call for enhanced participation as a way to bring together scientists, development practitioners and local communities in negotiating competing claims for natural resources and designing realistic pathways towards sustainable development. Despite such general consensus about the value of participation, the latter cannot be decreed nor imposed. Participation is an emerging quality of collective-action and social-learning processes. In this paper, the experience of participatory land-use planning conducted in Laos serves to illustrate a model of the science–practice–policy interface that was developed to facilitate the interactions between three groups of stakeholders, i.e. scientists, planners and villagers, in designing future landscapes. Emphasis was put on developing an approach that is generic and adaptive enough to be applied nationally while engaging local communities in context-sensitive negotiations. The set of tools and methods developed through action-research contributed to enhanced communication and participation from initial consultation and cooperation stages towards collective decision-making and action. Both the activity of landscape design and the resulting patterns can be improved by incorporating landscape science in strategic multi-stakeholder negotiations.

Vietnam's forest transition in retrospect: demonstrating weaknesses in business-as-usual scenarios for REDD.

One of the prerequisites of the REDD+ mechanism is to effectively predict business-as-usual (BAU) scenarios for change in forest cover. This would enable estimation of how much carbon emission a project could potentially prevent and thus how much carbon credit should be rewarded. However, different factors like forest degradation and the lack of linearity in forest cover transitions challenge the accuracy of such scenarios. Here we predict and validate such BAU scenarios retrospectively based on forest cover changes at village and district level in North Central Vietnam. With the government’s efforts to increase the forest cover, land use policies led to gradual abandonment of shifting cultivation since the 1990s. We analyzed Landsat images from 1973, 1989, 1998, 2000, and 2011 and found that the policies in the areas studied did lead to increased forest cover after a long period of decline, but that this increase could mainly be attributed to an increase in open forest and shrub areas. We compared Landsat classifications with participatory maps of land cover/use in 1998 and 2012 that indicated more forest degradation than was captured by the Landsat analysis. The BAU scenarios were heavily dependent on which years were chosen for the reference period. This suggests that hypothetical REDD+ activities in the past, when based on the remote sensing data available at that time, would have been unable to correctly estimate changes in carbon stocks and thus produce relevant BAU scenarios.

Connecting Marginal Rice Farmers to Agricultural Knowledge and Information Systems in Vietnam Uplands

Abstract In Vietnam, agricultural extension has contributed to rural development and poverty alleviation over the past two decades of agricultural decollectivization, but it was not very effective in reducing disparities within farmer communities. The study examined how better interactions of extension services with other agencies and information sources may help marginal farmers in catching up with the general improvement of living conditions in a mountainous area in northern Vietnam. It combined three complementary viewpoints on this issue: that of the agricultural extension staff, that of farmers and that of development experts with a long working experience in the mountains of Vietnam. The analysis of existing structures and functions of the extension system revealed a number of obstacles to the participation of marginal farmers in extension programmes and helped to identify relevant domains of intervention.

Towards new modes of governance of the research–development continuum to facilitate the dissemination of agricultural innovations in a mountainous province of northern Vietnam

The mountainous regions of northern Vietnam have, thus far, failed to share the impressive economic development that has blessed the rest of the country in the past decade. Despite the multiplicity of Research and Development (R&D) projects working there with the common objectives of agricultural development and poverty alleviation, lack of coordination among projects can limit the effectiveness of development actions beyond the original place they were carried out. Moving from experimental development projects to actual implementation of results on a large scale requires defining mechanisms for better coordination among R&D projects and testing them in a real development context. Since 2000, a collective of R&D projects has developed such an approach in Bac Kan Province. It involves both organisational and technical aspects such as the management of databases, the testing of innovation, the provision of decision support aid for the diffusion of innovation, and the formulation of development policies.

Facilitating the Diffusion of Alternative Cropping Systems for Mountain Agriculture in Vietnam

ABSTRACT In the mountain areas of Northern Vietnam, the past decade was marked by rapid changes in agricultural production systems. Under the new land policies, some farmers had no other choice than to return to the traditional slash and burn cropping systems. Now, however, land allocation to individuals prevents farmers from shifting cultivation to newly cleared land, which is necessary to regenerate soil fertility, and thus for slash and burn practices to remain sustainable. As a consequence, in some villages there is an increasing risk of land degradation. As livestock feeding relies mainly on natural resources, land degradation results in chronic shortages of forage and more generally to a crisis in traditional production systems. To tackle these issues, the Mountain Agrarian Systems Program has designed alternative cropping systems based on direct seeding under a cover crop. Beside their widely recognized role in the conservation of soil and natural resources, these innovative techniques also provide good forage for the farm animals. However, their diffusion implies a profound reorganization of the crop-livestock systems at complementary scales from field, farm, and up to the village community. Accompanying such changes requires that all partners jointly develop communication procedures based on a common knowledge base. In this paper we discuss the spatial compartment model, a graphic discussion and simulation tool used to represent a village in a way that allows both researchers and local stakeholders to understand and visualize their individual and collective situations. We used the model to test a set of cropping innovations through a participatory simulation with local farmers. The farmers were very interested in the new techniques, and some began to test them on their own land. The spatial compartment model proved to be an effective communication tool between scientists and local stakeholders.

Path coefficient analysis to assess yield losses due to a multiple pest complex in cotton in Thailand

A network of experiments was established in three different agroecological areas at the periphery of the Central Plain of Thailand during three successive years to assess the effect of a multiple insect pest complex on cotton yield loss. A large range of combinations of jassid and bollworm injuries was achieved from the application of several insecticide treatments and sowing dates. Other pests were of minor incidence. Seed-cotton yield varied from 0 to 3600 kg/ha, and yield losses due to pests ranged between 0 and 100% of the attainable yield. Damage mechanisms were addressed through path coefficient analysis of the interaction between injuries and plant compensation. Before boll production, jassids were the most serious pests, while bollworms had a positive effect on vegetative growth. At the fructification stage, bollworms were very harmful, while sucking insects such as jassids became progressively less important. Injuries did not necessarily lead to yield losses because of the plant compensation ability. Cotton response to pest injuries depended on the development stage and crop status. Decisions made on cotton protection against pests should thus consider the development stage of the crop and interactions between injuries instead of the traditional single pest population threshold. This study of a plant- pest system exemplifies the need to incorporate plant compensation processes in the design of pest management programmes aiming at reducing insecticide use.