Pressurised pastoralism in South Gobi, Mongolia: what is the role of drought?

The desert-steppe region of southern Mongolia is susceptible to drought and extreme winter weather ( dzud ) that in combination form Mongolia's worst natural hazard. Low precipitation and high climatic variability in this dryland environment impact the landscape and affect pastoralism, the dominant rural lifestyle. Using the Standardised Precipitation Index (SPI), this paper identifies drought occurrence in South Gobi Province, Mongolia. It then examines the relationship of drought with climate factors, interaction with vegetation (derived from Normalised Difference Vegetation Index - NDVI - data), and local human and livestock populations, and the dzuds of 1999–2001. Results show that drought is recurrent in the region, reaching extreme intensity most recently in 2005–2006. In contrast with the prevailing concept of drought impacting dzuds , the study did not find a connection between drought and dzud in South Gobi Province. Though repeated events, these natural hazards occur independently in the region. Climatic variables show increasing temperatures (>1°C), fluctuating precipitation patterns and a decline in vegetation cover. The principal long-term correlation of drought is with human population rather than natural factors, dzud or livestock numbers.     

The p‐Regions Problem. p‐区域问题

The p‐regions problem involves the aggregation or clustering of n small areas into p spatially contiguous regions while optimizing some criteria. The main objective of this article is to explore possible avenues for formulating this problem as a mixed integer‐programming (MIP) problem. The critical issue in formulating this problem is to ensure that each region is a spatially contiguous cluster of small areas. We introduce three MIP models for solving the p regions problem. Each model minimizes the sum of dissimilarities between all pairs of areas within each region while guaranteeing contiguity. Three strategies designed to ensure contiguity are presented: (1) an adaptation of the Miller, Tucker, and Zemlin tour‐breaking constraints developed for the traveling salesman problem; (2) the use of ordered‐area assignment variables based upon an extension of an approach by Cova and Church for the geographical site design problem; and (3) the use of flow constraints based upon an extension of work by Shirabe. We test the efficacy of each formulation as well as specify a strategy to reduce overall problem size.     

Co-Producing Mobilities: negotiating geographical knowledge in a conference session on the move

In an experimental session entitled Co-Producing Mobilities held at the 2014 Royal Geographical Society-Institute of British Geographers Annual Conference, 20 mobility scholars travelled around London on foot, by bus and by Tube to investigate how mobilities could be considered co-produced. In this paper, 18 participants reflect on this collaborative experiment and on how it influenced their thinking about mobilities, geographical knowledge and pedagogy. Contributions cast light on the function of conferences and the multiple forms of pedagogy they enable, and provide guiding resources for those now wanting to continue such experiments.     

Nothing Lasts Forever: Environmental Discourses on the Collapse of Past Societies

The study of the collapse of past societies raises many questions for the theory and practice of archaeology. Interest in collapse extends as well into the natural sciences and environmental and sustainability policy. Despite a range of approaches to collapse, the predominant paradigm is environmental collapse, which I argue obscures recognition of the dynamic role of social processes that lie at the heart of human communities. These environmental discourses, together with confusion over terminology and the concepts of collapse, have created widespread aporia about collapse and resulted in the creation of mixed messages about complex historical and social processes.     

Paleoindian technological provisioning strategies in the northwestern Great Basin

Great Basin populations during the Pleistocene–Holocene Transition (PHT) are often characterized as being mobile and focused on wetlands; however, the factors that influenced where Paleoindians selected residential campsites are poorly understood. Using predictions derived from optimal foraging-based patch choice models and GIS reconstructions of the PHT landscape, some researchers have argued that occupations in smaller wetlands should have been shorter than occupations in larger wetlands but such arguments have rarely been evaluated using empirical data. The PHT lithic record provides an opportunity to evaluate the relationship between wetland size and occupation span by applying Kuhn's (1995) concept of technological provisioning. Kuhn expects more mobile populations to provision individuals and more sedentary populations to provision places and suggests that: (1) a strategy of provisioning individuals should be reflected by a high proportion of more extensively used artifacts made on non-local raw materials; and (2) a strategy of provisioning places should be reflected by a high proportion of less extensively used artifacts made on local raw materials. We apply the technological provisioning concept to lithic assemblages from two of the Parman localities, extensive PHT sites in the northwestern Great Basin, and compare local and nonlocal artifacts to determine if Paleoindians shifted from provisioning individuals while moving to/from the sites to provisioning the place while occupying them. There is no relationship between artifact transport distance and artifact use intensity. We interpret these findings as evidence that Paleoindians did not alter their provisioning strategies while occupying the Parman localities, likely because occupations were brief within a small wetland poorly-suited to support groups for long periods.