The Rolt Memorial Lecture 2017: Conserving the Waterways Heritage

ABSTRACT

This article describes the work of the Canal & River Trust in managing and conserving the heritage assets and the wider historic environment of the Trust's waterways in England and Wales. Various types of heritage assets are described, and the ways in which these assets are managed, including via archaeological recording, along with conservation-led repairs to historic engineering structures and other historic waterway-related buildings, are considered. New directions that offer effective and efficient ways of dealing with heritage assets are examined.     

基于腾讯迁徙大数据的长三角城市群春运人口流动时空特征

开展城市群人口流动研究对促进区域人口有序流动和城市群协同发展具有重要的理论和实践指导意义。本文基于腾讯迁徙大数据，运用GIS空间统计和K-shell分解等方法，从人口流动总量、位序、时序和网络层级等方面，对我国长三角城市群2018年春运期间的人口流动特征进行系统研究。结果表明：①长三角城市群春运期间大规模的“返乡流”和“返城流”呈现明显的对称性，并分别于除夕和第一个工作日达到最高峰。②经济发展水平相对较高的上海、苏州、杭州等为劳动力输入型城市，而经济发展水平相对较低的盐城、安庆和滁州等为劳动力输出型城市。③长三角城市群内部人口流动网络具有明显的层级特征，其中上海和杭州是人口辐射核心城市，上海-合肥、上海-南京、上海-杭州等是人口流动的主体路径；空间上东部-西部横向人口流动最为频繁，大体呈现“Z”字形。     

Retracing Rivers and drawing swamps: Using a drawing tablet to reconstruct an historical hydroscape from army corps survey maps

Abstract

This article presents a novel geospatial approach to reconstructing and analyzing environmental change over extensive spatial and temporal scales, even in systems such as rivers and streams that are comparatively difficult to digitize. We used a drawing tablet and stylus to digitize features found on historical Army Corps maps across the spatially extensive landscape of the Lower Wabash River’s riparian zone, in Indiana and Illinois, USA. The methodology allows for an efficient reconstruction of sinuous and irregular environmental features, such as sloughs, and demonstrates the utility of digitizing historical maps to understand the evolution of surface water quantity and location across a landscape. We then compared these historical data to contemporary environmental datasets for the same study area to understand what changes have occurred over a 100?year period. This reveals that the hydroscape of the Lower Wabash River has been significantly altered by past human activity, notably through the reduction of swamps, wetlands, and sandbars, and the increase in drainage ditches and overall stream area. Notably, many of these historical alterations are not captured within current environmental datasets.     

Stone age predation on large African bovids

Crown height measurements are used to establish age distributions for several species of larger bovids represented in faunal samples from the Middle Stone Age (earlier Upper Pleistocene) deposits of the Klasies River Mouth Caves and the Later Stone Age (later Upper Pleistocene/Holocene) deposits of Nelson Bay Cave, South Africa. There are no obvious differences between the sites in the age distributions of the species they share, but there are significant differences in age distributions among species. Two basic patterns are apparent. In the first, characterizing the blue antelope (Hippotragus leucophaeus), roan antelope (Hippotragus equinus), Cape buffalo (Syncerus caffer), and giant buffalo (Pelorovis antiquus), the archaeological samples contain numerous very young animals and relatively few prime-age adults. At least in the buffalo samples, there is also a fair representation of old adults. In the second pattern, characterizing the bastard hartebeest (Damaliscus dorcas or D. niro) and especially of the eland (Taurotragus oryx), prime adults are far more prominent relative to younger and older age groups. The first pattern is similar to the natural pattern of attritional mortality that probably characterizes all healthy, stable populations of free-ranging large ungulates, while the second is more reminiscent of the age structure of live herds. The first pattern may reflect hunting focused on individual animals, particularly those whose age made them most vulnerable, while the second may reflect the susceptibility of certain species to driving, so that whole groups could be killed in traps in which differences in age had no meaning.