Development of Trigger Levels to Assess Catchment Disturbance on Stream Suspended Sediment Loads in the Magela Creek Catchment,Northern Territory,Australia

Trigger levels for fine suspended sediment (FSS) load in streams are required to identify rainfall-runoff events that have significantly elevated FSS loads, compared with expected background loads, as a result of catchment disturbance. Stream FSS load data collected in the mine-impacted Magela Creek catchment in the wet-dry tropics were used to derive water quality management trigger levels for two approaches – a Before-After-Control-Impact Paired difference design (BACIP) and a regression relationship between observed FSS load and corresponding event discharge characteristics. The results indicate that both the BACIP and regression relationship approaches behave similarly, with similar FSS load events elevated above trigger levels. Notwithstanding this, it is recommended that in order to reliably assess the location and magnitude of a catchment disturbance on FSS load, a combination of BACIP and regression relationship approaches must be adopted. In this study, an event with a FSS load above trigger levels associated with both BACIP and the regression relationship fitted for the downstream site is considered to be significantly elevated as a result of a disturbance within the mine-impacted region. While this technique cannot conclusively determine whether the cause of the disturbance is mine-related or natural (such as fire or bank erosion), it is an efficient statistical method of identifying events that warrant further investigation and management action, if required.     

Erosion and Nutrient Loss on Sloping Land under Intense Cultivation in Southern Vietnam

To help improve the well‐being of the local people, a joint Vietnamese‐UK team set out to establish a way of estimating soil and nutrient losses under different land management scenarios, using field data extrapolated through remote sensing and GIS, to obtain catchment‐wide estimates of the impact of land cover change. Immigration from remote provinces to the Dong Phu District of Binh Phuóc Province, about 120 km north of Ho Chi Minh City, has led to disruption of soil surface stability on easily eroded clayey sandstones, creating rapid nutrient depletion that affects crop yields and siltation in the channel of the Rach Rat river downstream. The poor farmers of the areas see crop yields drop dramatically after two or three years of cultivation due to the fertility decline. Soil loss varies dramatically between wet season and dry season and with ground cover. Erosion bridge measurements showed a mean loss of 85.2 t ha^?1 y^?1 under cassava saplings with cashew nuts, 43.3 t ha^?1 y^?1 on uncultivated land and 41.7 t ha^?1 y^?1 under mature cassava. The rates of erosion were higher than those reported in many other parts of Vietnam, reflecting the high erodibility of the friable sandy soils on the steep side‐slopes of the Rach Rat catchment. However, although the actual measurements provide better soil loss data than estimates based on the parameters of soil loss equations, a large number of measurement sites is needed to provide adequate coverage of the crop and slope combinations in this dissected terrain for good prediction using GIS and remote sensing.     

A GIS method for assessing the zone of human-environmental impact around archaeological sites: a test case from the Late Neolithic of Wadi Ziqlâb,Jordan

Assessing the impact of prehistoric sites on their local environment is difficult to accomplish with standard archaeological methods. Simulation modeling offers a solution to this issue, but it is first necessary to delimit a site catchment, or “zone of impact”, around archaeological sites in which to carry out human–environment interaction modeling. To that end, I have developed a new method for GIS-based catchment reconstruction and distilled it into a custom module (r.catchment) for GRASS GIS, which calculates catchments of a given area based on anisotropic travel costs from a point of origin. One method of applying this new module in exploratory catchment modeling is discussed using the pastoral economy of the Late Neolithic period in Wadi Ziqlâb, Northern Jordan as a test case. A model of Late Neolithic herding economy and ecology is constructed, which combines data from archaeology, phytogeography, range science, agronomy, and ethnohistory. Four sizes of pastoral catchments are then derived using r.catchment, and the herd ecology model is used to estimate the stocking-rate (carrying capacity) of mixed goat and sheep herds for each catchment. The human populations these herd numbers could support (between 3 and 630 people in the Wadi) are then compared with human population estimates derived from household architectural analyses (between 18 and 54 people in the Wadi) to determine the most probable catchment configurations. The results indicate that the most probable zone of impact around the known Late Neolithic sites in Wadi Ziqlâb was somewhere between 9 and 20 square kilometers, delineated by 3 and 4.5 km pasture radii respectively.     

Rugged Plateaus and Extensive Floodplains — Modelling Landform Evolution in a Northern Australian Catchment

Medium to large natural catchments are often more spatially heterogeneous than small catchments or single landforms. Attempting to model landform evolution of large areas is consequently more complex. This paper demonstrates that modelling landform evolution in medium to large catchments can be improved by calibrating the model to smaller, more geomorphologically homogenous sub‐catchments. The paper investigates landform evolution in the Ngarradj catchment in the Northern Territory of Australia (a medium scale catchment of approximately 67 km²). The catchment is complex and contains two distinct landform regions; an upland plateau region with highly dissected sandstone and shallow, sandy soils, and a lowlands region with gentle, wooded slopes and floodplains with deep, sandy soils. The SIBERIA landform evolution model is calibrated and applied to the Ngarradj catchment. The complexity of the Ngarradj catchment is incorporated into the modelling by dividing the catchment into three sub‐catchments (Swift Creek (SC), Upper Main (UM) and East Tributary (ET)) which are relatively homogeneous and for which hydrology and sediment transport data are available. A discharge‐area relationship and long‐term, sediment loss rates for the catchment are derived based on an annual series flood frequency analysis of a 20 year runoff record predicted in a previous study. Sediment transport modelling incorporates both suspended and bedload sediment loss. The denudation rates derived using these data are 37, 63 and 77 mm kyr^?1 for the SC, UM and ET sub‐catchments, respectively. Model predictions indicate that the UM sub‐catchment will have the greatest mean erosion. This is balanced by the large amount of deposition that will occur in the upper Ngarradj valley of the UM sub‐catchment. Further deposition occurs on the floodplain of Ngarradj, with the area between the SC and ET/UM (up‐stream) sub‐catchments experiencing a small net accretion of sediment (15 mm kyr^?1).     

汉晋变迁考古学研究的地域意义——以安徽马鞍山地区吴晋墓葬为材料

分区是考古学研究常用的方法,在历史考古学研究中,因文献记载的详细、考古材料的连续、集中,使具体地点的考古学分区研究有了进一步细化的可能。安徽马鞍山地区吴晋墓葬在孙吴和东晋两个时期有着显著的区域特征,这与该地特殊的区位有着很大的关联,而这些规律的总结正体现出汉晋变迁考古学研究的地域意义,从而对历史考古学研究的方法进行有意探讨。     

First contribution of the excavation and chronostratigraphic study of the Ruways 1 Neolithic shell midden (Oman) in terms of Neolithisation,palaeoeconomy, social-environmental interactions and site formation processes

The NeoArabia project tries to understand how environmental, social, economic and technological factors work in concert to influence settlement and abandonment along a latitudinal transect of 1200 km from UAE to southern Oman. This region was affected by wide north–south variations in the Indo-Arabian monsoon, marine upwelling activity and eustatic variations in the Mid-Holocene. On the local settlement scale, this transect is based on fine stratigraphic excavations and permits the reconstruction of the site formation processes and site catchment analysis. A large number of studies have been conducted on the Ruways-1 site, focusing on a deep stratified sequence corresponding to three millennia of occupation. These studies include on-site climate-environmental signal analysis, local palaeogeography and environmental reconstruction, reservoir effect studies, typo-technological studies, palaeoeconomic strategies, anthropological studies, sclerochronological studies and, finally, site formation processes, the understanding of which makes it possible to explain the potential and limits of the archaeological excavation. The first results confirm the richness of these archaeological archives for documenting the socio-environmental dynamics, but also the richness of its complex sedimentary structure and the importance of conducting fine and multidisciplinary excavations to answer questions about the rhythms and functions of occupations and the causalities of socio-environmental changes.     

Smolensk and the Varangians according to the archaeological data

The historical and archaeological sources from the Viking period which concern the city of Smolensk and the large cemetery at Gnyozdovo by the river Dnieper are discussed.

The author examines the most important find groups and grave types and asserts that extremely few specific Scandinavian traits are to be found.

His conclusion is that Smolensk was founded by the Slavs before the Gnyozdovo cemetery was established. The fact that only a few Scandinavian graves are known from the tenth century and none from the ninth and eleventh must mean that only small groups of Scandinavians had settled in the Smolensk area and these were rapidly assimilated with the Slav groups.     

学区化外部性对城市空间的影响

本文分析了学区房和学区的不同意义,进而对学区的正负外部性进行了解析,认为学区、学校、个人、政府间复杂的博弈关系最终导致了城市中的社会空间分异和居住空间分异的加强。在梳理发达国家主要城市经验、对比北京市与剑桥市的学区发展基础上,指出当前的划区政策增强了学区的稀缺性,却没有增加公平性,从而助推房价的高涨。为了更好地促进教育均等化实现,政府应努力提高优质教育学校的数量;形成资本性收入在学校和市场间的合理流动与分配;废弃以学区为主实施优质学区管理的办法,实施学校分层化管理,从而促进教育公平性和对人力资源开发这一综合目标的实现。     

The use of optimal foraging theory to estimate Late Glacial site catchment areas from a central place: The case of eastern Cantabria,Spain

By defining the area of economic influence associated with a given archaeological site, valuable information can be obtained about human occupation patterns, whilst differentiation of the surrounding biotopes facilitates research into the adaptive relationship between subsistence strategy and resource availability. Despite the inherent potential of this type of analysis, its development comes up against important conceptual and methodological limitations. The present article analyses the possibility of using optimal foraging theory, as representative of the hunting behaviour of hunter–gatherer groups, in the accurate objective estimation of the catchment areas of a site. The obtained results are applied to the study of the reasons behind the geographical site specialisations observed in eastern Cantabria, Spain during the Magdalenian.     

Integrating Geomorphological Assessments and Oral Histories in Catchment Management: Implications for the Mulgrave River,Northeastern Australia

The dramatic decline in the integrity of Australian river systems in recent decades has seen the development of landcare and catchment management groups across the continent as the main facilitators of river rehabilitation works. There is growing concern for the need to develop adaptive management frameworks that assist informed decision making through the integration of social and geomorphological knowledge into catchment planning. In the Mulgrave River Catchment of northeastern Queensland, difficult management decisions have to be made with limited access to knowledge of natural processes and baseline geomorphological data. To date management decisions have been based almost exclusively on oral histories that state that point bars are accreting and the river is becoming shallower due to bank erosion. As a result bank stabilisation and removal of sand from within the channel have been recommended in the absence of any geomorphological assessments. This study compares oral histories of river bank erosion in the Mulgrave River with geomorphic evidence to highlight the need for integrated landscape scenario planning. The results of grain size analysis of bank and bed material from 27 locations, involving 47 samples, suggest that bank erosion cannot be delivering sediments to point bars. Furthermore, qualitative analysis of historic parish maps and aerial photographs shows that there has only been moderate bank erosion at three locations along the Mulgrave River since European settlement. The study demonstrates the important role that geomorphological investigations have for catchment management and the need for management frameworks that integrate geomorphological processes and landholder priorities for sustainable river management.