Estimation of soil erosion on cultivated fields on the hilly Meghalaya Plateau,North-East India

The estimation of soil erosion rates in complex subtropical agricultural systems of hilly environment is difficult and most of the traditional methods have serious limitations. The ¹³⁷Cs technique allows to obtain relatively quickly retrospective medium term soil erosion results. The objective of this study was using ¹³⁷Cs approach to quantify soil loss under agricultural system which develops under growing human pressure on the hilly terrain of the Meghalaya Plateau. The measured values of caesium inventory for all sampling points are between 2% and 63% of the reference value of caesium inventory. The estimated annual soil loss for sampling points located on the slope are between 29 and 79 Mg·ha⁻¹·yr⁻¹ in the case of an improved mass balance model. It means that soil erosion in this manually tilled agricultural area cannot be neglected.     

Local Knowledge and Economic Realities Affecting Soil Erosion in the Rach Rat Catchment,Vietnam

Several parts of Binh Phuóc Province, southern Vietnam, suffer from degraded soils and vegetation as a result of both natural erosion of weak mud rocks and sandstones and intensive human activity, especially through land clearing for agriculture on unstable slopes, deforestation, and abandonment of poor farmland. The underlying cause of this land degradation has been the farming habits of migrants of varying ethnic groups who have settled in the area since 1980. The indigenous farming knowledge of these people and the role of that knowledge in soil erosion were examined by a series of household surveys. They enabled farming practices to be related to ground cover established from a 2002 Landsat 7 ETM (Enhanced Thematic Mapper), and erosion data from a series of erosion bridge measurements. A GIS (Geographical Information System) approach was piloted as a means of identifying areas vulnerable to erosion. This could then be combined with the understanding of farming practices to reveal the relative roles of farmer behaviour, crop cover, and slope and soil characteristics in the erosion process. Land use, local people's knowledge and economic realities are the main factors, as well as natural conditions, that drive this land degradation.     

Re‐sampling for Soil‐caesium‐137 to Assess Soil Losses after a 19‐year Interval in a Hunter Valley Vineyard,New South Wales,Australia

Soils in a lower Hunter valley vineyard, New South Wales, Australia, were sampled and analysed for caesium‐137, an indicator of soil erosion status, in 1984–1985 and 2004. From the time of the vineyard's first establishment in 1971 to 1985, estimated soil losses were 250 tonnes (equivalent to 64.2 t ha^?1 yr^?1). Re‐sampling in 2004 showed that soil losses were 48 tonnes in the 19 years since 1985, equivalent to 9.7 t ha^?1 yr^?1. The decline in erosion rates may be explained by a change in land and soil management from intensive cultivation to one of no cultivation (sod culture) in 1998, and a lower annual rainfall and fewer rain‐days per year in the period from 1986 to 2004.     

周文王之法新释

周文王在完成准备灭商事业过程中,曾经推行过一条法令--."有亡荒阅".史学界一直都把这条法令诠释为:"对逃亡的奴隶进行大搜捕",并引用这段史料来说明早期周族的社会性质.本文根据资料分析,"有亡荒阅"搜捕的不仅仅是奴隶,而是各阶层逃亡的人各归其主;而且这条法令在周灭商过程中,起了重大作用,它协调了西伯与各诸候国的关系,最终形成了推翻商朝的合力.     

Quantifying the effects of erosion on the archaeology of intertidal environments: A new approach and its implications for their management

Abstract

While the high archaeological and palaeoecological value of intertidal deposits has become well known, approaches to their management remain extremely restricted. Despite the often high levels of erosion experienced by some sites there has been very little development in methods aimed at understanding or quantifying the threats. This paper presents an approach aimed at monitoring erosion within the Humber estuary, UK, where previous finds including Bronze Age boat remains and trackways have made it an area of international importance. Two sites have been investigated and the results from these demonstrate both the high rate of sediment removal and also the highly variable nature of intertidal erosion. It is argued that global figures relating to rates of erosion are wholly inappropriate when attempting to manage archaeological deposits that have survived in intertidal environments. Rather, management of such archaeologically rich but threatened landscapes is only possible through regular quantitative monitoring. Such an approach offers coastal protection authorities a valuable opportunity to assess the long-term progress of erosion and coastal change. This methodology could be employed alongside management agreements within those particular coastal cells or process units that have been identified in a Shoreline Management Plan.     

清代东太湖地区的湖田与水文生态

清代的东太湖地区的湖田出现了快速增长。随着山区水土流失,东太湖的泥沙量大增,水面植被也出现大扩展,淤积和湖田扩展也因此加速。在西部出现大缺口,大缺口在清代很快合拢。东部湖田发展使出太湖的水流受阻,吴淞江北移瓜泾口,进而使东北部湖田快速发展。湖田形成时往往先是大圩,后是小圩,以后逐步形成纵向交错的河网。植桑又加速了湖田水稻土的培肥,优良的水稻土在小圩规模上逐步形成。植桑养蚕与稻作的配合维持了传统江南生态农业的持续。     

Soil erosion and flooding on the eastern South Downs, southern England, 1976–2001

The South Downs in southern England have been farmed for 5000 years: the initial loess cover is now a thin, stony remnant as a result of erosion. During the 1980s, field monitoring of erosion events in an area of 36 km² showed that average rates of erosion are low (0.5–5.0 m³ ha⁻¹ yr⁻¹), but that occasional storms result in losses of over 200 m³ ha⁻¹ yr⁻¹ on individual fields. On soils that are only 15 cm thick, such rates pose a threat to future farming. Almost all recent erosion has been on fields of winter cereals, which are bare in the wet autumn period. Of greater significance in the short term are the effects of soil-laden runoff (or muddy floods) on urban areas. Flood damage to property has been a regular event since the conversion of this area to winter cereals in the 1970s. Soil conservation measures have been negligible and flood protection has consisted mainly of engineering works and limited land-use change at sites where property damage has occurred. Conversion to grass under the Set Aside, and an Environmentally Sensitive Area (ESA) scheme, could be an effective soil conservation and flood protection approach. In the longer term, increasing stoniness of soils, the economic incentives for arable farming in marginal areas, and the success of legal proceedings relating to flood damage, will determine the future of erosion on the South Downs. Current farming systems clearly are unsustainable and would become more so under future climates without substantial site-targeted land use change.     

陕北明长城夯土密度与雨蚀破坏的量化研究

为量化研究夯土性质对陕北明长城遗址雨蚀破坏模式的影响作用,采用室内模拟降雨试验的方法对夯土密度和雨蚀量间的关系进行定量化分析。研究结果显示,大到暴雨条件下,干湿作用产生的破坏是低强度夯土(密度1.5 g·cm^-3、1.6 g·cm^-3)最主要的雨蚀破坏模式,冲刷破坏造成的雨蚀量较小;水力侵蚀产生的冲刷破坏和重力侵蚀引起的小范围掉块是高强度夯土(密度1.7~1.9 g·cm^-3)最主要的破坏模式,冲刷破坏造成的雨蚀量较大;当土体含水率在3%~7%区间时,夯土的雨蚀量和密度呈指数函数关系,二者呈现正相关性。研究结果为探索多因素作用下夯土雨蚀的破坏机制提供方法借鉴,是土遗址病害研究的重要组成部分。     

Study on the discovered ornaments from Jafar-Abad and Tu Ali-Sofla kurgans (second phase of excavations)

In this research, typology of bronze ornaments discovered from Jafar-Abad and Tu Ali-Sofla kurgans (second phase of excavations) near Aras River in Khoda-Afarin town was investigated. These kurgans belong to combatant and migrating Eurasian tribes, which migrated to northwest Iran in Iron Age II (1200–800 B.C.). From the total number of 103 discovered objects, 93 objects were bronze ornaments, including rings, bracelet, earring, buttons for clothes, and spiral. Discovery of ornaments of various types’ revealed the existence of a social classification system of people in these tribes. In addition, study on the discovered buttons from these kurgans showed that as a tradition in burial ceremonies, the deceased were buried wearing clothes. To understand the basics of metalworking of combatant and migrating Eurasian tribes, analytical investigations were also conducted on three jewelry items including a bracelet, a ring, and an earring from a total number of 93 bronze ornaments discovered.     

An example of the establishment of the Bronze Age cultural landscape in SW Scandinavia

In the Lake Hullsjön area, Västergötland, SW Sweden, the increase in the deposits of artifacts, the erection of monumental graves, and the intensification and expansion of cultivation and grazing, is discussed in terms of cultural landscape changes at the Neolithic/Bronze Age transition c. 2500–1500 B.C. The expansion included an intensified use of low‐lying clayey areas and caused an increase in soil erosion, as indicated by the sediment stratigraphy.     

Fallout 137Cs and natural 40K as tracers of topsoil development during slope processes — a case study from the Daugai environs, Southern Lithuania

Investigations of soil erosion by ¹³⁷Cs method brings uncertainties of different nature. The estimation of the ¹³⁷Cs local inventory is associated with problems of data comparison and instrumental errors. In order to avoid systematic errors, the rate of soil erosion determined by the ¹³⁷Cs method is compared with the values obtained for other radioactive elements. Soil parameters must be regarded too. The aim of the work was to test the character of ¹³⁷Cs and ⁴⁰K distribution in the topsoil vertical section for determination erosion-accumulation type and ratio in different time spans. The topsoil thickened by different types of erosion-accumulation processes was sampled at a 2–3 cm interval. Soil samples were analysed by means of scintillation gamma spectrometry. The relationship between ¹³⁷Cs and ⁴⁰K inventories was weakest in the topsoil formed by mixing of soil material during the installation of artificial drains. Based on climatic characteristics, variations of theoretical soil accumulation rate in the last 50 years were calculated for the topsoil accumulated predominantly by water erosion. ⁴⁰K and ¹³⁷Cs correlation in the bottom of vertical section of topsoil or arable horizon are closest and this section may be used as a complementary parameter determining the local inventory value.     

Evidence of the crested form of domestic hen (Gallus gallus f. domestica) from three post-medieval sites in Hungary

In this paper, the authors introduce finds of crested hen from three post-medieval Ottoman Period (16th–17th century) sites in Hungary. All the remains were found in Buda, the former capital of Hungary. Two sites are located within the castle area, while the third lies south of the royal palace. Since the animal bone assemblages yielding the skulls of crested hen under study showed Ottoman Turkish influence and the castle of Buda was a high status area, it is likely that crested hen represents one of the newly introduced breeds of domestic animals that arrived to Hungary with people of Balkan origins.     

中国南方气候环境下“软盖层”保护的模拟实验研究

"软盖层"保护遗址墙体是目前盛行于英格兰和苏格兰,且为中欧和北欧认可的一种保护技术。"软盖层"保护技术符合我国建设遗址公园的保护技术需求,根据苏格兰的研究报告推测"软盖层"保护技术适合在中国沿海域范围气候环境下应用。该项研究是对"软盖层"保护技术应用于安徽宣城广教寺遗址公园保护与展示工程实施可能性所做的模拟实验,实验地点于上海同济大学,实验周期为一年。实验方法为将两堵模拟实验墙分为四等部分,一部分墙头覆盖砖块模拟硬盖层保护和另外三部分墙头覆盖三种不同的植被(景天科植被、马尼拉草、四季青草)模拟软盖层保护,通过安装在各不同盖层下的温度数据记录仪每半小时采集的温度变化数据,通过手持式湿度仪于每月采集墙体的湿度数据,结合图像记录等方式采集每月墙体的表观变化和植被的生长情况变化。通过一年的实验研究及数据分析表明,在中国南方地区气候环境下,"软盖层"对墙体的保护效果主要体现在极端气候环境下。同时,"软盖层"在夏季对墙体的除湿功效显著,而且在冬季并没有增加墙体湿度的副作用。实验结果还表明,草的选择对"软盖层"的功效影响颇大,建议在进一步研究中需要寻找更适用作"软盖层"的植被和土壤。     

Late quaternary alluviation and soil formation in the southern Argolid: its history,causes and archaeological implications

In the context of an archaeological survey of the southern Argolid, Greece, studies have been carried out to elucidate the evolution of the landscape since its earliest known human occupation about 50,000 years ago. One of these studies was a detailed geological mapping of the late Quaternary alluvium and soils in the area. Dated by means of thorium-uranium disequilibria, archaeological finds, and historical information, seven periods of alluviation were identified, each of short duration relative to long intervening periods of stability and soil formation. The three earliest alluvial phases, falling before and during the last glacial interval, range from about 330,000 to 32,000 years in age. No alluviation accompanied the last glacial maximum around 20,000 years ago. In fact, a stable landscape persisted until about 4500 years ago, when debris flows and widespread aggradation in the valleys resulted from major slope destabilization and soil erosion, probably as a result of extensive land clearance in the Early Bronze Age. A subsequent stable period lasted through the many upheavals of the later Bronze Age, the Dark Ages, and the early historical period. It came to an end with a brief phase of alluviation between about 300 and 50 BC. Stability returned through the late Roman period, notwithstanding considerable expansion of the settled area. Another period of destabilization, this one marked by debris flows and hence major soil erosion, is poorly fixed in time, but probably coincides with expanded maquis clearance accompanying the resettlement of the area around AD 1000. Subsequent events of soil erosion and aggradation vary in nature and timing from one drainage to the next and, in some areas, continue today.Nature and chronology of the soil forming and alluviation events show that simple correlations with climatic events do not suffice to explain them. For the latter ones, past about 2500 BC, human activity seems to be the dominant cause, but once again the relation between cause and effect is not straightforward. Land clearing, or neglect of soil conservation efforts during economic downturns, appear to have a more devastating effect upon the landscape than do intensive land use or total land abandonment.     

Gorad Beuno: investigation of an ancient fish-trap in Caernarfon Bay, N. Wales

Aerial reconnaissance in 1989 revealed a semicircular structure lying just off the coast at Clynnog Fawr in Caernarfon Bay, North Wales. The similarity in shape of the structure to other coastal fish-traps in the area promoted further study. Several avenues of research were followed. Historical sources were scrutinized in an attempt to find a date for the construction of the structure. A hydrographic survey was used to obtain the exact position and shape of the anomaly. A survey of the cliff and beach directly inland of the site was also made.
The anomaly was seen to lie further out to sea today than would have been the case at the time of its construction, indicating an area of coastal erosion. In an attempt to understand this process, the marine and atmospheric forces acting on the area were examined. In association with the processes of coastal erosion, soil tests were undertaken to assess the nature of the material being eroded.
Using both historical and physiological evidence it was concluded that the anomaly was indeed a fish-trap, constructed at about the beginning of the 13th century. The results from the different avenues of study have shown a sea-level rise of about 2.84 m and a cliff recession of about 118 m since its construction.     

左江流域水土流失现状与治理措施

左江流域包括扶绥、崇左、宁明、龙州、凭祥、大新六县市,位于南宁地区的西南部。由于长期以来不合理的开发利用,致使水土流失现象十分严重,不但有面蚀、沟蚀,有些地方甚至发展成崩岗。该区域总面积15092.39Km²,水上流失面积525.81Km²,本文在分析水土流失现状及成因的基础上,提出相应的水土保持措施。     

The soils of an Iron Age farm site ‐bjellands⊘ynæ, SW Norway

Soil investigations have been carried out at an Iron Age farm site lying under natural vegetation. The soils of the area were mapped and described, and soil samples analysed for pH, organic carbon, total nitrogen, acid‐soluble phosphorus, and available sodium, potassium, calcium and magnesium. Two soil types were distinguished on the mineral soils ‐ Brown Podzolic Soils and Iron Humus Podzols. The former are associated with a higher pH, higher phosphorus contents, and a lower carbon‐nitrogen ratio. These differences arc difficult to explain by natural causes, and arc ascribed to cultivation and manuring of the soil during the occupation of the site.     

Methods for assessing stormwater management at archaeological sites: Copan Ruins case study

Archaeological sites may be discovered by fortuitous soil erosion, but their protection requires deliberative stormwater management plans and estimates of runoff volumes. This paper uses the Maya site of Copan, Honduras to demonstrate widely applicable methods to estimate runoff, including use of satellite rainfall data processed by single parameter models. Our analysis compares present day estimates of runoff and erosion with those of two historic periods, 900 A.D during peak Maya occupation of the Great Plaza, and 1800 A.D. prior to excavation when the site was mostly forest covered. For each period, the watershed area, soil, land cover, and rainfall data were used with a single parameter Curve Number model to estimate the runoff volume for annual to decadal storms. The maximum runoff depth and erosive potential in conveyance channels was then computed with the HEC-RAS model. The models did not predict runoff would occur for the forested period of 1800 A.D., but predicted that runoff for 900 and post-1800 A.D was large enough to cause the erosion observed in the drainage channel today. Our results provide runoff magnitudes that demonstrate the need for Copan Maya designed stormwater removal infrastructure described in earlier archaeological analysis. The need for stormwater removal was also designed into the wet Maya site of Palenque, while stormwater capture and storage was designed into the Maya sites of Tikal, a drier site due to local drainage characteristics and water availability. Methods used in stormwater runoff analysis can empower communities and managers to develop scientifically and culturally appropriate non-structural management methods to conserve archaeological sites.     

Tell formation processes as indicated from geoarchaeological and geochemical investigations at Xeropolis,Euboea, Greece

Xeropolis is a tell site on the island of Euboea, Greece just to the east of the village of Lefkandi, and was occupied from the Early Bronze Age to the Early Iron Age. Excavations in recent years have provided an opportunity to investigate site formation processes using geoarchaeological and geochemical techniques. Sediments derived from the tell on the southern side have been lost by coastal erosion whilst those on the north mantle the flanking slope. Of particular interest is a homogeneous and unstratified deposit of over 2 m which overlies the archaeology near the southern perimeter of the summit area. The soil structure as evident in thin sections indicates a high degree of bioturbation, probably stimulated by recent manuring and cultivation. The implication is that tillage erosion has had a major impact on the morphology as well as on the surface soils of the tell. Despite such reworking and redeposition of near surface materials, it is still possible from multi-element analysis to identify the geochemical distinctiveness of six archaeological contexts (pit, house, plaster floor, alley, road and yard); pits and floors have high loadings of all elements except Pb; in contrast pits and floors have the lowest elemental concentrations.