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Colloidal phosphorus (P), defined as P associated with particles within the size range from 1 to 1000 nm, is an often-neglected yet significant component of waterborne P, posing global water quality concerns. This comprehensive review elucidates the various sources and concentrations of colloidal P across diverse water environments, highlighting its prominence in agricultural wastewater, with mean concentrations of 122.6 μg/L (n = 437), compared to groundwater (52.3 μg/L, n = 26), surface freshwater (22.3 μg/L, n = 246), and seawater (5.4 μg/L, n = 36). Correlations between physicochemical water parameters, elemental composition and colloidal P concentrations are obtained, and the dominant subfractions and chemical species of colloidal P in water are identified. Notably from chemical speciation, colloidal organic P exhibits dominance in surface freshwater with higher abundance relative to colloidal inorganic P. Meanwhile, statistical analyses on physical fractions of colloidal P indicate that fine subfractions prevail in agricultural wastewater. Accordingly, this review investigates potential transformation mechanisms of colloidal P due to physical and chemical behaviors such as aggregation, desorption, and photodegradation, influenced by factors such as pH, salinity, coexisting elements and UV irradiation. Drawing on these insights, we propose eco-friendly mitigation strategies, including constructed wetlands or ecological drainage ditches and UV irradiation, aimed at treating water (especially agricultural wastewater) with elevated colloidal P levels. This review not only enhances our understanding of the occurrence and transformations of colloidal P, but also offers practical guidance for its effective environmental management. [ABSTRACT FROM AUTHOR]

Tailwater recovery system (TWR) sediment quality in Mississippi, USA, was evaluated seasonally within the storage reservoir and drainage ditch system from 2016 to 2019 for pesticide contamination, effects and bioavailability to Hyalella azteca (Saussure). Sediment bioassays (28-day) measured H. azteca survival and growth and tissue residue risks from sediment pesticide exposure. Sediment pesticide contamination comprised six current-use herbicides, three current-use insecticides, three legacy insecticides and one metabolite (p,p'-DDE). Sediment clomazone, bifenthrin and ΣDDT concentrations were greatest in drainage ditch sites during summer and fall. H. azteca tissue pesticide residues comprised three current-use herbicides and insecticides, as well as two legacy insecticides. Tissue residue clomazone, Ζ-cypermethrin and ΣDDT concentrations were greatest in drainage ditch sites during fall and winter. H. azteca survival and growth varied seasonally and spatially with lowest survival during fall and winter and lowest survival in the storage reservoir relative to drainage ditch sites during winter. Growth decreased during winter and spring with lowest growth in drainage ditches relative to the storage reservoir during spring. Patterns of associated survival and growth with tissue pesticide residues indicate increased risk during fall in TWR and where system water flows mobilise sediment pesticides increasing the risk of ecological impairment. [ABSTRACT FROM AUTHOR]

The mobility of a snake robot is limited by factors such as its length, mass distribution, and torque output. To overcome these limitations, the cooperation between two snake robots can be an effective strategy, inspired by the hand-in-hand interaction of humans. In this article, the cooperative strategies for the double snake robots are presented to improve their mobility in some extreme environments. In order to achieve the force interaction between snake robots, we introduce a docking strategy, which enables them to cross ditches and climb slopes. We further study these cooperative strategies and demonstrate their effectiveness through experiments. The snake robots can dock with each other and cross ditches with a width of half the length of each robot. Additionally, the robot at the top of a slope can help the robot at the bottom climb a steep slope of 63.2 $ ^{\circ } $ ∘ , which would be difficult to achieve with a single snake robot. [ABSTRACT FROM AUTHOR]

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Ditches are vital to water system data. To ease the task of matching multi-scale ditch data and enhance accuracy (Acc), it is essential to discern ditch data matching patterns. Despite its importance, limited research has been conducted on ditch matching patterns, and the primary reasons for variations in multi-scale geographical entities' matching patterns remain underexplored. Here, we introduce a supervised graph neural network (GNN) method, targeting the direct analysis of 1:10,000 ditch characteristics to identify the matching patterns between 1:10,000 and 1:25,000 datasets. The ditch network is depicted as a graph structure, with nodes representing ditch segments and edges indicating their connections. Subsequently, each ditch segment's geometric, semantic, and topological attributes are computed as node attributes, and their matching patterns with the 1:25,000 dataset are labeled as node annotations. Ditch segment matching patterns are then categorized using supervised learning. Experiments using Overijssel, Netherlands' ditch data reveal that this method achieves a 97.3% classification Acc, outperforming other GNN methods by 25.6–26.3% and traditional machine learning methods by 33%. These findings underscore the efficacy and superiority of the proposed supervised GNN approach in pinpointing ditch matching patterns. [ABSTRACT FROM AUTHOR]

Causeway Construction Three distinct phases of causeway construction were identified (see Figs. This section comprises a selection of highlighted projects or discoveries made across Britain and Ireland in 2021, with illustrated overviews of results, finds and contexts. On the balance of the evidence, this building formed the gatehouse opening into the inner precinct of the abbey that contained the conventual buildings and the graveyard. Salvage recording assigned a 13th- to 15th-century occupation date to the remains of a manor house, several isolated rectangular buildings of unknown function, and an extensive limestone-cobbled yard.[5] Manor Excavations The causeway, revealed by open-area excavation in 2021,[6] was probably related to the 13th- to 14th-century manor (Fig 1). [Extracted from the article]

Due to their burrowing lifestyles that make them difficult to sample, the distributions and habitat associations of most burrowing crayfishes are poorly understood. A distributional study was conducted in south-western Pennsylvania to better understand the range and habitat associations of the primary burrowing crayfish Cambarus dubius within the state. A total of 790 new sites and six previously surveyed sites were sampled between the Chestnut Ridge and Allegheny Mountains, with the majority of these localities being roadside ditches. Crayfish were collected using a combination of burrow excavation, baited lines, and by hand. We utilised permutation-based t-tests to determine differences in habitat variables between sites with and without C. dubius and sites with and without any burrowing crayfish species. Cambarus dubius was collected from 61 total sites, and active crayfish burrows were observed at 137 additional sites. Cambarus carinirostris was collected from 13 sites, Lacunicambarus thomai was collected from six sites, and an exuvia of Procambarus acutus was collected from a stream at one site. New behavioural observations for C. dubius juveniles were observed while collecting specimens with baited lines. Sites with C. dubius had significantly more canopy cover and deciduous forest land cover and significantly less pasture-hay land cover than sites without C. dubius. Sites with burrowing crayfishes (all species) had significantly more canopy cover and deciduous forest land cover and significantly lower elevation, depth to the water table, percent sand substrate and pasture-hay land cover than sites without burrowing crayfish. In Pennsylvania, Cambarus dubius has not expanded its range in comparison to its historical range, and populations appear to be concentrated primarily in the southern valleys of the Chestnut Ridge and Allegheny Mountains. [ABSTRACT FROM AUTHOR]

In its last decade, Rudin argues, the MMRA's penchant for constructing dams (five in all) on tidal rivers to block inflowing tides, rendering dykes - and future dyke maintenance - superfluous was "transformative." When considering the dykelands of Canada's Maritime provinces, scholars generally think in terms of the region's pre-Deportation Acadians and their skill in constructing dykes and aboiteaux to drain the marshlands washed by the extraordinary tides of the Bay of Fundy. In Rudin's reading of the marshlands, "First Nature" refers to the time when tidal waters flowed freely across the marshlands. [Extracted from the article]

Parameters as well as their corresponding reference values, adopted to control the compaction quality during the construction of High-speed Rail(HSR) embankments in different countries are summarised in this paper. Different measurement methods for the degree of compaction are analysed with the comparison of the features of various plate loading tests. To investigate the relationships between different compaction control parameters, we conducted in-situ compaction tests on three particular subdivisional railway earthworks at Zhangjiakou-Datong HSR and Inner Mongolia-Jiangxi Railway: a bridge foundation pit below the embankment-bridge transition section, a geogrid-reinforced cushion above embankment foundation, and an excavated channel for drainage ditch. We investigate the relations of the Dynamic Deformation Modulus (Evd) versus the Reaction Modulus (K30), Evd versus the compaction coefficient (K) by analysing the measured data. The analysis result shows good linear correlations between Evd and K30, as well as Evd and K. Based on the analysis performed in this paper combined with our engineering practices, recommended reference values of the compaction control indicators for bridge foundation pit below a transition section and the bottoms of drainage ditches are also proposed in this paper. [ABSTRACT FROM AUTHOR]

The load reduction mechanism of compressible material filled ditch covered with a geosynthetic layer is investigated. A mathematical model of the pressure on the roof of the culvert is established. Equations for calculating the earth pressure acting on the geosynthetic layer are derived. Considering the support effect of the compressible backfill underneath the geosynthetics layer, an equation is derived to calculate the deflection of the geosynthetic layer under the embankment fill loading. The pressure acting on the roof of the culvert is calculated by force analysis. The predicted results by the proposed method agree well with the test results. [ABSTRACT FROM AUTHOR]

Despite near-extinction in the nineteenth century, after efficient restoration measures the population of Eurasian beaver (Castor fiber L.) in Latvia currently is viable and growing. While the ecological effect of the species on water quality and biodiversity is generally positive, the high number of animals in production forests often creates challenges for management. Drainage ditches are among the most favoured habitats of beavers resulting in flooded stands, reduced tree growth and economical losses. The aim of the study was to evaluate the chemical properties of water in forest drainage ditches, affected by beaver activity, and their changes after the dam removal. Chemical composition of surface water in ditches was analysed in sampling points above dam, below dam and in the ditch itself after removal of the dam; results compared to pristine beaver site nearby on a small stream. Results did not show significant differences between concentrations above and below dams. After removal of the dams, significant increase in DOC, N-NO3-, N-NH4+ and TSS concentrations and significant decrease in TP concentrations were observed in some of the sites. Observed concentrations of all measured parameters were significantly lower in pristine beaver site than in beaver sites on drainage ditches. [ABSTRACT FROM AUTHOR]

This commentary threads the ideas about accompaniment in the lead paper (Markman, this issue) with linked areas of thinking. It looks at synchrony, musicality, and the importance in therapeutic technique of achieving a healthy balance right between closeness and distance. It looks at some of the neurobiology which sheds like on musicality, improvisation as well as thinking about trauma and hyper-vigilance, as well as what developmental capacities need to be in place, or developed, for a healthy accompaniment to take place on a therapeutic journey. [ABSTRACT FROM AUTHOR]

Historic irrigation canals are valuable socioecological systems capable of delivering several ecological and cultural services. However, ecological modernisation initiatives are leaving decommissioned ditches in limbo. A case study strategy is used to analyse the history of a decommissioned 700-year-old canal network in northeastern Spain and the unexpected intervention of several stakeholders who have attempted to redefine the former canals through new uses. The study relies on the analysis of documents and eight semistructured interviews with key stakeholders. We argue that this case reflects a policy failure in the application of multifunctionality, integrative planning and social participation principles presumably ingrained in European policies. The replacement of such principles with monosectoral action under a productivity paradigm, function segregation and a neoliberal management approach should be balanced with greater institutional commitment, increased coordination between stakeholders and rigorous planning controls if ecological and cultural functions and services are to be preserved. [ABSTRACT FROM AUTHOR]

Landowners and irrigators were required to take part in the construction, repair, and maintenance of the ditches, while a ditch master, or I mayordomo i , adjudicated disputes and coordinated irrigation schedules. Critical to the conservation of the ditches will be the building of an informed ditch public that understands and values the multiple functions of the ditches. [Extracted from the article]

In drained forest sites, ditch cleaning (DC) may be needed to restore the drainage function of ditches and maintain favourable growing conditions. The main aims of this study were (i) to estimate the growth responses of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies L. Karst) stands following DC, and (ii) to test the hypothesis that stand stocking should be less than 150 m3 ha−1 at DC to obtain a growth response. This survey included 14 ditched stands in Sweden on both mineral and peat soils. The methodology was based on evaluating growth rates before and after the DC operation (growth ratio), reconstructing the growth by taking increment cores from the tree trunks. The measured growth was related to growth derived using a growth simulator as if DC had not been conducted. The results showed an average growth increase of 1.6 m3 ha−1 yr−1 for about 25 years after DC in the stands containing 50–200 m3 ha−1. The growth response appeared to be positively related to stand age, trees ha−1 and site index, and negatively related to stand volume, supporting the hypothesis that stand stocking is an important factor to consider when assessing the need for DC. [ABSTRACT FROM AUTHOR]

Hydrological stochastic simulation is an important method for hydrologic analysis which needs a large amount of measured data to determine the variable distribution function. That impedes the development of the random simulation in small sample cases. The characteristics of daily runoff series in the middle reaches of Yangtze River has changed a lot since the Three Gorges dam was built in 2003. The measured hydrologic data since 2003 is insufficient for stochastic simulation with conventional methods. In order to overcome the difficulty, a simulation model coupling the support vector machine with the Copula function was established in this paper. The measured data of Hankou Hydrology Station from 2003 to 2015 was used as an applied example to verify the applicability of the model. The research showed that the model we established can maintain the statistical characteristics of the original daily runoff series well, it could be a new way for the random simulation in the case of insufficient data. [ABSTRACT FROM AUTHOR]

In arid agricultural irrigation regions, drainage ditches are important ecotones subjected to both soil salinity and artificial drainage. To explore plant community structures under varying levels of salt stress and the long-term distribution patterns of salt-tolerant species in arid open-ditch banks, a comprehensive study of soil-plant interrelationships was conducted in 39 drainage ditches of a Yellow River irrigation area of Northwest China. The results showed that larger drainage ditches exhibited higher NaCl-induced salt levels (mean >4.8 dS/m) but lower plant coverage and diversity in banks. In all, 21 families, 47 genera, and 62 plant species were detected; Phragmites australis presented the highest frequency and coverage. The high-salinity environment of >6.0 dS/m inhibited the appearance of nearly half of all species, and halophytes preferred K+-rich soils. Canonical correspondence analysis showed that mineral ions including K+, Ca2+, Mg2+, HCO3- and SO42- rather than macronutrients significantly affected the distributive heterogeneity of glycophytes under salt stress. This research revealed that smaller-sized drainage ditch habitats provided more abundant halophyte resources than larger ones and that high-diversity drainage ditches deserve more positive protection in ecologically fragile arid regions. The results of this study can aid the optimisation of plant diversity conservation strategies in agroecosystem management. [ABSTRACT FROM AUTHOR]

When the Bamun arrived in the late sixteenth century in the Noun Division of the western part of Cameroon, many sedentary farming communities shared the lands between the Mbam and Noun Rivers. In order to control and preserve this territory, the Bamun used different strategies. This paper discusses how, using oral and historical sources, it has been possible to reconstruct the evolution of their concepts of acquisition and conservation of territory. This, in turn, allows a chronology to be established for the implementation of the structures resulting from these strategies. Archaeological surveys and targeted test-pitting have also located and studied this defensive architecture. This research has revealed the serious state of deterioration of such structures and raises the question of their preservation in order to enhance the material cultural heritage of this region of Cameroon. [ABSTRACT FROM AUTHOR]

Ridge-tillage is an agricultural practice where crops are planted on elevated ridges, with furrows in-between. Ridge-tillage has been shown to significantly reduce erosion from croplands, but data on the presence of ridge-tillage is sparse and challenging to collect at the landscape scale. Thus, water quality models often do not account for ridge-tillage in a spatially-explicit manner, potentially overlooking the important impacts of this practice. We have developed a novel method that exploits the spectral, radiometric and linearity shape characteristics to identify both drainage ditches and ridge-tillage furrows using remote sensing of 0.5 m satellite data. We applied the method to the Sasumua watershed in Kenya, where we had false positives in only 3% of randomly selected polygons and we detected themajority of ditches in 59%of randomly selected polygons.We then assessed the potential value of including these data in sediment modelling, showing that representing these practices could reduce sediment export in the study area by roughly 80%. Being able to readily identify the presence of ditches and furrows could enable the development ofmore accurate water quality models and help identify priority areas for intervention to improve water quality (and possibly crop yields) through changing agricultural practices or policies. [ABSTRACT FROM AUTHOR]

Agricultural drainage ditches are essential to sustaining food production in arid irrigation regions, with various sizes and drainage characteristics as important buffer ecotones in agricultural areas. Bed vegetation and water properties were investigated in 39 agricultural drainage ditches in the Lingwu District of Ningxia Yellow River Irrigation Area in Northwestern China. The results showed that water depth, width, and velocity generally increased with larger ditch size. Water salinity was higher in drainage ditches (>1 g/L) than in croplands, canals, and the Yellow River. Total nitrogen and total phosphorus were at high levels: ∼1.6 and ∼0.1 mg/L, respectively. Forty plant species belonging to 19 families and 31 genera were identified, with higher plant richness and diversity found in smaller sized drainage ditches. Macrophytes dominated the bed vegetation with a mean vegetative coverage of >30% in all-sized ditches, andPhragmites australisoccurred with the most frequency. Water depth and salinity were considered as the primary factors affecting the distribution of vegetation in drainage ditch beds. The study suggests that practical conservation of smaller sized drainage ditches is conducive to increasing the plant diversity of agricultural landscapes. [ABSTRACT FROM AUTHOR]

Poor maintenance of drainage systems has been identified as one of Swedish agriculture's weak points, as impaired land drainage can lead to major environmental problems. Drain maintenance work is receiving increasing attention in work conducted within the European Union Water Framework Directive. Moreover, the functionality and maintenance of agricultural ditches will need to be improved to cope with predicted higher pressures on water infrastructure in a future climate. In Sweden, ditch maintenance work is mandatory, but must be carried out with great consideration for the environment. There is currently no simple method available in Sweden for assessing the comprehensive status of open drainage ditches and determining whether remedial measures are needed. This study tested an on-site method, Minnesota Agricultural Ditch Research Assessment for Stability, for evaluating the status of drains and the need for improvements. The study also included an evaluation of physical ditch properties that can be assessed visually on-site and the processes they represent. The results showed that it is viable to evaluate ditch properties such as bank stability, erosion and deposition susceptibility visually on-site. However, more intensive surveys are needed to identify the processes affecting bank stability. For assessing how improvement of drain status affects bank stability and hydraulic properties, Hydrologic Engineering Centre's River Analysis System simulations can be a useful tool when complemented with updated cross-section measurements and existing documentation. [ABSTRACT FROM AUTHOR]

Zoige Peatland in the eastern Tibetan Plateau, the largest alpine peatland in China, was widely ditched in 1970s for pasture expansion. The ditching is believed to have caused peatland degradation, but there is still no widespread agreement on this due to the absence of essential regional and temporal information about ditch drainage. Therefore, this study used both remote-sensing observations and field surveys to examine the ecological influences of ditching for this alpine peatland. In the study, ditch distribution was interpreted with remote-sensing imagery and the ecological responses were investigated with temporal observation by Moderate Resolution Imaging Spectroradiometer (MODIS) and field surveys. The results showed that there were ~1200 km ditches interpreted, mainly in three spatial patterns depending on hydro-geomorphologies. The MODIS enhanced vegetation index (EVI) was more sensitive to peatland surface water depth (R2 = 0.678,P < 0.001) than the normalized difference water index (NDWI) (R2 = 0.583,P < 0.001), because the latter would become saturated at a certain surface water depth (~50 cm in Zoige). The temporal MODIS imagery reflected the ecological responses of ditched peatland to drainage in terms of vegetation density and water conditions. This study indicated that ditching depressed the surface water depth of the Zoige Peatland in summer, but not to the extent of completely transforming peatland into steppe due to the recharging of local beneficial hydro-geomorphologies. The MODIS indices investigated in the study could be used to monitor the annual regional status of vegetation cover and surface water for Zoige peatland. [ABSTRACT FROM AUTHOR]

Catchment ditches along highways are designed to contain hazardous rock falls from cut slopes. RocFall, a rock fall simulation software, was used to evaluate the maximum roll-out distances of rock falls in order to determine rock fall catchment ditch dimensions for Ohio's cut slopes. Based on stratigraphy, cut slopes in Ohio were classified into five types. The parameters required for simulation process included friction angle between rock fall and slope face, coefficient of normal and tangential restitution, slope roughness and average weight of rock falls. A total of 400 simulations were performed for various slope heights, slope angles and catchment ditch slopes. The results are useful in designing catchment ditch for Ohio and neighbouring states where the stratigraphy consists of sub-horizontal, inter-layered hard and soft rock units. The widely used guidelines developed by the Oregon Department of Transportation do not work well for Ohio's stratigraphy. [ABSTRACT FROM AUTHOR]

Soil and water conservation technologies, such as mulching, grass strips and retention ditches, have been promoted in many areas of Sub-Saharan Africa. However, technology adoption rates have remained unsatisfactory. In this study, a logit model was used to examine the adoption of soil and water conservation technologies in the Rwizi catchment of Uganda using cross-sectional survey data from 271 smallholder farmers. Findings revealed that the likelihood to adopt these conservation technologies by smallholder farmers is explained by land size, tropical livestock units, access to extension services, value of gross output, gender of the household head and location of the farmers. Our results further showed that the quadratic term in land size was significant and negative, highlighting an acreage threshold to adoption. In general, our findings underscore the importance of information access and landownership in adoption of soil and water conservation technologies in the Rwizi catchment of Uganda. [ABSTRACT FROM AUTHOR]

Drainage ditches play an important role in maintenance of plant species diversity. We investigated plant species composition and diversity, and soil and water chemical properties in drainage ditches in the Hetao Irrigation Region of northern China. We compared species composition similarity within the same and among different drainage areas, and compared diversity of plant species, among different ditch sizes and slope positions. We identified a total of 70 plant species, which belonged to 64 genera and 30 families in the drainage ditch. The most frequent family was Compositae representing 15.7% of the total flora;Phragmites australis(Cav.) Trin. ex Steud was the most widespread species with a frequency of more than 60% in all plots. The highest similarity values occurred in lateral ditches within the same drainage areas, and in main ditches among different drainage areas. The coefficient of variation of total salt in soil was closely related to species similarity in all ditches. Ditch size and position were significantly correlated with the indexes of species diversity. Higher plant α-diversity occurred in smaller ditches and tended to be the highest at the transition zone and on the slope of the ditches. The response of species composition and diversity to environmental factors was significant for saline concentrations. Reducing the current water and soil saline contents, while maintaining current slope soil nitrogen content was suggested as an optimal way of maintaining high species diversity. [ABSTRACT FROM AUTHOR]

Many species in human-dominated landscapes find their habitat in linear elements, such as road verges, hedgerows and ditches. Local concentrations of species have been observed in the intersections of linear elements, but their spatial distribution and local population density in this linear habitat are not well captured by existing theory. Using a simple, spatially explicit individual-based GIS-model simulating hedgerow bird species with different movement abilities, local high population density of our model species in intersections and their reduced density or absence in linear habitat could be explained by limited movement. We hypothesise that, for species with low movement ability, intersections of linearly shaped habitat could contain several local populations. We argue that these predictions are valid for organisms occurring in linear habitat with limited movement relative to the dimensions of their habitat, and whose movement is directed by their habitat. Our findings support the importance of intersections for biodiversity in human-dominated landscapes, as they may serve as refuges from which individuals can (re-)colonise unoccupied habitat. [ABSTRACT FROM AUTHOR]

Although fieldwork is always cited as an important component of geographic education, there are many obstacles for executing high school fieldwork. Mobile electronic products are becoming popular and some schools are able to acquire these devices for mobile learning. This study attempts to provide a mobile-assisted means of guiding students through fieldwork without a teacher's presence. To explore these possibilities, a PDA (personal digital assistant) program, referred to as the Pocket Fieldwork Assistant (PFA), has been developed. A fieldwork course module that is concerned with local irrigation ditch issues is designed and implemented to evaluate how the PFA affects fieldwork learning in authentic settings. [ABSTRACT FROM AUTHOR]

The adsorption of two commonly used pesticides, diuron and tebuconazole, on an organic substrate (hemp), which was chosen as an analogue for natural substrates often found in agricultural ditches, has been studied using three different contact schemes: (1) contact in a beaker using a modified batch method; (2) contact in an experimental flume, with a dry start substrate; and (3) same as (2) but with the substrate initially saturated with water. Changes in pesticides concentrations as a function of time as well as adsorption after seven hours have been determined for each case. The highest adsorption is observed for the experiments with a flume initially containing dry hemp. In that case, both the initial condition (hemp initially without water) and the contact conditions between the pesticide solution and the substrate appear to favour adsorption. The lowest adsorption is obtained for the flume containing hemp initially saturated with water. In that case, samples that were obtained at different depths inside the hemp using capillary tubes showed that only the superficial part of the hemp was in equilibrium with the surface water. The presence of an initial water table appears to be a limiting factor for pesticides penetration and further adsorption onto hemp. An intermediate adsorption is obtained for the modified batch method. These results highlight the pronounced influence on adsorption of both the initial hemp wetness conditions and the contact conditions between the pesticides solution and the substrate. This influence should be studied further to assess the potential of agricultural ditches to mitigate pesticides contamination in surface water. [ABSTRACT FROM AUTHOR]

Pre-Columbian farmers built a variety of earthworks in the Llanos de Mojos, part of the Bolivian Amazon. Raised fields, canals, causeways, and mounds of various types in this region date to ca. 800 B.C-AD. 1600. In central Mojos, archaeological work was carried out along the Yacuma, a large west-bank tributary of the Mamoré River. Four ring ditches and two areas of associated raised agricultural fields were mapped. The Global Positioning System was used to document earthworks under the forest canopy which were analyzed within a Geographic Information System. Ceramic evidence is also included. The ring ditches in this study expand the known range of such earthworks in Mojos by 200 km. This revised distribution of ring ditches changes interpretations of the long-term history of Arawak speakers in Mojos and throughout Amazonia. While earthworks in Mojos clearly represent systems of intensive agriculture, they cannot be associated only with Arawak speakers or with Arawak languages. [ABSTRACT FROM AUTHOR]

Burial of wheat straw in ditches and incorporation of wheat straw are the two main ways of returning wheat straw prior to rice cultivation in China. To examine the effect of burying wheat straw in ditches on CH4 emissions from rice cultivation, a field experiment was conducted at Yixing, Jiangsu, China in 2004. CH4 flux was measured using a closed-chamber technique in three treatments (CK, no wheat straw application; WI, evenly incorporating 3.75 t ha−1 wheat straw into the 0.1 m topsoil; WD, burying 3.75 t ha−1 wheat straw in 0.14-m deep by 0.25-m wide ditches). Seasonal CH4 emissions ranged from 49.7 to 218.4 kg CH4 ha−1. The application of wheat straw in these two ways significantly increased CH4 emissions by 4.0-fold and 4.4-fold, respectively ( P < 0.05). Although CH4 flux from the non-ditch area in the WD treatment was as low as that in the CK treatment, it was counter-balanced by extremely high CH4 flux from the ditch, which was approximately 6.0-fold as much as that from WI, leading to comparability between treatments WI and WD in total CH4 emissions ( P > 0.05). No significant difference was observed between the three treatments in grain yield ( P > 0.05). The results indicated that burial of wheat straw in ditches is not a way to reduce CH4 emission from rice cultivation. [ABSTRACT FROM AUTHOR]

Traditional cultures in arid landscapes of the southwestern United States and northern Mexico developed irrigation systems to irrigate floodplain valleys along streams and rivers. Many of these traditional irrigation systems, referred to as acequias, continue to be used today. Population growth in the region is creating pressures to convert agricultural land and irrigation water to urban and other uses. Unique hydrologic features of the acequia systems suggest that, beyond providing crop irrigation, they may provide additional valuable hydrologic, riparian, and agroecosystem functions worth maintaining. We investigated in detail the seepage and the groundwater response to seepage from a traditional acequia irrigation ditch along the Rio Grande in north-central New Mexico. We found that 16% of ditch flow seeps into the ditch bed and banks. Groundwater levels near the ditch and midway between the ditch and the river rise 1 m or more within three to four weeks following the start of the irrigation season. The elevated groundwater table produced by ditch and field seepage is sustained until late summer when groundwater levels again drop. The seepage that provides this annual groundwater recharge also sustains riparian vegetation along the main ditch and side ditches. In light of our hydrologic analysis, we considered seepage-supported riparian areas and their ecological functions including aquatic habitat, terrestrial habitat, and water quality effects. Ace quia hydrology plays an important role in contributing to an ecologically healthy, agriculturally productive, and community-sustaining floodplain agroecosystem. [ABSTRACT FROM AUTHOR]

The article features the ditches and settlement policy in the Swan district of Western Australia during the governance of John Hutt. It discusses the life and behaviour of the farmers that settled in the said area and how these settlers came into building ditches, furrows, and fences around their land.

The article presents a study that determines the concentration of dissolve organic carbon (DOC) and the specific ultraviolet absorbance of 193 samples of water collected from groundwater, porewater, drainage ditches, and streams at peatlands in New Zealand. Results from the study shows that there was a wide range in DOC concentration in peatlands where there appeared to be large amount of iron. Also, DOC concentrations were large in ombrotrophic, or rain-fed peatlands.

This paper examines the role that slope-channel linkages and seasonal variations in vegetation play in explaining spatial and temporal variations in sediment flux through agricultural drainage ditches in eastern North Carolina. We used biannual cross- sectional surveys of drainage ditches to assess erosion/deposition during a five-year period in the headwaters of a small agricultural watershed. Although net accumulations of sediment were observed in three-fourths of the cross sections surveyed, the rate of sedimentation varied considerably from ditch to ditch and cross section to cross section. The ditches were sediment sinks during the growing season in summer and autumn when they became choked with dense vegetation growth, and more hydraulically efficient after removal of vegetation in December during annual maintenance operations. The ditches experienced erosion or modest deposition while the vegetation was dormant during the late winter! early spring. Sediment was delivered to the ditches from isolated gullies that linked the primary source of sediment, soil eroded on agricultural fields, to the channels. Except for these isolated linkages, ditches and fields are largely decoupled. [ABSTRACT FROM AUTHOR]

Transient and permanent farm ditches flowing to the Lower Fraser River tributary fish streams of British Columbia, Canada, were sampled at several locations in 2003–2004 to determine the occurrence and concentration of residues of selected pesticides, their transformation products, and soluble/extractable Cu ++ ions. Of the 43 compounds analyzed, 28 and 22 pesticides were detected in transient farm ditch water and sediments, respectively. About 34% fewer pesticides, however, were found in both matrices of permanent farm ditches. Average concentrations (μ g L -1 ) of those most frequently detected in permanent farm ditch water were atrazine (0.20), α -chlordane (0.06), desethylatrazine (0.13), diazinon (0.55), dieldrin (0.28), endosulfan sulfate (0.16), glyphosate (6), metalaxyl (0.27); and soluble Cu ++ ions (25). Those most often found in ditch sediments (μ g kg -1 ) were aminomethylphosphonic acid (AMPA) (2,300), 1,1,1-trichloro-2,2-bis-(4-chlorophenyl)ethane (DDT) (250), endosulfan sulfate (500), glyphosate (1,225); and extractable Cu ++ ions (58,000). The risk potential of these pesticide residues to non-target aquatic organisms inhabiting Fraser River tributary fish streams contiguous to permanent farm ditches is evaluated and discussed. [ABSTRACT FROM AUTHOR]

An excavation on the southern side of London Road, Staines, in 1999 revealed a dense concentration of ancient features surviving amidst the concrete foundations of a recently demolished office building. These features included a number of Bronze Age pits, many of which were intercut; pits, ditches arid a welt of late Roman origin; and the remains of approximately thirty inhumation burials, most or all of which were of late Saxon or early Norman origin. The majority, if not all, of the burials were of execution victims. Some of the bodies were face down within the grave, others had been decapitated, and some were in graves containing two or three bodies. The cemetery shares various characteristics with other excavated execution sites and the evidence from Staines is placed within a regional and national context. The site is one of few execution cemeteries dated by radiocarbon with a chronology spanning at least the eighth to the twelfth century. This longevity adds weight to the case for a centrally organized judicial system during the growth period of the major Early Anglo-Saxon kingdoms. [ABSTRACT FROM AUTHOR]

The site at 43–53 Narrow Street, located in the Ratcliff area, produced unprecedented finds relating to the period of London's expansion as a mercantile centre during the 17th century. The most extensive and interesting discoveries comprised a late 15th-century brick clamp, and building remains with associated pits and ditches dating from the 16th through to the 18th centuries. The remains dating to the late 16th through to the end of the 17th century proved to be former properties of people with a maritime focus, heavily involved in piracy and privateering. The pits and ditches, particularly those of 17th-century date, were filled with pottery, glass and other objects, a significant proportion of which originated in the Netherlands, France, Germany, Spain, Italy, Portugal, Turkey, Iran and China, and many of the examples recovered have otherwise rarely if ever been found in Britain. It is argued that the most appropriate interpretation of the finds assemblage is as the remains of booty and global mercantile and illicit trade at a time that access to the New World and the Far East was being opened up and fought over. The discoveries offered a unique opportunity to view a 17th-century community of intimately interacting seafaring families from the perspective of their land-based material culture and the remains of their homes. This paper focuses on the development of the site from the late medieval period to the early 18th century, and places the finds for this period in their historical context, providing a unique insight into the material culture of a new and emerging social class in early modern England. [ABSTRACT FROM AUTHOR]

Excavation has increasingly highlighted aspects of the continuity of settlement from the fourth into the sixth centuries. This paper offers an additional set of evidence to show that continuity of the field and cropping units associated with settlement is also detectable from this period using excavation, landscape and later manuscript evidence. The recognition that some late Roman ditches underlie later medieval headlands of open-field systems has been well explored already. In the east Midlands area of Northamptonshire and Cambridgeshire recent work indicates that in some cases a fossilization of Roman fields took place. That fossilization is indicated by areas of small medieval furlongs associated with sites of late Roman and early medieval date, and could indicate continuity within the fanned landscape with little interruption to the farming system. [ABSTRACT FROM AUTHOR]

Ditch run-off chemistry of 40 catchments was monitored before and for 2-3 yrs after maintenance of the peatland ditch network and compared with data collected from 34 control catchments. Increases in mean pH, electrical conductivity, and the concentrations of suspended solids and base cations (sodium, potassium, calcium and magnesium) and a decrease in the concentration of dissolved organic carbon were observed. Because of high concentrations in a few areas immediately after the digging operations and during the first post-treatment year in general, the mean concentrations of aluminium and iron also increased. No major changes occurred in the concentrations of total dissolved nitrogen (N) and total dissolved phosphorus. High phosphorus concentrations were observed at a few sites immediately after the digging operations. Concentrations of mineral N, especially NH[sub 4][sup +]-N, increased significantly, while the concentrations of organic N decreased. The largest relative changes in element transport during the 3 yr period following treatment were the increases in the loads of NH[sub 4][sup +]-N and suspended solids. From the point of view of water protection, the loading of suspended solids was considered the most harmful effect of ditch network maintenance. [ABSTRACT FROM AUTHOR]

A system has been developed that uses remote sensing data for the determination of the quantity of surface water stored in a network of ditches. The method combines Landsat TM images with ditch positions obtained from maps in order to derive 'Ditch Indices'. The results of the analysis show that the system is promising. The presence of the sub-pixel size ditches was clearly detected in the image and the monospectral 'Ditch Indices' correlated strongly with each other and with ground measurements. [ABSTRACT FROM AUTHOR]

The discovery and excavation of an extensive Neolithic site near the modern village of Makriyalos, in Pieria, northern Greece, have greatly enriched our knowledge of this distinctive, fiat-lying, ‘non-tell’ type of settlement. Such sites, spread over a sizeable expanse of land, and not restricted to a single, cumulative locus, have been recently recognized as dominant in Neolithic Macedonia. The site at Makriyalos is located on the gentle slopes of a natural hill and covers some 50 ha. During two discrete phases, both securely dated to the Late Neolithic Period, the habitation area was encircled by large earthworks. The 6-ha area of excavation allowed the first detailed examination of the internal organization and evolution of this type of settlement. This preliminary report presents the first results of continuing analysis of the settlement and its organization, and places Makriyalos within the wider Balkan context. [ABSTRACT FROM AUTHOR]

The introduction of agriculture to Europe was a complicated process that had a profound impact on human settlement and the natural landscape. Excavations at Ostonki in north-central Poland have revealed a settlement of early farmers from approximately 4300-4000 B. C. Between 1989 and 1994, 30 trapezoidal longhouses and 80 graves were revealed in an area of 15,000 sqm, along with numerous pitsfilled with household rubbish. A fortification ditch, built in two stages, is the first such Early Neolithic feature found in this part of central Europe. The analysis of the houses, burials, and pit contents permits the investigation of household organization and the procurement and use of various raw materials by the inhabitants of Oslonki. This article reports the preliminary results of this research. [ABSTRACT FROM AUTHOR]

At Plas Gogerddan, evidence was discovered for human presence from the middle of the fourth millennium B.C. up to the present day. Numerous pits and post-holes were excavated around a standing stone; one of these pits was dated to the tenth-fifteenth centuries B. C. To the west of the standing stone, three ring-ditches were constructed and used in the first millennium B.C.; in association with these ring-ditches were three iron age crouched burials. In the vicinity of the standing stone lay twenty-two east-west aligned, extended inhumation graves, three of which were surrounded by rectangular timber structures. A coffin stain from one of these graves was dated to the third-seventh centuries A.D. [ABSTRACT FROM AUTHOR]

A cropmark complex of ring-ditches and square-plan ditches in the Vale of Clwyd, North Wales has been partially excavated, Mesolithic activity is represented predominantly by lithic waste in local cherts. A small bronze age cemetery, dated to between about 1660-1400 b.c., comprises a large and small ring-ditch and a 'flat cemetery' associated with Beaker inhumation burials, and by cremation burials, of which some were found with Food Vessel Urns. The larger ring-ditch was superseded by an undated rectangular enclosure with causeways at the centre of each side. An early medieval inhumation cemetery, with associated dates of about a.d. 510 and a.d. 860, was established to one side of the larger ring-ditch. A small proportion of the graves are enclosed by square-plan ditches, two of which had a causeway at the centre of the eastern side. Generalized parallels are drawn with other sites in eastern and northern Britain and within Wales itself. [ABSTRACT FROM AUTHOR]

The article presents the result of the archaeological excavations of a ring-ditch at Tye Field, in the village of Lawford, Essex in England, which were undertaken from 1962-1963 and in 1971. The two excavations differ in terms of the nature of the surface within the central area and the nature of the features within the central area. In the 1971 excavations, no trace of the black layer was recovered and the layer of buff clay within the ring-ditch was not continuous. A report on the pottery and animal bones found in the area during these excavations is discussed.

The article presents an account of the Roman villa at West Park, Rockbourne in Hampshire, England resulting from work on a regional archaeological survey examining the setting of Bokerley Dyke. Difficulties In the interpretation of the excavation evidence arise because an assumption of substantial medieval interference, probably justified in some parts of the villa, often caused the early excavators to underestimate the need to dig down to the natural surface and to make an exact record of relationships and positioning. In this article, the objects found have been broadly reviewed but few have been reconsidered in detail.

The article traces the history of town defences in Beverley, England. The town had four main gates or bars which were augmented in the fifteenth century. Although several of the site names have not been proven, it is clear that the provision of entry points on the east side of the town was more flexible than on the north and west, where the circuit was stable. A defensive ditch ran east from North Bar and then turned south along Manor Road to Norwood Bar, the primary gateway at the Norwood-Hengate junction.

The article discusses various reports published within the issue, including one about the Western Australian fences, furrows, and ditches, another about the effect of the American news agencies on how Australians understand the Crimean war, and an article about Australian drinking habits.

This article focuses on excavation efforts at North Lodge, Barnwell in Northamptonshire, England which is funded by the Royal Archaeological Institute in 1986. It removed the limestone surface interpreted as a paved track leading north from the eastern end of the building to expose earlier gullies and beam slots. A rectangular gully was found in area D which has indications of being a robber trench. There were two dicthes at the southern end of the area. A series of post-holes, a shallow ditch and the remains of an insubstantial wall which seemed to encompass enclosure adjacent to the building were discovered in area e.