Extent Of Erosion Research Articles

Unconformities and their influence on lower Paleozoic petroleum reservoir development in the Tarim Basin

Abstract Ten regional unconformities punctuate the Lower Paleozoic carbonate succession of Tarim Basin. They can be divided into three orders and include four unconformity types. According to their extents and intensities of development, they can be categorized into three orders, a first-order unconformity of great lateral extent and depth of erosion, and second-order and third-order unconformities of lesser extent and erosional intensity. From the viewpoint of their origins, these unconformities can be classified into four types, structural unconformities, long-term exposure unconformities, synchronous sedimentary exposure unconformities and superimposed unconformities that include combinations of the previous three types. Through analyses of the geographic distribution of unconformity types across the geographic extents of the 10 unconformities and their temporal evolution, it was determined that unconformities of various orders have different effects on the development of carbonate reservoir beneath these unconformities. First-order and second-order unconformities are prominent in the development of karst reservoir of the Tarim Basin. Periodic exposure of carbonate rocks which occurs during erosion that generated third-order unconformities contributed to the development of multiple karst intervals. In addition, the abundance and size of karst intervals in progradational strata increased during sea level falls. Origins of unconformities control scales and types of karst reservoirs. Tectonic (angular) unconformities developed during tectonic uplift and denudation, which controlled the development of weathering crust karst reservoirs within zones containing buried-hill (e.g. low paleo-uplift). Long-term exposure (parallel) unconformities formed during long-term sea level fall which controlled the development of regional interlayer karst reservoirs within the platform. Synchronous sedimentary exposure unconformities formed due to intermittent exposure caused by sedimentary basinal infilling and subdued sea level fluctuations which controlled the development of penecontemporaneous karst reservoirs of smaller geographic extent along platform margins. Superimposed unconformities formed due to multiple superposed tectonic movements, which caused the superposition of multiple weathering crusts as individual karst reservoirs, or the stacking of karst reservoirs developed beneath different unconformity types.

Ризик фактори и интензитет на дентални ерозии на трајни инцизиви и први перманентни молари

ЦЕЛ: Целта на на нашата пилот студија беше да се утврди преваленцата на забните ерозии, како и влијанието пијалоците врз степенот на оштетувањето на перманентните заби. МАТЕРИЈАЛ И МЕТОДИ: Како матерјал вклучивме 105 испитаника со позитивни знаци за постоење дентални ерозии, на возраст од 10 до 60 и над 60 години, кај кои ги нотиравме степенот на ерозиите и навики за консумирање пијалоци. РЕЗУЛТАТИ: Степенот на ерозијата на првите трајни инцизиви кај испитаниците на возраст од 10-29 год. беа со површински губиток на емајлот и со возраста на пациентите поприсутна беше ерозијата каде освен губиток на емајлот имаше и присуство на експониран дентин. Испитувањата на ПТМ, според длабочината и возраста на испитаниците, укажа на постоење различни клинички слики, но со емајл во нормални граници немаше ниту еден испитаник. Резултатите говорат дека најголемиот дел од испитаниците газирани пијалоци консумирале 3-5 пати на ден Постоеше позитивна корелација помеѓу консумирањето на газирани пијалоци и овошни сокови и помеѓу вкупниот примерок на испитаници со дентални ерозии и сите возрасни групи на испитаници (р < 0.05) и помеѓу половите (р < 0.00). ЗАКЛУЧОК: Потребно да се направи студија со истражување на највлијателните етиолошки фактори кои би потпомогнале во подготвување превентивни стратегии.

Dental erosion among children aged 3-6 years and its associated indicators.

To analyze the status quo of dental erosion in 3- to 6-year-old children in Shanghai. A stratified, cluster, multistage random sampling methods was applied to 3- to 6-year-old children in Shanghai in 2012. Both questionnaire and clinical oral examination were performed in the survey. The questionnaire included general information, such as age, gender, parental education, dietary habit, oral health behavior, general medical health, and socioeconomic status. The clinical examination focused on the eroded tooth surface and dental erosion extent. SPSS v19.0 software package was utilized for statistical analysis. A total of 1,837 children aged 3-6 years were randomly selected in Shanghai. The overall dental erosion prevalence was 15.1 percent. Among different age groups, a relatively high prevalence of 17.1 percent was found in the 4-year-old group, and a relatively low prevalence of 12.0 percent was observed in the 3-year-old group. Surprisingly, there was no significant difference among the four age groups. The occurrence of dental erosion was influenced by habits of vinegar/coffee/tea consumption, mother's educational background, birthplace, and regurgitation (P < 0.05). The dental erosion prevalence in 3- to 6-year-old children in Shanghai appears to be close to that of other Chinese provinces as well as that observed in most of surveys carried out in different parts of the world. Efforts should be made to raise public awareness about the disease. Moreover, further studies targeted to explore the relationship between dental erosion and risk factors are needed. It is also necessary to establish a unified diagnostic standard for future epidemiological investigations.

Is the impact of the Messinian Salinity Crisis in the Black Sea comparable to that of the Mediterranean?

Erosional features have been observed along the Black Sea shelf in wells and on seismic reflection profiles that are broadly similar to the seismic stratigraphic signature of the Messinian Salinity Crisis (MSC) in the Mediterranean. In particular, the intra- (or Middle) Pontian unconformity has been suggested by some as the manifestation of the MSC in the Black Sea Basin. Missing strata and prominent lithological changes associated with the inferred MSC unconformity indicate erosional removal of parts of the underlying Cenozoic deposits in the shelf areas of the entire Black Sea. The magnitude of the relative sea level drop associated with this unconformity has been much debated, and ranges from tens of meters to thousands of meters.The suggestion of a very large (1600 m!) sea level drop in the Black Sea during the MSC is primarily based on the findings of shallow-water clastics and carbonates in Deep Sea Drilling Project (DSDP) wells 380 and 381. However, recently acquired long-offset seismic data clearly show that both of these wells penetrated gravity-driven mega-slumps and mass transport complexes. Therefore the interpreted shallow water MSC units in these deepwater wells do not represent in situ rock formations, but rather allochthonous strata derived from the basin margin.Moreover, compared to the typical seismic expression of the MSC in the Mediterranean, detailed interpretation of 2D/3D seismic data sets in the Bulgarian and Turkish Black Sea revealed considerably more complexity. This marked difference is tentatively attributed to the extent of erosion associated with the MSC in the Black Sea, i.e. the multiple MSC incisions occurred in a submarine setting, not on a subaerially exposed palaeoslope. Therefore the magnitude of the sea level drop and the overall impact of the MSC in the Black Sea appear to be significantly less than in the Mediterranean.

MP11-17 USING TRANSLABIAL ULTRASOUND AS AN EFFECTIVE TOOL TO VISUALIZE MESH EROSION INTO THE URETHRA AND BLADDER

You have accessJournal of UrologyImaging/Radiology: Uroradiology II1 Apr 2015MP11-17 USING TRANSLABIAL ULTRASOUND AS AN EFFECTIVE TOOL TO VISUALIZE MESH EROSION INTO THE URETHRA AND BLADDER Seth A. Cohen, Karoly A. Viragh, Leah Y. Nakamura, Anne L. Ackerman, Patkawat Ramart, Diana C. Kang, Judy M. Choi, Ja-Hong Kim, Steven S. Raman, and Shlomo Raz Seth A. CohenSeth A. Cohen More articles by this author , Karoly A. ViraghKaroly A. Viragh More articles by this author , Leah Y. NakamuraLeah Y. Nakamura More articles by this author , Anne L. AckermanAnne L. Ackerman More articles by this author , Patkawat RamartPatkawat Ramart More articles by this author , Diana C. KangDiana C. Kang More articles by this author , Judy M. ChoiJudy M. Choi More articles by this author , Ja-Hong KimJa-Hong Kim More articles by this author , Steven S. RamanSteven S. Raman More articles by this author , and Shlomo RazShlomo Raz More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.398AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Mesh grafts are commonplace for the repair of stress urinary incontinence in women. Women presenting with complications necessitating mesh removal will at times require excision, including a delicate dissection and reconstruction. Preoperative cystoscopy is not always informative in situations of previous partial mesh removal. Ultrasound can yield accurate information for location and position of mesh, which may impact surgical plan and patient expectations. This investigation sought to determine the sensitivity of translabial ultrasound for visualizing mesh erosion of the urethra and/or bladder. METHODS We retrospectively analyzed data from a database of mid-urethral sling patients who underwent translabial ultrasound and mesh removal, identifying those with erosion of the urethra and/or bladder documented intraoperatively. Patients with previous placement of additional mesh-products were excluded from the study. We reviewed the preoperative translabial ultrasound interpretations and calculated the sensitivity for ultrasound to identify mesh erosion. The translabial ultrasounds were performed with a standard technique each time including: images taken in the sagittal, coronal, and axial dimensions, dynamic phase (including cough, strain, Kegel), along with a 3-dimensional reconstruction. We classified the findings into extraluminal (mesh not touching the urethra or bladder), intramural (mesh is in continuity with the wall of the urethra or bladder), or intraluminal (mesh is protruding into the lumen). If mesh was found in the intramural or intraluminal position, it was included in the erosion category. RESULTS 200 patients with suburethral mesh slings underwent translabial ultrasound and mesh excision between 2007 and 2013. 17 were found to have intraoperative erosion of the urethra and/or bladder. Mean age of this cohort at time of mesh removal was 54.67 years old. Sensitivity of translabial ultrasound for erosion was 12/17 (70.5%). Position of mesh at time of ultrasound: 29% were extraluminal or not well visualized, 35% were intramural, and 35% were intraluminal. CONCLUSIONS Translabial ultrasound is effective at visualizing mesh in the urethra and bladder. This study can increase the yield of preoperative counseling for a patient undergoing mesh removal. Subclassification of the mesh position may allow us to more robustly grade the extent of erosion in the future. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e125-e126 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Seth A. Cohen More articles by this author Karoly A. Viragh More articles by this author Leah Y. Nakamura More articles by this author Anne L. Ackerman More articles by this author Patkawat Ramart More articles by this author Diana C. Kang More articles by this author Judy M. Choi More articles by this author Ja-Hong Kim More articles by this author Steven S. Raman More articles by this author Shlomo Raz More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

An aerodynamic approach in soil hydraulic conductivity estimation for investigating soil erosion degree

Abstract. We propose a new method for determining the degree of erosion for zonal soils of the East European Plain. This new approach uses soil porosity and filtration to determine a coefficient of aerodynamic similarity. We evaluated the degree of soil erosion on ranges of the major zonal soils of the eastern part of European Russia by applying this new method. Based on these data, we developed a diagnostic scale to determine the extent of soil erosion in this area.

Evaluation of soil erosion risk for watershed management in Shenmu watershed, central Taiwan using USLE model parameters

This study compiles the latest regional topographic data from field investigation and remote-sensing images to recalculate parameters of the universal soil loss equation (USLE) model of the Shenmu watershed; also to compensate for reduced accuracy of this model on small-scale slopes, this study incorporates soil erosion pin data which were collected periodically to measure the extent of soil erosion. Firstly, this study utilized the USLE model and soil erosion pin data to compare the soil erosion potential of the Chushui and Aiyuzi subwatersheds and concluded that soil erosion drastically increased if accumulated rainfall exceeded 200 mm; also, erosion depths were greater in the Aiyuzi subwatershed while estimated total erosion volume was higher in the Chushui subwatershed; this was attributed to the larger area of Chushui subwatershed and based on field measurements which supported the results of the USLE model. Secondly, this study utilized modified USLE model to compare the extreme event erosion resulting from typhoon Morakot which revealed that high rainfall intensity and long-duration rainfall events can generate large volume non-point sources of sediment that is estimated to far exceed 7–10 times of the annual soil erosion. Thirdly, this study related the C parameter of the USLE model to the existing land use in the Shenmu watershed using current, real data. Finally, this study established a post-typhoon Morakot soil erosion risk map composed of five categories of risk which was compared with post-event land cover to suggest high-erosion risk zones that may require further monitoring, remediation, and engineering measures to limit soil loss.

Areal Extent of Erosion and Accretion in and around the Gahirmatha Coast, NW of Bay of Bengal by Remote Sensing and GIS Analysis of Multi-Temporal Satellite Imagery

The shoreline morphology change due to erosion and deposition is a major concern for coastal zone management. In the present study, a highly dynamic coast of Gahirmatha on Bay of Bengal in northeast India is experiencing active erosion, which is mainly wave and tide erosion related hazard threat ending human habitation and sustainability of the coast. In our study, high resolution satellite imagery of time series provided detailed sequence of coastal morphology and their changes in all respects. Comparison study of relative shoreline positions on time series satellite data spanning three decades from 1973 to 2004 covering for the years of 1973, 1983, 1987, 1990, 1998, 2000 and 2004, provided regional changes with accelerated erosion and accretion. The result of the studies have revealed that the areas of severe erosion found along the coast are confined to the promontories of the present day mouths itself of the Baitrani at Dhamra and Brahmani at Maipura inlets. In this background, it is significant to understand the magnitude of factors that are responsible for prograding or retrograding of coast. The present study is an attempt in this direction.

Ризик фактори и интензитет на дентални ерозии на трајни инцизиви и први перманентни молари

AIM: The aim of our pilot study was to determine the prevalence of dental erosion, the impact of beverages on the level of damage to the permanent teeth.MATERIAL AND METODS: For the purpose of the study we have included 105 respondents with positive indications of dental erosion aged 10 to 60 and &lt; 60 years, and on specially prepared forms we have noted the extent of erosion and beverage consumption habits.RESULTS: The results of the level of erosion on the respondents' first permanent incisors indicated that on age 10-29 they were with surface enamel loss, and with patient's age the erosion was more present, where besides the loss of enamel there was presence of exposed dentin. Studies of the dental erosion on first permanent molars, related to the depth, depending on the age of respondents, indicated different clinical pictures. There was no respondent with enamel within normal limits. Surface loss was most present among respondents aged 10-29, loss of enamel with exposed dentin had the majority of respondents from the elderly group that also had respondents with attacked enamel and dentin but also an exposed pulp. The results show that most of the respondents consumed soft drinks 3-5 times a day, while most of them where male, and the consumption of fruit juices several times a day unfortunately was as present among male as among female respondents. There was positive correlation between the consumption of soft drinks and fruit juices in the total sample of respondents with dental erosion and all groups of respondents (Ñ€ &lt; 0.05), and between male and female respondents (Ñ€ &lt; 0.00). CONCLUSON: In conclusion, it is necessary to prepare a study by exploring the most influential etiological factors that would help in structuring preventive strategies.

Estimating Storm-Induced Dune Erosion and Overtopping along U.S. West Coast Beaches

Mull, J. and Ruggiero, P., 2014. Estimating storm-induced dune erosion and overtopping along U.S. West Coast beaches.Coastal foredunes protect lives, infrastructure, and ecosystems during severe storms. A range of approaches, ranging from simple (e.g., geometric) to complex (e.g., process based) predictive models, have been developed to quantify overtopping and foredune retreat during storms. At present, however, there is no widely accepted approach for assessing the vulnerability of coastal foredunes to erosion and overtopping hazards. Because different coastal regions have distinct storm and geomorphic characteristics, models need to be assessed and possibly adapted before they can be successfully applied to each unique region. In this study we apply a total water level (TWL) model and three simple foredune erosion models and assess their suitability for U.S. West Coast vulnerability analyses. The erosion models include a geometric model, an equilibrium profile model, and a wave impact model. We discuss the assumptions required to implement each model and force them with hydrodynamic conditions associated with a large-scale laboratory dune erosion experiment and a major winter storm approximately equivalent to the 30 year return period (TWL) event in the U.S. Pacific Northwest. The models are each applied with beach and foredune characteristics extracted from airborne topographic LiDAR (light detection and ranging) data collected along the coasts of Oregon and Washington. Sensitivity tests reveal distinct differences in model dependence on beach slope, a critical parameter in determining storm water level elevations and ultimately the extent of foredune retreat. Without detailed, reliable field observations of storm-induced dune erosion from the region, the accuracy of each model is determined using results of the dune erosion experiment. Estimates of both overtopping and erosion extent are normalized by foredune dimensions, enabling comparisons of relative vulnerability between different reaches of coast.

Properties of Encapsulated Fish Oil in Electrospun Zein Fibres Under Simulated In Vitro Conditions

In this study, omega-3-rich fish oil was encapsulated in electrosprayed zein beads and electrospun zein fibres using 10 or 20 % (w/w) zein protein solutions, respectively. The zein solutions were prepared in either 70 % (w/w) aqueous ethanol or isopropanol solvents dispersed with 30 % (w/w) fish oil. Scanning electron microscopy revealed that the ethanolic zein protein solutions generated smooth fibres while isopropanol-based solutions resulted in beads with an average size of 1 μm. The release of encapsulated fish oil from the zein encapsulant subjected to in vitro gastrointestinal conditions was evaluated using simulated gastric and intestinal fluids with and without the presence of digestive enzymes. The electrospun/electrosprayed matrices exhibited a combination of swelling and erosion. The extent of matrix swelling, erosion and diffusion of fish oil determined the kinetics of fish oil release from zein protein carriers. Fourier transform infrared spectroscopy analyses were conducted to study the changes of the secondary structure of zein as functions of protein concentration, solvent types and digestive treatments. An increased percentage of α-helical was detected under ethanolic formulation and at higher concentration of zein protein. Enzymatic treatment further disrupted the formation of α-helical and produced higher percentage of random coil structures.

INDICADORES MACRO E MICROMORFOLÓGICOS DA QUALIDADE FÍSICA DE UM LATOSSOLO VERMELHO TEXTURA MÉDIA CULTIVADO COM CANA-DE-AÇÚCAR NA MICRORREGIÃO DE QUIRINÓPOLIS, GOIÁS

Quirinópolis Micro region depicts great expansion of sugar cane production on the clayed Red Latossols but due to the increasing demand of new areas the naturally less fertile, the dystrophic Red Latosol of medium texture was done. Such soils are considered weak to the extent of structural stability and impact installation such erosion and compression, this one primarily due to highly high technified management, as though the sugar cane, which heavy machinery during all stages of culture. The aim of this study was to evaluate the physical quality of LVd with current use of sugar cane, however previously varied successions (soybeans, pasture and grazing succession/soybean), with reference to soil profiles of areas with remaniant vegetation. Thus, we obtained macro and micromorphologic indicators, physical and penetration resistance. The results revealed changes in micro and macrostructure, consistency, clay dispersion, soil bulk density and penetration resistance on cultivated soil profiles compares with natural cover profile, indicators compatible of degradation by compaction, however moderate.Key words: Saccharum spp, structure, degradation, compaction.

Tillage erosion and controlling factors in traditional farming systems in Pinar del Río, Cuba

Traditionally, research on soil degradation focused on water erosion. Recent studies, however, point to the importance of tillage operations as a source of soil translocation in traditional animal-powered farming systems comparable to those applied in the Cuyaguateje watershed, Cuba. Together with the effect of some controlling factors, the extent of tillage erosion on a Ferralsol (Ferralítico Rojo) caused by the traditional ox-drawn mouldboard plough, the ‘arado americano’, and a harrow, the ‘rastrillo’, were studied with a tracer experiment on a Ferralsol with 30 plots on moderate slopes ranging from 4% to 16.5%. Two tillage directions were considered: (i) parallel to the contour and (ii) up and down the slope. Due to the shallow average tillage depth of tillage with the ‘rastrillo’ (3.8cm), net mean downslope displacement could not be observed. Average tillage depth with the ‘arado americano’ was relatively shallow (11.5cm) as well and resulted only in the up and downslope direction in a significant downslope soil flux. This downward movement showed no significant relation with the slope gradient, nor with tillage depth, tillage speed and plant cover. While the potential for tillage erosion is considerable with the ‘arado americano’, actual erosion rates in our study were low compared to previous tillage erosion studies. Single soil movements up to 44cm were detected, but taking crop rotation and tillage frequencies into account, soil transportation rates of accumulated tillage operations only ranged from 8.78 to 26.34kgm−1yr−1. This is mainly due to the moderate slope range, the low tillage depth and the good farmers' practice of tilling alternately in opposing direction.

Erosive wear of boiler steels by sand and ash

Erosive wear of four boilers steels: 16Mo3, P265GH, P91 and 304L, was examined using a four-channel centrifugal erosion tester, two types of sands and one type of ash as the erodant, the particle velocities of 10 and 20ms−1 and the impact angles of 30°, 45° and 90°. The erodants varied in terms of abrasivity, which may be explained by their different composition, shape and size. Concerning the sands, abrasivity and erosivity went hand in hand, with impacts by angular and only silicon- and oxygen-containing Sand 1 causing essentially more material losses than those by Sand 2. Furthermore, because steady-state erosive wear was reached in the tests conducted with the sands, correlation between the extent of erosion and particle velocity could be established, enabling the deduction of the wear coefficient K and exponent n. Among the studied boiler steels, wear coefficient K was the highest for the grade P265GH, suggesting the greatest efficiency of material removal by the particle impacts. When the ash was used as an erodant, steady-state erosion was not reached and abrasivity and erosivity of the particles did not exhibit clear correlation. These results are presented and discussed in this paper.

Clinical analysis of secondary acquired cholesteatoma

ObjectiveThis study aimed to analyze the clinical features of patients who underwent surgery for secondary acquired cholesteatoma (SAC). Materials and methodsThe subjects were 30 patients who underwent surgery for SAC in 30 ears. We investigated the age distribution, sex, tympanic membrane (TM) findings, temporal bone pneumatization, morphology of TM epidermis invasion, extent of cholesteatoma invasion, ossicular erosion, surgical methods and surgical results. ResultsThere were 10 males (33.3%) and 20 females (66.6%), with a mean age 54.9years. The TM perforation was medium-sized or larger in 27 ears (90%). Temporal bone pneumatization was poor or bad in 90% (18/20) of the evaluated ears. The cholesteatoma invaded from the malleus manubrium to the promontory in 23 ears (76.7%). There were no patients in whom the cholesteatoma invaded the antrum or mastoid. The ossicles were affected in 19 ears (63.3%). Ossiculoplasty with a columella on the stapes was the most frequent procedure, performed for 16 ears (53.3%). There were no hearing results with a postoperative air-bone gap of more than 31dB. ConclusionsAlthough SAC is rare, it is important for the clinician to keep this type of cholesteatoma in mind.

Stability Of ZnO Nanorods Coated On The Channel Wall Under Continuous Flow Conditions

The damage given to the ZnO nanorod coating immobilized at the bottom of a rectangular channel by water flow is assessed in this work. The experiments were conducted in complete darkness to determine the inherent stability of the nanorod coating without the interfering effect of UV radiation. The quality and morphology of the nanorod arrays before and after use were determined by x-ray diffraction, scanning electron microscopy; rod breakage, by dynamic light scattering; and the extent of erosion, by concentration and weight measurements. The effect of pH of the flowing water in the range 4pH10, and the effect of the volumetric flow rate in the range, 3.333 cm 3 /s are investigated in this work as parameters. ZnO erosion reaches a low- level plateau in the pH range of 6pH10. Within this range, water velocity and alignment of the nanorods control the extent of dissolution. Dissolution of ZnO nanorods essentially takes place on the polar (0001)-Zn plane of ZnO, resulting in the formation of serrated surfaces. Furthermore, inclined rods joining at the top surface is subjected to further dissolution through pit formation originating at the junction interface, and extending outwards. ZnO nanorod arrays could be used as a photocatalyst in the photocatalytic water treatment processes, where the dissolution from nanorods is in the range of 2.0−2.5 wt% after 24 h of operation under a flow rate of 3.30 cm 3 /s (≈12 L/h), well under the requirements of World Health Organization. Copyright © 2014 VBRI press.

THU0254 Residual Inflammatory Activity Assessed by A Multi-Biomarker Disease Activity Blood Test is Linked to Structural Damage in RA Patients in Low Disease Activity/Remission and Normal C-Reactive Protein Level

BackgroundThe autoantibody positive (AAB+) subset of rheumatoid arthritis (RA) patients is prone to develop bone damage. Since the extent of bone erosion in AAB+ RA shows substantial variation, we hypothesized...

Digital Mapping of the Coastline Evolution of Cocos Bay (Manzanilla), Trinidad

The Manzanilla barrier beach at Cocos Bay has been undergoing marine erosion for decades due to its position against the high energy environment of the Atlantic Ocean. The barrier beach borders the Ramsar listed freshwater Nariva Swamp, offering protection from the marine environment whilst helping to maintain the delicate ecosystem in the wetland. Visible ongoing coastal erosion at this beach threatens the longevity of this internationally protected wetland. Previous studies of coastline erosion at this beach have been restricted to the analysis of beach profile data over short time periods. This paper examines the evolution of the coastline over a 36 year time period from 1958 to 1994. Digital analysis of shorelines from 1958 and 1994 aerial photographs permitted the identification of areas where erosion or deposition was the dominant process over a 36 year time period. Identification of these areas of coastal change, allowed for the lateral extent of erosion or deposition to be quantified using the Digital Shoreline Analysis System (DSAS 4.0). These calculations gave an insight into the long-term rates of erosion and deposition operating within the bay. Direct coastal measurements were also made in the short-term as a calibration of the rates of erosion and deposition from the longer-term GIS analysis. The long-term GIS analysis revealed much slower erosion rates than previously reported in short-term studies. Results indicate that analyzing short-term erosion rates alone may exaggerate the true rates of erosion at this bay.

Integrated Remote Sensing and Geographic Information System Based RUSLE Modelling for Estimation of Soil Loss in Western Himalaya, India

Soil loss due to water erosion was estimated in Kangra region of western Himalaya using revised universal soil loss equation modelling (RUSLE) in conjunction with Remote Sensing (RS) and Geographic Information Systems (GIS). The various parameters such as rainfall erosivity (R), soil erodibility (K), topographic factor (LS), crop management factor (C) and support practice factor (P) were derived using standard techniques. The study revealed that forest cover, crop land and scrub/grass land constitute 87.4 % of soil erosion susceptible area. The rate of depletion of soil was estimated at 25.63 t/ha/yr. It was highest in stony/barren land (60.3 t/ha/yr) and lowest in case of tea garden (16.09 t/ha/yr). It was felt that there is a need of implementation of soil and water conservation measures in the region to curb the soil loss. The undulating nature of terrain was observed as the main contributing factor for soil erosion. It was concluded that RS and GIS based RUSLE model can be efficiently used in mountainous regions to determine the status and extent of soil erosion.

English

This study was conducted during the cropping season of 2010 at Degem wereda. The objectives were to assess the extent of genetic erosion of barley and justify reasons for its conservation at community and household levels. Formal and informal surveys were made aimed at assessing causes for genetic erosion and quantify the level of genetic erosion. Collected data were subjected to descriptive statistics; Chi-square test and relative regression analysis and analyzed with SPSS software version 15. Accordingly, 17 farmers&rsquo; variety (FV&rsquo;s) were grown before 1994 and during 2010 only 5 FV&rsquo;s (35%) were grown. The estimated loss accounts for 65%. The major causes for genetic erosion were introduction of improved varieties, replacement of other crops, weather variability, and change in land use pattern and lack of policy support (76, 14, 14, 8, 13 and 90%, respectively). Moreover, socio-economic factors affected genetic erosion and statistically and highly significant at p&lt;0.001 for Chi-square and at p&lt;0.05 for regression analysis. Wealth of traditional sayings, poems and songs gave a picture of the importance of barley in society&rsquo;s daily life. Therefore, attention should be given to conservation of farmers&rsquo; varieties. Involving farmers&rsquo; participation is very important in order to use their indigenous knowledge for conservation of FVs&rsquo;, varieties end-use and share their socio-cultural preferences. On farm conservation strategies should be practiced for FVs&rsquo; sustainable use and attain food security. &nbsp; Key words: Genetic erosion, barley, conservation, varieties.