renyi dimensions of soil pore size distribution abstract the existence of fractal scaling for pore volume size distribution has been empirically shown and several fractal models have been constructed to replicate it deriving also other important physical properties one step forward may be given by using multifractal analysis which achieves a better characterization of a distribution by means of a singularity spectrum whenever suitable scaling properties are present renyi dimensions are a classical tool to characterize complex distributions that are closely related to the multifractal singularity spectrum but having an easier handling and interpretation in this article renyi dimensions of pore size distributions are computed from data obtained by 2 d image analysis of soil samples analyzed samples show suitable scaling properties the renyi dimensions d q appear defined with r 2 greater than 0 95 within a significative range of q s the variation of d q with respect to q and the shape of the renyi spectrum reveal that pore size distributions have properties close to multifractal self similar measures these results show that renyi dimensional analysis is an appropriate tool for characterizing soil pore size distribution and thus may be used as indicator of soil structure as well as for deriving important soil physical properties moreover this characterization opens the possibility of simulating the real distributions by adequate self similar models of fractal geometry as iterated function systems and related ones with the corresponding benefits for prediction purposes

synoptic flow structures in the confluence region of the kuroshio and the ryukyu current 1 in the southeastern region of kyushu japan the kuroshio from the east china sea encounters the ryukyu current from the east of the ryukyu islands by analyzing synoptic sections of water properties and geostrophic velocity in august 2004 and october 2005 we distinguished the waters in the kuroshio southeast of kyushu to be separated into an offshore region and a shallow onshore one the onshore water is derived from the east china sea while the offshore water originates from both the east of amami oshima island and the interior region of the north pacific the water mass transport from the east of amami oshima island may become equivalent to that of the kuroshio in the east china sea as in october 2005 the volume transport averaged temperature of the kuroshio southeast of kyushu is significantly lower than that in the east china sea because of the confluence with the colder ryukyu current east of the amami oshima island

the northeastward current southeast of the ryukyu islands in late fall of 2000 estimated by an inverse technique 1 the northeastward current nc southeast of the ryukyu islands is estimated using an inverse technique with hydrographic section data collected in december 2000 the inversion results show the nc flowing over the continental slope with a subsurface maximum velocity of 34 cm s 1 at 270 dbar depth southeast of okinawa and 67 cm s 1 at 400 dbar depth east of amami ohshima the nc volume transports are nearly equal at the two lines 15 sv and their vertical profiles exhibit similar subsurface maximum structure at both lines these results strongly suggest that the nc off amami ohshima originates from the nc off okinawa during our observation period

comment on current system east of the ryukyu islands by a nagano et al 1 in a recent paper nagano et al 2007 hereafter n2007 discussed the variation of current structure and volume transport of the ryukyu current system rcs east of the ryukyu islands using an inverse technique with hydrographic section data collected from three cruises their paper appears to be important for understanding this western boundary current since it is based on repeated hydrographic surveys in the region east of the ryukyu islands but acquiring meaningful results from inverse calculations requires great care fiadeiro and veronis 1982 p 160 say because inverse analysis always supplies a solution it appeared that the assumed reference level matters less in inverse theory than in the hydrographer s level of no motion approach actual computations have shown that is not true a bad assumption leads to bad results the advantage of inverse theory is that one sees how bad the results are the inverse technique minimizes the velocity at the reference level and that point is indeed raised in the final paragraph of n2007 which used the reference level of 100 dbar to determine whether this shallow reference level is an appropriate condition or not one should investigate the effect of choosing other reference levels in particular deeper levels in this note we perform two inverse calculations to calculate the current east of the ryukyu islands from the same data as one of the n2007 cruises but using a reference level of 2000 dbar the resulting rcs circulation field is we believe more realistic than that of n2007 2 three hydrographic surveys were carried out during may june september and october 2002 along three lines ae e os east of the ryukyu islands figure 1 may june and september cruises used xctd xbt casts along the e line but the october cruise collected ctd casts along all three lines surprisingly absolute geostrophic velocity sections determined by n2007 with a 100 dbar reference level revealed large values up to 30 40 cm s 1 at 1000 dbar the deepest level shown figures 2 3b and 4c in n2007 we have calculated full depth absolute geostrophic velocity sections using the inverse results of n2007 and plotted them to 3000 dbar figures 2a 2b 3a 3b 4a and 4b figures 2b 3b and 4b show strong deep currents with maximum speeds of 20 50 cm s 1 on each line in each case note the contour lines of velocity are nearly vertical and strong currents extend to the bottom for example a current velocity of 57 cm s 1 touches the bottom near 3100 dbar in the ae section is the computed strong deepcurrent field real or is it an artifact of the shallow reference level we address this question by carrying out the inverse calculation using a reference level of 2000 dbar instead of 100 dbar and compare results using the two reference levels we present results for the october cruise data only because the xbt xctd casts reached only 1000 dbar also the ctd measurements provide more accuracy in the inverse calculations

proposition for a new classification of gully erosion using multifractal and lacunarity analysis a complex of gullies in the palmital stream watershed minas gerais brazil abstract the pressure that humanity applies to the environment is reaching alarming levels prevention mitigation and recovery measures need to be put into practice to conserve the environment for future generations in cases such as large scale gully erosion the problem of soil removal is irreversible but adequate management could stabilize this impact in this sense we studied the palmital stream watershed in minas gerais state brazil and applied a new approach to the study of gully erosion based on two main aspects the temporal evaluation of gullies using multifractal and lacunarity analysis and a proposition for a new gully design a complex of gullies using remote sensing and geoprocessing we obtained images of the gullies in the palmital stream watershed for the years 2002 2007 2014 and 2016 the gully designs were binarized and used in two free software programs multifractal analysis and scaling system mass from the international potato center cip peru and fraclac a plugin for imagej from the national institutes of health nih united states of america to perform multifractal and lacunarity analyses after that we segmented the entire watershed image and re evaluated it using the same software we found that the gullies were multifractal translationally invariant not random relatively homogeneous and grouped which means that these gullies behave more as groups linked to an environmental characteristic fault and shear zones with northwest southeast direction for instance than individual gullies therefore we proposed a new classification called the complex of gullies to rearrange their designs as connected features then we performed multifractal and lacunarity analysis of these new complex images following the same steps as those performed on the initial images and found better results compared to the former designs this new approach could help land managers prevent gully advancement and develop more efficient recovery projects and we recommend further studies to improve the validation of the proposition

variations of current path velocity and volume transport of the kuroshio in relation with the large meander abstract the variations of the kuroshio current path and their relations with current velocity volume transport and upstream position of the kuroshio are examined using sea level data after the long time non large meander nlm path during 1963 75 the kuroshio takes a large meander lm path during most of 1975 91 1975 80 1981 84 1986 88 and 1989 91 the study of these meanders confirms the description of the path of the kuroshio based on the three typical paths and the transitions between them with an exception being the 1981 84 lm path the formation and decay of the large meander are associated with velocity and position of the kuroshio in the tokara strait south of kyushu a small meander precursor of the large meander seems to be formed southeast of kyushu in relation with a temporary increase of kuroshio velocity and a northward shift of the kuroshio in the tokara strait an eastward propagation of the small meander leading to the lm formation is associated with remaining in the northe

differentiation and mechanisms on physical properties of reconstructed soils on open cast mine dump of loess area soil reconstruction on the open cast mine dump is an important part of land reclamation this study took soils at the south dump in antaibao open cast mine of china coal pingshuo group as the research object and focused on analyzing the physical properties and differentiation mechanisms of the reconstructed soils collected from the dump along the slope and platform of shady slope half shady slope sunny slope and half sunny slope of the open cast coal mine at the overall level site level and terrain level respectively during the soil rock mixture discharge process the results are following 1 the variation coefficients of soil bulk density soil porosity soil mass water content as well as soil gravel content are at a state of medium variability 2 after a long time of vegetation restoration soil bulk density is decreased soil porosity is increased and soil mass water content quality is improved 3 the physical properties of reconstructed soils at platform are slightly but not significantly better than those at slope 4 most physical properties of the reconstructed soils are significantly different at the slope and aspect levels but not at the altitude level 5 at the slope level the physical properties of reconstructed soils are significantly different between the moderately steep slope and high steep slope 6 at the aspect level soil bulk density soil porosity and soil gravel content sunny slope are obviously different from those at half sunny slope and soil mass water content at shady slope is significantly different from that at half shaded slope lastly we proposed some specific measures to optimize land reclamation technologies

hydraulic conditions in experimental rill confluences and scour in erodible soils 1 few studies have examined processes active within rill networks or the effect of confluence geometry on rill sediment flux and it is not clear if observations from river confluences also apply at rill scale laboratory experiments were carried out in artificial rectangular rill channels with fixed and erodible beds to identify the effects of confluence geometry on hydraulic conditions and scour patterns symmetrical and asymmetrical confluences with angles from 19 to 90 were used hydraulic changes in the confluence zone in fixed bed experiments included decreased flow velocity increased shear velocity transition from supercritical to subcritical and from transitional to turbulent flow bed scour in the confluence zone resulted generally increasing with confluence angle but a more important influence was junction symmetry or asymmetry symmetrical confluences produced a symmetrical scour pattern mirroring the original channels but in asymmetrical confluences scour was more complex evolving to a symmetrical pattern with confluence angles higher than the original system results are consistent with channel evolution to an optimally branched system controlled by minimum power criteria but validation requires testing with more precise velocity measurement

energetics of eddy mean flow interactions along the western boundary currents in the north pacific abstractthe energetics of eddy mean flow interactions along two western boundary currents of the north pacific the kuroshio and ryukyu currents are systematically investigated using 22 years of n

observations of flow variability through the kerama gap between the east china sea and the northwestern pacific the kerama gap near the middle of the ryukyu island chain is the deepest channel with a sill depth of 1050 m connecting the east china sea ecs to the northwestern pacific we measured the flow through the kerama gap from june 2009 to june 2011 the 2 year mean transport 2 0 0 7 sv is into the ecs from the northwestern pacific it contributes about 11 of the mean kuroshio transport in the ecs at the pn line subtidal standard deviation of the transport through the kerama gap is 3 2 sv comparable to that of the pn line kuroshio transport 4 0 sv suggesting a significant effect of kerama gap transport on temporal variability of the kuroshio transport in the ecs comparison with time series of satellite measured sea surface height maps reveals that temporal variability of the kerama gap transport is related to the arrival of mesoscale eddies from the east high low transport into the ecs is associated with the presence of a cyclonic anticyclonic eddy south of the kerama gap

satellite altimeter monitoring the kuroshio transport south of japan in 1993 1995 we carried out observations of the kuroshio south of japan including direct current measurements and repeated hydrographic surveys along a satellite track of the topex poseidon altimeter the velocity field of the kuroshio is determined by geostrophic calculation using the repeated hydrographic survey data referenced to velocities observed at mid and abyssal depths the volume transport of the kuroshio is estimated from this velocity field the estimated transports of the kuroshio have a high correlation with sea surface height differences across the kuroshio having this relationship and using the altimeter data we obtained a time series of the kuroshio transport over seven years at ten day intervals the kuroshio transport excluding contributions by local recirculations is estimated to be 42 106 m sec on average the correlation between sea surface height difference and transport provides a practical method of long term monitoring of the kuroshio transport using satellite altimetry

extraordinary subsurface mesoscale eddy detected in the southeast of okinawa in february 2002 1 in february 2002 a subsurface mesoscale eddy with extraordinary features was detected at a depth of about 300 dbar in the southeast of okinawa a part of the ryukyu islands the water mass occupying this subsurface eddy is characterized as the north pacific subtropical mode water npstmw with salinity maximum and thick thermostad its temperature salinity and potential density at the core of the eddy are 18 4 c 34 81 and 25 06 respectively thickness and width of the eddy are about 300 m and 100 km respectively mixing between the eddy and the surrounding water mass is also found such eddy with the npstmw has never been detected during ten years

multifractal analysis of discretized x ray ct images for the characterization of soil macropore structures a correct statistical model of soil pore structure can be critical for understanding flow and transport processes in soils and creating synthetic soil pore spaces for hypothetical and model testing and evaluating similarity of pore spaces of different soils advanced visualization techniques such as x ray computed tomography ct offer new opportunities of exploring heterogeneity of soil properties at horizon or aggregate scales simple fractal models such as fractional brownian motion that have been proposed to capture the complex behavior of soil spatial variation at field scale rarely simulate irregularity patterns displayed by spatial series of soil properties the objective of this work was to use ct data to test the hypothesis that soil pore structure at the horizon scale may be represented by multifractal models x ray ct scans of twelve water saturated 20 cm long soil columns with diameters of 7 5 cm were analyzed a reconstruction algorithm was applied to convert the x ray ct data into a stack of 1480 grayscale digital images with a voxel resolution of 110 microns and a cross sectional size of 690 690 pixels the images were binarized and the spatial series of the percentage of void space vs depth was analyzed to evaluate the applicability of the multifractal model the series of depth dependent macroporosity values exhibited a well defined multifractal structure that was revealed by singularity and renyi spectra the long range dependencies in these series were parameterized by the hurst exponent values of the hurst exponent close to one were observed indicating the strong persistence in variations of porosity with depth the multifractal modeling of soil macropore structure can be an efficient method for parameterizing and simulating the vertical spatial heterogeneity of soil pore space

fractal scaling of surface roughness in artificially weathered smectite rich soil regoliths abstract laboratory trials were established to simulate under controlled conditions the natural weathering sequence of smectite rich soil regoliths from a highly degraded badland area at vallcebre eastern pyrenees range spain experiments were carried out to deepen the knowledge on the response of the bulk materials to experimental freezing thawing and wetting drying cycles and the role of the mineral components in the path of surface structure detachment during the experiments variation of surface roughness was determined by measuring consecutive transects of the artificially weathered samples with a noncontact laser profile meter and data were analysed with a program written for this purpose the analysis of data was based on the calculation of the fractal dimension according to the richardson equation of sequential surface profiles of samples in frozen thawed wetted and dried conditions in order to achieve a dynamic description of surface aggregate shape arrangement along the whole sequence and at different scale ranges the hurst exponent of selected bulk data was also calculated in order to find added evidence of the nature of surface which in some cases appeared to be multifractal with the richardson diagram the fractal model applied allowed to obtain fractal dimension values of surface roughness which were used to explain how the pedological characteristics of a given material containing clay and carbonate association may react to applied climatic extremes thereby showing differential surface arrangement and weathering paths freezing and thawing as well as wetting and drying events modified the sample s surface and these effects describe the material susceptibility to weathering against individual climatic components and may be useful in erosion modelling at the catchment scale

introduction of spatial smoothness constraints via linear diffusion for optimization based hyperspectral coastal ocean remote sensing inversion 1 an optimization based shallow water remote sensing inversion algorithm was recently developed by lee et al 1999 that simultaneously derives bottom depth and water column inherent optical properties only measured remote sensing reflectance is required as input which is a noted advantage however the algorithm is sensitive to noise given the observation that bottom depth and optical properties generally change slowly over the spatial domain we applied a smoothness assumption by modifying the lee algorithm to accommodate a spatial smoothness constraint spatial constraints were introduced through a linear diffusion process the new spatial constraint model retrievals were compared with those from the original lee model as well as from the original model plus smoothing performed as postprocessing synthetic and real field data experiments were performed for the synthetic experiments the lee method was the most sensitive to noise and posted the largest absolute and standard errors for the field experiments portable hyperspectral imager for low light spectroscopy sensor phills imagery was acquired over optically shallow water an in situ acoustic sensor mounted on a towed hyperspectral tethered spectral radiometer buoy htsrb provided measured bottom depth transects and remote sensing reflectance was htsrb derived bathymetry estimates were validated in this research lee method bottom depth retrievals were more erratic than those generated via the other methods unlike postsmoothing the spatial constraint method corrected large deviations of the lee method spanning several transect points overall our spatial constraint method yielded the most accurate estimates and represents a significant improvement upon the lee method mean absolute estimation errors for the lee postprocessing and spatial constraint methods were 0 412 0 389 and 0 335 m respectively

current system east of the ryukyu islands 1 the ryukyu current system rcs is a northeastward current southeast of the ryukyu islands the variation of current structure in the rcs region was investigated on the basis of the absolute geostrophic velocity estimated by inverse calculation using hydrographic data three realizations of the rcs are examined from cruises in may september and october 2002 it was found that the current structure in the rcs region is divided into upper and lower layers by an isopycnal surface of 26 the currents in both layers proceed northeastward along the eastern slope east of the ryukyu islands the current in the upper layer merges with the inflow from the interior region resulting in larger northeastward volume transport southeast of amami oshima island than southeast of okinawa island the volume transport from the east reaches more than 40 of that southeast of amami oshima island on the other hand the current in the lower layer is not affected by inflow from the east it is also found that the upper rcs gains heat mainly through the advection of warm water from the east resulting in an increase in the downstream temperature by about 0 5 c on average

multi fractal characteristics of the particle distribution of reconstructed soils and the relationship between soil properties and multi fractal parameters in an opencast coal mine dump in a loess area soil reconstruction is at the core of mine land reclamation reconstructed soil from an opencast mine dump in a loess area is a complex composite that was assembled by humans using multiple reconstruction technologies the soil is composed of varied soil particles with irregular shapes and has self similar structure to better quantify the characterization of reconstructed soil in this dump the soil particle size distribution from four modes of soil reconstruction in the shanxi pingshuo antaibao opencast coal mine dump was analyzed using multi fractal theory soil reconstruction modes included loess material containing gravel lg loess material containing coal gangue cg total loess material al and loess material containing ginger stone lgs soil particle composition gravel content field water capacity soil bulk density soil organic matter total nitrogen tn soil ph and electrical conductivity ec of different soil layers from different reconstruction modes were measured a generalized dimension spectrum d q multi fractal singularity exponent q and multi fractal spectrum function f q were calculated relationships between soil properties and fractal parameters were analyzed the results led to the following conclusions 1 the soil particle distribution of reconstructed soil had significant multi fractal characteristics in an opencast coal mine dump in a loess area d 0 d 1 d 1 d 0 and f can reflect the non uniform particle size distribution characteristics d 0 d 1 d 0 and f or d 0 d 1 d 0 and can be simplified as three parameters to quantify the multi fractal characterization of the reconstructed soil particle distribution 2 after reclamation the soil quality from different layers of different profiles in different reconstruction modes shows some improvement 3 there were strong correlations between multi fractal parameters and soil properties d 1 and increased and d 1 d 0 and f decreased with increasing gravel content soil bulk density organic matter tn and soil ec however it was opposite for ph and field water capacity gangue and gravel have a definite impact on the dispersion degree of soil particles in reconstruction this study provides a theoretical basis for land reclamation and quantitative expression of reconstructed soil particles distribution in opencast coal mine dumps in loess areas

surf zone megaripple orientation measurements and models 1 two existing models for bed form orientation are tested against measurements of megaripple crest line orientation from scripps beach optical time averaged images of the surf zone sand bed at 10 min intervals are processed with an automatic crest line tracing algorithm flow measurements concurrent with images of the sand bed collected during 3 7 april and 17 23 july 1999 are used as input to the gross bed form normal transport model bed forms align to maximize gross transport across crests predicting steady state crest orientation and the defect model bed forms reorient at a rate proportional to the differential velocity of crest line ends or defects predicting a time dependent orientation generally poor agreement was found between predictions and measurements of crest line orientation the gross bed form normal transport model predicted crest line normal orientation within 20 of measured orientation for 38 of records with increased agreement coinciding with longitudinal and oblique bed forms the defect model predicted crest line normal orientation within 20 of measurements for 22 of records when the ratio between defect and transport event timescales is assumed 1 and 14 of the records for the ratio 1 although migration and mean sediment transport direction are assumed to coincide in both models rms deviation in bed form migration direction from the calculated 30 min mean sediment transport direction was found to be 38 additionally rms deviation of megaripple migration direction from crest line normal orientation was 39

the northeastward current southeast of okinawa island observed during november 2000 to august 2001 1 in order to estimate the variability of current structure and mean geostrophic volume transport in the southeast of okinawa island the round trip acoustic travel times between sea bottom and surface at nine sites were measured by inverted echo sounder with pressure gauge pies from november 2000 to august 2001 vertical sections of geostrophic velocity are calculated by using vertical profiles of specific volume anomaly derived by the gravest empirical mode method from the pies data in the upper 500 m layer over a slope shallower than 1000 m depth the northeastward current reached up to 60 cm s 1 during the occupation of an anticyclonic eddy and decreased to 15 cm s 1 during the occupation of a cyclonic eddy around the mean of 20 cm s 1 the temporal mean geostrophic volume transport relative to the 2000 dbar level was estimated to be 6 1 sv 1 sv 106 m3 s 1 northeastward in the west of 128 85 e