沉河的诗歌:从生命走入生活

沉河的诗歌创作可以分为三个阶段,这三个阶段不是前后断裂的,而是统一于他对'生命与生活'的思考之中。早期诗歌多远离现实生活,构建属于自己的想象世界,表现出在幻想世界漫游的深沉与孤独。成为中学教师后,他不得已把目光转向现实世界,现实世界的纷繁复杂使他的诗歌呈现出痛苦与焦虑。当他观察世界的方式发生了变化,逐渐以积极的心态介入现实,关注现实意义中的存在,现实意义中的人后,他的诗歌开始以生活为依托,抒发自己对生命更真切的感受,从生活的细微之处寻找诗意。

沉河的诗(组诗)

汉江不宽阔，也不狭窄，很多时，水很低露出绵软的河床。很中庸的样子。亲切，静谧。从此岸可以大致清晰地看到彼岸，树木，野草。

Spatial Distribution of Carbon and Nitrogen in Sediments of Xiangxi River

[Objective] This study was conducted to explore the spatial distribution of carbon and nitrogen in the sediments of Xiangxi River, which was the biggest tribu- tary near the Three Gorges Dam. [Method] Sediment samples were collected using customized cylindrical samplers at three sites along Xiangxi River estuary in May, 2015 to measure the contents of total carbon, total nitrogen and an isotope of car- bon δ^13C. [Result] The total carbon content in the sediments varied from 1.74% to 3.52%, and the total nitrogen content varied from 0.1% to 0.3%. The average total carbon content in the sediments near the estuary was lower than in the upstream. The total carbon content in the sediments near the estuary gradually decreased with depth increasing. However, the variations in total nitrogen content in both horizontal direction （along the river from the estuary to the upstream） and vertical direction were not so obvious as in total carbon content. The isotopic analysis showed the δ^13C value increased with depth increasing. The overall δ^13C near the estuary was lower than that in the upstream. [Conclusioal The results will provide scientific refer- ences for the distribution of biogenic elements in sediments of Xiangxi River and the evolution process of aquatic ecosystem.

Assessment of Heavy Metal Pollution in Estuarine Surface Sediments of Tangxi River in Chaohu Lake Basin

A total of 30 surface sediments samples from the estuary wetland of the Tangxi River, Chaohu Lake Basin were obtained and tested. Enrichment factor （EF） and geoaccumulation index （Igeo） as well as multivariate statistical analysis methods including Factor Analysis （FA） and Hierarchical Cluster Analysis （HCA） were applied for the assessment of heavy metal pollution in surface sediments. The results of EF values show that the pollution of copper （Cu） and cadmium （Cd） occurs in the estuarine sediments, and that zinc （Zn）, lead （Pb） and chrome （Cr） may originate from crustal materials or natural weathering process. The mean EF values of the five heavy metals are in the decreasing order： Cu〉Cd）Zn〉Pb〉Cr. Based on the lgeo of target heavy metals, the surface sediments collected from the study area can be approximately categorized as unpolluted with Zn, Pb and Cr, and moderately polluted with Cu and Cd. The degree of heavy metal pollution decreases in the order of Cu〉Cd〉Zn〉Pb〉Cr. Three groups of pollution factors are presented from FA： Zn-TOC, Cu-Cd and Cr-Pb, which respectively accounte for 27.22%, 25.20% and 21.05% of variance. By means of HCA, a total number of seven groups are distinguished from 30 sampling sites. Results indicate that Cu and Cd are the prior controlled pollutants in the estuarine sediments of the Tangxi River.

Sediment flux and source in northern Yellow Sea by ^(210)Pb technique

Sedimentation of fine-grained deposits on coastal zones and continental shelves are important because of the association with chemical pollutants, and the implication to the impact on biological processes, the stratigraphic correlations, and changes in sedimentary environments. The Yellow Sea continental shelf receives large quantities of sediment from the Huanghe （Yellow） River. Unfortunately, little attention has been yet paid to the sedimentation on the shallow shelf and its features, and the vertical sediment flux in the area is poorly understood. In this study, nine cores were collected in northern Yellow Sea by the R/V Science 1 in September, 1998 and 1999 to examine the sedimentation rate, sediment flux and the provenance with ^210Pb analysis. The 2^210Pb activity profiles showed that the vertical sediment flux ranged from 0.06 to 1.18 g/cm^2·a in the region. In central part of the area, there was a patch of fine-grained mud, with the flux below 0.33 g/cm^2·a. Most profiles were featured in two-segment model. Differences in the profiles reflected spatial and temporal variations in hydrodynamic and sedimentary processes. In order to determine the provenance and sedimentary setting in the area, the geochemistry of Ca, Fe, Sr, Cu, Ti and Rb in 11 surficial sediment samples were studied, which showed that in the central northern Yellow Sea, the mud deposit was from multi-source but mainly from the Huanghe River.

Equilibrium bed—concentration of nonuniform sediment

Knowledge of the equilibrium bed-concentration is vital to mathematic a l modeling of the river-bed deformation associated with suspended load but prev i ous investigations only dealt with the reference concentration of uniform sedime nt because of difficulties in observation of the bed-concentration. This work i s a first attempt to develop a theoretical formula for the equilibrium bed-conce n tration of any fraction of nonuniform sediment defined at the bed-surface. The f ormula is based on a stochastic-mechanistic model for the exchange of nonunifor m sediment near the bed, and described as a function of incipient motion probabil ity, non-ceasing probability, pick-up probability, and the ratio of the averag e single-step continuous motion time to static time. Comparison of bed-concentra ti on calculated from the proposed formula with the measured data showed satisfacto ry agreement, indicating the present formula can be used for solving the differe ntial equation governing the motion of suspended load.

Characteristics of Heavy Metals and Their Evaluation in Sediments from Middle and Lower Reaches of the Huaihe River

We have collected 18 samples corresponding to 18 locations in the middle and lower reaches of the Huaihe River. The sediment samples were tested for their pH level,percentage of solids,organic matter and five heavy metals (Cr,Cu,Zn,Cd and Pb). The average concentrations of Cr,Cu,Zn,Cd and Pb of the 18 sampling locations were re-spectively 56.1,22.2,70.0,0.17 and 20.4 μg/g. Compared with their background values,the average concentrations of Zn and Cu in sediment samples from the Huaihe River were slightly higher,while the average concentrations of Cr and Pb were slightly lower. The concentration of Cd in all sediment samples was higher than its background value,while the average concentration of Cd in all sediment samples was about twice the amount of the background value. The concen-tration of the five heavy metals was lower than that of the Yangtze River. A correlation analysis revealed that heavy metals have similar geochemical feautures. The geo-accumulation index (Igeo) was used to evaluate the degree of pollu-tion of the Huaihe River sediments. The index reveals that the sediment samples are largely ranked from zero pollution to no to medium pollution.

Effect of Water and Sediment Regulation on Lower Yellow River

According to the results of the water and sediment regulations of the Yellow River in year 2002—2007,the effect of erosion and deposition on the lower reaches,the amount and distribution of erosion and deposition in the river mouth area,the adjustment of river regime,the effect of river regulation projects and changes of flowing capacity of the channel are analyzed.It is revealed that the water and sediment regulation is efficient to reduce deposition and improve the flowing capacity and the conditions of sediment transport.

Change in Sediment Provenance Near the Current Estuary of Yellow River Since the Holocene Transgression

Sedimentary sequence and sediment provenance are important factors when it comes to the studies on marine sedimentation. This paper studies grain size distribution, lithological characteristics, major and rare earth elemental compositions, micropaleontological features and ^(14)C ages in order to examine sedimentary sequence and sediment provenance of the core BH6 drilled at the mouth of the Yellow River in Bohai Sea. According to the grain size and the micropaleontological compositions, 4 sedimentary units have been identified. Unit 1(0–8.08 mbsf) is of the delta sedimentary facies, Unit 2(8.08–12.08 mbsf) is of the neritic shelf facies, Unit 3(12.08–23.85 mbsf) is of near-estuary beach-tidal facies, and Unit 4(23.85 mbsf–) is of the continental lake facies. The deposits from Unit 1 to Unit 3 have been found to be marine strata formed after the Holocene transgression at about 10 ka BP, while Unit 4 is continental lacustrine deposit formed before 10 ka BP. The provenances of core BH6 sediments show properties of the continental crust and vary in different sedimentary periods. For Unit 4 sediments, the source regions are dispersed while the main provenance is not clear, although the parent rock characteristics of a few samples are similar to the Luanhe River sediments. For Unit 3, sediments at 21.1–23.85 mbsf have been mainly transported from the Liaohe River, while sediments above 21.1 mbsf are mainly from the Yellow River and partially from the Liaohe River. For Unit 2, the sediments have been mainly transported from the Yellow River, with a small amount from other rivers. For Unit 1, the provenance is mainly the Yellow River catchment. These results help in better understanding the evolution of the Yellow River Delta.

Phosphorus Speciation in Wetland Sediments of Zhujiang (Pearl) River Estuary,China

Phosphorus fractions and adsorption-release characteristics of sediments in the Zhujiang （Pearl） River estuary wetland were investigated. Results showed that the total phosphorus （TP） content in surface sediments ranged from 648.9 mg/kg to 1064.0 mg/kg; inorganic phosphorus （IP） was the major fraction of TP and ranged from 422.5 mg/kg to 643.9 mg/kg. Among the inorganic phosphorus, the main fractions were phosphorus bound to A1 and Fe （Fe/A1-P）, and calcium-bound phosphorus （Ca-P）, accounting for 23%-42% and 21%-67% of IP, respectively. The vertical distribution of TP contents were significantly positive correlated with organic phosphorus （Org-P） and Fe/A1-P contents. The bio-available phosphorus contents in vertical sediments varied from 128.6 mg/kg to 442.9 mg/kg, mainly existed in Fe-AI/P fraction, and increased from the bottom to top sediments. The transport of phosphorus in sediment-water in- terface was controlled by the soil characteristics. The active Fe and A1 content was considered as the main factor that determines adsorp- tion capacity in vegetated marsh wetland. The P buffering capacity of the sediments in vegetated marsh wetland was greater than that in mudflat wetland. The potential risk of eutrophication in the study area is high. Reducing terrestrial phosphorus discharge and preventing the sediment Fe/A1-P release to the interstitial water are the possible solutions to reduce the risk of eutrophication in estuary wetlands, and planting vegetation in estuary wetland can also reduce the release of phosphorus in surface sediment.

MECHANISM AND EFFECT OF CHANNEL EVOLUTION AT ESTUARY OF WEIHE RIVER TO HUANGHE RIVER

The channel at the estuary of the Weihe River to the Huanghe (Yellow) River has changed markedly since the 1970s. The Huanghe River has swung westwards about 5km and there was retrogressive deposition along the Weihe River. The mechanism and effect of channel evolution at the entrance of the Weihe River to the Huanghe River was analyzed with the survey data, historical statistic data and Landsat TM images of 1987 and 2002. Following conclusions were reached: 1) Physiognomy factors at the entrance, irrigation project and integrated environment evolvement in the Weihe River basin are the main factors for channel evolution at the entrance of the Weihe River to the Huanghe River. 2) The channel evolution not only reduces the ability of controling flood in the lower reaches of the Weihe River due to shrinking of the riverbed, but also increases the flood threat in the lower reaches of the Weihe River because the Huanghe River water inversely flows into the Weihe River. And there is a complexion of small flux, high water level and big disaster, which leads to the expansion of the alkali-saline cropland in the conflux area of the two rivers. 3) The regionalism and local protection must be broken to implement the integrated planning of the watershed and to decline the height of Tongguan to stabilize the physiognomy at the estuary.

Sedimentary facies of the subaqueous Changjiang River delta since the late Pleistocene

The sedimentary facies of the subaqueous Changjiang （Yangtze） River delta since the late Pleistocene was studied based on lithology and foraminifera analysis for two boreholes, CJK07 and CJK11, along with 14C dating. Four sedimentary facies were identified, namely fluvial, tidal flat, offshore, and prodelta facies. The fluvial sedimentary facies is comprised of fluvial channel lag deposits, fluvial point bar deposits, and floodplain deposits, showing a fining-upward sequence in general with no benthic foraminifera. A layer of stiff clay overlies the fluvial deposits in core CJK07, indicating a long-term exposure environment during the Last Glacial Maximum （LGM）. During the postglacial sea-level rise around 13-7.5 cal ka BP, the tidal flat facies was deposited in core CJK11, characterized by abundant silt-clay couplets. Euryhaline species dominate the subtidal fiat foraminiferal assemblages, while almost no foraminifera was found in the intertidal fiat. The offshore environment was the major sedimentary environment when the sea level reached its highest level around 7.5 cal ka BP, with a maximum accumulation rate of 10 mm/a found in core CJK11. Prodelta sediments have been deposited in core CJK11 since -3 cal ka BP, after the formation of the Changjiang River delta. The difference in sedimentary facies between core CJK07 and CJK11 is due to their location： core CJK07 was in an interfluve while core CJK11 was in an incised valley during the LGM. Furthermore, AMS 14C dating of core CJK07 shows poor chronological order, indicating that the sediments were reworked by strong tidal currents and that sediment deposited since -7.7 cal ka BP in core CJK07 was eroded away by modem hydrodynamic forces caused by the southward shift of the Changjiang River delta depocenter.

Particle reworking by the sediment-living polychaetes Perinereis aibuhitensis

The infaunal polychaete Perinereis aibuhitensis Grube, distributes widelyalong Asian coasts and estuaries. In this research the particle reworking function of P.aibuhitensis was investigated in Beitang Estuary, Tianjin. The result showed that P.aibuhitensis displayed significant particle mixing function, in which small grain sizesediment particles were mixed more than the large size ones. Some small grain sizesediment particles could be ingested by P. aibuhitensis and egested with fecal pellets.

Paleo-fluvial sedimentation on the outer shelf of the East China Sea during the last glacial maximum

Evidence from lithology, foraminiferal assemblages, and high-resolution X-ray fluorescence scanning data of core SFK-1 indicates tidally influenced paleo-fluvial sedimentation during the last glacial maximum (LGM) on the outer shelf of the East China Sea. The paleo-fluvial deposits consist of river channel facies and estuarine incised-valley-filling facies. Different reflections on the seismic profile across core SFK-1 suggest that the river channels shifted and overlapped. River channel deposition formed early in the LGM when sea level fell and the estuary extended to the outer shelf. Channel sediments are yellowish- brown in color and rich in foraminifera and shell fragments owing to the strong tidal influence. Following the LGM, the paleo-river mouth retreated and regressive deposition of estuarine and incised-valley-filling facies with an erosion base occurred. The river channel facies and estuarine incised-valley-filling facies have clearly different sedimentary characteristics and provenances. The depositional environment of the paleo-river system on the wide shelf was reconstructed from the foraminiferal assemblages, CaCO3 content and Ca/Ti ratio. The main results of this study provide further substantial constraints on the recognition of late Quaternary stratigraphy and land-sea interactions on the ECS shelf.

Partitioning of grain-size components of estuarine sediments and implications for sediment transport in southwestern Laizhou Bay, China

Sediment transport in estuarine systems has been of increasing interest for scientists during the past few decades. However, the mechanisms for sediment redistribution remain unclear. We characterized in detail sediment transport in the Xiaoqing River estuary using the mathematical Weibull function to partition grain-size components of surface sediments in the southwestern Laizhou Bay, Northeast China. Four partitioned components: finer than 4,4.6-12.5, 23.4-63.3, and 67.1-132.6 μm were interpreted in terms of hydrodynamic conditions. During sediment transport, silt grains were suspended and moved seaward from three depositional centers, whereas fine-grained sands moved generally landward. Overall, sediments are transported clockwise in a generally NNE direction near shore and then turn eastward offshore. The mathematical partitioning method showed a great potential for future estuarine environmental studies.

Identifying the sources of organic matter in marine and riverine sediments of Bohai Bay and its catchment using carbon and nitrogen stable isotopes

Carbon and nitrogen stable isotopes are useful tracers for distinguishing marine and terrestrial plant sources of sedimentary organic matter(OM),and for identifying OM from different types of plants.By analyzing the carbon and nitrogen stable isotopes of marine and riverine sediments from Bohai Bay and its catchment,we were able to identify the source of OM in these sediments.The stable carbon isotope values of Bohai Bay sediments were between-22.94‰ and-23.90‰,while those of riverine sediments were from-24.45‰ to-32.50‰.Marine algae were the main source of OM in Bohai Bay sediments.However,lacustrine algae were the main source of riverine sediments,not terrestrial OM.The nitrogen isotopes in Bohai Bay sediments decreased in eastward direction,with increasing distance from the coastline,which suggested a higher degree of impact from human activities along the coast.

Research on 3D Distribution of Meandering River Sand Body Using Sedimentary Facies Method and 3D Geological Modeling

Sedimentary facies study is an important method in describing the property and distribution of reservoir. 3D geological modeling is a powerful tool in 3D characterization of geological bodies. By combining the sedimentary facies study with 3D geological modeling to generate 3D sedimentary facies model, the 3D geometry and distribution feature of sand bodies can be more accurately characterized, particularly in 3D view. In Liuchu oilfield of Jizhong depression, the Ed2IV formation was recognized as meandering river deposition facies and five sedimentary facies were identified, which include point bar sand, levee, channel margin, abandoned channel and floodplain. All the 24 sand body facies in Ed2IV were mapped and the 3D sedimentary facies model established based on 2D facies maps. The result shows that the 3D sedimentary facies model is well matched for the research result of sedimentary facies. Being an extension of traditional sedimentary study, the 3D sedimentary facies model can be used to describe the 3D geometry and distribution orders of a single sand body more reliably and more accurately.

Assessment of heavy metals in sediment in a heavily polluted urban river in the Chaohu Basin, China

The Nanfei River （Anhui Province, China） is a severely polluted urban river that flows into Chaohu Lake. In the present study, sediments were collected from the river and analyzed for their heavy metal contents. Multivariate statistics and the fuzzy comprehensive assessment method were used to determine the sources of pollution, the current pollution status, and spatial and temporal variations in heavy metal pollution in sediments. The concentrations of arsenic （As）, cadmium （Cd）, chromium （Cr）, copper （Cu）, mercury （Hg）, nickel （Ni）, lead （Pb）, and zinc （Zn） in sediments ranged from 5.67-113, 0.08-40.2, 41.6-524, 15.5-460, 0.03-4.84, 13.5-180, 18.8-250, and 47.9-1 996 mg/kg, and the average concentrations of each metal were 1.7, 38.7, 1.8, 5.5, l 8.8, 1.3, 2.5, and 11.1 times greater than the background values, respectively. Multivariate statistical analysis demonstrated that Hg, Cu, Cr, Cd, and Ni may have originated from industrial activities, whereas As and Pb came from agricultural activities. The fuzzy comprehensive assessment method, based on the fuzzy mathematics theory, was used to obtain a detailed assessment of the sediment quality in the Nanfei River watershed. The results indicated that the pollution was moderate in the downstream tributaries of the Nianbu and Dianbu Rivers, but was severe in the main channel of the Nanfei River and in the upstream tributaries of the Sill and Banqiao Rivers. Therefore, sediments in the Nanfei River watershed are heavily polluted and urgent measures should be taken to remedy the status.

A research on statistical retrieval algorithms and spectral characteristics of the total absorption coefficients in the Yellow Sea and the East China Sea

This paper suggests a group of statistical algorithms for calculating the total absorption coefficients based on in situ data of apparent optical property and inherent optical property collected with strict quality assurance according to NASA ocean bio-optic protocols in the Yellow Sea and the East China Sea in spring 2003. The band-ratios ofRrs412/Rrs555, Rrs49o/Rrs555 are used in the algorithms to derive the total absorption coefficients （at） at 412, 440, 488, 510, 532 and 555nm bands, respectively. The average relative errors between inversed and measured values are less than 25.8%, with the correlative coefficients （R2） being 0.75-0.85. Error sensitivity analysis shows that the maximum retrieval error is less than 24.0% at ＋5% error in Rrs＇s. So the statistical algorithms of this paper are practicable. In this paper, the relations between the total absorption coefficients at 412, 488, 510, 532, 555 nm and that of 440nm are also studied. The results show that the relations between the total absorption coefficients of 400-600 nm and that of 440 nm are correlated well and all of their correlative coefficients R2 are greater than 0.99. Furthermore, a regression analysis is also done for the slope of the linear relations and wavelengths, and the R2 is also 0.99. Thus it is possible to retrieve other bands＇ total absorption coefficients with only one band absorption value, which significantly reduce the number of unknown parameters in studying other ocean color related problems.

Physical and Chemical Properties of Sediments in Huainan Segment of Huaihe River

The chemical and physical properties of nitrogen and phosphorus as well as their concentrations in the over- lying water, pore-water and sediments in Huainan segment of the Huaihe river were analyzed. The chemical forms of phosphorus in sediments were differentiated by a sequential fraction method. The results revealed that the NH+4 -N content in pore-water of 6 surface sediments is obviously higher than that in overlying water, indicating that there is a dynamic tendency of releasing NH+4 -N from sediment into overlying water. Chemical compound of nitrogen differs among segments of the river, while phosphorus has no such difference. Calcium bound phosphate (Ca-P) and iron bound phosphate (Fe-P) accounts for 60 % of the total phosphorus, and occluded-P (O-P) accounts for less than 20 %. Our findings indicate that 1) industrial waste water and domestic sewage have contributed to the excessive nu- trient salts in Huaihe river, 2) decreased water flow during low water periods, and the interaction between sediments and overlying water disturbed by transport ships accelerate nutrient salt releasing into overlying water, which results in eutrophication of the river.