浓江流域湿地水文站建设方案研究

湿地水文测验是湿地科学研究中的一项基础性工作。根据浓江流域湿地特征,为了有效监测湿地保护区水资源恢复前、恢复过程和恢复后的湿地水文特征,验证保护区水资源补充方案的可行性,识别保护区湿地水资源环境是否朝着好的方向演替,同时为开创我国湿地水文监测事业作出试点和积累经验,在浓江流域建立湿地水文测验站非常必要。根据洪河保护区水资源恢复方案、黑龙江洪水水位、大力加湖水库调洪水位以及浓江河洪水过程线计算成果,设计了洪河保护区和浓江下游水文测站建设的布局方案和建设内容,并对其机构设置和运行管理等方面进行简要说明。

浓江流域湿地生态水文过程恢复途径研究

浓江流域内分布有洪河国家级自然保护区和三江国家级自然保护区的一部分。浓江流域湿地生态水文特征在三江平原具有较好的代表性,但最近20多年来,由于农业开垦活动和水利工程设施的建设,使得水文过程受到强烈干扰,生态功能明显下降。基于流域湿地水文过程的演变原因,建议浓江流域湿地生态水文过程的恢复途径为:(1)首先应以本文所提供的洪河保护区水资源恢复方案实现该保护区水资源恢复;(2)增大黑龙江洪水倒灌浓江下游河段和大力加湖的水量;(3)限制浓江流域中上游水稻田的种植面积;(4)恢复连接洪河和三江保护区之间的浓江河道的水流连通性;(5)开发流域水资源共管机制是进行生态水文过程恢复的重要保障;(6)开发以保护湿地生态廊道为目的的洪水保险机制,缓减浓江中下游农户由于浓江河道洪水泛滥所带来的经济风险。本研究用来分析、诊断和恢复流域湿地生态水文过程的思想与方法,适用于三江平原其他流域,同时也是从工程与非工程措施相结合的角度进行我国退化湿地保护与恢复的一次理论、技术、政策和经济方面的有效尝试。

三江盆地浓江凹陷烃源岩热成熟度定量预测

三江盆地浓江凹陷的勘探程度低,地震和钻井资料稀少,区内有效烃源岩的分布不明确,严重制约着研究区的油气勘探。针对存在的问题,以怀利公式及孔隙度-镜质体反射率的经验公式为基础,综合应用钻井曲线、叠加速度谱及地震资料,通过改进层速度的求取方法,形成了一套适合研究区的烃源岩热成熟度地震预测技术,并对该区的烃源岩热成熟度平面分布进行了预测,初步落实了该区的勘探潜力,同时为类似新区的早期资源潜力评价提供参考。

三江盆地浓江凹陷古近系层序地层及主要烃源岩发育特征

通过对浓江凹陷前参2井古近系地层层序充填特征和主要烃源岩生烃潜力研究发现,浓江凹陷古近系地层层序可划分为2个Ⅲ级层序5个体系域,主力烃源岩分布于层序Ⅰ(达连河组中下部)低水位体系域的泥岩,厚度稳定,有机质丰富,以Ⅱ1、Ⅱ2型干酪根为主,处于低成熟演化阶段。结合地震资料解释结果,预测出盆地的有效生油岩面积98km2,评价前参2井北部浓桥次凹是油气成藏的有利区。

三江盆地浓江凹陷新生代断层活动及构造演化

浓江凹陷经历了多期构造运动,新生代构造特征、演化及其与油气的关系尚不清楚。通过对地质录井、物探测井、地震资料进行综合分析,剖析了浓江凹陷新生代断裂特征及其活动性,利用平衡剖面法分析了凹陷构造演化史,探讨了构造演化对油气条件形成及运聚的影响。研究结果表明,浓江凹陷断裂走向以北东向为主,发育张性构造和扭性构造。在达连河组沉积时期为初始断陷期,凹陷具有双断结构。宝泉岭组沉积时期为强烈断陷期,东部洼陷发育规模明显大于西部洼陷,具有南沉北翘的特点。宝泉岭组沉积末期,凹陷经历了复杂断坳转换,地层抬升遭受剥蚀,西部洼陷带削截现象明显,富锦组沉积时期以坳陷沉积作用为主,沉积末期为挤压反转期,东部洼陷带发生挤压反转,地层上拱遭受明显剥蚀。道台桥组沉积开始,凹陷进入稳定沉降期。研究区构造演化与油气关系密切,构造活动控制着烃源岩的分布、圈闭类型及展布以及油气的运聚成藏。

三江盆地浓江凹陷前参2井油源对比

三江盆地浓江凹陷东南部钻探的前参2预探井发现油气显示,但油气来源尚不清楚。本文将前参2井油砂与盆地内三套烃源岩的生物标志化合物等地球化学参数进行分析比对,发现油砂与下伏新安村组和达连河组含煤泥质烃源岩具有类似的生物标志化合物分布特征,但成熟度很不匹配。结合周边盆地原油及烃源岩的地化参数特征,推断浓江凹陷原油可能来自深部古近系烃源岩或中生界含煤层系烃源岩,但浓江凹陷目前并未钻遇到更深的烃源岩,因此判断原油可能由其它盆地运移而来。

浓江凹陷烃源岩地球化学特征及勘探潜力分析

通过对浓江凹陷烃源岩地球化学特征进行分析发现,浓江凹陷暗色泥岩发育,有机质丰度高、类型好,但热演化程度较低,仅达连河组下部发育有效烃源岩,且处于低成熟演化阶段,烃源岩条件一般。但该区有可能存在低成熟生物气,因此具有一定的勘探前景。

快乐比赛庆丰收——浓江农场举办首届农民趣味运动会

"加油!加油!"9月22日,我省垦区浓江农场庆祝农民丰收节暨农民趣味运动会拉开序幕。在开镰收割、"捆蟹达人"劳动技能大赛、浑水摸鱼等项目中,参赛农民使出了浑身解数,各显神通,争当第一。此次趣味运动会的召开,不仅丰富了农民的生活,也让他们在运动中同庆同乐,在快乐中享受着自己的节日、享受着丰收的喜悦。

Numerical simulation on the process of saltwater intrusion and its impact on the suspended sediment concentration in the Changjiang(Yangtze)estuary

To study the relationship between sediment transportation and saltwater intrusion in the Changjiang (Yangtze) estuary, a three-dimensional numerical model for temperature, salinity, velocity field, and suspended sediment concentration was established based on the ECOMSED model. Using this model, sediment transportation in the flood season of 2005 was simulated for the Changjiang estuary. A comparison between simulated results and observation data for the tidal level, flow velocity and direction, salinity and suspended sediment concentration indicated that they were consistent in overall. Based on model verification, the simulation of saltwater intrusion and its effect on sediment in the Changjiang estuary was analyzed in detail. The saltwater intrusion in the estuary including the formation, evolution, and disappearance of saltwater wedge and the induced vertical circulation were reproduced, and the crucial impact of the wedge on cohesive and non-cohesive suspended sediment distribution and transportation were successfully simulated. The result shows that near the salinity front, the simulated concentrations of both cohesive and non-cohesive suspended sediment at the surface layer had a strong relationship with the simulated velocity, especially when considering a 1-hour lag. However, in the bottom layer, there was no obvious correlation between them, because the saltwater wedge and its inducing vertical circulation may have resuspended loose sediment on the bed, thus forming a high-concentration area near the bottom even if the velocity near the bottom was very low during the transition phase from flood to ebb.

Key nitrogen biogeochemical processes revealed by the nitrogen isotopic composition of dissolved nitrate in the Changjiang River estuary, China

Seasonal variations in the nitrogen isotopic composition of dissolved nitrate （δ15NO3） were investigated in the surface waters of the Changjiang River estuary in 2009 and 2010. δ15NO3 varied between -4.6‰ and 8.9%0 with changes in temperature, salinity, dissolved oxygen concentrations, and the composition of the dissolved inorganic nitrogen pool. In February, biological processes decreased because of low temperature, and the mean δ15NO3 near the river mouth was 2.4%0. In May, δ15NO3 was the highest in the surface waters among all seasons. Analysis on the conservative mixing revealed assimilation, and this finding is supported by positive relationship between Chl a and δ15NO3. The fractionation factor of assimilation was estimated to be 2.0‰ by the Rayleigh equation. Nitrification was supported based on the mixing behaviors in November 2010 and the low δ15NO3 values in May and November 2009. The high ammonium concentrations in the adjacent marine area and positive relationships between total organic nitrogen and δ15NO3 in November 2010 indicated that mineralization was taking place.

Radium isotopes assess water mixing processes and its application in the Zhujiang River estuary

Radium （Ra） isotopes are useful for tracing water mass transport and examining estuarine hydrological dynamics. In this study, several hydrological parameters, nutrients, ehlorophyll-a （ehl-a）, suspended particulate matter （SPM） and Ra isotopes （223Ra, 224Ra and 226Ra） of surface waters of the Zhujiang （Pearl） River estuary （ZRE） were measured. This was done for both winter （December） and summer （July） seasons, to quantitatively understand the seasonal characteristics of river plume flow rate and trajectories, as well as the ecological response. The results show that Ra concentrations in summer were higher than in winter, especially Z24Ra （about 2-5 times higher）. The spatial distribution of three Ra isotopes and relative Ra water ages indicated that river water mainly flushed out of ZRE through the western side in winter, where the water transport was about 5 days faster than in the eastern zone. In summer, diluted river water expended to the east side, resulting in fairly similar water ages for both sides of the river mouth. Although nutrients were higher during the summer season, lower chl-a concentrations indicated that reduced primary production might be caused by high SPM （low light penetration）. The results obtained from this study will provide knowledge needed for effectively developing and managing the ZRE.

Heavy Metal Transfer from Soil to Vegetable in Southern Jiangsu Province, China

Vegetable fields in peri-urban areas receive large amounts of extraneous heavy metals because of rapid urbanization and industrialization in China. The concentrations of Cu, Zn, and Pb in 30 soil samples and 32 vegetable samples, collected from 30 different sites in southern Jiangsu Province of China, were measured and their transfer from soil to vegetable was determined. The results showed that the soil samples had wide ranges of pH （4.25-7.85） and electrical conductivity （EC） （0.24-3.42 dS m^-1）. Among the soil samples, there were four soil samples containing higher Cu and two soil samples containing higher Zn concentrations than those specified in the Chinese Soil Environmental Quality Standard II. However, no vegetable sample was found to contain a high level of Cu or Zn. In contrast, one vegetable sample contained 0.243 mg Pb kg^-1 FW, which was above the Chinese Food Hygiene Standard, whereas the corresponding soil Pb concentration was lower than the Chinese Soil Environmental Quality Standard II. The transfer coefficients of Cu of all vegetable samples exceeded the suggested coefficient range, implying that extraneous Cu had high mobility and bioavallability to vegetables. There was no significant correlation between extractable soil heavy metal concentrations with four kinds of extractants and soil pH, EC, heavy metal concentrations in vegetables and soils, except that soil pH correlated well with the extractable soil Cu, Zn, and Pb concentrations with 1.0 mol L-1 NH4NO3. Moreover, diethylenetriamine pentaacetic acid （DTPA） extraction method was a more efficient method of extracting heavy metals from the soils independent of soil pH and EC than other three methods used.

Combined effects of water temperature and copper ion concentration on catalase activity in Crassostrea ariakensis

A central composite experimental design and response surface method were used to investigate the combined effects of water temperature(18–34℃) and copper ion concentration(0.1–1.5 mg/L) on the catalase(CAT) activity in the digestive gland of C rassostrea ariakensis. The results showed that the linear effects of temperature were significant(P <0.01), the quadratic effects of temperature were significant( P <0.05), the linear effects of copper ion concentration were not significant(P >0.05), and the quadratic effects of copper ion concentration were significant(P <0.05). Additionally, the synergistic effects of temperature and copper ion concentration were not significant(P >0.05), and the effect of temperature was greater than that of copper ion concentration. A model equation of CAT enzyme activity in the digestive gland of C. ariakensis toward the two factors of interest was established, with R 2, Adj. R 2 and Pred. R 2 values as high as 0.943 7, 0.887 3 and 0.838 5, respectively. These findings suggested that the goodness of fit to experimental data and predictive capability of the model were satisfactory, and could be practically applied for prediction under the conditions of the study. Overall, the results suggest that the simultaneous variation of temperature and copper ion concentration alters the activity of the antioxidant enzyme CAT by modulating active oxygen species metabolism, which may be utilized as a biomarker to detect the effects of copper pollution.

Simulation of Water Quality of Neijiang River Based on RMA4 Model

Using the RMA4 water quality model to simulate the water quality of Neijiang river in Zhenjiang, the result showed that： in the dry season the ranges of the concentration of various pollutants simulation of Neijiang were BOD5 3.2-5.2 mg/L, CODMn 4.7-6.8 mg/L, NH3-N 0.46-1.8 mg/L, TP 0.23-0.48 mg/L, and in the rainy period, the ranges of the concentration of various pollutants simulation of Neijiang were BOD5 0.69-0.73 mg/L, CODM, 1.9-2.3 mg/L, NH3-N 0.25-0.38 mg/L, TP 0.14-0.17 mg/L.These simulated values were closed to the monitoring values of pollution concentrations of Neijiang, which indicated that RMA4 was certain practical in the river water quality simulation, and simulation results have a certain degree of reliability, and it provides a scientific planning and management method for the river pollution control.

Effects of land use and changes in cover on the transformation and transportation of iron:A case study of the Sanjiang Plain,Northeast China

Wetland reclamation has been ongoing in the Sanjiang Plain since the mid-1950s,which has resulted in major changes in wetlands and the agriculture ecosystem in the region that have influenced the iron output to the Sea of Okhotsk and limited the primary productivity in the North Pacific Ocean.This study was conducted to investigate the chemical forms of iron in different aquatic environments(agricultural water including groundwater,paddy water,and canal water;wetland water including marsh water,marsh streams,and main streams) with the cross-flow filtration method to reveal the transportation and transformation characteristics of iron in response to major land use changes.In addition,the factors affecting iron behavior in different water bodies were reviewed.In marsh water and streams,the concentrations of dissolved iron were higher due to the high organic matter contents and marsh water becoming the main iron source for river water.The conversion of dissolved iron into acid-labile iron occurred during the discharge of wetland water into marsh rivers.Iron primarily existed in both the >0.7 and <0.01 μm size fractions,accounting for about 58.3% and 26.4% of the total dissolved iron,respectively.In agricultural irrigation systems,ferrous ion entered the paddy fields from groundwater,and a fraction of this ferrous iron was subsequently converted into high molecular weight and medium molecular weight iron(colloid iron) in paddy and canal water.However,the concentrations of total dissolved iron decreased by 62.5% from underground to the surface due to the formation of precipitates.Despite this,water discharge in agriculture is still an important iron source for rivers and has the potential to supplement iron due to its higher acid-labile iron concentrations.Land use and cover change and agricultural irrigation increased the iron content of surface soil,but reduced the output of iron in water systems.Overall,the concentration of total dissolved iron in water systems has been reduced to 42.6% by wetland reclamation.

Background concentrations of reactive gases and the impacts of long-range transport at the Jinsha regional atmospheric background station

Lorentz curve fittings are applied to frequency distributions of the concentrations of O3, CO, NOx and SO2 recorded at the Jinsha regional atmospheric background station （JSH） from June 2006 to July 2007, and the peak concentrations of these species for the different seasons are obtained. The peak concentrations are considered to be representative of different background levels for certain processes. The peak concentrations are compared with the corresponding mean （median） concentrations, and the suitability and limitations of the mean （median） values as the background levels are discussed. The mean （median） values might represent the background concentrations in the region under some circumstances, but in other cases these values often underestimate or overestimate the true background concentrations owing to the transport of pollutants and other factors. The effects of air masses transported from different regions on the pollutant background concentrations are obtained by analyzing the 72-hour backward trajectories of air masses 100m above the ground at JSH, These trajectories are estimated using the HYSPLIT model and then clustered for the measurement period. The spatial distribution and seasonal variations of trajectories and the corresponding mean concentrations of O3, SO〉 NOx and CO for different clusters are analyzed. After filtering the seasonal changes in pollutant concentrations, the relative influences of air masses from different regions are obtained. The results show that JSH can be used to obtain the atmospheric background information of different air masses originating from or passing over the Yangtze River Delta, Central South China and the Jianghan Plain. Air masses from Central China, South China, and the western Yangtze River Delta contribute significantly to O3 at JSH. Air masses from the north and northeast of JSH （i.e., the Jianghan Plain, Huang-Huai Plain and North China Plain） and the south （Central South China） contribute significantly to SO2, CO and NOx concentrations. Air masses originating from the ocean often bring clean air. Air masses originating from high altitudes over northwestern regions often have lower CO and NO3 concentrations, lower relative humidity, and higher concentrations of O3 and SO2.

Effect of total dissolved gas supersaturated water on early life of David's schizothoracin (Schizothorax davidi)

The effect of total dissolved gas （TDG） supersaturation on fish living downstream of dams is one of the main ecological risks of high dam construction. A strategy for mitigating the negative effects is needed urgently since many high dams are under construction in the upper reaches of the Yangtze River in China. Experiments on the hatching process of David＇s schizothoracin were carried out and the results show that the hatching rate decreased with increasing TDG levels, and that most eggs hatched within a very short time in the higher TDG saturation groups. By using a stereomicroscope, damages to the head, yolk sac, body, anus, etc. were found in larvae which hatched in TDG supersaturated water. Results show that the lesion rate increased with increasing TDG levels. Furthermore, 7-d-old David＇s schizothoracin were exposed to TDG supersaturated water levels of 100%, 105%, 110%, 115%, 120%, 125%, 130%, 135%, and 140% for testing their tolerance to TDG supersaturation. We found that the median lethal concentrations （LC50） for 13, 14, 20, 35, 52, 73, and 96 h exposure were 138%, 138%, 134%, 130%, 129%, 128%, and 126%, respectively. The median lethal times （LTs0） were 7.49, 11.04, 19.25, and 35.38 h for exposure to water with TDG levels of 145%, 140%, 135%, and 130%, respectively.