周期性淹水对消落区水土环境的影响及控制对策

三峡库区消落区生态脆弱,在水土交互作用下消落区土壤母岩风化成土进度加快、土壤侵蚀加剧、土壤氮磷等营养物质及重金属大量溶出,其中N、P、COD和重金属是主要的溶出因子,淹没的耕地是主要的污染源。成库初期消落区生态脆弱性增强、水土流失加剧、地质灾难增加、岸边污染加重,尤其在水流缓慢的库湾将会出现局部的富营养化现象;随着消落区稳定的库岸湿地生态系统的形成,水土耦合呈现正的环境效应。为了尽快构建健康的消落区生态系统,防止三峡库区消落区水土环境的退化,必须加强和发挥政府宏观调控职能、建立消落区土地保护区域、推广复合生态技术并做好库区污染防治与修复工作。     

干湿交替灌溉与硝化抑制剂对水稻产量及土壤性状的影响

探明干湿交替灌溉与硝化抑制剂对水稻产量以及土壤性状的影响,以期为水稻高效栽培提供理论依据和技术参考。采取干湿交替灌溉方式,以“金香玉1号”和“扬稻6号”为试验材料,设置4个处理,分别为尿素（CK）、尿素+双氰胺（DCD）、尿素+3,4-二甲基吡唑磷酸盐（DMPP）、尿素+DCD+DMPP。DCD和DMPP为硝化抑制剂。结果表明,在相同灌溉方式下,与CK处理相比,硝化抑制剂的添加有利于获得较高的产量,提高了穗粒数和结实率。与CK处理相比,添加DCD、DMPP以及DCD与DMPP配施,均提高了水稻生育时期的土壤脲酶和蔗糖酶活性,降低了水稻生育时期土壤硝酸还原酶活性。另外,各硝化抑制剂处理均显著提高了水稻生育时期土壤铵态氮含量,降低了硝态氮含量,在此基础上增加了土壤有效态氮含量。其中DMPP抑制效果优于DCD,且2种抑制剂同时配施作用效果优于其单独施用。在干湿交替灌溉方式下,硝化抑制剂处理在水稻关键生育期有利于产生较高土壤养分,能进一步增加水稻产量。     

菜地土壤磷素淋失及其影响因素

以菜地为供试土壤,研究了0~100 cm菜地土壤Olsen-P、CaCl2-P、NaOH-P的空间分布状况及其相关关系。结果表明,0~20 cm菜地Olsen-P、CaCl2-P、NaOH-P含量分别为:123.8~399.6 mg/kg、9.1~27.2 mg/kg、184.9~608.9mg/kg。土壤Olsen-P、CaCl2-P、NaOH-P主要积累在0~20 cm土层,随着土壤深度的增加土壤磷的积累量逐渐降低;土壤Olsen-P与CaCl2-P、NaOH-P呈显著正相关关系。土壤Olsen-P含量高于55.6~63.0 mg/kg时,土壤CaCl2-P显著增加,此时的Olsen-P含量为土壤磷渗漏淋失显著增加的“突变点”。     

影响玉米蛋白质电泳谱带的几个因素

利用蛋白质电泳法鉴定玉米种子纯度 ,影响电泳谱带的因素很多 ,往往造成判断错误 ,导致鉴定结果不准确。笔者经过多年的观察、试验、分析和研究 ,把影响电泳谱带的因素归纳为以下几方面 :1　种子的成熟度玉米蛋白质电泳所利用的盐溶蛋白是一种贮藏蛋白 ,种子成熟越好 ,盐溶蛋白的含量越高 ,电泳所形成的蛋白质谱带就越清晰 ,即谱带活性 (颜色深浅 )越强。种子蛋白质的组分受遗传基因控制 ,种子的成熟度只会影响本品种某些谱带的宽窄、清晰度 ,而不会影响该品种蛋白质谱带的数量及迁移率 (Rf)。我们对不同成熟度的同一品种鉴定时要特别注意…     

农药污染对土壤的影响及防治措施

综述了农药对土壤的污染途径及原因、农药在土壤中的转化方式、农药污染对土壤的影响。同时．概括了解决土壤农药污染的可能措施。     

三明市耕地土壤交换性镁含量空间分布特征及影响因素分析

为了解三明市耕地土壤交换性镁含量空间分布特征及影响因素,利用三明市4833个土壤样品化验结果和相关数据,应用统计学和地理统计学方法对三明市耕地土壤交换性镁含量空间分布特征及其影响因素进行了分析。结果表明：三明市耕地土壤样品交换性镁平均含量处于中等水平,平均值为62.7 mg/kg。各县（市、区）土壤样品交换性镁含量差异达到显著水平。土壤交换性镁含量缺乏样品所占比例和缺乏的耕地面积所占比例分别达到44.15%和40.72%。除土壤类型分组的交换性镁含量差异不显著外,其他影响因素分组的土壤交换性镁含量差异均显著。因此施用有机肥、调节土壤pH、客土改良砂土类质地土壤、补充镁肥等可以作为调控三明市土壤交换性镁含量的主要措施。     

基于农户意愿的三峡库区消落带弃耕经济补贴标准估算及影响因素分析

目前在三峡库区消落带耕种行为给三峡库区带来生态环境恶化,通过经济补贴让农户弃耕可以防治库区生态环境恶化。采用意愿调查法,对库区消落带沿岸农户进行随机入户调查。以农户受偿意愿为依据,估算经济补贴标准,并分析影响补贴意愿值的因素。分析统计数据得出：（1）农户对消落带土地依赖性很强,72.1%的农户在消落带土地上有农作行为;（2）农户对消落带生态环境问题感知度高,94.7%的农户愿意接受经济补贴放弃消落带耕地;（3）对农户的补贴意愿值进行加权求平均值得到549.7元/年·户的受偿平均值;（4）农户补贴意愿值与消落带耕地面积呈显著正相关。     

不同管理措施对三峡库区柑橘园土壤养分和径流氮磷流失的影响

综合考虑施肥管理方式和植物配置,本研究设置了常规施肥(CF)、常规施肥+生草覆盖(CF+GC)、常规施肥+生草覆盖+植物篱(CF+GC+PH)、水肥一体化(IWF)、水肥一体化+生草覆盖(IWF+GC)、水肥一体化+生草覆盖+植物篱(IWF+GC+PH)等管理措施,采用野外径流小区法,研究了不同管理措施对三峡库区柑橘园...     

平凉市耕地土壤有效态微量元素丰缺评价及影响因素研究

研究旨在系统阐明区域内耕地土壤有效态微量元素的丰缺状况,探究微量元素间的相关性及其影响因素,为平凉市推进测土配方施肥、提高肥料利用率、促进土壤改良与地力提升提供科学依据。以Cu、Zn、Fe、Mn、B、Mo和S为主要研究对象,系统评价平凉市耕地土壤有效态微量元素丰缺状况。采用统计学方法,对微量元素及其影响因素进行相关分析和回归分析。统计结果表明,平凉市耕地土壤有效Cu、Zn、Fe、Mn、B、Mo、S平均含量分别为1.04、0.92、13.18、11.03、0.51、0.11、15.11 mg/kg。有效S含量在空间上为强变异,其余元素含量均属于中等程度变异。评价结果显示,不同区域耕地土壤有效Cu、Zn含量丰缺水平为低—中等,有效Fe、Mn为低—高等,有效Mo为较低—低等,有效B、S为极低—较低等;不同土类土壤有效Cu含量丰缺水平为低—中等,有效Zn、Fe、Mn为低—高等,有效B为较低—低等,有效Mo为较低—中等,有效S为极低等。土壤pH、有机质和有效态微量元素之间存在一定的影响关系。总体而言,平凉市耕地土壤整体缺乏有效B、Mo、S,且有效S为极缺乏,有效Cu、Zn、Fe、Mn普遍处于适中...     

The influencing factors of N2O emission and denitrification in the soil of water-level-fluctuation zone in the Three Gorges Reservoir area

In order to study the influences of water filled pore space (WFPS), temperature, the addition of nitrate (NO -3) and carbon source on N2O emission and denitrification in the soil of water-level-fluctuation zone in the Three Gorges Reservoir area, C2H2 in hibition incubation experiments are applied. Results from experiments in laboratory and in situ field are analyzed. Results show that the WFPS is a main factor determining N2O emission and denitrification. Denitrification rate increases while the WFPS increases, and the maximum denitrification rate and the maximum N2O emission rate appear when the WFPS is 100% and 60%, respectively. In addition, while the temperature is between 10 ℃ and 40 ℃, the increase of temperature contributes to the increase of the N2O emission and denitrification rates. Furthermore, it is found that the N2O emission and denitrification rates are significantly and positively correlated with temperature. The addition of carbon source could increase denitrification performance in soil. However, the addition of nitrate has a negative impact on the denitrification performance, because nitrogen source is not the main factor determining denitrification performance and excessive nitrate could inhibit the denitrification in these experiments. The addition of glucose, which is a carbon source easily be utilized by denitrifying bacteria, could significantly increase the denitrification rate in soil, and the maximum denitrification rate takes place while the carbon content in per kilogram soil is 240 mg.     

三峡库区支流域澎溪河浮游动物的季节性变化与水质评价

为研究三峡库区北岸最大支流澎溪河中浮游动物与水质状况的关系。本研究分别于2009年春季（3月）、夏季（7月）在澎溪河流域上游至下游5个河流断面进行采样,对水体中浮游动物的种类及数量进行监测,并应用Margalef丰富度指数(d)、Shannon-Wiener指数(H)和Pielou均匀度指数(J)对水体营养状况进行评价。研究发现：使用浮游动物评价水质状况得出的结论与营养水平评价结论存在较大差异,基于浮游动物种类及优势度评价得出的水质富营养化程度轻于基于营养盐的评价。     

1D hydrodynamic model on Pengxi (Xiaojiang) River Backwater Area in the Three Gorges Reservoir

A 1D hydrodynamic model on Pengxi Backwater Area (PBA) in the Three Gorges Reservoir during its preliminary operation period (2007 2008) is set up based on HEC RAS. In the large submerged area or water fluctuation zone, virtual levee is set up in the model between the conveyance channel and the storage area. The Manning’s n in PBA is calibrated and selected in the range of 0.27〖XC半字线.tif,JZ〗0.35. Calibrated model has good modeling results. Quasi Steady simulation approach is applied to calculate 1D hydrodynamic condition in the PBA during the study period. Analysis on the hydrodynamic condition in the PBA show that in the low water level operation stage, average velocity of upper reach in PBA will exceed 0.5 m/s, which is close to natural river. The Gaoyang Lake is formed as a relative independent and semi closure dam lake in the middle reach of PBA. Due to the enlarged cross section, the velocity at downstream of PBA is significantly decreased. In the high water level operation stage, no remarkable difference of velocity among cross sections in the PBA, indicating a significant hydrological characteristic of deep river based reservoir. The variation of reservoir capacity and hydraulic retention time in the PBA is 8.26×10 8〖XC半字线.tif,JZ〗2.51×10 8 m 3 and 157.0〖XC半字线.tif,JZ〗3.8 d respectively. The variation of reservoir capacity in PBA is impacted by the water level fluctuation more significantly. The hydraulic retention time in the PBA is impacted by both and river discharge dually. Frequency analysis show that 17.8% of hydraulic retention time data in the PBA is showed to be overflow reservoir type and 82.2% of that data showed to be transition type.     

Geological Disasters and Their Damage in Three Gorges Reservoir Area

In this paper, the possible geological disasters in Three Gorges Reservoir Area are reviewed. Firstly, the types of geological disasters are classified and their influencing factors and growth characteristics are analyzed, then the damages, which have happened in this area up to now, are listed. On this basis, five aspects of dangers brought by geological disasters to society and economic environment are analyzed. Finally, a conclusion was drawn that the geological disasters in Three Gorges Reservoir Area have done some harms to this area and the situation becomes worse than before. So some reasonable measures should be taken quickly.     

Analytical and Calculative Method of Stability of MingShan Landslide in the Three Gorges Reservoir Area

After the dam of the Three Gorges is built, the raising water will inevitably cause the revival of the part of ancient landslide and the generation of new landslide ,which will influence the town development and traffic safety in the Three Gorges Reservoir Area. In the light of the specific conditions of the Three Gorges Reservoir Area, this paper, taking Fengdu's MingShan landslide in Chongqing for an example, has considered ten typical calculative projects, offered the correspondent load systems acting on the sliding mass and put forward the analytical and calculative method to evaluate the stability of a landslide. The ten typical calculative projects include dry season(natural state), raining season (rainstorm or rain for a long period of time), dry season and water level (175m ) of the reservoir, raining season and water level (175 m) of the reservoir, dry season and earthquake, raining season and earthquake, dry season and water level (175 m ) of the reservoir and earthquake, raining season and water level (175 m) of the reservoir and earthquake, dry season and water level lowered from 175 m to 145 m, raining seasons and water level lowered from 175 m to 145 m, and so on.     

Nonlinear Science and Control about the Geological Hazards in the Three Gorges Reservoir Area

Such the geological hazards as landslide, rockfall, debris-flow and so on frequently occur in the Three Gorges Reservoir Area, so it is a very practical and immediate job to explore the mechanism caused the geological hazards and how to forecast and control the geological hazards. For this reason, this paper introduces the situation of the geological hazards occurred in the Three Gorges Reservoir Area and the major type and feature of the geological hazards occurred in Chongqing, and discusses the basic principle about the modern nonlinear science applied to the geological hazards and the creep-slip, stick-slip occurred on the joints of rock mass and the monitoring technology of the geological hazards.The basic thinking is put forward which can be applied the modern nonlinear science to the geological hazards occurred in the Three Gorges Reservoir Area.     

三峡库区肉羊屠宰加工企业HACCP管理模式的建立

作为控制食品安全的一种手段,很多国家和地区已经实施了HACCP体系,对羊肉生产过程中的各个环节可能存在的潜在危害进行了生物的、化学的、物理的分析,根据HACCP原理确定相应的关键控制点(CCP)和关键限值,并制定了相应的预防措施,建立了监控方法,将生产过程中的危害因素降低到最低程度,从而最大限度提高羊肉的食用安全性,旨在促进库区肉羊屠宰加工产业的发展。     

Study on Adsorption of Suspended Sediments to Phosphate in the Three Gorges Reservoir Area

Suspended sediments play an important role in the transformation process of pollutants in rivers.The adsorption characteristic of suspended sediments in Three Gorges Reservoir Area to phosphate was studied in this paper.Based on the indoor adsorption balancing experiment and kinetic modeling experiment,the main factors for adsorption process of sediments(particle size of sediment,initial concentration etc.) were discussed.The major results of the experiment were as follows:(1) Three kinds of suspended sediments with different particle sizes were used for the study of adsorption characteristic with different sediment concentration.The amount of phosphate adsorption increased with the increase of the sediment concentration and sediment particle size.(2) With the help of Langmuir isotherm theory,the related parameters in kinetic model were estimated,the experiment results indicated that the adsorption isotherm of phosphate in Three Gorges Reservoir Area fitted with the fifth type of Langmuir adsorption isotherm,the maximum amount of phosphate adsorption would emerge when the phosphate concentration was relatively high,but it would move down when the phosphate concentration increased afterwards.(3) Phosphate adsorption increased with the increase of initial phosphate concentration,the average time for adsorption balance was 2-4 hours.     

Estimation of the N and P Contributions to the Water Quality of the Three Gorges Reservoir

The elements N and P are crucial to the water quality of Three Gorges Reservoir. After the present situation and characteristics of N and P pollutions analyzed and statistical method, flux method and modeling method adopted to estimate the quantity of N and P from upstream and reservoir area, the pollution loads of point and no-point pollution source, the conclusion that the main source of N and P pollutants are from both upstream of Reservoir and non-point pollution.