Applicationg of Ultraviolet Spectrophometry to Determination of Total Nitrogen in the Three Gorges Reservior

The eutrophication of water body will destroy the balance of ecological environment.To determine the total nitrogen content in water body exactly,is one of the most important evaluating indicators that whether the water body has been polluted by eutrophication or not.After the foundation of the Three Gorges Reservoir,current velocity lowers and it may result in the eutrophication of water body.In terms of the Lambert-Beer Law,the authors adopt potassium sulpersulphate oxidation-ultraviolet spectrophotometry to determine the total nitrogen content in the Three Gorges Reservoir.By analyzing a variety of possible factors,they bring forward a method to determine the total nitrogen which can be used in lab and also have high performance.With this improved method,the authors determine the factual water samples of the Three Gorges Reservoir in the main urban area of Chongqing,and the result is that the total nitrogen content is(0.6~1.0) mg/L,less than the limiting value(2.0 mg/L) in national standard.So the water body of the Three Gorges Reservoir still eutrophication does not take place.So eutrophication does not take place in water body of the Three(Gorges) Reservior.     

Relationship Between pH Value of the Water and Release Silt Bottom of Nitrogen & Phosphate in the Three Gorges

By experimental study of release characteristics bottom silt of total nitrogen (TN) & total phosphate (TP) in the Three Gorges, the influence and cause of pH value to Three Gorges bottom silt TN & TP release are analyzed. pH values is between 3.98 to 11.05 the release capacity of TN & TP reaches maximal in 3 days and pH values is between 11.05 to 11.94 the release capacity of TN reaches maximal in the 3 days. While pH value between 11.05 to 11.94, the release capacity of TP reaches maximal in 1 days; If pH value is lowered, the maximal release capacity of TN is enhanced: The maximal release capacity of TP basically has no changes on the condition of pH values between 3.98 and 10.07, but its maximal release capacity rises extremely obvious if pH value is between 10.07 to 11.05. At the same time, the existence of latent danger of the Three Gorges bottom silt TN & TP to water quality is explained, and the basis of eutrophication treatment in the aspects control of N & P nutrients for theThree Gorges is supplied.     

低氮胁迫下三峡库区玉米地方品种的苗期植株形态及生理效应

以10个来自三峡库区的玉米地方品种为材料,通过盆栽实验和设置低氮胁迫处理,研究低氮胁迫下玉米地方品种的苗期植株形态和生理效应.结果表明,低氮胁迫对玉米地方品种幼苗植株形态和生理有不同程度的不利影响,不同玉米地方品种的耐低氮特性存在明显差异.不同地方品种的同一植株性状和同一地方品种的不同植株性状的耐低氮胁迫指数存在差异.侧根数、叶面积、根体积和植株干重可作为玉米地方品种耐低氮种质筛选的形态指标,硝酸还原酶活性和丙二醛含量可作为耐低氮种质筛选的生理指标.此外,三峡库区玉米地方品种中有较丰富的耐低氮种质可供玉米育种利用.     

Study on the Critical Load for Acid Rain of Four Typical Soils Taken from the Three Gorges Reservoir Reglon

Acid titration was performed to probe the acid buffering capacity of four types of typical soils from the Three Gorges Reservoir Region.The acid buffering capacity of soil was also applied to calculate the critical load for acid rain.The results indicated that the higher the pH value and CEC content of the soil,the greater the basic ions and acid buffering capacity of the soil would be.The critical load for acid rain was obviously different for four types of typical soils from the Three Gorges Reservoir Region.The order of the critical load for acid rain was red-brown purplish soil>red purplish soil>grey-brown purplish soil>yellow soil.The sensitivity of red-brown purplish soil to acid was much less than that of other three soils.     

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.     

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.     

三峡库区花岗岩母质石英砂土不同经济林模式土壤养分特征研究

为了解三峡库区花岗岩母质不同经济林模式的土壤养分状况,研究了各模式下土壤pH、有机质、全量养分和速效养分的特征,并利用主成分分析法对不同模式的土壤质量进行了综合评价。结果表明,除土壤pH外,经济林土壤有机质、全氮、全磷、全钾、碱解氮、有效磷、速效钾等含量的变异较宽,为中等变异。随土壤层次的增加,各模式下土壤有机质、全氮、速效氮、速效磷和速效钾含量呈递减趋势,而全磷和全钾则存在不规律变化。土壤有机质、全氮和速效钾对经济林土壤质量的高低产生着主要作用,土壤养分综合排名表现为柑橘（精细管理）>柑橘（常规管理）>板栗林>茶园。因此,利用生物措施和精细化管理措施,可有效提高该区域经济林的土壤质量。     

Present Situation and Countermeasure of Water Pollution in Yulin River, Yubei District, Chongqing

Yulin River is the major secondary stream of Three Gorges Reservoir Area. According to the requirement of "The Prevention Plan of Water Pollution in Three Gorges Reservoir Area and the Upper Areas (2001-2010)", the water environment pollution in Yulin River valley should be controlled. In this paper the reason of the water pollution is analyzed through investigation and evaluation on the present situation of Yulin River in North Chongqing area, and then a proposal on the prevention and cure measure of water pollution of Yulin River is presented.     

Fathering Benefit Research of Slopng Cultivated Land Erosion in Three Gorges Reservior

To prevent and reduce the threats to the sustainable development of agriculture of Three Gorge Reservoir caused by the serious soil erosion and degradation of sloping cultivated land, seeking the means of suitable utilization of sloping cultivated land is very necessary. Due to the different cultivating modes make great influence to the lost of water, soil, and fertility, aiming at the utilization status and existing problems of sloping cultivated land in Three Gorge Reservoir, the characteristics and respective adaptability of different cultivating modes are analyzed using the relation between different cultivating modes and the water and soil lost of sloping cultivated land. And the research methods of lost of water, soil, and fertility of sloping cultivated land in different cultivating modes are summarized and the perspective of the development, utilization and protection of sloping cultivated land are given as well.     

Protection and Ecological Restoration of Water Level Fluctuation Zone in the Three Gorges Reservoir

Water level fluctuation zone(hereinafter referred to as "WLFZ") is a transitional ecosystem between terrestrial ecosystem and aquatic ecosystem,and also a key area to control its neighboring terrestrial and aquatic ecosystem. After the Three Gorges Reservoir was put into use,ecological environment of its WLFZ has aroused wide concern from domestic and foreign experts. On the basis of introducing characteristics of WLFZ of the Three Gorges Reservoir,current ecological environment and main problems of this area were analyzed,plant selection and configuration was elaborated as well as the implementation effect of many WLFZ protection and ecological restoration modes. In view of the actual conditions,pertinent suggestions were proposed for WLFZ of the Three Gorges Reservoir,namely classified protection and ecological restoration,enhancing monitoring and assessment of current situation and change tendency,carrying out technical researches and demonstration of WLFZ wetland ecological restoration.     

三峡库区次级河流污染现状与对策研究

沉水植物金鱼藻和黑藻在治理三峡库区次级河流水体污染具有广阔前景,对保护三峡水库的水环境贡献很大,在库区水体中可以发挥强大的环境生态功能。本文通过分析三峡库区次级河流的环境问题,预测了金鱼藻和黑藻在库区的应用前景,即防止水体富营养化、有机物污染、重金属污染、抑制藻类生长,以及维持生物多样性、生态完整性和稳定性。     

Study on Treatment and Utilization of Industrial Solid Wastes after Completion of Three Gorges Reservoir of Yangtze River

After completion of Three Gorges Reservoir at Yangtze River, protecting and improving the ecological environment of this area is becoming increasingly important factor in comprehensive progress of the economy and society of Chongqing City. The industrial solid wastes are one of the crucial factors influencing the environment quality of Three Gorges Area and they are also the hot and difficult problems influencing the development of economy and society of Chongqing City. At this point, firstly, the discharge, present situation, prospect and development of treatment and utilization of industrial wastes in Chongqing are summarized. Secondly, the experience at home and abroad are analyzed. Then, the way and foreground for recycling the wastes with new technology are also discussed. Finally, countermeasure for treatment and utilization of industrial solid wastes after completion of Three Gorges Reservoir at Yangtze River is brought up. The study on treatment and utilization technology of industrial solid wastes will be beneficial not only to the protection of ecological environment of Three Gorges Area, but to the development of new Chongqing City as well. In a word, it will have great environmental, social and economic benefits.     

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.     

三峡库区澎溪河消落带落干期土壤硝化强度及影响因素

研究了三峡库区澎溪河落干期消落带不同地点、不同高程段、不同土地利用方式下土壤硝化强度及影响因素。结果表明,研究区域消落带硝化强度范围为0.76~9.76 mg/kg·d,平均值为3.76±0.76 mg/kg·d,明显低于国内其他研究区域土壤硝化强度。澎溪河消落带从上游汉丰湖到下游黄石,土壤硝化强度呈现递减的趋势。随着高程的增加,消落带土壤硝化强度逐渐降低,但没有显著差异（P >0.05）。消落带不同土地利用方式中,河滩地土壤硝化强度显著高于耕地土壤硝化强度（P<0.05）,是耕地土壤硝化强度的1.82倍。消落带土壤硝化强度与土壤pH值呈显著正相关（P<0.05）,与有机质含量及亚硝化菌数量呈极显著正相关（P<0.01）,周期性的淹水影响了消落带土壤pH值和有机质含量,从而影响了消落带土壤硝化强度。     

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。     

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.     

Study on Economic and Ecological Environment Effects of Ecological Cropping Patterns in Small Watershed

在三峡库区典型紫色土坡耕地,设置了四种生态种植模式,进行经济和生态环境效应的研究。结果表明：投入产出比,梨×连翘/花生＞桃×连翘/花生＞桃/花生＞梨/花生＞CK,其中梨×连翘/花生与桃×连翘/花生模式分别比对照提高69.9%和65.5%,;影响果树冠幅的主要因子是土层厚度、坡位与种植模式;套种连翘的二种模式须根量明显比其它模式高,树种根系分布特征、种植密度和土层厚度是影响须根量的主要因素;种植模式和坡位均显著影响土壤孔隙度的发育,各种植模式的土壤孔隙度顺序：梨×连翘/花生＞桃×连翘/花生＞桃/花生＞梨/花生     

双季稻种植下洞庭湖区不同类型土壤连续施用控释氮肥的效应研究

在洞庭湖区3种主要类型土壤上进行连续4年的微区试验,研究水稻控释氮肥在双季水稻种植体系下的连续施用效应。试验设不施肥（CK）、尿素、等N量控释氮肥及70%N量控释氮肥4个处理。结果表明,等N量控释氮肥处理产量最高,在河沙泥、紫潮泥和红黄泥上平均比尿素处理分别增产10.3%、8.0%和2.4%,70%N量控释氮肥处理分别增产6.1%、2.6%和-0.8%;在3种土壤上早、晚稻及全年平均吸N量均表现为等N量控释氮肥>70%N量控释氮肥>尿素>对照。等N量控释氮肥处理在上述3种土壤上的肥料利用率分别为60.7%、59.6%和56.3%,比尿素处理分别高23.8%、19.4%和16.3%,早稻随施用年份的延长其利用率呈增加趋势,且高于70%N量控释氮肥处理,晚稻连施3年时利用率由上升转呈下降。连续施用控释氮肥可缓解土壤氮素肥力和有机碳含量的下降,特别是在河沙泥稻田中。施用控释氮肥有利于水稻增产、氮肥利用率的提高及土壤培肥。     

Properties of Solid Waste from Townships in the Three Gorges Reservoir Area of P. R. China

Solid waste pollution in small towns of the Three Gorges Reservoir area in P. R. China has become increasingly serious. To solve this problem and discover the properties of solid waste, on site investigations were conducted in the region in thirteen typic     

Multilevel Fuzzy Theory Evaluation of the Tourism Resources in the Three Gorges Reservoir

Complexity of mutual act and different sensation of different tourists are important factors influencing regional tourism resources evaluation. Fuzzy mathematic method can be used to up quantitative evaluation method on tourism resources evaluation. Taking Wushan Small Three Gorges as an example, the author carries out the evaluation of the tourism resources in the Three Gorges Reservoir. At the same time, the authors consider that five factors, such as improvement of the comunication of tourism resources, quickening the Steps of urbanization in reservior area, must be done well.