水文过程对农业小流域氮素迁移的影响

以江西低丘红壤区农业小流域为研究对象,在自然降雨条件下对小流域内试验小区、上游灌渠和小流域出口径流中的氮素浓度进行监测,旨在从小区尺度和小流域尺度阐明农业小流域氮素流失与降雨和径流的关系。结果表明:在小区坡面流中,硝态氮浓度随降雨径流的变化趋势不明显,铵态氮和全氮浓度随降雨径流的增加呈先增加后降低的趋势;壤中流对硝态氮的流失有主要影响,而坡面流对全氮的流失作用不可忽视。小流域的氮素流失主要发生在4~6月,其间氮素NH4 -N、NO3--N和TN的流失量在上游干旱地灌渠分别占年流失量的74%、61%和62%;在小流域出口分别占年流失量的82%、70%和79%。年全氮流失量达43.8kg/hm2,占氮素施用量的22.6%。     

Interlaboratory comparison of olfactometry in Japan.

In 2000, 2001, and 2002, interlaboratory comparison of olfactometry was carried out in order to collect basic data for the establishment of a quality control procedure and the determination of quality criteria for the triangular odour bag method. In 2000, interlaboratory comparison was conducted by using a measurement method for samples taken at smoke stacks. On the other hand, the measurement method for samples taken at boundary lines was used for interlaboratory comparison in 2001. A total of seven olfactometry laboratories in Japan participated in each test, and mean values, repeatability standard deviations, reproducibility standard deviations, and standard deviations under intermediate conditions of detection threshold of ethyl acetate were calculated from the results. These values can be used in a quality control process of olfactometry. In 2002, interlaboratory comparison was carried out by using a measurement method for samples taken at smoke stacks. A total of 137 olfactometry laboratories in Japan participated in the test, and 69% of them lay within the permissible range of the odour index.     

缺资料流域农业面源污染负荷研究与综合评价

在充分考虑降雨和地形对面源污染物传输影响的条件下,为能有效解决缺资料流域农业面源污染定量化估算和综合评价的问题,以古蔺县境内的古蔺河流域为例,基于改进的输出系数法和源强系数法,将研究区内3类污染源和4种污染物的输出负荷进行定量估算;采用等标污染负荷法对该流域农业面源污染进行综合评价。结果表明:研究区中农业面源污染严重,其中主要污染源为农村居民生活污水和畜禽养殖,占总等标污染负荷的74.19%;主要污染物为TN、TP和NH3-N,占总等标污染负荷的95.83%;对古蔺河污染贡献度较大的乡镇依次为古蔺镇、双沙镇和石宝镇,占总等标污染负荷的23.32%。根据分析结果,古蔺河流域应加强农村居民生活污水、畜禽养殖粪便及废水等有机废物的治理,合理施肥,减少氮磷流失。     

亚热带农业小流域暴雨过程硝态氮迁移特征及水文示踪研究

为揭示亚热带丘陵区农业小流域暴雨过程中硝态氮迁移规律及其主要水文输送途径,本研究通过对紫色土丘陵区典型农业小流域典型暴雨过程跨尺度(从3~1 236 hm2)连续监测,分析径流硝态氮迁移动态特征及其尺度效应,并对比δ18O和硝态氮作为示踪剂的端元混合分析(EMMA)解析结果,探讨硝态氮作为暴雨过程水文示踪剂的可行性。结果表明:(1)两场暴雨事件中源头小流域苏荣小流域(含集镇污水)径流中硝态氮浓度最高,而到达梯级小流域出口处(万安小流域)硝态氮浓度最低,林地来水的贡献是较大尺度小流域径流硝态氮浓度降低的主要原因,坡耕地壤中流补给可能是径流消退过程中硝态氮出现浓度峰值的主要原因。(2)EMMA模型解析结果显示:δ18O与硝态氮均能示踪农业小流域径流消退期间壤中流补给过程;但硝态氮在受人居活动强烈影响子流域的示踪应用需谨慎。以农业为主的亚热带丘陵区小流域中,硝态氮具有同时作为环境效应指示剂和水文示踪剂的潜力,但其应用效果仍有待于进一步验证。     

Assessment of nitrogen excess in an agricultural area using a nitrogen balance approach.

A pilot study has been initiated to develop an approach for quantification of nitrogen excesses from agricultural activities that involve greenhouse farming in Kumluca Plain, Turkey. Detailed calculations utilizing the nitrogen balance method (NBM) were carried out at nine different locations within the plain over a time period of one year. The major contributing factors and governing operative mechanisms taken into consideration were nitrogen application rates both as organic and chemical fertilizers, irrigation water application practices, and nitrogen uptake by plants. The adopted approach yielded valuable information such as plant nitrogen uptake efficiencies, excess nitrogen, leaching rates and leachate nitrogen concentrations. Further, a site specific multiple linear regression model has been developed to estimate the ratio (N(leachate)/N(groundwater)) as a function of independent variables: farming age, excess nitrogen application and SEEPAGE Index Number. The negative sign of the model parameters implies that the ratio (N(leachate)/N(groundwater)) decreases as values of the independent variables increase. The adopted approach and the obtained results can beneficially be applied to similar sites to establish basic parameters of irrigation and fertilizer application operations.     

日本韩国的水环境治理

2002年底,北京市水利局组团赴日韩考察。考察主要目的是通过与同行技术交流及参观日韩河道、湖泊环保治理工程实例,学习借鉴发达国家在水资源管理和水环境治理中的先进经验,特别是生物生态技术在水污染治理中的应用,提高北京地区水库、河湖水资源管理和水环境治理水平。考察团走访了许多工程管理和研究机构,实地参观了不少工程项目。我们感到此次考察确有许多东西值得借鉴,对我们找出差距、更新观念、调整思路大有裨益。     

A deterministic model to quantify pathogen loads in drinking water catchments: pathogen budget for the Wingecarribee.

This paper describes the development and testing of a mathematical model as a tool to quantify pathogen loads in Sydney's drinking water catchments. It has been used to identify, quantify and prioritise sources of Cryptosporidium, Giardia and E. coli in the Wingecarribee catchment. The pathogen model promotes understanding of the relative significance of different sources of pathogen risks as well as their fate and transport as they move through the subcatchments. This pathogen model not only enables water utility managers to identify those catchment segments that may contribute the highest load of pathogens, but also where management options will be most effective.     

Integrating principles of nitrogen dynamics in a method to estimate leachable nitrogen under agricultural systems.

Surplus nitrogen (N) in ground and surface water is of concern in intensive agricultural regions. Surplus N leaches during lengthy periods where annual crop systems are used in temperate regions. This paper presents a model to estimate the surplus N available for leaching to ground water beneath agricultural systems and applies the model to watersheds in an intensive maize and soybean production system. The model utilizes commonly available georeferenced data on soils, crops, and livestock, making it applicable to watersheds in many regions. The model links stocks of N in soil, crops, livestock, fertilizer and the atmosphere. Nitrogen flow centers on exchange between the soil N stocks. Nitrogen mineralization rates are defined for three soil organic matter pools, crop residue, and manure based on carbon:N ratios. Nitrogen exports from the system are harvested crops, livestock and losses to the atmosphere. Application of the model in 26 Iowa watersheds finds surpluses of 18 to 43 kg-N/ha. Surpluses exceeded measured annual nitrate-N loads in regional streams by amounts equivalent to denitrification rates in groundwater. Deficits in soil N were sufficiently small to suggest that the system is in equilibrium with soils of the region.     

Estimation of annual pollutant loadings in two small catchments and examination of their differences caused by regional properties.

A series of runoff surveys was conducted for more than one year in two small catchments of the Kamo River basin (75.4 km2) and the Takano River basin (66.8 km2) in Kyoto, Japan, which adjoin each other, and may have the same precipitation pattern. The investigation consisted of a high-frequency periodic survey, a long-term regular survey and a storm event survey. The survey results were compared with the regional properties of the basins, and the following results were obtained. (1) Pollutant loadings were successfully estimated as two portions of base discharge and storm events discharge from the survey results. (2) Estimated annual loading of the sites was 2.9-4.5, 1.3-1.8, 17-27, 1.3-2.2, 0.076-0.97 t/km2/y, respectively for COD(Mn), DOC, SS, TN and TP. (3) 52-53% of the whole flow, which was caused by rainfall events, conveyed 81-87, 68-73, 92-95, 64-67, 76-81% of the whole loading, respectively for COD(Mn), DOC, SS, TN and TP. (4) Differences of regional properties in two basins cause different runoff patterns, but the differences in runoff patterns also depend on the rainfall patterns. In general, a more urbanized basin receives early and strong influence of precipitation on the storm event runoff.     

Constructed wetland attenuation of nitrogen exported in subsurface drainage from irrigated and rain-fed dairy pastures.

Nitrogen removal performance is reported for constructed wetlands treating subsurface drainage from irrigated and rain-fed dairy pastures in North Island, New Zealand. Flow-proportional sampling of inflow and outflow concentrations were combined with continuous flow records to calculate mass balances for the wetlands. Drainage flows from the irrigated catchment were 2.5-4 fold higher and N exports up to 5 fold higher per unit area than for the rain-fed catchment. Hydraulic and associated N loadings to the wetlands were highly pulsed, associated with rainfall, soil water status, and irrigation events. Transient pulses of organic nitrogen were an important form of N loss from the rain-fed landscape in the first year, and were very effectively removed in the wetland (> 90%). Median nitrate concentrations of approximately 10 g m(-3) in the drainage inflows were reduced by 15-67% during passage through the wetlands and annual nitrate-N loads by 16-61% (38-31 7 g N m(-2)y(-1)). Generation in the wetlands of net ammoniacal-N and organic-N (irrigated site) partially negated reduction in nitrate-N loads. The results show that constructed wetlands comprising 1-2% of catchment area can provide moderate reductions in TN export via pastoral drainage, but performance is markedly influenced by variations in seasonal loading and establishment/maturation factors.     

紫色土丘陵区小流域非点源氮迁移特征研究

对长江上游紫色土丘陵区盐亭县林山乡典型的集镇小流域和农林复合小流域的非点源氮迁移过程进行了同步监测，比较分析了两不同类型小流域的径流过程及降雨-径流过程中氮素各形态浓度、负荷变化特征。结果表明了集镇小流域和农林复合小流域径流过程与非点源氮迁移过程均存在较大差异：（1）集镇小流域径流过程与降雨过程迅速响应，径流过程呈现“暴涨暴落”的特点。相反，农林复合小流域径流过程显著滞后于降雨过程，呈现出显著的“滞后效应”。（2）集镇小流域总氮（TN）、颗粒态氮（PN）以及铵态氮（NH4+-N）浓度在降雨径流初期迅速升高，而后迅速下降，呈现明显的“单峰”。相反，农林复合小流域在小雨事件中氮素浓度变化较小，但在中雨和暴雨事件过程中，初期径流中氮浓度较低，而中后期逐渐升高。（3）集镇小流域TN、PN、NH4+-N迁移过程体现了显著的“初始冲刷效应”，其中初期25%的径流量平均携带了50%的TN负荷、71%的PN负荷、64%的NH4+-N负荷，而农林复合小流域TN、可溶性氮（DN）、硝态氮（NO3--N）则体现了一定的“末期冲刷”的特点。     

紫色土丘陵区小流域非点源氮迁移特征研究

对紫色土丘陵区典型集镇小流域和农林复合小流域非点源氮迁移过程进行同步监测,比较2种不同类型小流域的径流过程及径流中各形态氮素浓度、负荷变化特征。结果表明：（1）集镇小流域径流过程与降雨过程迅速响应,径流过程呈现“暴涨暴落”的特点,而农林复合小流域径流过程显著滞后于降雨过程,呈现显著的“滞后效应”。（2）集镇小流域总氮（TN）、颗粒态氮（PN）及铵态氮（AN）浓度在径流初期迅速升高,达到“峰”值后迅速下降;而农林复合小流域在小雨事件中氮浓度变化较小,中雨和暴雨事件过程中,初期径流氮浓度较低,中后期逐渐升高,     

Management of regional German river catchments (REGFLUD) impact of nitrogen reduction measures on the nitrogen load in the River Ems and the River Rhine.

The REGFLUD-project, commissioned by Germany's Federal Research Ministry (BMBF), addresses the problem of reducing diffuse pollution from agricultural production. The objective of the project is the development and application of multi-criteria scientific methods, which are able to predict diffuse pollution in river basins subject to economic feasibility and social acceptability. The selected river basins (Ems and Rhine basins) cover a variety of landscape units with different hydrological, hydrogeological and socio-economic characteristics. This paper focuses on the analysis of the effects of certain policy measures to reduce diffuse pollution by nitrogen. For this purpose a model system consisting of an agricultural sector model, a water balance model and a residence time/denitrification model was developed and applied. First results indicate a wide range of annual nitrogen surpluses for the rural areas between less than 10 kg N/ha up to 200 kg N/ha or more depending on the type and intensity of farming. Compared to the level of nitrogen surpluses the level of nitrogen inputs into the surface waters is relatively moderate because of degradation processes during transport in soil and groundwater. Policy impact analysis for a nitrogen tax and a limitation of the livestock density stress the importance of regionally tailored measures.     

东风水库COD氨氮衰减系数分析

利用2006-2009年38次东风水库入库、出库水质、水量数据,采用常规监测资料估算法,分析率定COD、氨氮衰减系数,破解了通过水质模型计算纳污能力的核心难题,为实现最严格的水资源管理制度,明确水功能区限制纳污红线,产格控制入河排污总量提供技术支撑.     

Sludge storage for countering nitrogen shock loads and toxicity incidents

Spare nitrification capacity is usually needed for a nitrifying activated sludge plant to counter nitrogen shock loads and/or toxicity incidents. The traditional way to provide this capacity is to apply a sludge retention time which is much longer than what needed to obtain a stable nitrification, resulting in over designed plants. Another approach, which is investigated in this paper, is to store the spare biomass in a separate sludge storage tank and return it to the main stream process when a shock nitrogen load or a toxicity incident occurs. Model based analysis reveals the unique feature of the scheme: different particulate components in the sludge have a different retention time, and more specifically, active biomass stays longer in the plant than inert solids. This results in that a plant with a storage tank can have the same amount of active biomass as a traditional plant but less sludge, opening the potential of reducing the volume of the plant. Analysis shows that a plant with a sludge storage tank can be about twenty percent smaller than a traditional plant that has the same treatment capability. Analysis is verified by simulation studies.     

区域农田土壤水和氮素行为的模拟

本文以华北平原为研究区域,根据第二次全国土壤普查资料，应用地理信息系统的方法(ARC/INFO)，研究了土壤类型的区域分布，并得出了以72个典型土壤剖面为代表的华北平原土壤类型分布的概化图。通过对作物生长发育参数、土壤和气候资料的简化处理，将土壤水、热、氮联合模拟模型应用于区域农田土壤水、氮素行为的模拟计算。结果表明，通过模型计算与地理信息系统相结合，便于评价不同水氮管理、不同降雨年型条件下区域农田土壤水、氮素行为。通过以中等水氮处理为例的计算，评价了不同降雨年型所得到的水分利用效率(WUE)和氮素利用效率(NUE).区域内WUE明显在干旱年型下最高，湿润年型下最低，而NUE的规律相似但不太明显。各指标在区域上分布有一定的规律，与气候分异和土壤类型分异密切相关。     

Application of nitrogen and phosphorus criteria for streams in agricultural landscapes

Efforts to control eutrophication of water resources in agriculturally dominated ecosystems have focused on managing on-farm activities to reduce nutrient loss; however, another management measure for improving water quality is adoption of environmental performance criteria (or 'outcome-based standards'). Here, we review approaches for setting environmental quality criteria for nutrients, summarize approaches developed in Canada for setting 'ideal' and 'achievable' nutrient criteria for streams in agricultural watersheds, and consider how such criteria could be applied. As part of a 'National Agri-Environmental Standards Initiative', the Government of Canada committed to the development of non-regulatory environmental performance standards that establish total P (TP) and total N (TN) concentrations to protect ecological condition of agricultural streams. Application of four approaches for defining ideal standards using only chemistry data resulted in values for TP and TN spanning a relatively narrow range of concentrations within a given ecoregion. Cross-calibration of these chemically derived standards with information on biological condition resulted in recommendations for TP and TN that would likely protect aquatic life from adverse effects of eutrophication. Non-point source water quality modelling was then conducted in a specific watershed to estimate achievable standards, i.e. chemical conditions that could be attained using currently available and recommended management practices. Our research showed that, taken together, short-term achievable standards and ultimate ideal standards could be used to set policy targets that should, if realized, lower N and P concentrations in Canadian agricultural streams and improve biotic condition.     

Spatial and temporal pollutant budget analyses toward the total maximum daily loads management for the Yeongsan watershed in Korea.

This paper delivers two issues: water quality in the Yeongsan (YS) watershed which is one of the major watersheds in Korea and new watershed management plans with respect to the total maximum daily loads (TMDL) management. Field studies were conducted to estimate the pollutant loads according to the spatial and temporal distribution based on the biochemical oxygen demand (BOD) concentration and the volumetric flow rate (VFR) data from YS watershed. The results of both spatial and temporal analyses show the main pollutant source was originated from the city of Gwangju and the pollutant load from the city to YS watershed was the most out of five cities during this study period. Concerning YS reservoir located downstream of YS watershed, it also shows the worst water quality in the entire watershed during the study period. These results collectively demonstrate that the city of Gwangju is a main region which generates numerous point and non-point pollutant sources and eventually the pollutants are accumulated in YS reservoir. Based on the results, we suggest two different management plans for YS watershed. One is the flow-control approach that is to increase the amount of dam discharge in order to guarantee the river management flow for the midstream region. The other is the mass-control approach that is to dredge the contaminated sediments in YS reservoir for removing pollutants chronically accumulated in the sediment. Simulations for the former and the latter provide the pollution mitigation rate in the watershed up to 6 and 8% for BOD5, respectively. The methodology proposed here for TMDL management can be applied to a wide range of watersheds in Korea.     

基于改进型DNDC模型的小流域非点源氮迁移过程模拟与空间拓展应用

以长江上游紫色土区截流堰小流域（0.35 km2）和大兴小流域（4.65km2）为研究对象,应用基于水文过程的生物地球化学循环模型—改进型DNDC模型对紫色土区小流域径流、泥沙和氮流失过程进行研究。本文采用截流堰小流域2007～2009年和2010～2011年径流、泥沙和氮迁移监测数据分别对模型进行参数率定和验证,检验模型在紫色土区的适用性,然后利用大兴小流域2011年水文、水质监测数据对该模型进行拓展验证,探讨模型在具相似空间结构特征的小流域实现尺度拓展的可行性。结果显示：率定期和验证期月径流、土壤侵蚀、氮流失Nash-Sutcliffe效率系数Ens大多超过0.80,相对误差Re均在15%以内。拓展验证期间,月径流、土壤侵蚀、总氮（TN）和颗粒态氮（PN）的Nash-Sutcliffe效率系数Ens分别为0.70、0.55、0.76和0.71,相对误差Re分别为6.2%、31.2%、9.5%和30.4%,模型较好的反映了大兴小流域径流、泥沙和氮迁移过程。但是模型拓展验证期间,泥沙、颗粒态氮的模拟偏差有所增大。     

Estimation of Zn and Cu unit output loads from animal husbandry facilities

Zinc (Zn) and copper (Cu) are toxic to aquatic organisms at very low concentrations that do not affect humans. We measured the daily output of Zn and Cu in wastewater from livestock farms to aquatic environments because waste from animal husbandry operations contains high levels of Zn and Cu. At most pig farms in Japan, a mixture of urine, some faeces, and service water is treated in onsite wastewater treatment facilities and discharged into a water body. Some dairy farms also have wastewater treatment facilities. We surveyed 21 pig farms and six dairy farms. The unit (i.e., per head) output load from piggery wastewater treatment facilities ranged from 0.13 to 17.8 mg/head/d for Zn and from 0.15 to 9.4 mg/head/d for Cu. Over 70% of pig farms had unit output loads of Zn and Cu below 6 and 2 mg/head/d, respectively. For dairy farms, the unit output load from wastewater treatment facilities was estimated at 1.8-3.6 mg/head/d for Zn and 0.6 mg/head/d for Cu. The unit output load for Zn from piggery wastewater treatment facilities was similar to that from treatment facilities for human waste. However, pig farms generally raise several thousand to tens of thousands of pigs; pig farms are therefore presumed to be a significant point source of Zn in rural areas.