Assessment of nitrogen leaching from arable land in large river basins: Part I. Simulation experiments using a process-based model

A two-step procedure for analysing nitrogen leaching from arable land in large river basins is suggested: (1) application of a process-based dynamic model for a set of representative conditions in a large river basin to simulate water and nitrogen fluxes and (2) development of a fuzzy-rule based metamodel using the simulated nitrogen fluxes in Step 1 as a training set. After that the metamodel can be used for rapid assessment of water quality inside the considered ranges of parameters, describing natural conditions and management practices. This paper describes Step 1 of the procedure. Step 2 is described in an accompanying paper (Haberlandt et al., Ecological Modelling 150 (3) (2002) 277–294). The advantage of this approach is that it combines the ‘process-based foundation’ with the resulting simplicity of the metamodel. Simulation experiments for analysing nitrogen (N) leaching from arable land were performed using the Soil and Water Integrated Model (SWIM) for a set of representative conditions in the Saale basin (23 687 km²) in Central Europe. The Saale River is one of the main tributaries of the Elbe. In advance, hydrological validation of the model was done for the whole Saale basin and validation of nitrogen dynamics was fulfilled in two mesoscale sub-basins of the Elbe. For the simulation experiments the drainage basin area was sub-divided into five climate zones and nine representative soil classes were chosen. The basic rotation and fertilisation schemes were established using regional information obtained from literature. In addition, the effects of changing the basic rotation to more/less intensive ones and changing fertilisation rates by 50% increase/decrease were studied. The ranges of simulated nitrogen fluxes for the basic rotation and fertilisation schemes are comparable to available regional estimates and differences between sub-regions and soils are plausible. The relative importance of natural and anthropogenic factors affecting nitrogen leaching for the Saale River basin was as follows: (1) soil, (2) climate, (3) fertilisation rate and (4) crop rotation. The simulation experiments provide a basis for a fuzzy-rule based metamodel approach, which aims at rapid water quality assessment of large regions.     

From meso- to macro-scale dynamic water quality modelling for the assessment of land use change scenarios

The implementation of the European Water Framework Directive requires reliable tools to predict the water quality situations in streams caused by planned land use changes at the scale of large regional river basins. This paper presents the results of modelling the in-stream nitrogen load and concentration within the macro-scale basin of the Saale river (24,167 km²) using a semi-distributed process-based ecohydrological dynamic model SWIM (Soil and Water Integrated Model). The simulated load and concentration at the last gauge of the basin show that SWIM is capable to provide a satisfactory result for a large basin. The uncertainty analysis indicates the importance of realistic input data for agricultural management, and that the calibration of parameters can compensate the uncertainty in the input data to a certain extent. A hypothesis about the distributed nutrient retention parameters for macro-scale basins was tested aimed in improvement of the simulation results at the intermediate gauges and the outlet. To verify the hypothesis, the retention parameters were firstly proved to have a reasonable representation of the denitrification conditions in six meso-scale catchments. The area of the Saale region was classified depending on denitrification conditions in soil and groundwater into three classes (poor, neutral and good), and the distributed parameters were applied. However, the hypothesis about the usefulness of distributed retention parameters for macro-scale basins was not confirmed. Since the agricultural management is different in the sub-regions of the Saale basin, land use change scenarios were evaluated for two meso-scale subbasins of the Saale. The scenario results show that the optimal agricultural land use and management are essential for the reduction in nutrient load and improvement of water quality to meet the objectives of the European Water Framework Directive and in view of the regional development plans for future.     

Assessing water quality in the Ceyhan River basin (Turkey) with the use of aquatic macrophytes

As a major biotic component of many lotic ecosystems, macrophytes consist a major component of running waters are often used as indicators within the European Water Framework Directive (WFD) to establish ecological quality. In this study, we investigated macrophyte community structure (e.g. composition, abundance and diversity) in Ceyhan River Basin located in the Southeastern Anatolian Region in Turkey. Data was collected during 2014–2015 from river sites located throughout the basin to evaluate the relationship between aquatic vegetation and river physico-chemical factors. The ecological status of the river basin was also calculated based on Macrophyte Biological Index for River (IBMR). In total, 33 macrophyta taxa were observed. According to their biological classification (life form), filamentous algae (FA), free floating (FF), floating leaved (FL) and submersed (S) macrophytes reached their maximum abundance value in summer, while emergent (E) macrophytes were at their maximum abundance in both summer and autumn. The ecological status of the Ceyhan River basin ranged from moderate to bad. The values found are reasonably comparable to IBMR scores recorded in rivers of other Mediterranean countries. IBMR index may be suitable to some extent to establish a basis for ecological quality assessment in Turkish River systems.     

Predicting water quality data in an unfilled reservoir using microcosm sediment-water simulation

The technique of microcosm sediment-water simulation was used to obtain predictive water quality data for the proposed Jordanelle Reservoir, Heber City, Utah. Sediment-water microcosms were prepared for four sites located in the north arm of the reservoir basin, including two sites located in an abandoned acid mine tailings pond. Data obtained from the tailings pond microcosms indicated that low pH water and high trace metal concentrations may exist in this area of the reservoir. These data suggested that the tailings material should be contained or removed prior to reservoir filling. Other sites in the reservoir basin exhibited water quality considered normal for reservoirs of similar elevation and basin geology. Near the proposed dam, anaerobic conditions could develop rapidly due to available concentrations of organic carbon, and the subsequent release of Zn, Fe, and Mn may pose a water quality problem. At the sampling site near Keetley, simulation data indicated that anaerobic conditions will not develop as quickly or be as severe as conditions expected near the dam. Overall, the availability of nitrogen and phosphorus in the Provo River and Jordanelle sediments indicated that problems with algal blooms may exist in the reservoir. Also presented is a brief discussion of the advantages and disadvantages associated with microcosm sediment-water simulation.     

近年来长江流域气溶胶光学厚度时空变化特征分析

利用2000年3月至2011年2月MODIS Level3遥感反演大气气溶胶光学厚度（AOD）产品数据,结合中国地形的3大阶梯分布,分析近年来长江流域气溶胶光学厚度的时空变化特征。结果表明,近12年来,长江流域的年平均AOD值在0．38,～,0．44之间变化,其中“第一阶梯”年平均AOD呈极显著下降趋势（P〈0．01）,“第二阶梯”和“第三阶梯”则呈上升趋势,但趋势不显著（P〉0．05）;4季平均AOD除春季呈下降趋势,其他3季均为上升趋势,其中冬季上升速率最快,线性倾向率为0．004·a-1（P〈0．05）,春季AOD与其他季节的差距在逐步减小;长江流域3大阶梯AOD具有鲜明的季节变化特征,基本上是春夏季较大,秋冬季较小,具体表现为春季最大,从夏季到冬季逐渐减小,冬季到来年春季跳跃性增高,但由于地理位置、地形、气候、人类活动等因素的影响,不同区域又有所差异;AOD年平均值和四季平均值均表现为“第三阶梯”〉“第二阶梯”〉“第一阶梯”。长江流域年平均AOD变化空间差异显著,其中显著减少区域占整个流域面积的17．54％,主要分布在“第一阶梯”;显著增加的区域仅占流域总面积的5．23％,主要分布在“第二阶梯”和“第三阶梯”。另外,由于海拔、地形及山脉阻挡等诸多因素影响,导致在地形阶梯间高程突变线左右两边的狭窄区域,AOD分布存在低处明显大于高处的现象。这些结果有助于长江流域的区域气候变化和环境研究。     

Ammonium in Fließgewässern des Saale-Einzugsgebietes

Exposure assessment of rarely measured substances or newly identified chemicals requires the usage of mathematical methods. The georeferenced exposure model GREAT-ER was designed to accurately predict the concentration of ‘down-the-drain’ chemicals under consideration of their spatial and temporal variability in surface waters. In the past, successful validations of the model have been performed predominantly for small and middle-sized catchments and were accompanied by extensive monitoring of the detergent-ingredients boron and linear alkylbenzene sulphonate (LAS). A proof of the adaptability of GREAT-ER to large catchments is given here by example of the Saale river basin. Furthermore, it could be shown that ammonium is a suitable parameter for validations of the model. This corroborated the hypothesis that the non-point-emissions of ammonium are of less importance in comparison to the ammonium loads in the effluents of wastewater treatment plants.     

Aquatic ecological health assessment of Shaying River Basin based on indices of physico-chemistry and aquatic organisms北大核心CSCD

With a variety of ecosystem services, river ecosystem plays an important role in the process of human society development. On the other hand, health condition of most aquatic ecosystems is seriously threatened by human activities. Restoring and maintaining a healthy ecosystem has already become a vital goal of river management. As a basis of river management, river health assessment is therefore particularly important. Based on indices of physics, chemistry and aquatic organisms, this research tried to establish a comprehensive evaluation system of aquatic ecological health suitable for the situation of Shaying River Basin. The system included 6 factors including riparian zone, river morphology, nutrients, oxygen balance, periphyton and benthic macroinvertebrates, which were defined into 19 indices reflecting the aquatic ecological health from different aspects. The assessment results indicated that the health condition of overall basin was normal, varying among different parts of the region, with Shahe River, Lihe River and Beiru River in the upper part sub-healthy, and Jialu River in the same part sub-sick. The middle region was generally in normal or sub-sick level; the health condition of the lower part was comparatively better due to a good condition. Within the indices, the nutrients and benthic macroinvertebrates were the major constraining factors to the health condition of Shaying River Basin for their poor health condition. The health conditions showed significant differences among the rivers (P < 0.01), with Jialu River being the worst. The result indicated that the aquatic ecological health of Shaying River Basin is affected by many factors, with urban and industrial sewage being the main ones, And that different protective measures should be employed for rivers of different conditions. The result can provide theoretical basis for the ecological restoration of Shaying River Basin and reasonable exploitation and conservation of the water resource of the whole Huaihe River Basin.     

Perspectives on small watershed management in China: the case of Biliu

River basin management in China has focused on large rivers, such as the Yangtze and Yellow Rivers. However, there are also about 20,000 small river basins that deserve attention. The Biliu River basin in Liaoning Province, northeast China, which is 156 km in length, has many features common to small river basins, including divided jurisdiction among governments leading to vertical and horizontal fragmentation. In the Biliu basin, the key municipalities are Dalian with a population of almost 6 million people and Yingkou with about 2.28 million people. Each has different interests and needs, making coordination and collaboration difficult. The literature and practice suggest that effective integrated water resource management (IWRM) requires at least six features: (1) vision, policy and strategy; (2) a legislative or statutory basis to provide credibility and authority; (3) a river basin organization to coordinate development and management; (4) specification of functions and authority of the river basin organization; (5) public participation and community involvement; and (6) an IRWM strategy and plan. Water management in the Biliu River basin is assessed relative to these features of IWRM, with recommendations offered regarding changes to have water management in the Biliu River basin to reflect what is expected in an IWRM approach.     

甘肃省耕地资源转变为建设用地的价值损失评估

依据耕地资源具有的社会保障功能、生态系统服务功能和经济产出功能,初步建立耕地资源的价值评估体系,综合运用市场价值法、替代法、机会成本法和影子价格法等评价方法,估算了甘肃省12个市(州)2007年耕地转变为建设用地所导致的正面效应价值损失。结果表明,由于建设用地占用耕地造成的价值损失相当巨大,2007年全省建设所占用耕地的总面积为1 564.66 hm2,造成的价值损失多达95 904.09万元,各市(州)1 hm2土地的损失都超过了45万元。从价值损失的构成来看,损失的直接使用价值为45 712.77万元,间接使用价值达50 191.32万元。可以看出,耕地资源除为社会提供直接产品价值外,还有巨大的间接使用价值,而且这种价值对人类的贡献比农产品的产出价值更为显著。     

Effects of wind-driven circulation on river intrusion in Lake Tegel: modeling study with projection on transport of pollutants

Prediction of mixing intensity of water masses in riverine Lake Tegel (Berlin, Germany) can be used to trace the fate of pollutants that enter the lake through several inflows. Because the contributions of each inflow have not yet been quantified and because the lake features complex bathymetry and numerous islands, a hydrodynamic circulation model with high spatial resolution and dynamic wind forcing is useful. We applied the two-dimensional version of the Princeton Ocean Model to separate the influences of wind and river discharge on the currents and mass transport in Lake Tegel. For model validation, we compared the simulation results with 1?year of electrical conductivity data, which was used as a conservative tracer to distinguish between water from the River Havel and water supplied by a smaller second inflow. Calculation of currents alone is insufficient to investigate water exchanges between rivers and lakes, especially when several islands create multiple pathways for river intrusion. Therefore, mass transport simulations are applied. Our calculations based on archetypical scenarios indicate that the proportion of (polluted) water from the River Havel in the main basin of Lake Tegel fluctuates with river discharge and wind, which either amplify or neutralize each other.     

Identifying and quantifying nitrogen and phosphorus loadings from agriculture and livestock waste in the Penios River Basin District

The nitrogen and phosphorus loadings coming from diffuse, non-point pollution sources related to agriculture and animal husbandry in the Penios river basin in the region of Thessaly, Greece, were estimated. Detailed data on types of crops and field area as well as types and numbers of animals bred in the municipal districts included in the Penios River Basin District were collected from agricultural cooperatives and rural agencies in Thessaly. Related nitrogen and phosphorus loadings were calculated and all data were mapped in a geographic information system (GIS) environment to show how diffuse pollution is spatially distributed in the Penios basin and to identify areas with the highest anthropogenic pressures. This type of data is useful to a driving forces–pressures–state–impacts–responses (DPSIR) analysis – a tool suitable for the analysis of environmental decisions in the direction of sustainable development.     

Effects of climate change on surface water management of Seyhan basin,Turkey

The goal of this study was to set-up the basis for climate change adaptation of water resources management policies in Seyhan River basin. The first priority was to identify the balances between water resources and water users with respect to existing and planned projects. In this respect various aspects of Seyhan basin were evaluated, including evaluation of existing water resources, determination of water demand of existing and planned projects, and water resources supply-demand characteristics. The global climate change model was downscaled to the basin scale, the results were associated with hydrometeorological monitoring network and finally the impact of climate change on surface water resources and demands were determined for specific projection years. Water resources management scenarios were developed to evaluate adaptation alternatives to climate change scenarios at the basin level. It was determined that even though there was no water stress in Seyhan basin in 2010, many parts of the basin were expected to suffer significant shortages over the coming years.     

黑河流域生态功能区划及其保护

根据整体性、主导性、综合性原则 ,运用叠置法 ,将黑河流域划分为 3个生态功能区、9个亚区 ,分析了各个功能区的生态特征及存在的生态问题。分区提出了生态保护措施 ,并探讨了黑河流域生态保护及管理对策。     

Ground water pollution by pesticides at the watershed‐soil catena scale: Lindane at the lower Colorado river basin (Argentina)

The movement of Lindane from application points at the surface soil towards the underground water and further transport within this compartment at the watershed‐soil catena scale, was inspected by measurements of the pesticide concentration in soil water at a controlled experiment where it was applied at a usual label dose. The concentrations of Lindane in soil water and the upper phreatic level were also measured at successive dates in samples obtained from a net of phreatimeter probes distributed over the area (1,500 km²) of the lower Colorado River basin (Bs. Aires, Argentina). The location of cultivated‐irrigated areas within the watershed was inferred from NDVI (Normalized Difference Vegetation Index)‐1 km‐10 day AVHRR images obtained at successive dates during the irrigation season. Feasible paths of underground gravitational water flows were computed by means of a GIS‐simulation model on the basis of local terrain slopes and aspects. The pattern of Lindane distribution over the basin was explained on the basis of the distribution of diffuse sources, the patterns of percolation and groundwater flows and the thermodynamic characteristics of the pesticide.     

Molecular Evidence for a Unique Evolutionary Lineage of Endangered Sonoran Desert Fish (Genus Poeciliopsis)

Efforts to restore an endangered species in its former range should be based on a sound understanding of evolutionary relationships among remaining natural populations. In this study mitochondrial (mt) DNA diversity within and among Gila River drainage populations of the endangered Sonoran topminnow ( Poeciliopsis occidentalis ) in Arizona was compared to that from neighboring populations in Sonora, Mexico, where the species remains locally abundant. No mtDNA diversity was detected within or among samples from the Gila River basin in Arizona. But considerable variation was found within and among populations from several river systems in Sonora. Examination of mtDNA from a population that inhabits the upper reaches of the Río Yaqui in southeastern Arizona revealed substantial divergence between it and all other populations examined. We comment on the implications of this divergent population for topminnow management in Arizona and argue for more-detailed genetic and morphological studies to determine the distributional limits and specific status of this highly divergent form.     

流域生态补偿理论探讨

流域生态补偿是协调流域生态环境保护和经济发展之间矛盾,调整流域内区域间损益关系的有效手段。文章从流域内人类活动产生的损益人手,论述了流域生态补偿的概念、理论基础和运行机铷,并利用经济学原理,对生态补偿的必要性和补偿标准进行了理论解析,给出了流域生态补偿必要性的理论依据和需要补偿量的理论值。在此基础上,根据流域人类活动的正负外部性等原则,对流域生态补偿进行了分类。依据流域生态补偿分类,梳理出了我国流域生态补偿重点区域。通过对流域生态补偿理论探讨,以期作为进一步研究和应用实践的参考和启示。     

基于SPOT—VGT的黄河流域植被覆盖时空演变

植被是土地覆盖中的最主要部分,是连接土壤、大气和生物等要素的自然“纽带”。植被覆盖动态变化对全球能量循环和物质循环具有重要影响,是全球变化研究的重要内容之一。黄河流域作为我国重要的粮食生产基地,其环境变化直接影响到流域经济的可持续发展。为了快速准确地提取地表植被状况,了解黄河流域生态环境,利用1998—2011年的SPOT-VGT遥感数据,结合地理信息技术,采用均值法和趋势分析法对黄河流域植被NDVI时空分布特征和变化趋势进行了动态监测。结果表明,（1）黄河流域14年NDVI均值的空间分布整体特征是东南部平原、盆地和西部山地植被状况要好于北部地区。其次,黄河流域属于干旱半干旱地区,植被发育主要依赖于水文条件,所以沿黄河干流和支流区域也具有较高的植被NDVI值。（2）黄河流域植被NDVl年均值近14年间整体呈缓慢增长趋势,1998--2000年呈现急剧减少态势,2001--2003年出现了较为快速的增长,2004--2011年又出现了较长时间的连续增长过程。（3）黄河流域植被NDVI基本不变的区域约占研究区总面积的71．13％;植被NDVI轻微改善的区域约占流域总面积的27．30％,且主要分布于流域东南部的盆地、平原和西部的山地、丘陵地区,植被NDVI退化的区域面积约占流域总面积的0．98％。黄河流域自1998年以来,植被NDVI整体在不断提高,生态环境在不断改善。     

Assessment of non-point source pollution using a spatial multicriteria analysis approach

Eutrophication caused by the enrichment of nutrients from diffusing sources is degrading surface water quality throughout the world. Assessing the potential contributions of different land areas in diffuse nutrient export has become an important task in non-point source (NPS) pollution control. Existing methods were often limited by the availability of local data and the complexity of model formulation. This study developed a spatial multicriteria method to evaluate the nitrogen loss potential at the basin level. Four criteria were formulated to characterize the source capacity of nitrogen export, the flow path to water body, the efficiency of runoff generation and the climatic driving force. The proposed method is a low-effort approach since the required data is either already available in a global context or easily produced with limited inputs. Being implemented in GIS environment, this method generates maps that can be easily interpreted to provide decision support. The method was applied to the Huai River Basin, China. The results were validated based on the correlation between the nitrogen loss potential of sub-basin and the water quality class of river. The maps of nitrogen loss potential were helpful for examining the regional pattern of diffuse nitrogen loss, and could facilitate the decisions of NPS pollution management at the provincial or basin level.     

Aufkommen und Verteilung von Feststoffen in Kanalsystemen

Suspendend solids (SS) are important parameters in the assessment of potential effects of emissions out of sewer systems. This is due to the fact that many pollutants are transported with particles in the sewer systems and therefore are emitted into receiving waters. In this paper, significant emissions in commonly applied sewer systems (combined sewer system [CSS], separate sewer system [SSS]) are mentioned, and typical concentration ranges of SS are listed. Furthermore, data from selected pollutants (lead, polycyclic aromatic hydrocarbons [PAH]) are collected and concentration ranges in typical flow types of the sewer systems are calculated. In the second part of the paper results from pollution load simulations are introduced. The calculations are based on assumptions from literature and were conducted in a hypothetical catchment. Main interest was the comparison of emissions out of SSS and CSS, shown for selected parameters SS, lead and PAH. Results of the pollution load simulation show that emissions for surface runoff related compounds like lead are extremely high in the SSS in comparison to the CSS. This is mainly reasoned by the high elimination rate in the waste water treatment plant (WWTP). In summary, a general answer, which sewer system emits higher pollution loads is not possible. It is extremely dependent on the considered substance and its specific properties and resulting behaviour in the sewer systems. For a first estimation, new classes of substances are distinguished considering their origin (surface runoff versus dry weather flow) and their elimination capacity in the WWTP.     

Modelling nutrient emissions from river systems and loads to the coastal zone: Po River case study,Italy

The nutrient emission model MONERIS (MOdelling Nutrient Emissions into River Systems) is applied to the Po catchment, a large (>70,000 km²), densely populated, highly agriculturally exploited and industrialized landscape. The catchment is located in northern Italy. The Po River discharges into the northwestern Adriatic Sea. Model runs cover the period 1991–2000. The purpose is to model the catchment in 2001, estimating nutrient emissions and natural background in the basin and loads to the coastal area. The model was calibrated with data for the period 1990–1995. After validation with data for the period 1995–2000, the model is used to evaluate future catchment management scenarios.MONERIS is a spatially distributed parameters steady state model with a time scale of 5 years. The emissions considered are originated from diffuse and point sources and delivered trough various pathways (groundwater, erosion, overland flow, atmospheric deposition, urban systems and WWTPs). In order to estimate nutrient loads to the river system, MONERIS includes a retention model.An overview of model input requirements, data needs and related problems and solutions adopted is presented in the paper. Simulated and measured data of several sections along the river are compared for calibration and validation. The relative importance of different nutrient generation pathways are evaluated. Finally, forecasted yearly nutrient loads at the outlet of PO basin for the years 2001, 2008 and 2016, consequence of different basin management scenarios, are presented. The results are ready to be supplied to a water quality Coastal Zone Model, allowing us to evaluate significant switches in trophic state conditions of the coastal ecosystem [see Artioli, Y., Bendoricchio, G., Palmeri, L., this issue. Defining and modelling the coastal zone affected by the Po River (Italy). Ecol. Model.].