Welfare Improvisation from the Receiving Waters of Urban Wastewater Systems in the Context of the Water Framework Directive

The compliance of wastewater authorities with the Water Framework Directive (WFD, 2000/60/EC) although may highly contribute to a “good” ecological status in aquatic ecosystems, is alleged to require disproportionally high costs in relevance to the anticipated benefits. This is mainly due to the limited yet research in the assessment of the economic welfare derived by the compliance with the WFD. In this light, the direct and indirect economic benefits emerged by the attaining of WFD are investigated. The wastewater treatment plant of Athens (Greece) is demonstrated as a comprehensive pilot case.     

Groundwater Exploration and Assessment in Rural Communities of Yobe State, Northern Nigeria

The provision of adequate water supply and sanitation to the rapidly growing urban populations is increasingly becoming a problem for governments throughout the world. The continuing expansion of the numbers of people in cities who need water and sanitation services form a continuous pressure to either invest in additional production capacity or to stretch the available supplies to serve more people. Due to rapid increase in population growth in the Yobe State north of Nigeria, there is a shortage in the water supply to Damaturu city the capital of the state and surrounding villages. At the present the total water supply is about 10,000 m³/day abstracted form the shallow alluvial groundwater aquifer using 29 production wells. Due to the expected increase in water demand and the limited potentiality of shallow aquifer system, other deep aquifers were explored and investigated to evaluate their potentiality for future water demand. Vertical Electrical Sounding Method was used for the geophysical survey of the study area. Groundwater flow model was developed and calibrated against the historical information. Three wellfields were designed to provide Damaturu city and surrounding villages with the required water. The calibrated model has been used to evaluate the aquifer potentiality and the effect of future withdrawals on the deep aquifer system. It was found that the aquifer system within the study area consists of two main layers. The upper layer is the Chad formation comprises an alluvial sand and gravel with intercalation of thin sility clay layers. The second layer is Keri-Keri formation consists of sandstone formation which is not explored before. During this study the Kerri-Kerri aquifer system was investigated as an alternative source for groundwater for future demand. The study presents an integrated groundwater resources management strategy for present and future water supply for rural communities.     

Response of aquatic macroinvertebrate density and diversity to wetland management and structure in the Montezuma Wetlands Complex,New York

We investigated how water management and other covariates affected aquatic macroinvertebrate density and diversity of wetlands in the Montezuma Wetlands Complex (MWC) of the Lake Ontario watershed, New York, USA. We conducted aquatic macroinvertebrate sampling during May–July in 2016–2018 to coincide with when juvenile wetland birds require these protein foods. Models that best explained aquatic macroinvertebrate density and taxon richness included water drawdown treatment, water depth, and water drawdown treatment from the prior year. Predicted mean density of aquatic macroinvertebrates was 117.2% greater in partial drawdown than passive wetlands (i.e., wetlands without active water removal) and increased by 516.2% with 15.5–48 cm increase in water depth. Density of aquatic macroinvertebrates also was ≥ 2.6 times greater in wetlands with a full drawdown the year prior. Taxon richness and Shannon Wiener Diversity Index (H′) varied positively with water depth, and there was greater diversity in partial drawdown than passive wetlands. Taxon richness was nearly 2 times greater in areas with full drawdown the year prior than those with partial drawdowns and passive wetlands. Other competing models for H′ also included negative effects of percentage monotypic cattail and invasive plant taxa. These findings are consistent with aquatic macroinvertebrate adaptation to dynamic wetland hydrology, and we recommend that managers actively manipulate hydrology to provide abundant and diverse food resources for birds at managed wetlands in the Great Lakes region.     

改进SWAT模型在强人类活动地区的应用

摘要：SWAT模型是一个具有较强物理机制的、长时段的流域水文模型。针对中国人类活动强烈的流域水循环特点，在二元水循环理论的指导下，以SWAT模型为基础，进行了灌溉和人工耗用水模块的开发和改进，构建了适用于此类区域的二元水循环模型。利用改进后的模型对全世界用水最为强烈的区域之一——天津市的水循环过程进行了模拟，结果表明，改进后的模型模拟的NASH效率系数从0.62提高到0.89，相关系数从0.79提高到0.91，比改进前有明显的提高。模型构建和改进的成功，对分布式水文模型在高强度人类活动影响流域的水资源水环境研究和管理将起到积极的作用。     

Groundwater management and protection in Denmark: a review of pre-conditions,advances and challenges

Denmark is making continuous efforts to attain sustainable groundwater management. With groundwater constituting virtually the only resource for all water uses, groundwater management was addressed early on and has progressed over the last century. This article gives an overview of the advances, along with past and present challenges in securing sustainable groundwater utilization. The objective is to document comprehensively the Danish case and to highlight some of the unique conditions and principles that have shaped and facilitated groundwater management in the country.     

江西省2021年地下水水质现状分析评价

根据2021年收集到的江西省47口地下水监测井的实测数据,利用地下水单项组分和综合评价法,进行了地下水水质现状的评价,确定了水质类别和级别,评价为V类水和极差水占比均达到了50%以上。另选用内梅罗综合污染指数法进行地下水污染程度分析,确定了其主要污染因子为铁、锰、氨氮、挥发性酚,统计出全省有80%的地下水监测井受到了不同程度的污染,分布于省内各地区,同时提出了相应的防治对策。     

Geostatistical Assessment of Groundwater Nitrate Contamination with Reflection on DRASTIC Vulnerability Assessment: The Case of the Upper Litani Basin, Lebanon

Groundwater constitutes the largest single source of fresh water in many parts of the world and provides a risk buffer to sustain critical water demands during cyclic and prolonged dry periods, especially in semi-arid and arid regions. However, unprecedented socio-economical growths are threatening the viability of these precious resources through fast depletion of already critically low stocks accompanied by persistent degradation of water quality due to salinization, and contamination by pesticides and fertilizers, urban sewage and industrial waste. These circumstances are particularly true of the Upper Litani Basin (ULB), which houses over 500,000 of Lebanon’s 4 million population and provides the bulk of the country’s agricultural output. Uncontrolled urban, agricultural and industrial growths following a prolonged civil strife and foreign occupation have resulted in the deterioration of the quality of the basin’s surface water and potentially its groundwater resources. An assessment study of groundwater quality conditions in the ULB was conducted in support of efforts to manage water quality in the basin. Geostatistical analysis of groundwater nitrate levels was conducted using data collected through an extensive basin-wide water quality survey sponsored by the USAID and covered two periods representing the summer and winter periods. The results of analysis include maps of nitrate contamination and probability of exceedance of drinking-water nitrate regulatory limit. The results indicate a significant, widespread and persistent nitrates contamination of groundwater in the ULB. Nitrate levels in groundwater exceed standard limits for drinking water in many parts of the basin. These findings were examined with respect to those of a DRASTIC groundwater vulnerability assessment conducted by the USAID BAMAS project. Comparative analysis of the two assessments shed the light on several issues related to the application and interpretation of DRASTIC scores and the groundwater nitrate contamination process.     

Towards Sustainable Water Policy in Kuwait: Reforms of the Current Practices and the Required Investments, Institutional and Legislative Measures

The water policies of Kuwait are in need of major reforms in order to cope with the ever-increasing demands without burdening the country’s economy. As it stands, the simple approach of increasing desalination capacities and groundwater withdrawal to meet the demands is hurting the economy as well as the natural resources, and is bound to lead the country into a serious water crisis. In this context, this paper discusses the potential alternatives to the current water policies of Kuwait. Adopting two of the IWRM Toolbox axis, namely potential impact of the proposed reforms and readiness of the enabling environment (investment/benefits, institutional setup, and regulative requirements), as a basis for discussion and evaluation, this study presents, evaluates and prioritizes a set of what is widely regarded as the main reforms of the current policies in the hope of focusing attention on those that are most effective. Overall, the necessary investments are moderate. In contrast, failure to implement the reforms would cost Kuwait well above $1 billion/year. Institutional changes are expected to be minor, while significant efforts are needed to amend the regulatory setup. Using an arbitrary rating system based on the available evidence, four reforms are recommended for implementation as high priority (mandating water conserving devices, restructuring the water tariff, reallocation of resources, and awareness programs), three reforms are considered medium priority for implementation (penalizing wasteful practices, water auditing and groundwater protection), and two reforms are not recommended (reduction of leakage in the main network and tighter immigration laws). On the other hand, three reforms have a high potential impact but there are too many ambiguities regarding their technical feasibility. These reforms are recommended for further research, two as high priority (alternative desalination technology and artificial recharge using RO water) and one as low priority (artificial recharge using harvested water). Cultural and political issues that are expected to influence the reforms have been briefly discussed.     

Assessment of Contributions of Climatic Variation and Human Activities to Streamflow Changes in the Lancang River,China

The construction and operation of hydropower reservoirs on the Lancang River have drawn worldwide concern, because streamflow changes have occurred in this river since the introduction of dams. To address these concerns, it is necessary to quantitatively assess relative contributions of climatic variations and human activities to these changes. In this research, Mann-Kendall method was used to assess the trends in hydro-climatic data. The streamflow data were divided into a reference period (1956–1985) and a change period (1986–2008) based on hydropower reservoir construction timeline. The Back-Propagation Artificial Neural Network (BP-ANN) model was used to reconstruct natural streamflow. The contributions of climatic variations and human activities were investigated at the yearly, seasonal and monthly time scales. The results indicate that human activities exerted a slightly greater impact on flow changes than did climatic variations, at the yearly time scale (54.6 and 45.4 %, respectively). At the seasonal time scale, climatic variations made a greater contribution (65.8 %) during the wet season, while the contribution of human activities became the dominant factor during the dry season (85.3 %). At the monthly time scale, the contribution of climatic variations in January, June, August, and September was greater than that of human activities, while in the remaining eight months, human activities exerted a greater contribution than did climatic variation. The relative contributions of human activities and climatic variations (RCs) were also determined during the single- and cascade-dam periods; these did not always increase at the three time scales when dam system shifted from single-dam to cascade-dam.     

Conjunctive use of groundwater and surface water to reduce soil salinization in the Yinchuan Plain,North-West China

Abstract

Poor water resource management is an important factor in soil salinization in arid areas. In this study, the status of soil salinization and its controlling factors are summarized for the Yinchuan Plain, North-West China. The conjunctive use of surface water diverted from the Yellow River and groundwater abstracted from a shallow aquifer is proposed to alleviate soil salinization in the plain. Scenarios are designed and simulated to determine the optimal proportions at which groundwater should be exploited for irrigation in the three cities of the plain. Policies and suggestions regarding sustainable water resources and soil salinization research in the plain are recommended.     

Urban and river flooding:Comparison of flood risk management approaches in the UK and China and an assessment of future knowledge needs

Increased urbanisation,economic growth,and long-term climate variability have made both the UK and China more susceptible to urban and river flooding,putting people and property at increased risk.This paper presents a review of the current flooding challenges that are affecting the UK and China and the actions that each country is undertaking to tackle these problems.Particular emphases in this paper are laid on(1) learning from previous flooding events in the UK and China,and(2) which management methodologies are commonly used to reduce flood risk.The paper concludes with a strategic research plan suggested by the authors,together with proposed ways to overcome identified knowledge gaps in flood management.Recommendations briefly comprise the engagement of all stakeholders to ensure a proactive approach to land use planning,early warning systems,and water-sensitive urban design or redesign through more effective policy,multi-level flood models,and data driven models of water quantity and quality.     

Analysis of Impacts of Climate Change and Human Activities on Hydrological Drought: a Case Study in the Wei River Basin,China

Climate change and human activity are the two major drivers that can alter hydrological cycle processes and influence the characteristics of hydrological drought in river basins. The present study selects the Wei River Basin (WRB) as a case study region in which to assess the impacts of climate change and human activity on hydrological drought based on the Standardized Runoff Index (SRI) on different time scales. The Generalized Additive Models in Location, Scale and Shape (GAMLSS) are used to construct a time-dependent SRI (SRI_var) considering the non-stationarity of runoff series under changing environmental conditions. The results indicate that the SRI_var is more robust and reliable than the traditional SRI. We also determine that different driving factors can influence the hydrological drought evolution on different time scales. On shorter time scales, the effects of human activity on hydrological drought are stronger than those of climate change; on longer time scales, climate change is considered to be the dominant factor. The results presented in this study are beneficial for providing a reference for hydrological drought analysis by considering non-stationarity as well as investigating how hydrological drought responds to climate change and human activity on various time scales, thereby providing scientific information for drought forecasting and water resources management over different time scales under non-stationary conditions.     

新建水厂并网对管网水质的影响及控制

新建水厂的并网工作往往对周边的现有管网影响较大,经常出现水质波动等问题。通过总结金海水厂并网期间的操作,分析归纳了并网工作中几种常见的问题及应对策略。由于管网水质中的浊度是一个综合性、代表性的指标,主要以管网水浊度作为主要监测指标。     

探索南水北调西线工程两利双赢方案——原西南电管局局长、资深专家王尊相访谈录

南水北调西线工程是被称为世界上规模最大的调水工程。西线调水将会严重影响西电东送。西水北调是解决问题的两利双赢方案。这样浩大的工程必须遵照党中央的指导方针,尊重科学、尊重实践、尊重专家,广泛听取意见,多方论证,使决策符合实际,减少失误。     

Identifying and alleviating low flows in regulated rivers: the case of the Rivers Bulbourne and Gade,Hertfordshire, UK

This paper examines evidence for the occurrence and causes of low flows, and strategies for their mitigation, in two regulated, chalk‐fed streams. The rivers occupy adjacent catchments of similar topography, have long histories of water exploitation and land‐use change, and are subject to conflicting demands of water resource development and increased pressure for environmental improvement. In one case, a strategy of low‐flow mitigation based upon reduced groundwater abstraction has been proposed. Although flows are shown to be declining through time, and low flows are more common over the last decade, analysis of rainfall records and groundwater levels produce inconclusive evidence for the causes of low flows. Despite their natural similarities, the catchments are shown to have very different sensitivities to low flow. When concentrating upon quantity of low flow, the River Gade appears to be most compromised, but when consideration is taken of water quality, the Bulbourne is more severely affected. An examination of catchment changes over a longer time period provides the best rationale for these sensitivities and contrasts. The study illustrates the potential danger of starting with a solely climatic–hydrological perspective to low flows which then progresses to a hydrological ‘solution’. Consideration of catchment land‐use history, and of the importance of water quality, suggest limited applicability of reduced abstraction in mitigating low‐flow problems in these kinds of environments. The study reinforces calls for further studies of groundwater–surface water interaction as essential inputs to appropriate and sustainable water resource management strategies. Copyright © 2000 John Wiley & Sons, Ltd.     

Urban water demand,climatic variation,and irrigation-water insecurity: interactive stressors and lessons for water governance from the Angat River basin (Philippines)

Climatic variation and intersectoral water competition increasingly challenge the effective provision of irrigation services. This article explores their combined effects on irrigation allocation from the Angat Reservoir (Philippines), where domestic water use in Metro Manila has overtaken regional irrigation as the dominant right-holder. Rules protecting Metro Manila’s large right to water ‘interact’ with dry spells to affect irrigation security in wet and dry seasons. Historically, irrigators were uncompensated because re-allocation’s cause was contested as (1) an unforeseeable climatic event (releasing domestic utilities of liability), or (2) produced by urban demand (requiring compensation). Trade-off rules must be prepared to navigate combinatory effects.     

Reconceptualization of the Transboundary Water Interaction Nexus (TWINS): approaches,opportunities and challenges

ABSTRACT

Using a critical hydropolitics approach, we broaden the context of the Transboundary Water Interaction Nexus framework to provide a tool to analyze interstate relations on the sideline of selected water-related issues regardless of the legal status of actors; distinguish nuances between six intensities of cooperation and conflict; and simultaneously evaluate water events as a form of cooperation, conflict, or both.     

Maturation ponds, rock filters and reedbeds in the UK: statistical analysis of winter performance.

Wastewater treatment technologies suitable for serving large populations are generally reliable and reasonably cost-effective, yet they are almost always financially inappropriate for small communities (< 2,000 p.e.). Comparative cost data suggests that waste stabilization ponds should be an attractive option for small communities, yet perceptions relating to land costs, climate and effluent quality have limited their application in the UK. This paper details typical UK land costs, climate and winter performance data for a pilot-scale waste stabilization pond with various upgrading technologies: system A, two tertiary maturation ponds in series; B, two tertiary maturation ponds in series followed by a reed bed channel; C, a control rock filter; D, an aerated rock filter; and E, a constructed wetland. System D was found to perform best, closely followed by system B.     

Impacts of Climate Change and Human Activities on the Surface Runoff in the Tarim River Basin over the Last Fifty Years

The impacts of climate change and human activities on the surface runoff were analyzed by the Mann–Kendall and trend analysis methods based on the hydrological, meteorological and socioeconomic data over the last 50 years in the Tarim River basin. Results show that the runoff in the headstreams increased but that in the mainstreams decreased significantly during the past 50 years. The former is a response to climate change, and the later is due to human activities. The surface runoff in the mainstreams decreased by 41.59, 63.77 and 75.15% in the 1970s, 1980s and 1990s, respectively, as compared to that without being disturbed by human activities in the same period. The main human activities are the irrigated agriculture combined with population increase in the region. As a consequence, the ecosystem in the lower reaches of Tarim River has degenerated, largely owing to inappropriate allocation of water resources.     

Examining 20th century water quality and ecological changes in the Lake of the Woods, Ontario, Canada: A paleolimnological investigation

Comparisons between diatom assemblages preserved in modern and pre-industrial sediments were made to provide a lake-wide paleolimnological assessment of environmental change in 17 sites located throughout the Ontario portion of the Lake of the Woods (LoW). Diatom changes were consistent across all sites, although the magnitude of these changes varied along a trophic gradient (i.e., main channel sites versus isolated bays). The most notable taxonomic shift was towards a higher relative abundance of small, centric Cyclotella taxa and other planktonic, pennate diatoms (e.g., Asterionella formosa, Fragilaria crotonensis) in the modern sediments, with corresponding lower relative abundances of heavily silicified Aulacoseira taxa and small benthic Fragilaria taxa. To aid in determining whether changes in nutrients can explain the diatom trends, weighted-averaging partial-least-squares (WA-PLS) techniques were used to develop a diatom-based inference model to reconstruct changes in total phosphorus (TP) concentrations. Diatom-inferrred TP (DI-TP) reconstructions revealed that 88% of the sites showed either no change or a slight, but not significant decline in DI-TP since pre-industrial times. Diatom-based inferences suggest that TP concentrations at many sites in the Ontario portion of the LoW were moderately elevated in nutrients prior to any major human disturbances (i.e., pre-1850). Results suggest that substantial increases in temperature over the last few decades, and the associated changes to ice cover and water column properties, have likely exacerbated the effects of existing stressors on the system and were key factors influencing a lake-wide restructuring of the diatom communities over the past ca. 150 years.