NeStRes – Model for Operation of Non-Strategic Reservoirs for Irrigation in Drylands: Model Description and Application to a Semiarid Basin

Water availability in dry inhabited environments has usually been promoted by large strategic reservoirs, but small non-strategic ones, built by farmers and communities, are unable to cope with long term droughts and inappropriate for human supply. Nevertheless, small reservoirs promote water spatial distribution and play a major role for livelihood in rural areas. To fill the gap of operation methods for non-strategic reservoirs used for irrigation where water is a limiting factor, the NeStRes model was developed. The model is composed of three modules: i) hydrological: to define the reliability of water withdrawals from the reservoir; ii) agricultural: to simulate crop production based on water availability; iii) economic: to compute the possible income from irrigated agricultural crops. NeStRes was applied to 91 reservoirs of the semiarid Banabuiú River Basin – BRB, Brazil. The simulations indicated that the maximum income from the cultivation of maize is obtained when the reservoirs are intensely used, drying completely in one to two thirds of the time. Adoption of a fixed reliability level of daily water supply (54%, in the BRB) generates at least 85% of the maximum possible income for all simulated reservoirs. This model application suggests a paradigm change in the operation of small non-strategic reservoirs in drylands: to use water for crop production and save the revenue, instead of saving water, which is susceptible to evaporation. Although high reliability level is desired for human supply by strategic reservoirs, non-strategic ones can be more intensely explored to generate income from irrigated agriculture in drylands.

     

Water–food–energy nexus in Chile: the challenges due to global change in different regional contexts

This paper modifies the traditional representation of the water–food–energy (WFE) nexus by emphasizing the flows or influences between components. This allows a better representation of the dynamic nature of the WFE nexus in response to global change drivers. It applies a conceptual figure to synthesize the status and future challenges of the nexus in four regions of Chile that are currently under pressure due to climate variability, relative water scarcity and strong competition for water from different sectors.     

Assessment of the Irrigation Advisory Services’ Recommendations and Farmers’ Irrigation Management: A Case Study in Southern Spain

The Local Irrigation Advisory Services (LIAS) carry out essential work to achieve an efficient use of irrigation water at field and irrigation scheme level, which is crucial in Mediterranean irrigation systems. However, it is unusual to find agronomic and economic assessments of LIAS advice. In this work, the LIAS operating in the Genil–Cabra Irrigation Scheme (southern Spain) was evaluated during the first 5 years of its advice. Acceptance by farmers of the LIAS recommendations was evaluated by using agronomic indicators, such as ARIS (Annual Relative Irrigation Supply). ARIS_LIAS (actual irrigation applied v. recommendation of LIAS) with values ranging from about 0.23 for wheat and sunflower, and 0.94 for maize, also detecting a high variability between farmers, which indicated a scant acceptance of the LIAS recommendations. The economic evaluation of irrigation was made through two economic indicators, Irrigation Water Productivity (IWP) and Irrigation Water Benefit (IWB). IWP values varied significantly between different crops: around 0.23 € m⁻³ in wheat, sunflower and maize, about 0.53 € m⁻³ in cotton and sugar beet, and values higher than 2.0 € m⁻³ in garlic, for optimal irrigation schedules. For IWB, trends were similar, emphasizing the low IWB values in wheat and sunflower (average values of 0.06 and 0.13 € m⁻³, respectively). Consideration of these economic indicators by LIAS could not only help to obtain more suitable and economically profitable irrigation schedules, but also contribute towards a greater acceptance of advisory services by farmers, by shifting the emphasis from maximizing production to maximizing irrigation profitability.     

Winds of change – Predicting water-based recreationists' support and opposition for offshore wind energy development in the Great Lakes

This study examined the factors influencing water-based recreationists' perceptions of support and opposition towards off-shore wind energy development (OWD) on Lake Erie. Much of the proposed or future Lake Erie OWD infrastructure may either be within or adjacent to public lands, waters, and protected areas, raising concerns about the potential environmental and social impacts upon recreation stakeholders. The limited body of OWD research within the United States has suggested there are numerous factors that may influence overall perceptions of support and opposition such as political orientation and beliefs in climate change. Moreover, recent research has proposed that the perceived recreation impact of OWD may be the most important predictor of support and opposition. This study confirmed this premise and found the perceived recreation impact of OWD to be the strongest predictor of support. Results of a multiple linear regression suggested that political orientation (β?=?0.135), beliefs in the anthropogenic causation of climate change (β?=?0.207), beliefs in the occurrence of climate change (β?=?0.213), and the perceived recreation impact of OWD among water-based recreationists (β?=?0.439) were significant predictors of support for OWD on Lake Erie (R²?=?0.46). Study findings corroborated previous research which suggested that regional climate change beliefs and political attitudes may influence support for OWD. From a policy and management standpoint, study results highlight the importance of assessing and communicating recreation experience and use impacts when planning, developing, and managing OWD and related decisions in the United States.     

Are hydropower and irrigation development complements or substitutes? The example of the Nam Ngum River in the Mekong Basin

Hydropower and irrigation developments to address rising demand for food and energy are modifying the water balance of the Mekong Basin. Infrastructure investment decisions are also frequently made from a sub-catchment perspective. This paper compares river flows with irrigation development stages in the Nam Ngum sub-basin where the potential for irrigation and hydropower expansion is largely untapped. It shows that full hydropower development in this basin allows irrigation water use to triple, even as it reduces competition with environmental flow requirements. The implications for the wider Mekong are, however, unclear, particularly given uncertainty over parallel transformations elsewhere in the basin.     

The 1997 United Nations Convention on the Law of Non-navigational Uses of International Watercourses: what contribution to the development of the Water Charter for the Volta Basin?

In 2007, the six riparian countries of the Volta Basin adopted the Convention on the Status of the Volta River and the Establishment of Volta Basin Authority (Volta Basin Convention). This legal framework is strongly inspired by the United Nations Convention on the Law of Non-navigational Uses of International Watercourses (UNWC). However, the Volta Basin Convention merely states the major international river management principles without specifying either the terms or the procedures for their implementation. This article examines the potential contribution of the UNWC provisions to the development of a water charter.     

Distributive hydraulic engineering,cross-scale landscape planning,and climate change resilience: On the water-adaptive strategy in the Huai'an–Yangzhou Section of China's Grand Canal

Water system plays a key role in the coupled human-nature system, and ancient people's experiences to build a water-adaptative way of life still shed light on human's pursuit for climate resilience today with their innate traditional ecological wisdom. In this paper, taking the Huai'an-Yangzhou Section of China's Grand Canal, and particularly its hydraulic engineering system as an example, we show the system's success in addressing the multi-dimensional challenges in a historical geographical context, as well as its landscape-shaping power across the entire lower Yellow-Huai River Basin up until today. Therefore, we argue that the system is not merely a hydraulic engineering project, but a cross-scale adaptive strategy that has deeply impacted generations of people's way of livelihood with its intrinsic resilient nature. We attribute the success to the advantages brought about by the “distributive hydraulic engineering” approach, which is reflected in the ancient Grand Canal-management, over the “master-structure dependent” approach which appears to be the common practice in modern hydraulic engineering. For testing the hypothesis, we build complex system models representing the two approaches with the Qingkou Hydraulic Nexus as an example, and by running long-term simulation, we evaluate the performance of the two approaches with respect to long-term resilience. We show from a complex network perspective that the former has significant flexibility advantages, and outperforms the former in multi-goal fulfillment capacities and long-term resilience especially under a low-tech, tight resource constraints condition. We conclude the paper with discussions on the implications of the findings, and argue that though with limitations, the traditional ecological wisdom as reflected in the Grand Canal case, with its holistic approach and flexibility design, still sheds lights on today's large-scale hydraulic engineering projects that pursue a resilient solution for long-term adaptive survival for the mankind.     

Water Quantity and Quality in the Zerafshan River Basin: Only an Upstream Riparian Problem?

In discussing the 1997 UN Watercourses Convention, McCaffrey (1998) gave a theoretical example of the late-developer problem. This paper complements that theoretical example with a real case study of the Zerafshan basin in Central Asia. While McCaffrey addressed the water quantity issue in his example, the focus here also includes water pollution. The aim of the paper is to analyze some of the provisions of the mechanisms in the field of international water law—the Helsinki Rules and the UN Watercourses Convention—for water quantity and quality aspects, as well as to provide an insight into the basin regarding these two aspects.     

Large variation in periphyton δ13C and δ15N values in the upper Great Lakes: Correlates and implications

Stable isotope ratios of carbon (δ¹³C) and nitrogen (δ¹⁵N) are frequently used to examine food web structure. Despite periphyton's importance to lake food webs, little is known about spatial variation of periphyton δ¹³C and δ¹⁵N values in the Great Lakes. We present periphyton δ¹³C and δ¹⁵N values from 28 sites the upper Great Lakes, including Lake Superior, the north shore of Lake Michigan, and Green Bay. We also examined variation in periphyton isotope values relative to several water quality parameters (TP, TN, TKN, NO₃⁻, K_d) as well as periphyton C:N. There was a large range in both periphyton δ¹³C (range = 13.5‰) and δ¹⁵N (range = 10.2‰) among sites. Periphyton in more eutrophic sites had more depleted δ¹³C and more enriched δ¹⁵N compared to more oligotrophic sites. Our finding of high variability in periphyton isotope values in the Upper Great Lakes has implications for stable isotope-based reconstructions of food web structure.     

Participatory and decentralized water resources management: challenges and perspectives for the North Paraíba River Basin committee - Brazil

The Brazilian Water Resources Policy (Law 9433/1997) establishes participatory and decentralized management, involving civil society, water users and governmental bodies, with the basin committees as the basis of this process. Fifteen years after its implementation, it is possible to perceive accomplishments, but, at the same time, there are some difficulties in regards to the operation of the basin committees in the country. Considering the North Paraíba River Basin - which is completely included in the State of Paraíba, Northeastern Brazil, and presents great social and economic importance for the state - this article analyzes the process of formation, installation and functioning of its Basin Committee (CBH-PB), focusing on its composition, the reasons for the mobilization and demobilization of its members, the intra-relations between segments, and the inter-relations between the CBH-PB and other entities of the State Water Management System (the Water Executive Agency and the State Water Resources Council). The level of decentralization and the quality of participatory management (as it is being performed at the CBH-PB) are discussed and guidelines are suggested in order to allow greater effectiveness to the committee.     

Our current understanding of lake ecosystem response to climate change: What have we really learned from the north temperate deep lakes?

Climatic change is recognized as an important factor capable of influencing the structural properties of aquatic ecosystems. Lake ecosystems are particularly sensitive to climate change. Several long time-series studies have shown close coupling between climate, lake thermal properties and individual organism physiology, population abundance, community structure, and food-web structure. Understanding the complex interplay between climate, hydrological variability, and ecosystem structure and functioning is essential to inform water resources risk assessment and fisheries management. The purpose of this paper is to present the current understanding of climate-induced changes on lake ecosystem phenology. We first review the ability of climate to modulate the interactions among lake hydrodynamics, chemical factors, and food-web structure in several north temperate deep lakes (e.g., Lake Washington, Lake Tahoe, Lake Constance, Lake Geneva, Lake Baikal, and Lake Zurich). Our aim is to assess long-term trends in the physical (e.g., temperature, timing of stratification, and duration of ice cover), chemical (e.g., nutrient concentrations), and biological (e.g., timing of the spring bloom, phytoplankton composition, and zooplankton abundance) characteristics of the lakes and to examine the signature of local weather conditions (e.g., air temperature and rainfall) and large-scale climatic variability (e.g., ENSO and PDO) on the lake physics, chemistry and biology. We also conducted modeling experiments to quantify the relative effect of climate change and nutrient loading on lake phenology. These modeling experiments focused on the relative changes to the major causal associations underlying plankton dynamics during the spring bloom and the summer stratified period. To further understand the importance of climate change on lakes, we propose two complementary directions of future research. First, additional research is needed to elucidate the wide array of in-lake processes that are likely to be affected by the climate change. Second, it is essential to examine the heterogeneity in responses among different water bodies. The rationale of this approach and its significance for dealing with the uncertainty that the climate signals cascade through lake ecosystems and shape abiotic variability and/or biotic responses have been recently advocated by several other synthesis papers.     

Renovation and Innovation: It’s Time for the Great Lakes Regime to Respond

This commentary reports on a project to explore and evaluate options for Great Lakes governance renewal in anticipation of the 2006–2007 review of the Canada–US Great Lakes Water Quality Agreement (GLWQA). The research included expert interviews and scholarly analysis of governance regimes in 2006, leading to a Great Lakes St. Lawrence River Governance Expert Workshop held in June 2007 (Krantzberg et al. 2007). The two authors have been participants and at times leaders in the institutions this commentary addresses, Krantzberg with the International Joint Commission and Ontario Ministry of the Environment and Manno with the New York Great Lakes Research Consortium and Great Lakes United. Our familiarity with the topic and many of the people involved was helpful in gaining participation and is in itself a rich source of knowledge and experience. In discussing a topic of contemporary controversy, it also understandably can make readers question the objectivity of our assessment. We are also trained in social science scholarship and have taken precautions against biasing the outcomes. This is not intended to be merely a presentation of data. We believe our experience is a net asset in addressing these questions but we leave it to the interested reader to review the reports referenced herein and judge for themselves whether our findings are fairly presented.     

Water Resources Development in the SãTo Francisco River Basin (Brazil): Conflicts and Management Perspectives

Abstract

Water scarcity is matter of growing concern in Brazil, especially in the semi-arid, inland area of the Northeast, where the São Francisco River flows. This paper concentrates on the relations between the concrete experience of water resources development and the remaining demands for efficient water management in that river basin. The emphasis is on its Sub-Middle section, which since 1948 has been the preferential area for irrigation projects and hydropower generation. Recent modifications in the Brazilian legislation provide for a new approach to water resources policy, which is in favor of more decentralized and proactive forms of water management. In spite of such institutional evolution, conservative political groups in the SãTo Francisco River Basin have put obstacles before the transformation of established practices. In addition, there are other structural limitations contributing to hinder the adoption of a more comprehensive framework of water management. Resulting water conflicts have raised increasing demands for proper attention to the social, economic and environmental requirements of the sustainable management of water. The requisites for that go beyond the water question itself because they involve broader political and socio-economic controversies. At the local level, priority must be given to measures aimed at achieving water efficiency and conservation. It is fundamental to address the reduction of human vulnerability to climatic risks and to adopt alternatives of better utilization of water resources     

Participatory Irrigation Management and Transfer: Setting the Guiding Principles for a Sustaining Monitoring & Evaluation System – a Focus on the Mediterranean

A major shortcoming of Participatory Irrigation Management and Irrigation Management Transfer (PIM/IMT) is the absence of Monitoring & Evaluation (M&E) systems that accompany these processes and become a major instrument to correct, improve and learn. Although at the global level some countries have exerted efforts to implement M&E systems, these still present limitations, as the review of the international experiences shows. The Mediterranean situation is even more dramatic since only Tunisia implements an M&E system, whereas Egypt has shyly moved in this direction with a limited practical application. This state of affairs led the authors to develop a set of guiding principles to develop an M&E system to be applied in countries where PIM/IMT is adopted. This paper revises the main international efforts devoted to assess the performance of PIM/IMT and the state of the art of these processes in Southern and Eastern Mediterranean Countries. Moreover, it sets the framework and analyses the main sustaining factors for the development of a new M&E system for these countries.     

Response to “Model assumptions limit implications for nitrogen and phosphorus management”: The need to move beyond the phosphorus = biomass = toxin doctrine

In commentary about our recent model of microcystin production by Microcystis, Stow and colleagues argued our efforts ignored the ecology of the lake system and did not result in identical biomass predictions made by existing models. We provide below responses to their statements and show that their commentary does not refute our model. While all models require assumptions to be made, we reiterate the reproducibility of our model and its potential future value in Adaptive Management.     

When free-riders become the agents for change—migrant fishers,institutional resilience,and adaptive fisheries management in Malawi

Fisheries co-management in Malawi has not achieved the successes anticipated. Mobility of fisherfolk is frequently blamed for the poor effectiveness of local institutions, and this often leads to calls for access limitation. However, recent research in Malawian water bodies suggests that fisher mobility increases livelihood sustainability for all lakeshore residents involved, and is well adapted to these contexts of fluctuating and uncertain fisheries. Therefore, the abilities of fisherfolk to move into and out of different local fisheries can arguably be judged to enhance fisheries resilience overall. In addition to these benefits, we present data from two ethnographic case studies to illustrate the positive impacts that migration has had on some of Malawi's more successful fisheries co-management institutions (known as Beach Village Committees or BVCs).Despite preexisting concerns regarding unsustainable local fishing practices, local stakeholders were unwilling or unable to address these challenges until conflicts with migrant fisherfolk prompted changes. In some cases, the ability of migrants to circumvent BVC regulations has highlighted the BVC's lack of local legitimacy. Additionally, when threatened with losing benefits to “outsiders,” local stakeholders are more willing and able to come together and take corrective action. We therefore argue against policies limiting access to local fisheries as these remove valuable catalysts for adaptive institutional learning in decentralized natural resources management.     

Long-term changes in hypolimnetic dissolved oxygen in a large lake: Effects of invasive mussels,eutrophication and climate change on Lake Simcoe, 1980–2012

Lake Simcoe has been influenced by multiple environmental drivers over the past decades, especially by reductions in phosphorus (P) loading, climate change, and invasive species such as dreissenid mussels (DM) which became firmly established in 1996. We examined the cumulative impact of these drivers on the volume-weighted hypolimnetic dissolved oxygen concentration (VWHDO) below 18?m at station K42 in Kempenfelt Bay during ice-free seasons from 1980 to 2012. Hypolimnetic DO depletion began in early spring when thermal stratification was observable but weak and continued throughout the ice-free season until cooling sufficiently lowered water column stability. In comparison to the pre-DM invasion period (1980–1995), mean annual VWHDO_init was 2.4?mg?L^?1 higher in the post-DM period (1996–2012), VWHDO_min was 1.54?mg?L^?1 higher and the mean duration of the depletion period (L) was 16?days longer. Mean DO depletion rate (DR) and temperature adjusted DO depletion rate (DR_adj) were slightly lower (7% and 5%, respectively) after 1996. P controls and DM had a positive effect on VWHDO, presumably by lowering productivity and diverting organic matter away from the hypolimnon. However, longer L apparently offset improvements in VWHDO_min. If lengthening of L associated with regional warming continues, then additional efforts to reduce P loads will be necessary to achieve the goal of maintaining VWHDO_min above the target of 7?mg?O₂?L^?1 throughout the summer and fall.     

A Site-Specific Index to Control the Total Effect of Point Sources Discharges and to Achieve ‘Good Chemical Status’ in Effluent Dependent and Effluent Dominated Water Bodies: Application on Ergene River Basin

In this study, a simple site-specific index entitled “Discharge Effect Index (DEI)” was developed to rank and control the potential risks of point sources discharges effects to Ergene River and its branches. The basin is densely populated and heavily industrialized and all the water bodies in the basin are effluent-dependent or dominated. A case study is presented to assess the most important pollution parameters in the water bodies and to evaluate relationship between toxicity to Vibrio fischeri organism and chemical parameters in receiving waters. The aim of the study was to develop a simple site-specific control approach for seriously polluted and effluent-dominated water bodies in this developing country, Turkey and guide to decision makers about controlling point sources pollution in such heavily industrialized basins and achieve ‘good chemical status’ in ambient waters. The results of the study should be useful to encourage site-specific policies on point sources pollution especially to who had such these pollution problems in their receiving water bodies.