Human-water Interactions Research Articles

Assessing the Riparian Squeeze in the Greater Bay Area based on multisource data

ABSTRACT Riparian zones provide critical services for human societies and ecological systems, yet rapid urban expansion exerts substantial pressure on these interfaces, leading to global-scale consequences including biodiversity loss, pollution, water supply stress, and escalated flood risks. To address the imperative of assessing human–water interactions in urban environments, this study introduces the Riparian Squeeze Index (RSI) framework. Using the Greater Bay Area as a case study, we developed a multi-dimensional measurement system that integrates spatial distances between waterbodies and infrastructure with demographic, economic, and environmental metrics. Analysis of 392,583 sample points revealed a median distance of 55.13 m between waterbodies and nearby infrastructure, with significant spatial heterogeneity across the region. While riparian zones occupy 37% of the total area, they contain 57% of points of interest and 59% of the population, demonstrating concentrated human activity near waterbodies. The RSI results indicate a development-vulnerability paradox where less-developed cities show higher socioeconomic vulnerabilities despite lower spatial pressure. This research provides a standardized tool for evaluating human pressure on riparian zones across diverse geographical contexts, offering valuable insights for sustainable urban planning and water resource management. The framework's adaptability makes it applicable for similar assessments in other urban agglomerations worldwide.

Quantifying the value of stakeholder-elicited information in models of coupled human–water systems

ABSTRACT Causal loop diagrams (CLDs) based on expert or stakeholder inputs inform the structure of socio-hydrological models (SHMs). Here, we explore the sensitivity of SHMs, a category of system dynamic models that simulate human–water feedback to varying degrees of stakeholder inputs. We develop three alternative CLDs to understand the dynamics of a large multi-purpose reservoir in southern India. CLD1 is a conventional water balance-based reservoir model that simulates surface water availability in the region. CLD2 incorporates reservoir operators’ judgement and groundwater pumping. CLD3 further incorporates adaptive behaviour of water users by adjusting demand in response to droughts. CLD2 and CLD3 were developed via semi-structured interviews. SHM outputs were validated via reservoir storage, groundwater levels in the command area, and ratio of surface to groundwater for farming during 2000–2013. SHM3 outperformed SHM1 and SHM2, especially in the post-drought period, highlighting the importance of testing different SHM structures to better understand human–water interactions under extreme conditions.

Human-water interactions associated to cercarial emergence pattern and their influences on urinary schistosomiasis transmission in two endemic areas in Mali

BackgroundMali is known to be a schistosomiasis-endemic country with a limited supply of clean water. This has forced many communities to rely on open freshwater bodies for many human-water contact (HWC) activities. However, the relationship between contact with these water systems and the level of schistosome infection is currently receiving limited attention. This study assessed human-water interactions including cercarial emergence pattern and their influences on urinary schistosomiasis transmission in two communities in the Kayes district of Mali.MethodsWe carried out a parasitological study first in children in September 2021, then a cross-sectional study of quantitative observations of human-water contact activities in the population, and finally a study of snail infectivity at contact points in September 2022. The study took place in two communities, Fangouné Bamanan and Diakalèl in the Kayes region of western Mali. The chronobiological study focused on cercarial release from naturally infected snails. Released cercariae were molecularly genotyped by targeting the cox1 region, and the ITS and 18S ribosmal DNA gene (18S rDNA) regions of the DNA. Links between sociodemographic parameters, human water-contact points and hematuria were established using multivariate statistical analysis or the logistic regression model.ResultsThe main factor predisposing the 97 participants to water contact was domestic activity (62.9%). Of the 378 snails collected at 14 sampling sites, 27 (7.1%) excreted schistosome cercariae, with 15.0% (19/126) at Fangouné Bamanan and 3.3% (8/252) at Diakalel. The release of Schistosoma cercariae shows three different patterns in Fangouné Bamanan: (i) an early release peak (6:00–8:00 AM), (ii) a mid-day release peak (10:00 AM–12:00 PM) and (iii) a double peak: (6:00–8:00 AM) and (6:00–8:00 PM) cercariae release; and two release patterns in Diakalel: early release (6:00–8:00 AM) and (ii) mid-day release (12:00–2:00 PM). All cercariae released during early diurnal (6:00–8:00 AM) or nocturnal emission patterns (6:00–8:00 PM) were hybrids parasite having an cox1 S. bovis or S. curassoni associated with an ITS and 18S rDNA of S. haematobium while the cercariae released during diurnal, or mid-day patterns (8:00 AM–6:00 PM) were pure S. haematobium.ConclusionsOur study showed that domestic activity is the main source of exposure in the Kayes region. Two and three cercariae emission patterns were observed at Diakalel and Fangouné Bamanan respectively. These results suggest that the parasite adapts to the human-water contact period in order to increase its infectivity.Graphical

Water on the mind: Mapping behavioral and psychological research on water security

AbstractWater security as a concept recognizes the profound connections between the physical and social aspects of water. Yet, water security research features limited perspectives from two disciplines directly concerned with human behavior—the behavioral and psychological sciences. This review aims to characterize the main areas of research on water (including floods and droughts) which do feature concepts and methods from the behavioral and psychological sciences, discuss knowledge gaps, and draw attention to their potential to contribute to water‐related research. Bibliometric mapping of published water research identifies five research clusters and associated sub‐clusters: risk perception and flood, climate change and drought, water quality and water conservation, drinking water and bottled water, and mental health and WASH. A summary of research in each cluster and sub‐cluster highlights the application of many conceptual frameworks and behavioral determinants associated with water‐related behavior. Few articles focus on the role of governance or structural factors, and studies in low‐ and middle‐income countries are less represented in some clusters. The discussion considers the scope to apply higher level organizing frameworks for structuring behavioral and psychological science applications in water security and for exploring synergies with the physical and wider social sciences. In conclusion, further engagement with behavioral and psychological science within, between, and beyond the clusters identified here, could potentially deepen understanding of human–water interactions and enhance the design of measures to promote water security.This article is categorized under: Human Water > Water Governance Human Water > Water as Imagined and Represented Science of Water > Water and Environmental Change

Key drivers and pressures of global water scarcity hotspots

Global freshwater resources are vital to humanity and Earth’s ecosystems, yet about one third of the global population is affected by water scarcity for at least one month per year. In these areas, the overuse of freshwater resources can lead to the threat of depletion, marking them as the global ‘water scarcity hotspots’. This study combines outputs from a global hydrological model (PCR-GLOBWB 2) with an extensive literature search to provide a comprehensive intercomparison of the key drivers, pressures, states, impacts and responses (DPSIR) that shape the water gap between water demand and availability at the most important water scarcity hotspots worldwide. Hydroclimatic change, population growth, and water use for the industrial, municipal and agricultural sectors are the most important driving and pressuring forces on the water gap, affecting both water quality and quantity. These drivers and pressures have been showing increasing trends at all hotspots, which is concerning for the future development of the water gap. Additionally, we identify and characterize seven clusters of hotspots based on shared DPSIR patterns, revealing their common mechanisms. Our work highlights the diversity of water scarcity related issues at hotspots, especially the variety of impacts involved and governmental responses in place. The results of our DPSIR analysis provide valuable insights for building causal networks representing water gap dynamics at the hotspots. They form a foundation for conceptual models that illuminate human-water interactions, trade-offs, and synergies at the hotspots, while guiding policymakers in addressing the multifaceted challenge of closing the water gap.

Understanding Water Governance in the Central Rift Valley of Ethiopia: Governance Framework, Coherence and Practices.

Water governance demands multi-sector participation beyond the state; and, appropriate laws, policies, regulations, and institutions need to be developed and put in place for sustainable use of water resources. A good water policy, a critical and integral instrument of water governance, guides water use schemes and ensures equitable water distribution among users. The Ethiopian Central Rift Valley (CRV) is rich in water resources, but these water resources are currently under severe strain owing to an imbalance in human-water interactions. This study examined the state of water resources governance framework, policy coherence, actors' engagement and transparency, accountability, and participation in irrigation water supply in the CRV of Ethiopia. Key informant interviews (KII), focused group discussions, and document reviews were used to gather data for the study. The NVivo 11 program was used to organize, code, and analyze the data. The results revealed that water resources governance practices such as water allocation and apportionment, water resources protection, and conservation activities were inappropriately exercised. Water resources management policy mechanisms were not fully put in place. Lack of coherence in water policy implementation, absence of clear roles and responsibilities of stakeholders, absence of transparency and accountability in irrigation water service delivery, and lack of meaningful participation of key actors in water governance decision-making were observed. As a result, over-abstraction, deterioration of buffer zone areas, and chemical erosion from surrounding farming are attributed to the reduction in water volume and quality in the CRV. These challenges have influenced aquatic ecosystem services and threaten the livelihoods of the surrounding communities. Hence, reforms relating to policy coherence and enforcement, stakeholder engagement, water distribution strategies, and the implementation of water governance principles must be given adequate emphasis.

Water as elemental medium and heritage: The case of Sangyuanwei Polder embankment system

This paper argues that elemental media studies, which emphasize the entanglements between humans and non-humans, can offer new avenues for addressing the challenges faced by post-humanist heritage studies. Due to the importance of tourism for heritage revitalization, this paper examines the limitations of the local tourism industry’s understanding of the water element in the context of the tourism plan of the Sangyuanwei Polder Embankment System, particularly the neglect of the destructiveness of water. It also investigates human-water interactions in the history of SPES through elemental analysis, examining how water as a medium of life has inspired human affects, feelings, actions, as well as facilitated the transformation of and communication with water through the development of water-related engineering and social institutions. By focusing on the affective aspects of the elements, as well as revisiting the histories and local knowledge, elemental aesthetics derived from elemental analysis aims to reconnect humans to the elements as media of life, thus allowing for the initiation of dialogs with heritage management and tourism. The elemental aesthetics of water for the life of heritage sites aiming at flood control has often included the destructive characteristics of water, as well as the complex feelings of fear, awe, reverence, and dedication that it stirs. Based on this, this paper also points out a possible new orientation for the future development of water-related heritage sites.

A lighthouse to future opportunities for sustainable water provided by intelligent water hackathons in the Arabsphere

Complex water-related challenges hunger, poverty, climate change, biodiversity, land-use change, desertification agriculture, industrialization, urbanization, human population, and hygiene, need wise and urgent actions to overcome them. Globally, many drivers such as the U.S.-Chinese competition, the Russo–Ukrainian war, food security, pandemics, and human overpopulation, have water-related impacts. Freshwater is a truly complex interdisciplinary topic that requires innovative intelligent-inclusive ideas to reconcile limited water resources with expanding water demands. The article explores how artificial intelligence (AI) could rethink human-water interactions, remake water practices, humanize water science, and enhance daily water life. The Global Goals could be viewed as an integrated framework of human effort to face pressing today’s issues and to formulate a more sustainable and better world. Goal 6 (SDG 6 “sustaining water”) devoted to sustaining water and related actions for all humans is the skeleton of global goals (GGs). The Arabsphere faces severe water quality, quantity, and practice challenges to ensure the smooth achievement of global goals (GGs). Compared with the whole world and its main regions, the overall water stress indicator in the Arabsphere is greater than 100% (critical). This article explores how applied intelligence could be strengthened to achieve Goal 6, focuses on the “water stress” indicator, and how to ensure a sustainable water future (SWF) in the Arabsphere. The Intelligent Water Hackathon is a collaborative open science event. The hackathon was designed to mitigate water stress (WS) in the Arabsphere. The hackathon process involves four main phases: problem identification, team building, solution proposing, and presentation. The paper concludes hackathons could be a valuable process for the water researchers’ community to generate new and creative ideas and collective knowledge. Hackathon events could mitigate water stress, strengthen community engagement, and improve water resources outcomes. In closing, artificial intelligence (AI) methodologies are efficient providers to mitigate water stress, scarcity, and related risks. A future-driven Arab water vision based on artificial intelligence (AI) and intelligent water systems (IWSs) should be prioritized.

Understanding human-water nexus in a floodplain district of the Brahmaputra Valley, India: An integration of socio-hydrological and rural hydrological approaches

The present study delves into the complex human-water relationships that have a significant impact the concerned socio-cultural practices and economic livelihoods. The primary objective of this research is to explore and comprehend the dynamic relationships between local communities and water systems in the villages in Nagaon district, situated in the floodplain of the Brahmaputra Valley, India. By integrating socio-hydrology and rural hydrology, the study seeks to gain a holistic understanding of water usage patterns, land management practices, and human adjustments to the district's diverse hydrological environment. To achieve its objectives, the research adopts a comprehensive methodology involving extensive field visits, household and oral surveys, participatory rural appraisal, focus group discussions, rapid rural appraisal, rapid assessment procedure, and hydro-pattern analysis. The findings of the study reveal the profound influence of water on the socio-cultural and economic foundations in the rural areas of Nagaon district. Local communities have displayed resilience by adapting with their traditional strategies in response to changes in field and wetland hydrology. The shift from river-based water usage to ring wells, tube wells, electric motor pumps and diesel water pumps has altered human-water interactions and thus, contributed to the degradation of once-revered rivers. The study's significance lies in informing sustainable water management and addressing complex human-water interactions for the district and beyond. The interdisciplinary approach promotes community well-being while preserving the ecological integrity of the area, with global implications for water resource management.

Construction of River Health Assessment System in Areas with Significant Human Activity and Its Application

The assessment of river health holds paramount significance in diagnosing the conditions of river water environments, and its research serves as a crucial foundation for the functional management and restoration of rivers. We discuss the concept and assessment criteria of health in areas characterized by significant human activity. Utilizing the “over the riverbank” and “under the riverbank” quantification criteria as the framework, a comprehensive river health assessment index system is developed, encompassing seven aspects (riparian zone condition, pollution discharge condition, human–water interaction, physical structure, water environment, water ecology, and socio-economic service function) and 35 indicators. This study introduces the River Health Index (RHI), specifically tailored for regions with significant human activity, facilitating the quantitative assessment of river health status and precise calculation of the River Health Index in these areas. The research employs the RHI to assess the health condition of the Cangzhou section of the Qingliang River in China. The results indicate that the Qingliang River is in a suboptimal state of health, with the key limiting factors being the aspects of “water environment” and “water ecology”. The research demonstrates that the proposed river health assessment system for areas with significant human activity effectively reflects the objective reality of the Qingliang River, exhibiting a high level of reliability and applicability.

Spatial and temporal assessment of human-water interactions at the Inle Lake, Myanmar: a socio-hydrological DPSIR analysis

Freshwater resources as a key aspect of socio-economic development, provide a large number of services in human and environmental systems. Nevertheless, human appropriation of these water resources and the modification of landscapes lead to potential threats on water availability and quality from local to global scales. The Inle Lake in Myanmar is an economically, traditionally, and ecologically important freshwater ecosystem that faced severe degradation from the 2000s. In its catchment area, a Driver-Pressure-State-Impact-Response (DPSIR) framework is applied for an assessment period of 30 years from 1990 to 2020. The analysis results are complemented with a socio-hydrological survey, water quality assessment, a land use classification based on ground truth and satellite data, and hydrologic models. The resulting land use changes, − 13% forest, + 13% agriculture, and + 5% urban areas, lead to increased water yield, decreased evapotranspiration, and increased sediment yield. Together with other drivers and pressures such as climate change and anthropogenic pollution, these human activities are major threats for freshwater resources and the ecosystem. However, the existing awareness of the local population for the environmental degradation is obstructed by national and international crises and responses to negative developments can accelerate degradation if they are unplanned and short-term solutions. Our study shows that environmental degradation processes have a complex nature and can only be tackled in a coordinated way with a long-term perspective. DPSIR is a suitable approach to assess human-water dynamics and disentangle the complex interconnectedness of social and environmental systems in freshwater ecosystems, even in data-scarce regions.

System Archetypes Underlying Formal-Informal Urban Water Supply Dynamics

Contrary to developed countries, developing countries have been observed to have an increased reliance on a diversity of water supply options to meet their daily demands, where formal supply systems are incapable of fulfilling the daily needs of consumers. In filling a demand-supply gap, informal supply systems are increasingly being associated with issues of long-term sustainability, higher consumer cost, and inequity. Emerging formal-informal dynamics in developing countries require a thorough understanding of complex human-water interactions for policy direction, in order to best support the advancement of urban water sustainability. Accordingly, system archetypes offer a platform to explain the behaviors of complex systems. This paper identifies common system archetypes that define urban waterscapes in the developing world. In this way, Causal Loop Diagrams (CLDs) are used to present relationships and identify common archetypes that define the complexity of urban water supply systems in Hyderabad, Pakistan. These archetypes include ‘fixes that fail’, ‘shifting the burden’, ‘limits to growth/success’ and ‘growth and underinvestment’. These archetypes demonstrate that increases in formal infrastructure capacity and the number of informal suppliers to increase supply reliability are symptomatic solutions, restrained by financial and technical resources, and thus have unintended consequences. Further, a number of policy instruments are discussed as leverage points to achieve financial sustainability of formal systems. This paper emphasizes the need of a policy framework for informal supply system in national and regional water policies to ensure its service reliability as a short to medium term solution.

To which extent are socio-hydrology studies truly integrative? The case of natural hazards and disaster research

Abstract. Given the recent developments in socio-hydrology and its potential contributions to disaster risk reduction (DRR), we conducted a systematic literature review of socio-hydrological studies aiming to identify persisting gaps and discuss tractable approaches for tackling them. A total of 44 articles that address natural hazards or disasters were reviewed in detail. Our results indicated that: (i) most of the studies addressed floods, whereas few applications were applied to droughts and compound or multi-hazard events; (ii) none of the reviewed articles investigated interactions across temporal and spatial scales; (iii) there is a wide range of understandings of what “social” means in socio-hydrology; (iv) quantitative approaches were used more often in comparison with mixed and qualitative approaches; (v) monodisciplinary studies prevailed over multi- or interdisciplinary ones; and (vi) one-third of the articles involved stakeholder participation. In summary, we observed a fragmentation in the field, with a multitude of social and physical components, methods, and data sources being used. Based on these findings, we point out potential ways of tackling the identified challenges to advance socio-hydrology, including studying multiple hazards in a joint framework and exploiting new methods for integrating results from qualitative and quantitative analyses to leverage the strengths of different fields of knowledge. Addressing these challenges will improve our understanding of human–water interactions to support DRR.

Streamflow droughts aggravated by human activities despite management

Human activities both aggravate and alleviate streamflow drought. Here we show that aggravation is dominant in contrasting cases around the world analysed with a consistent methodology. Our 28 cases included different combinations of human-water interactions. We found that water abstraction aggravated all drought characteristics, with increases of 20%–305% in total time in drought found across the case studies, and increases in total deficit of up to almost 3000%. Water transfers reduced drought time and deficit by up to 97%. In cases with both abstraction and water transfers into the catchment or augmenting streamflow from groundwater, the water inputs could not compensate for the aggravation of droughts due to abstraction and only shift the effects in space or time. Reservoir releases for downstream water use alleviated droughts in the dry season, but also led to deficits in the wet season by changing flow seasonality. This led to minor changes in average drought duration (−26 to +38%) and moderate changes in average drought deficit (−86 to +369%). Land use showed a smaller impact on streamflow drought, also with both increases and decreases observed (−48 to +98%). Sewage return flows and pipe leakage possibly counteracted the effects of increased imperviousness in urban areas; however, untangling the effects of land use change on streamflow drought is challenging. This synthesis of diverse global cases highlights the complexity of the human influence on streamflow drought and the added value of empirical comparative studies. Results indicate both intended and unintended consequences of water management and infrastructure on downstream society and ecosystems.

Improvement of socio-hydrological model to capture the dynamics of combined river and urban floods: a case study in Lower Kelani River Basin, Sri Lanka

Identifying the complex patterns of human-flood interactions over longer periods of time is very important in floodplain management activities. The recently introduced socio-hydrology (SH) model contributes to capture these long-term behaviors of human-flood systems. This model can be utilized to explain the long-term dynamics of human-water interaction in floodplains. The current SH model exclusively illustrates the impact of river floods on floodplain communities. However, in some river basins, urban floods (due to high intensity rainfall) are dominant, whereas in other river basins, both river floods and urban floods influence the dynamics of the system. It is often difficult to distinguish the type of flood from actual local disaster data sets. In this study, we proposed an improvement to the existing SH model to capture the dynamics of both river floods and urban floods based on a case study from the Lower Kelani Basin, Sri Lanka, using simulated historical flood damages. The improved model was applied to capture flood damages in the target watershed, and the results further emphasize the importance of flood risk perception in flood damage reduction.

Assessing the Operational Performance and Stakeholders’ Perceptions on the Management of Three Irrigation Projects in Kano, Nigeria

A study was conducted to assess the level of operational performance and stakeholders’ participation in, and perceptions on, the management of three major irrigation projects in Kano State, Nigeria (Kano River Irrigation Project KRIP, Watari Irrigation Project WIP and Tomas Irrigation Project TIP). The study uses questionnaire, site visit and focus group discussions during the 2019/2020 irrigation season to generate crucial information related to the hydraulic infrastructures and operational performances. The study identified some problems related to operational performance affecting the three irrigation projects including illegal water use, faulty water conveyance infrastructures and conflict among water users and between water users and managers. Moreover, the study observed that a continuous flow water allocation method is being used in all three irrigation projects, leading to poor water allocation performance. Based on this, the study recommends a rotation water allocation method. About 50% of the total water users from KRIP, WIP and TIP do not participate in the maintenance of the irrigation infrastructures. The study revealed that the majority of the farmers have no confidence in water managers’ competence whereas water managers accused irrigators to lack enthusiasm and provided evidence of unlawful water usage as about 12, 8 and 39% of the irrigators from KRIP, WIP and TIP admitted to having been lifting water using pumps which have been considered as illegal since their farms were initially considered non-irrigable. Some of the underlying issues that led to these problems include lack of sensitization and awareness campaigns, seminars and workshops to facilitate farmers’ involvement in the maintenance of irrigation infrastructures. This can be achieved through sensitization and awareness campaigns to enlighten farmers on resolving conflicts, efficient use of limited water, and facilitating water users’ participation in irrigation management activities such as agency-farmer joint management. If such dialogue programs do not bring an end to these problems, other law enforcement measures such as legal actions need to be deployed. It is, therefore, recommended that the existing irrigation project management strategies need to be changed with new ones that encourage sensitization campaigns, law enforcement and participation. Also, in-depth coupled human-water interaction studies (socio-hydrology) need to be conducted to gain insights and propose solutions that could lead to sustainable irrigation system management and operation.

Comprehensive assessment of water environmental carrying capacity for sustainable watershed development

Due to insufficient understanding of human-water interaction, many water-related problems arise in watersheds, posing severe threats to the sustainability of watershed development. Although water environmental carrying capacity (WECC) is a powerful tool to support sustainable development of watersheds, few studies considered aquatic ecological factors and uncertainty in indicator values, leading to losses of sample information in the evaluation of WECC. This paper developed a systematic framework for comprehensive WECC assessment that included the indicator system and a novel variable fuzzy pattern recognition (VFPR) approach. The WECC index system incorporated aquatic ecological factors, and addressed uncertainties associated with the indicator values. The proposed VFPR-based assessment model could realize successive evaluation to retain more original information of the sample and distinguish similar result values by treating the sample as having a continuous degree of membership instead of the traditional point form. In addition, it could be more adaptable to various circumstances including extreme cases, and closely reflect the impacts of indicator changes on the results. The established evaluation framework has been applied to Dongjiang River Basin in Guangdong Province. The spatial differences and main influencing factors of WECC in the study area were analyzed. Results show that 50% and 16.7% of the sub-regions in the study area would be subject to a poor level of WECC under pessimistic and optimistic circumstances, respectively. WECCs in the upper and lower reaches are the best and worst, respectively, which is in line with the levels of economic development in the Dongjiang River Basin. The proposed method can also be applicable to many other problems involving numerous indicators.

Extending a Large-Scale Model to Better Represent Water Resources without Increasing the Model’s Complexity

The increasing impact of anthropogenic interference on river basins has facilitated the development of the representation of human influences in large-scale models. The representation of groundwater and large reservoirs have realised significant developments recently. Groundwater and reservoir representation in the Global Water Availability Assessment (GWAVA) model have been improved, critically, with a minimal increase in model complexity and data input requirements, in keeping with the model’s applicability to regions with low-data availability. The increased functionality was assessed in two highly anthropogenically influenced basins. A revised groundwater routine was incorporated into GWAVA, which is fundamentally driven by three input parameters, and improved the simulation of streamflow and baseflow in the headwater catchments such that low-flow model skill increased 33–67% in the Cauvery and 66–100% in the Narmada. The existing reservoir routine was extended and improved the simulation of streamflow in catchments downstream of major reservoirs, using two calibratable parameters. The model performance was improved between 15% and 30% in the Cauvery and 7–30% in the Narmada, with the daily reservoir releases in the Cauvery improving significantly between 26% and 164%. The improvement of the groundwater and reservoir routines in GWAVA proved successful in improving the model performance, and the inclusions allowed for improved traceability of simulated water balance components. This study illustrates that improvement in the representation of human–water interactions in large-scale models is possible, without excessively increasing the model complexity and input data requirements.

Spatial and Temporal Distribution of Bacterioplankton Molecular Ecological Networks in the Yuan River under Different Human Activity Intensity.

Bacterioplankton communities play a crucial role in freshwater ecosystem functioning, but it is unknown how co-occurrence networks within these communities respond to human activity disturbances. This represents an important knowledge gap because changes in microbial networks could have implications for their functionality and vulnerability to future disturbances. Here, we compare the spatiotemporal and biogeographical patterns of bacterioplankton molecular ecological networks using high-throughput sequencing of Illumina HiSeq and multivariate statistical analyses from a subtropical river during wet and dry seasons. Results demonstrated that the lower reaches (high human activity intensity) network had less of an average degree (10.568/18.363), especially during the dry season, when compared with the upper reaches (low human activity intensity) network (10.685/37.552) during the wet and dry seasons, respectively. The latter formed more complexity networks with more modularity (0.622/0.556) than the lower reaches (high human activity intensity) network (0.505/0.41) during the wet and dry seasons, respectively. Bacterioplankton molecular ecological network under high human activity intensity became significantly less robust, which is mainly caused by altering of the environmental conditions and keystone species. Human activity altered the composition of modules but preserved their ecological roles in the network and environmental factors (dissolved organic carbon, temperature, arsenic, oxidation–reduction potential and Chao1 index) were the best parameters for explaining the variations in bacterioplankton molecular ecological network structure and modules. Proteobacteria, Actinobacteria and Bacteroidetes were the keystone phylum in shaping the structure and niche differentiations in the network. In addition, the lower reaches (high human activity intensity) reduce the bacterioplankton diversity and ecological niche differentiation, which deterministic processes become more important with increased farmland and constructed land area (especially farmland) with only 35% and 40% of the community variation explained by the neutral community model during the wet season and dry season, respectively. Keystone species in high human activity intensity stress habitats yield intense functional potentials and Bacterioplankton communities harbor keystone taxa in different human activity intensity stress habitats, which may exert their influence on microbiome network composition regardless of abundance. Therefore, human activity plays a crucial role in shaping the structure and function of bacterioplankton molecular ecological networks in subtropical rivers and understanding the mechanisms of this process can provide important information about human–water interaction processes, sustainable uses of freshwater as well as watershed management and conservation.

Human-Water Dynamics and their Role for Seasonal Water Scarcity \u2013 a Case Study

Ensuring sustainable management and an adequate supply of freshwater resources is a growing challenge around the world. Even in historically water abundant regions climate change together with population growth and economic development are processes that are expected to contribute to an increase in permanent and seasonal water scarcity in the coming decades. Previous studies have shown how policies to address water scarcity often fail to deliver lasting improvements because they do not account for how these processes influence, and are influenced by, human-water interactions shaping water supply and demand. Despite significant progress in recent years, place-specific understanding of the mechanisms behind human-water feedbacks remain limited, particularly in historically water abundant regions. To this end, we here present a Swedish case study where we, by use of a qualitative system dynamics approach, explore how human-water interactions have contributed to seasonal water scarcity at the local-to-regional scale. Our results suggest that the current approach to address water scarcity by inter-basin water transports contributes to increasing demand by creating a gap between the perceived and actual state of water resources among consumers. This has resulted in escalating water use and put the region in a state of systemic lock-in where demand-regulating policies are mitigated by increases in water use enabled by water transports. We discuss a combination of information and economic policy instruments to combat water scarcity, and we propose the use of quantitative simulation methods to further assess these strategies in future studies.