Exploring Critical Zone Processes for Sustainable Water Management: The Case of Circus Lake Park, Bucharest

The southwestern region of China is the largest exposed karst area in the world and serves as an important ecological security barrier for the upstream of Yangtze River and Pearl River. Different from the critical zone of non-karst areas, the epikarst, formed by an interwoven network of denudation pores, is the core area of karst critical zone. Water is the most active component that participates in internal material cycle and energy flow within the critical zone. We reviewed relevant research conducted in the southwestern region from three aspects: the characte-rization of critical zone structure, the hydrological processes of soil-epikarst system, and their model simulations. We further proposed potential research hotpots. The main approach involved multi-scale and multi-method integrated observations, as well as interdisciplinary collaboration. Precisely characterizing the eco-hydrological processes of the vegetation-soil-epikarst coupling system was a new trend in the future research. This review would provide scientific reference for further studies on hydrological processes in critical zones and regional hydrological water resource management in karst areas.

Beavers (Castor canadensis) have not been adequately included in critical zone research, yet they can affect multiple critical zone processes across the terrestrial-aquatic interface of river corridors. River corridors (RC) provide a disproportionate amount of ecosystem services. Over time, beaver activity, including submersion of woody vegetation, burrowing, dam building, and abandonment, can impact critical zone processes in the river corridor by influencing landscape evolution, biodiversity, geomorphology, hydrology, primary productivity, and biogeochemical cycling. In particular, they can effectively restore degraded riparian areas and improve water quality and quantity, causing implications for many important ecosystem services. Beaver-mediated river corridor processes in the context of a changing climate require investigation to determine how both river corridor function and critical zone processes will shift in the future. Recent calls to advance river corridor research by leveraging a critical zone perspective can be strengthened through the explicit incorporation of animals, such as beavers, into research projects over space and time. This article illustrates how beavers modify the critical zone across different spatiotemporal scales, presents research opportunities to elucidate the role of beavers in influencing Western U.S. ecosystems, and, more broadly, demonstrates the importance of integrating animals into critical zone science.

Processes within the critical zone—spanning groundwater to the top of the vegetation canopy—have important societal relevance and operate over broad spatial and temporal scales that often are not included in existing frameworks for ecosystem services evaluation. Here we expand the scope of ecosystem services by specifying how critical zone processes extend context both spatially and temporally, determine constraints that limit provision of services, and offer a potentially powerful currency for evaluation. Context: A critical zone perspective extends the context of ecosystem services by expressly addressing how the physical structure of the terrestrial Earth surface (e.g., parent material, topography, and orography) provides a broader spatial and temporal template determining the coevolution of physical and biological systems that result in societal benefits. Constraints: The rates at which many ecosystem services are provided are fundamentally constrained by rate-limited critical zone processes, a phenomenon that we describe as a conceptual “supply chain” that accounts for rate-limiting soil formation, hydrologic partitioning, and streamflow generation. Currency: One of the major challenges in assessing ecosystem services is the evaluation of their importance by linking ecological processes to societal benefits through market and nonmarket valuation. We propose that critical zone processes be integrated into an evaluation currency, useful for valuation, by quantifying the energy flux available to do thermodynamic work on the critical zone. In short, characterization of critical zone processes expands the scope of ecosystem services by providing context, constraints, and currency that enable more effective management needed to respond to impacts of changing climate and disturbances.

CSA NewsVolume 60, Issue 2 p. 10-10 ScienceOpen Access Critical Zone Services: Expanding Context, Constraints, and Currency beyond Ecosystem Services First published: 03 February 2015 https://doi.org/10.2134/csa2015-60-2-2 Adapted from Field, J.P., D.D. Breshears, D.J. Law, J.C. Villegas, L. López-Hoffman, P.D. Brooks, J. Chorover et al. 2015. Critical zone services: expanding context, constraints, and currency beyond ecosystem services. Vadose Z. J. 14(1). View the full article online at https://doi.org/10.2136/vzj2014.10.0142 AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Humans derive many ecological, economical, water, and nutritional benefits from the critical zone (CZ), which is defined by the National Research Council (2001) as the area extending from the top of the vegetation canopy to the vertical depth of the freely moving groundwater. It is very important to note that soil in the CZ takes hundreds of thousands of year to form, whereas erosion or human disturbance can wash it away or otherwise reduce the productive nature of this important feature of the biosphere. The January 2015 issue of Vadose Zone Journal includes an article introducing a vision of ecosystem services and its connection to CZ processes. The authors propose a new perspective that incorporates CZ processes to expand the traditional focus within the four categories of ecosystem services: (a) provisioning—outputs of food, water and energy; (b) regulating—water quality, floods, and disease; (c) supporting—helping animals and plants maintain genetic diversity; and (d) cultural—recreational, educational, and aesthetic services. This work helps to expand the role of these services and the constraints thereon by explicitly considering CZ processes under the categories of context, constraints, and currency. Context describes the millions of years and the interaction of the physical, chemical, and biological processes that helped in the formation of the CZ. The time scale for CZ processes, such as formation of the soil, hydrologic partitioning, and landscape evolution is much longer than the conventional ecosystem services paradigm. Constraints describe physical processes that limit the delivery of goods and services. Examples include the rate of groundwater recharge and soil formation, both of which take place over centuries and millions of years, respectively. Currency is the valuation of the ecosystem service of the CZ for the ecological processes/services that are the output of the system. This could be the energy available to do work in the physical, chemical, and biological contexts. The authors suggest incorporating CZ processes into the conventional definition of ecosystem services by considering the physical nature of the soil, processes that result in the formation of the soil that are on much longer time scales, and the interconnectedness of the physical, chemical, and biological processes. Incorporating CZ processes into the valuation of ecosystem services, which is receiving substantial attention by national and international bodies, provides a more thorough and effective framework by which policy makers can assess impacts from climate change and associated disturbances. Critical zone services provide context, constraints, and currency that enable more effective management and valuation of ecosystem services (adapted from MEA, 2005). Reference National Research Council (NRC). 2001. Basic research opportunities in the earth sciences. National Academies Press, Washington, DC. Volume60, Issue2February 2015Pages 10-10 ReferencesRelatedInformation

<p>Critical Zone science studies the system of coupled chemical, biological, physical, and geological processes operating together across all scales to support life at the Earth's surface (Brantley et al., 2007). In 2020, the  U.S. National Science Foundation funded 10 Critical Zone Collaborative Network awards. These 5-year projects will collaboratively work to answer scientific questions relevant to understanding processes in the Critical Zone such as the effects of urbanization on Critical Zone processes; Critical Zone function in semi-arid landscapes and the role of dust in sustaining these ecosystems; processes in deep bedrock and their relationship to Critical Zone evolution; the recovery of the Critical Zone from disturbances such as fire and flooding; and changes in the coastal Critical Zone related to rising sea level. In order to support community data collection, access, and archival  for the Critical Zone Network community, the development of new cyberinfrastructure (CI) is now underway that leverages prior investments in domain-specific data repositories that are already operational and delivers data services to established communities. The goal is to create the infrastructure required for managing, curating, disseminating, and preserving data from the new network of Critical Zone Cluster projects, along with legacy datasets from the existing Critical Zone Observatory Network, including digital management of physical samples. This CI will have a distributed architecture that links existing data facilities and services, including HydroShare, EarthChem, SESAR (System for Earth Sample Registration), and eventually other systems like OpenTopography as needed, via a central CZ Hub that provides tools and services for simplified data submission, integrated data discovery and access, and links to computational resources for data analysis and visualization in support of CZ synthesis efforts. Our goal is to make data, samples, and software collected by the CZ Network Cluster projects Findable, Accessible, Interoperable, and Reusable following the FAIR guiding principles for scientific data management and stewardship, by taking advantage of existing, FAIR compliant, domain-specific data repositories. This collaboration among domain repositories to deliver integrated data services for an interdisciplinary science program will provide a template for future development of integrated interdisciplinary data services.</p>

Soil is the central interface of Earth's critical zone—the planetary surface layer extending from unaltered bedrock to the vegetation canopy—and is under intense pressure from human demand for biomass, water, and food resources. Soil functions are flows and transformations of mass, energy, and genetic information that connect soil to the wider critical zone, transmitting the impacts of human activity at the land surface and providing a control point for beneficial human intervention. Soil functions are manifest during bedrock weathering and, in fully developed soil profiles, correlate with the porosity architecture of soil structure and arise from the development of soil aggregates as fundamental ecological units. Advances in knowledge on the mechanistic processes of soil functions, their connection throughout the critical zone, and their quantitative representation in mathematical and computational models define research frontiers that address the major global challenges of critical zone resource provisioning for human benefit. ▪ Connecting the mechanisms of soil functions with critical zone processes defines integrating science to tackle challenges of climate change and food and water supply. ▪ Soil functions, which develop through formation of soil aggregates as fundamental eco-logical units, are manifest at the earliest stages of critical zone evolution. ▪ Global degradation of soil functions during the Anthropocene is reversible through positive human intervention in soil as a central control point in Earth's critical zone. ▪ Measurement and mathematical translation of soil functions and critical zone processes offer new computational approaches for basic and applied geosciences research.

Core Ideas IML‐CZO is structured to study system responses through event‐based monitoring. Management legacy has shaped critical zone processes. Management and weather affect landscape heterogeneity and surface–subsurface pathways. In intensively managed landscapes, interactions between surface (tillage) and subsurface (tile drainage) management with prevailing climate/weather alter landscape characteristics, transport pathways, and transformation rates of surface/subsurface water, soil/sediment, and particulate/dissolved nutrients. To capture the high spatial and temporal variability of constituent transport and residence times in the critical zone (between the bedrock and canopy) of these altered landscapes, both storm event and continuous measurements are needed. The Intensively Managed Landscapes Critical Zone Observatory (IML‐CZO) is comprised of three highly characterized, well instrumented, and representative watersheds (i.e., Clear Creek, Iowa; Upper Sangamon River, Illinois; and Minnesota River, Minnesota). It is organized to quantify the heterogeneity in structure and dynamic response of critical zone processes to human activities in the context of the glacial and management (anthropogenic) legacies. Observations of water, sediment, and nutrients are made at nested points of the landscape in the vertical and lateral directions during and between storm events (i.e., continuously). The measurements and corresponding observational strategy are organized as follows. First, reference measurements from surface soil and deep core extractions, geophysical surveys, lidar, and hyperspectral data, which are common across all Critical Zone Observatories, are available. The reference measurements include continuous quantification of energy, water, solutes, and sediment fluxes. The reference measurements are complemented with event‐based measurements unique to IML‐CZO. These measurements include water table fluctuations, enrichment ratios, and roughness as well as bank erosion, hysteresis, sediment sources, and lake/floodplain sedimentation. The coupling of reference and event‐based measurements support testing of the central hypothesis (i.e., system shifts from transformer to transporter in IML‐CZO due to the interplay between management and weather/climate). Data collected since 2014 are available through a data repository and through the Geodashboard interface, which can be used for process‐based model simulations.

The increasing global demand for water, outpacing population growth, poses a critical challenge by intensifying concerns about water resource accessibility and exacerbating global water scarcity across various sectors. Ongoing global warming, changes in precipitation patterns, and the heightened frequency and severity of extreme weather events are significantly impacting agricultural systems. These impacts include alterations in growing cycles, crop yields, and the prevalence of pests and diseases. Focusing on the medium and long term, this study aimed to identify adaptation priorities to mitigate risks associated with water scarcity in the agricultural system of Puglia, one of Italy’s most agriculturally productive regions. To achieve this, an exhaustive review synthesized existing literature on water scarcity, analyzing the interactions among climate change, irrigation systems, and agricultural practices. By examining grey and peer-reviewed literature on Puglia’s water challenges for agriculture, the review critically assessed current irrigation practices, water management issues, and the ecological consequences of intensive irrigation across the region. The results outline both current and projected water scarcity for agriculture in Puglia, highlighting the areas already addressed and the potential implications. By providing a comprehensive understanding of existing studies that inform the relationship between water scarcity and irrigation systems in the region, this study aims to guide future strategies for sustainable water management in Puglia and other agricultural areas facing climate-induced challenges.

The concept of a critical zone (CZ) supporting terrestrial life has fostered groundbreaking interdisciplinary science addressing complex interactions among water, soil, rock, air and life near Earth’s surface. Pioneering work has focused on the CZ in areas with residual soils and steady-state or erosional topography. CZ evolution in these areas is conceptualized as progressive weathering of local bedrock (e.g. in the flow-through reactor model). However, this model is not applicable to areas in which weathering profiles form in transported materials including the formerly glaciated portion of the Central Lowland of North America. We present a new conceptual model of CZ evolution in landscapes impacted by continental glaciation based on investigations at three study sites in the Intensively Managed Landscapes Critical Zone Observatory (IML-CZO) The IML-CZO is devoted to the study of CZ processes in a region characterized by thick surficial deposits resulting from multiple continental glaciations, with bedrock at depths of up to 150 m. Here the physical (glacial ice, loess, developing soil profiles) and biological (microbes, tundra, forest, prairie) components of the CZ vary significantly in time. Moreover, the spatial relationships between mineral components of the CZ record a history of glacial-interglacial cycles and landscape evolution. We present cross-sections from IML-CZO sites to provide specific examples of how environmental change is recorded by the structure of the mineral components of the CZ. We build on these examples to create an idealized model of CZ evolution through a glacial cycle that represents the IML-CZO sites and other areas of low relief that have experienced continental glaciation. In addition, we identify two main characteristics of CZ structure which should be included in a conceptual model of CZ development in the IML-CZO and similar settings: (1) mineral components have diverse origins and transport trajectories including alteration in past CZs, and, (2) variability in climate, ecosystems, and hydrology during glacial-interglacial cycles profoundly influence the CZ composition, creating a legacy retained in its structure. This legacy is important because the current physical CZ structure influences the occurrence and rates of CZ processes, as well as future CZ responses to land use and climate change.

The critical zone (CZ)-from treetops to groundwater-is an increasingly studied part of the earth system, where scientists study interactions between water, air, rock, soil, and life. Groundwater is both a boundary and an essential store in this integrated system, but is often not well considered in part because of the difficulty in accessing it and its slow movement relative to other parts of the system. Here, we describe some fundamental areas where groundwater hydrology is of fundamental importance to CZ science, including sustaining streamflow and vegetation, reacting with minerals to produce dissolved solutes and regolith, and influencing energy fluxes across the land-atmosphere interface. As the timing and type of precipitation change with climate, groundwater may play an even more important role in CZ processes as a sustainable water source for plants and streamflow. Many open questions also exist about the role of CZ processes on groundwater. Many data streams are needed and important to quantifying the integrated response of the CZ to groundwater and vice versa, but long-term data records are often incomplete or discontinued due to limited funding. We argue that the long timescales of processes that involve groundwater necessitate data collection efforts beyond typical federal funding timespans. Sustaining monitoring networks and developing new ones aimed at testing hypotheses related to slow-moving, groundwater-controlled CZ processes should be a scientific priority, and here we outline some open questions that we hope will motivate groundwater scientists to get involved in CZ science.

Biochar has been put forward as a potential technology that could help achieve sustainable water management in agriculture through its ability to increase water holding capacity in soils. Despite this opportunity, there are still a limited number of studies, especially in vulnerable regions like the tropics, quantifying the impacts of biochar on soil water storage and characterizing the impacts of biochar additions on plant water composition. To address this critical gap, we present a case study using stable water isotopes and hydrometric data from melon production in tropical agriculture to explore the hydrological impacts of biochar as a soil amendment. Results from our 10-week growing season experiment in Costa Rica under drip irrigation demonstrated an average increase in volumetric soil moisture content of about 10% with an average moisture content of 25.4 cm3 cm−3 versus 23.1 cm3 cm−3, respectively, for biochar amended plots compared with control plots. Further, there was a reduction in the variability of soil matric potential for biochar amended plots compared with control plots. Our isotopic investigation demonstrated that for both biochar and control plots, there was a consistent increase (or enrichment) in isotopic composition for plant materials moving from the roots, where the average δ18O was −8.1‰ and the average δ2H was −58.5‰ across all plots and samples, up through the leaves, where the average δ18O was 4.3‰ and the average δ2H was 0.1‰ across all plots and samples. However, as there was no discernible difference in isotopic composition for plant water samples when comparing across biochar and control plots, we find that biochar did not alter the composition of water found in the melon plant material, indicating that biochar and plants are not competing for the same water sources. In addition, and through the holistic lens of sustainability, biochar additions allowed locally sourced feedstock carbon to be directly sequestered into the soil while improving soil water availability without jeopardizing production for the melon crop. Given that most of the expansion and intensification of global agricultural production over the next several decades will take place in the tropics and that the variability of tropical water cycling is expected to increase due to climate change, biochar amendments could offer a pathway forward towards sustainable tropical agricultural water management.

This comprehensive review explores the landscape of Urban Water Management in the United States, focusing on sustainable practices aimed at addressing the challenges posed by rapid urbanization and climate change. With urban areas facing increasing water stress, this study aims to identify, analyze, and evaluate a range of sustainable practices implemented across the country. The review encompasses diverse aspects of Urban Water Management, including water efficiency measures, green infrastructure initiatives, climate change resilience strategies, and pollution mitigation efforts. In examining water efficiency measures, the study investigates technological innovations and policy frameworks that have contributed to optimizing water use in urban settings. Additionally, the role of green infrastructure is explored, emphasizing its benefits and applications through case studies of successful implementations, shedding light on how nature-based solutions can enhance water sustainability. The review delves into the critical dimension of climate change resilience in urban water systems, analyzing the impacts of climate change on water resources and exploring adaptation and mitigation strategies. Infrastructure improvements and integrated planning approaches are examined as essential components in building resilient urban water systems. Addressing pollution mitigation, the study focuses on stormwater management and wastewater treatment. Best management practices and regulatory measures are scrutinized to understand how urban areas are effectively managing and treating water to mitigate pollution and protect water quality. Furthermore, the review highlights the significance of integrated water resources management as a holistic approach to addressing water challenges in urban contexts. Stakeholder engagement and cross-sectoral coordination are emphasized as integral elements in implementing sustainable and comprehensive water management strategies. Through case studies of successful urban water management projects, the review extracts valuable lessons and insights for future implementations. The challenges and opportunities in the current landscape are explored, providing a nuanced understanding of the barriers to sustainable practices and identifying emerging opportunities. This review synthesizes key findings, implications, and recommendations for advancing sustainable urban water management practices in the United States. The insights generated contribute to the ongoing dialogue on effective water management strategies in the face of evolving urban and environmental dynamics.
 Keywords: Urban Water Management, Sustainable Practices, Water Efficiency, Climate Change, Resilience, United States, Pollution Mitigation, Water Infrastructure.

Critical Zone Science (CZS) represents a powerful confluence of research agendas, tools, and techniques for examining the complex interactions between biotic and abiotic factors located at the interface of the Earth’s surface and shallow subsurface. Earth’s Critical Zone houses and sustains terrestrial life, and its interacting subsystems drive macroecological patterns and processes at a variety of spatial scales. Despite the analytical power of CZS to understand and characterize complicated rate-dependent processes, CZS has done less to capture the effects of disturbance and anthropogenic influences on Critical Zone processes, although some Critical Zone Observatories focus on disturbance and regeneration. Methodological approaches from biogeography and ecology show promise for providing Critical Zone researchers with tools for incorporating the effects of ecological and anthropogenic disturbance into fine-grained studies of important Earth processes. Similarly, mechanistic insights from CZS can inform biogeographical and ecological interpretations of pattern and process that operate over extensive spatial and temporal scales. In this paper, we illustrate the potential for productive nexus opportunities between CZS, biogeography, and ecology through use of an integrated model of energy and mass flow through various subsystems of the Earth’s Critical Zone. As human-induced effects on biotic and abiotic components of global ecosystems accelerate in the Anthropocene, we argue that the long temporal and broad spatial scales traditionally studied in biogeography can be constructively combined with the quantifiable processes of energy and mass transfer through the Critical Zone to answer pressing questions about future trajectories of land cover change, post-disturbance recovery, climate change impacts, and urban hydrology and ecology.

Seasonal snowfall is the largest component of the water budget in many mountain headwater regions around the world. In addition to sustaining biological water needs in drier, lower elevation areas throughout the year, mountain snowpack also provides essential water inputs to the Critical Zone (CZ) - the outer layer of the Earth’s surface, which hosts a variety of biogeochemical processes responsible for transforming inorganic matter into forms usable for life. Water is a known driver of CZ activity, but uncertainty exists in its spatial and temporal interactions with CZ processes, particularly in the complex terrain of heterogeneous mountain areas. Increasing pressure on the CZ due to climate change and human land use needs creates an urgency to better understand the CZ system and how it may change in the future. An important variable for water driven CZ behaviors in mountain areas is the spatial extent of snow, also known as snow-covered area (SCA). SCA in mountain areas can change quickly over small scales of time and space with large impacts on the rest of the system. It has been difficult historically, however, to measure snowpack extent for large areas on very fine spatial and temporal scales due to a lack of remote sensing datasets with both of these fine scale characteristics. In this study we use the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) to fill this historic knowledge gap for the East River watershed in Colorado, USA. By fusing low spatial and high temporal resolution data from MODIS (500-m, daily) with high spatial and low temporal resolution data from Landsat (30-m, 16 days), a fine resolution, 30-m daily dataset can be created. This study is one of the first to use this model with the primary intent of monitoring SCA in a mountain watershed. The first component of the study in this thesis presents a comprehensive validation of STARFM for use in monitoring snow cover in mountain areas. Normalized Difference Snow Index (NDSI) values from MODIS and Landsat are used as input to the STARFM model, and synthetic NDSI values at 30-m resolutions are obtained for days without Landsat data acquisitions. After converting NDSI to binary snow cover, we then examine the temporal performance of STARFM for an entire calendar year. The model’s performance is also analyzed for different landscape features known to influence snow cover. Accuracy, precision, recall, and F-score values indicate that the model is able to successfully predict the location of SCA in the landscape when validated with Landsat data. The second component of the study describes the process of creating the daily, 30-m NDSI dataset with STARFM for 20 water years of analysis and provides examples of how these data can be used to monitor SCA in a mountain watershed. We examine patterns of percent annual snow cover for three of the water years from the dataset, a dry, average, and wet water year. Here we find that predictable patterns of SCA occur over those years, with the highest percent annual snow cover occurring during the wet year and the lowest occurring during the dry year. Despite these differences, however, elevation is clearly the dominating factor in determining the spatial variability of snow cover in the landscape for all three water years. We also connect our snow cover analysis back to CZ processes by examining the timing of snow cover disappearance with the peak of annual stream discharge at the watershed outlet. The results of this work provide a multi-decadal dataset of snow cover information for the East River that can be used for future research into snowpack and streamflow forecasting, modeling of the movement of water through the CZ, and the effects that climate change may have on these processes. This study also provides examples of methods that can be used for further snow monitoring work in the East River watershed and other snow-dominated mountain catchments similar to it.

Water Sowing and harvesting application for water management on the slopes of a volcano