Basin Level Research Articles

THE INFLUENCE OF GREEN FINANCE ON THE HIGH-QUALITY DEVELOPMENT OF CITIES: AN EMPIRICAL STUDY ON THE YELLOW RIVER BASIN

The establishment of the Equator Principles provides strict industry standards for promoting green environmental protection. Ecological protection and high-quality development of the Yellow River Basin are major national strategies and frameworks in China. This study aims to provide a theoretical basis for promoting the efficient development of the Yellow River Basin and to explore the imbalance between the development level and the development quality of green finance in various regions of the Yellow River Basin. The study implements an evaluation index system to quantify the economic development level and green finance development level of the Yellow River Basin. Moreover, a panel model analyzes the impact mechanism of green finance on the high-quality development of the basin as well as the moderating role of government supervision. The results show that most cities in the Yellow River Basin of China are at a medium level of green financial development, and some cities have a low level. Green financial development can promote high-quality development, and green regulatory and fiscal policies play a moderating role in this process. This study makes relevant policy recommendations for improving top-level design and preserving the environment.

Long-term water level dynamics in the Red River basin in response to anthropogenic activities and climate change

Understanding the regular variations in water levels and identifying the potential drivers under the combined pressures of anthropogenic activities and climate change can offer valuable insights into riverine management. In this study, we analyzed long-term daily observational data, including water levels and water discharge, spanning from the ~1950s to 2021 at seven gauging stations within the Red River basin. We investigated the spatiotemporal variation in mean water levels using standard analytical tools, including the Mann-Kendall (MK) test, rating curves, and Empirical Orthogonal Function (EOF). Specifically, we observed a notable and substantial decline in water levels downstream of the major tributaries, including Da, Red, and Lo Rivers, as well as at their confluence, starting at the end of 2008. Notably, a strong correlation between water levels and discharge is found, highlighting the pivotal role of discharge in influencing water levels. Surprisingly, relationships between water levels and climatic factors such as rainfall and air temperature proved less influential. This suggests that water levels are predominantly shaped by discharge and anthropogenic activities, rather than climate change. The study emphasized the substantial impact of human-induced activities, particularly dam operation and sand mining, on downstream water levels in the Red River basin. An intriguing finding revealed that upstream dynamics, particularly at the Hoa Binh dam, led to significant water level increases with the same discharge, attributed to channel deposition and reservoir water storage. The research's novelty is the comprehensive evaluation of long-term water level trends and its elucidation of the combined effects of anthropogenic activities and climate change, offering valuable insights for riverine management and emphasizing the influence of anthropogenic factors, notably dam regulation and sand mining, in driving shifts in water levels.

Population-wise labeling of sulcal graphs using multi-graph matching.

Population-wise matching of the cortical folds is necessary to compute statistics, a required step for e.g. identifying biomarkers of neurological or psychiatric disorders. The difficulty arises from the massive inter-individual variations in the morphology and spatial organization of the folds. The task is challenging both methodologically and conceptually. In the widely used registration-based techniques, these variations are considered as noise and the matching of folds is only implicit. Alternative approaches are based on the extraction and explicit identification of the cortical folds. In particular, representing cortical folding patterns as graphs of sulcal basins-termed sulcal graphs-enables to formalize the task as a graph-matching problem. In this paper, we propose to address the problem of sulcal graph matching directly at the population level using multi-graph matching techniques. First, we motivate the relevance of the multi-graph matching framework in this context. We then present a procedure for generating populations of artificial sulcal graphs, which allows us to benchmark several state-of-the-art multi-graph matching methods. Our results on both artificial and real data demonstrate the effectiveness of multi-graph matching techniques in obtaining a population-wise consistent labeling of cortical folds at the sulcal basin level.

A Study on Areal Rainfall in the Han River Basin Based on Radar Data

Areal rainfall is an essential factor used in the basin-scale hydrological analyses, and accurate areal rainfall is required to ensure the reliability of the associated hydrologic output. Areal rainfall is the average of the rainfall that occurs in a watershed. Areal rainfall calculation methods based on point observation networks are based on the assumption that point rainfall is representative of the entire basin. Radar can provide spatially continuous rainfall data to obtain realistic areal rainfall. In this study, radar rainfall data was used to evaluate the relationship between conventional and actual areal rainfall. Consequently, a significant difference was noted between the conventional area rainfall and the actual area rainfall because the conventional area rainfall did not reflect the distribution characteristics of rainfall in the basin and the variability of quantitative characteristics. Therefore, radar rainfall that can reflect the distribution of rainfall in the basin must be considered when analyzing the hydrological volume at the basin level, and an appropriate correction plan must be prepared based on the results of this study when using the conventional area rainfall.

Mainstreaming nature-based solutions through five forms of scaling: Case of the Kiiminkijoki River basin, Finland.

Nature-based solutions (NBS) are considered as means to tackle climate change and biodiversity loss while simultaneously enhancing human well-being. Yet, it is still poorly understood how NBS could be mainstreamed. We address this gap by proposing a framework on NBS and employing it in Finland's Kiiminkijoki River basin through participatory workshops and a questionnaire. We examine socio-environmental challenges and visions, existing and emerging NBS to reach the visions, and ways to scale-up NBS to a river basin level. In the river basin, water quality is the priority challenge, due to its relationships with local culture, climate change, and biodiversity. Our results consider how (1) to ensure the relevance of NBS for local actors, (2) instrumental, intrinsic, and relational value perspectives can be enhanced simultaneously by NBS, and (3) site specific NBS can be mainstreamed (i.e., by scaling up, down, out, in, deep) to the river basin level and beyond.

Building a multi‐scale, collaborative, and time‐integrated digital crust: The next stage of the Macrostrat data system

AbstractMacrostrat is a platform for deep‐time geoscientific research that integrates stratigraphic columns and geologic maps into a digital description of the crust. The database and supporting software track crustal evolution and provide location‐based geological information to geoscience end users. Macrostrat houses multiple scales of mapping and stratigraphic data, from continent‐ and basin level summaries to single quadrangles and measured sections. Currently, Macrostrat's primary data holdings consist of regional stratigraphic columns with a spatial footprint weighted heavily to North America. While the data are of sufficient scale and resolution to generate insights about Earth evolution, increasing resolution and expanding spatial coverage will allow a new generation of scientific and interpretive uses. The next phase of Macrostrat's development will increase the detail and complexity of Macrostrat's multiscale data holdings, largely by engaging a wider range of geoscientists in entering stratigraphic data. To support broad collaboration, we are building new web‐based software to assemble and visualize regional stratigraphic sequences, refine multiple working age models, and compose regional records from measured stratigraphic sections. These tools will allow Macrostrat to draw on the expertise of a wide range of geoscience workers and grow a dataset with global relevance and a variety of end uses. New capabilities will pave the way to processes for submission, review, coordination, and assimilation of community‐contributed stratigraphic datasets. Digital compilation of geological maps and columns requires substantial effort, and well‐designed systems for distributing this work in the geoscience community will allow Macrostrat to build more adaptable and scientifically relevant products.

Élet az édesvízhiánnyal: vízkészlet-gazdálkodás Namíbiában

Namibia is an arid country in Southern Africa. It frequently experiences a state of freshwater deficit and must employ a range of measures to manage this scarce resource sustainably and equitably. The Ministry of Agriculture, Water and Land Reform coordinates the water sector. A state-owned enterprise, NamWater, is the bulk water supplier and manages large water infrastructure. The country follows a policy of integrated water resource management and has devolved some of the decision-making on water issues to river basin level. Transboundary catchments are managed through legal agreements and multinational permanent commissions representing the basin states. Technologies such as dams in ephemeral rivers, intra- and inter-basin water transfer schemes, reclamation of wastewater to potable standards, artificial aquifer recharge, desalination, and conjunctive use of various water sources are employed to supply water to consumers. Water demand management, particularly education, information, restrictions and tariffs, curbs wasteful use of water.

Critical Examination of the Scope and Methodology of Water Resources Economics, Accounting and Auditing

The paper is central on accounting for water use and productivity water to improve water savings from accountability to sustainability. It critically examination of the scope and methodology of water resources economics, accounting and auditing. This paper presents a conceptual framework for water accounting and provides generic terminologies and procedures to describe the status of water resource use and consequences of water resources related actions. The exploratory study involves Water resources economics, water scarcity in economic theory, water accounting frameworks, water accounts, water consumption and water use, water valuation, water accounting and ‘water budgets’, water balance approach, water accounting plus (Wa+) and water accounting using remote sensing. Water accounting is a method of organising and presenting information relating to the physical volumes of water in the environment and economy as well as the economic aspects of water supply and use. The framework applies to water resource use at three levels of analysis: a use level such as an irrigated field or household, a service level such as an irrigation or water supply system, and a water basin level that may include several uses. An increase in water demands, exacerbated by climate change and the tightening of environmental requirements, leads to a reduction in available water resources for economic uses. This situation poses challenges for water resource planning and management. Water accounting has emerged as an appropriate tool to improve transparency and control in water management. There are multiple water accounting approaches, but they generally involve a very exhaustive list of accounted concepts.

Modelling micropollutant cycle in Lake Como in a winter scenario: Implications for water use and reuse, ecosystem services, and the EU zero pollution action plan

The fate and effects of 42 pharmaceuticals was studied in Lake Como (Italy), in wastewater treatment plants delivering water to the lake, in two rivers and in potable water obtained from lake water. Lake Como is one of the deepest and largest lakes in Northern Italy, serving important ecosystem services (i.e., drinking water, recreational, industrial, irrigation uses), some of which are currently at risk giving the current water scarcity and climate change scenarios. The highest concentrations measured in lake water were those of diclofenac, followed by carbamazepine, its metabolite, and clarithromycin. The data measured allowed to calibrate and run a fugacity-based lake model, which showed that the most important chemical load generally comes from the advective water from the north of the lake, rather than from the direct wastewater treatment plant (WWTP) discharges. This indicates that only an important reduction of chemical discharge (reduced use or extensive treatment) at a drainage basin level could significantly reduce concentrations in water. This has strong implications on how to implement the EU zero pollution action plan to significantly improve water ecosystem and human health protection.

LATE GLACIAL PALAEOENVIRONMENT AND DEVELOPMENT OF PROGLACIAL LAKES ON THE NORTHERN COAST OF THE SAMBIAN (KALININGRAD) PENINSULA<a href="#FN1"><sup>1</sup></a>

Comprehensive investigations of the northern coast of the Sambian (Kaliningrad) Peninsula, that included geomorphological survey, lithostratigraphic description of the section logs, diatom, botanical and LOI analyses, radiocarbon dating, and GNSS survey relating lithological boundaries and sampling levels to the sea level and determining terrace elevations, were performed. New data on the regional palaeogeographic settings of the Late Glacial period and the stages of development of the large proglacial basin, the Baltic Ice Lake (BIL) were obtained. It has been established that after the degradation of the last glaciation, erosional (subaquatic) processes prevailed in the coastal area, while in the interval of 14–13 cal kyr BP subaerial conditions established at the study site, and tree-moss phytocenoses formed during the Allerød warming. At the end of the warming period there was a shallow, isolated lake, with decreasing depth. During the Younger Dryas oscillation, ca. 12 000 cal kyr BP, the area was flooded by waters of a vast freshwater, ultra-oligotrophic basin with high content of suspended fine mineral particles. The conditions of a shallow bay of the BIL sheltered from the main basin by a moraine ridge at least 4–5 m high, are suggested for this period. The lake drainage took place around 11 660 cal kyr BP. Since then, no accumulation or alternating accumulation and erosion conditions prevailed in the study site until the late Holocene. The obtained results allow us to speak about two stages of flooding of the northern coast of the Sambia Peninsula during the Late Glacial, possibly caused by the BIL transgressions. The occurrence of BIL deposits in the northern part of the Sambia Peninsula above sea level suggests that the Late Glacial basin level in the study area may have exceeded the present sea level.

Environmental regulation and economic justification of integrated water resources management in the region

A study of ecological and economic approaches to the creation of a system of integrated integrated water resources management at the basin level is presented. As an example, the basin of the Kuyalnitsky estuary of the Odessa region is considered. To create a system of integrated management of the territory's water resources and assess individual components of the water balance, methodological economic and environmental approaches were used. The work used an ecosystem approach based on the notion that "nature is an equal partner". Water resources management took into account their significant transformation under the influence of water management, as well as operational data on the hydrometeorological characteristics of the Kuyalnitsky estuary. The results obtained show that the development of an integrated water resources management system should be based on a general calculation of all components of natural and anthropogenic influence, which allows balancing the assessment of water resources and developing a rational management system.

Simulating drip irrigation in large-scale and high-resolution ecohydrological models: From emitters to the basin

Drip irrigation is deemed as a solution to the water conflict between agricultural and ecological needs in arid regions, but assessing hydrological impacts of drip irrigation remains challenging. This study developed a new approach to simulating drip irrigation at a basin scale, with the configuration of irrigation system explicitly represented and the emitter-scale wetted soil volume directly modeled, and incorporated the approach into HEIFLOW, a fully distributed and physically based ecohydrological model. The improved model, named HEIFLOW-drip, was used to study the potential implementation of drip irrigation in the Zhangye basin in Northwest China. Due to the recycling effect of irrigation return flow, the basin-scale water-saving efficiency (WSE) of drip irrigation fully implemented in the irrigated farmlands is 16.8%, less than half of its field-scale WSE (36.5%). This discrepancy indicates that accounting the water saved in fields may lead to notable overestimation of the basin-wide water saving by drip irrigation in basins with strong surface water-groundwater interactions. If fully implemented, drip irrigation would significantly alter the regional water balance, increasing the stream outflow by approximately 30%, while causing a decline in groundwater level. This tradeoff can be alleviated by tuning the management parameters of drip irrigation, which can achieve a synergistic effect of increasing the streamflow while preventing dramatic groundwater depletion. Another effective strategy is to implement drip irrigation in part of the basin. Given the intricate impacts of drip irrigation on hydrological processes, the determination of the scale and location of drip irrigation should be thought through at the basin level. Further analyses indicate the importance of proper management of the water saved by drip irrigation, which is crucial to prevent the paradox of irrigation efficiency. The findings of this study have great implications for addressing the complex water-food-ecosystem nexus in arid endorheic river basins.

Intensification of Extreme Rainfall in Indian River Basin: Using Bias Corrected CMIP6 Climate Data

AbstractThe changing frequency of extreme rain events in the past few decades over the Indian river basins (IRBs) contributed to floods and drought and resulted in economic losses and gross domestic product. In this study, we evaluated the performance of 12 Global Circulation Models from the Coupled Model Intercomparison Project Phase 6‐ experiment with India Meteorological Department observed data sets to reproduce the extreme rainfall events as well as project the changes in frequency and intensity of the hydroclimate extremes in future. We found that under low emission scenarios (SSP1‐2.6), the frequency of extreme rainfall is going to increase over the western ghat and northeast IRBs, while an increase in heavy rainfall intensity (14.3%) noticed under SSP2‐4.5 in the upper Ganga and Indus basin. Also, approximately 4%–10% of the heavy rainfall is projected to increase over the western part of IRBs during the Near (2021–2040) and Mid (2041–2060) future. The study explored the new hotspot regions for future urban flooding due to increasing pattern of heavy rainfall in future. Moreover, the lower Ganga basin will experience agricultural drought in near future due to decreasing areal mean rainfall, which needs to be seen by policymakers for managing the excess (less) water. Also, India's northern, central, and western river basins may experience more extremes under high‐emission (SSP5‐8.5) scenarios that indicate challenges to mitigation. The findings of this study highlight the importance of developing long‐term adaptation and mitigation strategies aimed at reducing hydroclimate vulnerability. It emphasizes the need to implement measures that enhance resilience and minimize risks associated with hydroclimate extremes at the basin level.

Role of microhabitats in shaping diversity of periphytic diatom assemblages

Diverse macrovegetation can provide heterogeneous habitats for benthic diatoms. The removal of macrophytes as direct plant control, however, can be considered as a threat, which can even lead to remarkable microhabitat alterations. Lake Tisza (Hungary) has a high nature conservation value, but it is also an important recreation centre, which is why very delicate water management is necessary including vegetation thinning. Here, we studied the importance of microhabitat heterogeneity (emergent, submerged and floating macrophytes) in maintaining diverse periphytic diatom assemblages. We hypothesized that the substrate type has greater influencing role on the composition and diversity of diatoms than the lake heterogeneity related to basins. We also assumed that floating vegetation hosts the most different and least diverse diatom assemblages. Our results mostly proved these hypotheses. Heterogeneous assemblages were formed on the different substrates (support hypothesis), however, the basin level differences were also detected (reject hypothesis). Our results also highlighted, that macrophyte species with lesser morphological complexity hosted the least diverse periphytic assemblages (support hypothesis). However, many unique and red list taxa were found on floating plants (reject hypothesis). These findings emphasize the key role of microhabitat complexity in maintaining diverse and healthy functioning of microbial assemblages in a multi-purpose reservoir.

Australian country paper: Integrated approaches to irrigation management in the future

AbstractIrrigation in Australia expanded dramatically during the early to mid‐twentieth century under an economic and social development regime of government. This led to overallocation and overuse of many of the country's water resources to the detriment of the rivers and riverine environments. To address this degradation federal and state governments have come together to implement a range of reforms at national, basin and catchment level to return water to the rivers but not at the expense of rural communities and a range of policy reforms to implement water resource best management practice including cost recovery pricing, accuracy in measurement (resource availability and extraction). The three most significant components of these reforms are the Murray–Darling Basin Plan, the National Water Initiative and the Sustainable Rural Water Use and Infrastructure Programme (SRWUIP). These actions are complemented by infrastructure and management improvements at on‐ and off‐farm levels and examples are documented.

Rainfall-Runoff modelling using SWAT and eight artificial intelligence models in the Murredu Watershed, India.

The growing concerns surrounding water supply, driven by factors such as population growth and industrialization, have highlighted the need for accurate estimation of streamflow at the river basin level. To achieve this, rainfall-runoff models are widely employed as valuable tools in watershed management. For this specific study, two modelling approaches were employed: the Soil and Water Assessment Tool (SWAT) model and a set of eight artificial intelligence (AI) models. The AI models consisted of seven data-driven approaches, namely k-nearest neighbour regression, support vector regression, linear regression, artificial neural networks, random forest regression, XGBoost, and Histogram-based Gradient Boost regression. Additionally, a deep learning model known as Long Short-Term Memory (LSTM) was also utilized. The study focused on monthly streamflow modelling in the Murredu River basin, with a calibration period from 1999 to 2003 and a validation period from 2004 to 2005, spanning a total of 7years from 1999 to 2005. The results indicated that all nine models were generally suitable for simulating the rainfall-runoff process, with the LSTM model demonstrating exceptional performance in both the calibration (R2 is 0.97 and NSE is 0.96) and validation (R2 is 0.97 and NSE is 0.92) periods. Its high coefficient of determination (R2) and Nash-Sutcliffe efficiency (NSE) values indicated its superior ability to accurately model the rainfall-runoff relationship. While the other models also produced satisfactory results, the findings suggest that selecting the most efficient model, such as the LSTM model, could significantly contribute to the effective management and planning of sustainable water resources in the Murredu watershed.

Unintentional Recharge of Aquifers from Small Dams and Dykes in Spain: A GIS-Based Approach to Determine a Fractional Volume

Conducting an accurate hydrological water balance at the regional and country-wide scales is paramount to assessing available water resources and adequately allocating them. One of the main components of these balances is the anthropogenic recharge of groundwater either intentionally, through managed aquifer recharge (MAR), or unintentionally, where infiltration from dams and dykes can play a significant role. In Spain, proper management of water resources is critical due to the arid to semiarid conditions prevalent in most of the territory and the relevance of water resources for maintaining a robust agricultural sector. Previous work estimated country-wide recharge from MAR at 150 to 280 Mm3/year. Recently, water authorities pointed out that, according to hydrological water balances, the total unintentional recharge volume from water courses may exceed 500 Mm3/year. The present research aims to present a new inventory of transverse structures (also referred to as small dams and dykes) in Spain and use it to estimate country-wide unintentional recharge. The inventory, compiled by the Spanish Ministry for the Ecological Transition and the Demographic Challenge, has 27,680 structures and includes construction and impoundment characteristics, which allow for estimating the wet perimeter and the infiltration area. To this end, structural data from the inventory were crossed through map algebra in a GIS environment with thematic layers, such as lithology, permeability, the digital elevation model, the transverse structures’ wetted area, the average groundwater levels, and a clogging correction factor. Two analytical formulas to compute infiltration from small dams and dykes were tested. The resulting volume of unintentional recharge from transverse structures ranges between 812.5 and 2716.6 Mm3/year. The comparison against regional and national water balances suggests that the lowest value of the range (i.e., 812.5 Mm3/year) is probably the most realistic. Anthropogenic recharge from MAR and transverse structures is likely in the range of 1012.5–1514.8 Mm3/year. This rough figure can help close the hydrological balance at the national and river basin levels and contribute to calibrating regional models. Furthermore, they provide an order of magnitude for anthropogenic recharge at a national scale, which is difficult to obtain.

Assessing environmental, economic, and social impacts of inter-basin water transfer in China

Inter-basin water transfer (IBWT) has been widely implemented to address water deficit problems in many parts of the world. IBWT projects can pose various environmental, economic, and social impacts on both water recipient and source basins. This study presents an analysis of multi-dimensional impacts of China’s IBWT at the sub-basin scale, using three newly developed indicators. The analysis is based on China’s operating IBWT projects in 2016, which had a collective capacity of transferring ∼48 billion m3/yr water across sub-basins. Results indicate that IBWT helped improve environmental flow conditions in 20 out of 26 recipient sub-basins, with 6 out of 17 source sub-basins experiencing critical environmental flow conditions. IBWT generated net economic benefits of approximately 4.2 billion US dollars and net social benefits of providing domestic water use for 170 million people. IBWT posed overall positive environmental, economic, and social impacts, with the most benefits delivered to the North China Plain (i.e., the Huai and Hai River Basins). However, a few water source basins with relatively low local water availability were faced with a high risk of low environmental flows and high socio-economic costs, especially under low water resources conditions. Large spatial variations of IBWT impacts were found across sub-basins, which cannot be known by assessment at the major basin level. This highlights the need to assess IBWT impacts at finer spatial scales, considering regional differences in local water resources and social-economic development conditions. This study for the first time reveals multi-dimensional impacts of IBWT in China at the sub-basin scale. The results can be used by policymakers to inform water transfer and water management policies.

Research on coupled socio‐ecohydrological systems—implementing a highly integrative and interdisciplinary research agenda in the Doctoral School “Human River Systems in the 21st Century (HR21)”

AbstractThe access to an adequate quantity and quality of water is vital to sustain healthy ecosystems and human socioeconomic development. However, the shift from an agrarian, solar energy based to an industrialized, fossil fuel‐based socio‐metabolic regime has put natural water resources under stress and led to dramatic transformations of riverine landscapes in the Anthropocene. Thus, we need interdisciplinary research approaches that integrate the knowledge and methods from ecology, humanities, and engineering. The Doctoral School “Human River Systems in the 21st Century” (HR21) studies riverine landscapes as coupled socio‐ecohydrological systems (SEHS) within four research clusters, that is, connectivity, metabolism, vulnerability, and governance. HR21 analyzes the transformation processes and coevolution of nature and society in rivers and their response to future environmental, social, cultural, and economic drivers of change. HR21 aims to improve the understanding of the coupling of the socioeconomic, ecological, and hydrological systems within industrialized riverine landscapes to support their urgent, more sustainable transformation. To discuss how this agenda can be implemented, five different HR21 PhD projects are presented, clearly routed in one scientific domain, applying a combination of the research clusters and addressing various topics: (i) hydropower effects in high alpine river ecosystems, (ii) wastewater impacts on carbon storage and greenhouse gas fluxes in tropical wetlands, (iii) the nutrient retention and ecosystem service potential of floodplains in large river catchments, and the influence of hydrometeorological variables on (iv) the runoff response and on (v) the transit time distribution of runoff, both impacting water resource management at the basin level. These examples highlight how disciplinary PhD research can be framed within an interdisciplinary research agenda to coupled SEHS.

Return(s) on investment: Restoration spending in the Columbia River Basin and increased abundance of salmon and steelhead.

The decline in salmon and steelhead populations in the Columbia River Basin has been well documented, as have the decades-long, $9 billion restoration spending efforts by federal and state agencies. These efforts are mainly tied to Endangered Species Act (ESA) mandates for recovery of wild, naturally-spawning threatened or endangered fish species. The impact of these efforts remains poorly understood; many observers, including the federal courts, have long been concerned by the lack of evidence of recovery. Most studies evaluating restoration efforts have examined individual projects for specific species, reaches, or life stages, which limits the ability to make broad inferences at the basin level. There is a need to ask: is there evidence of an overall increase in wild fish abundance associated with the totality of these recovery efforts? To that end, the current study estimates fixed-effects panel regression models of adult returns of four species. Results indicate that restoration spending combined with hatchery production are associated with substantial increases in returning adult fish. Evidence of benefits to wild fish alone, however, require indirect approaches given the commingling of restoration spending with spending on hatchery releases, the impacts of spending on hatchery fish survival, and the density dependence effects of hatchery releases. To accomplish this, the models' predicted adult returns (both hatchery and wild fish) attributed to both spending and hatchery releases are compared to independent estimates of returning hatchery fish based on hatchery survival estimates (smolt-to-adult ratios). The comparison finds the model-predicted levels of adult returns due to spending and hatchery releases do not exceed the survival-rate based estimates for hatcheries alone, so that we are unable to reject the hypothesis of no benefits to wild fish from the restoration spending.