查看更多>>摘要：Error correction methods play an important role in improving the reliability and accuracy of hydrological modeling. The Dynamic system response curve (DSRC) is a novel and effective error correction method, but it may have the problem of over-correction. Therefore, two multi-model integrated error correction models based on DSRC and Bayesian model averaging (BMA) were proposed in this paper, namely DSRC-BMA and BMA-DSRC. The Sunshui River catchment is selected for a case study. First, three hydrological models including Xinanjiang model (XAJ), Hydrologiska Fyrans Vattenbalans modell (HBV) and vertically hybrid yield model (VHY) were employed. Then, a standard BMA model and three DSRC-based models were constructed separately. Finally, two multi-model integrated error correction models (DSRC-BMA and BMA-DSRC) were applied. The performance of these nine models was compared by Nash-Sutcliffe Efficiency coefficient (NSE), root mean squared error (RMSE) and percent bias (PBIAS). Results showed that the DSRC-based models presented better results than the standard BMA method and most DSRC-based models. Moreover, the uncertainty in BMA, DSRC-BMA and BMA-DSRC models were assessed. The 90% confidence interval of the BMA-DSRC model had high containing ratio values and low average relative bandwidth. Overall, the proposed multi-model integrated error correction methods are effective and can be applicable in improving streamflow modeling.
查看更多>>摘要：The large-scale implementation of water market programs worldwide has increased attention, while little research has paid attention to the water quality-related incentive coordination in water markets. Through the case of the water market of the East Route of China's South-North Water Transfer Project (SNWTP-ER), this study adopts a differential game perspective to examine the role of coordination mechanisms in water markets critically. By drawing on a large number of literature, which conceptualizes the incentives of the water market as rooted in market environmentalism, this study opens up the view on incentive-compatible coordination in water markets. By combining the numerical illustration of SNWTP-ER, this study finds that the coordination mechanism can mobilize a series of incentive-compatible coordination techniques and practices to achieve the optimal state of individuals and society simultaneously. In addition, the incentive-compatible coordination mechanism overcomes current water markets' inability to improve water quality and water allocation simultaneously, reflecting that market environmentalism may be a feasible solution to environmental crises. Finally, designing an incentive-compatible coordination mechanism in water markets is still challenging. The mechanism depends not only on the price and quality elasticity of water demand but also on finding the optimal coordination coefficient.
查看更多>>摘要：Coastal aquifers are affected by seawater intrusion (SWI), which causes their salinization, and yield submarine groundwater discharge (SGD), which feeds marine ecosystems. Characterizing groundwater dynamics in coastal aquifers is fundamental for understanding both processes and their interaction. In order to gain insights into SWI and SGD, we developed a 100 m-scale experimental field site located in a coastal alluvial aquifer at the mouth of an ephemeral stream on the Maresme coastline (Barcelona, Spain). Given the complexity of coastal aquifers and the dynamism of the processes occurring therein, understanding of the coupled processes can be achieved by combining methods and approaches across different hydrogeological disciplines. In this study, we conduct a detailed aquifer characterization based on the four pillars of hydrogeology: geology (lithological description and core samples analyses), geophysics (downhole and cross-hole measurements), hydraulics (pumping and tidal response tests) and hydrochemistry (major and minor elements, together with stable and Ra isotopes). Each discipline contributed to the characterization of the aquifer: (1) geological characterization revealed that the aquifer consists of fluvial sediments, organized in fining upwards sequences with alternating layers of gravel, sand and silt; (2) geophysics helped in identifying silt layers and their continuity, which play a segmenting role in the aquifer hydrodynamics; (3) hydraulics tests, specifically tidal response tests, evidenced that tidal loading, rather than hydraulic connection to the sea, drives the tidal response; and (4) hydrochemistry revealed a surprising high reactivity, as most ions reflect some reaction, beyond the expected cation exchange. The summary is that the aquifer, which initially looked like a homogeneous unconfined aquifer 22 m thick, effectively behaves as a multi-aquifer and reactive system with freshwater discharging beneath saltwater at several depths. The fact that thin silt layers caused such a significant impact opens new paths beyond this study both for coastal aquifer management (the possibility of transient pumping for freshwater resources) and marine ecology (expect diffuse groundwater discharge).
查看更多>>摘要：Hydrothermal activity and seismicity are abundant along the Yushu-Ganzi-Xianshuihe fault system (YGXFS) in the eastern Tibetan Plateau. However, the processes and factors that control hydrothermal fluid circulation at a regional scale remain less constrained, and the relationship between geothermal anomaly and seismic activity is poorly known. In this study, we report an integrated dataset of thermal water chemistry (delta O-18(H2O), delta D-H2O, and delta C-13 of dissolved inorganic carbon (DIC)) to identify the origin, circulation path, and reservoir properties of hydrothermal fluids and then reveal the relationship between fluid circulation and seismic activity. The thermal waters are mainly classified as Na-HCO3 type with minor Ca-Na-HCO3 and Na-HCO3-Cl types. The delta O-18(H2O) (-18.7 parts per thousand to -14.5 parts per thousand) and delta D-H2O (-142 parts per thousand to -110 parts per thousand) values indicate recharge of meteoric waters, which infiltrated along the YGXFS to 2-6 km depths and underwent mixing with deep fluids prior to their discharge at the surface. A mass balance model based on delta C-13(DIC) values (-4.3 parts per thousand to 5.9 parts per thousand) and DIC contents of thermal waters reveals the involvement of CO2-bearing fluids from mantle and thermo-metamorphic decarbonation of crustal marine limestones in tectonic CO2 outgassing from the active fault. The estimated reservoir temperatures (85-336 degrees C) based on silica geothermometer of the thermal waters decrease from southeast to northwest along the YGXFS. Notably, the epicenters of strong earthquakes (Ms >= 6) are mostly located in the transition zone of geothermal anomalies according to spatial distribution of the reservoir temperatures. Combined with geological and geophysical information, we suggest that the heterogeneity of crustal thermal structure and the upwelling of deep fluids may play an essential role in the distribution of thermal springs and the high frequency of earth-quakes along the YGXFS.
查看更多>>摘要：Soil is a major natural resource fundamental for food production, and a habitat for living organisms. It is therefore extremely important to prevent its erosion. It is assumed that 50% of erosion at the global scale is caused by water. A relatively low number of studies model soil loss in Northern and Eastern Europe. Although that region currently contributes to total soil loss the least, the projected long-term climate change in Europe is likely to affect soil loss due to changes in rainfall characteristics. This study quantifies historical soil loss rates based on high-resolution datasets, and assesses the impact of the projected climate change on long-term average annual soil erosion rates in Poland, located in the temperate climate zone, using the Revised Universal Soil Loss Equation (RUSLE) model. The study investigates the projected changes for two future time horizons, namely: 2021-2050 (near future - NF) and 2071-2100 (far future - FF), under two different Representative Concentration Pathways (RCP) 4.5 and 8.5. To account for the uncertainty of individual climate models, an ensemble of nine EURO-CORDEX model scenarios was used. Based on the multi-model ensemble median, the average soil erosion rate in Poland for the historical period is 0.48 t ha(-1) yr(-1). The total annual soil loss in Poland is estimated at 14 Mt. The highest soil loss rate is observed in the south of Poland with mean annual erosion rate of 1.7 t ha(-1) yr(-1). Although it occupies only 16% of the territory of Poland, its share in total soil loss in the country is 62% (8.6 Mt year(-1)). The average projected potential soil erosion by water in the future increases gradually, reaching +7% (RCP4.5 NF), +8% (RCP8.5 NF), +13% (RCP4.5 FF), and +18% (RCP8.5 FF). The results of this study might be valuable for the development of the national soil conservation policy. The study fills the spatial gap in modelling of changes in soil erosion caused by climate in the Northern and Eastern part of Europe. Due to the lack of other national studies in the region, the directions of such changes could be transferrable to countries in the same climate zones, with a similar vegetation cover structure.
Rabideau, AlanZhu, ZhenduoTorres, Mara NarineMatott, L. Shawn...
11页
查看更多>>摘要：The installation of Green Infrastructure (GI) is a popular strategy for reducing stormwater runoff that contributes to Combined Sewer Overflows (CSOs). However, quantifying the impact of proposed GI systems on CSO discharges is a difficult task that requires the simulation of runoff in a complex network of land parcels, drainage controls, and sewer pipes. In this study, the performance of Porous Pavement (PP) was examined, with a focus on how the spatial design of PP features affects predicted CSO volume. Numerical experiments were performed to explore how simulation-based designs can identify specific subcatchments for cost-effective PP implementation subject to budgetary constraints. Among the alternative design strategies considered, simulation-optimization was effective at finding cost-effective solutions. The experiments showed that PP can achieve substantial CSO reductions across a range of rainfalls, budgets, and CSO drainage characteristics, but the performance is sensitive to the spatial configuration of the features. Good-performing systems were also identified by generating multiple realizations via a randomized clustering strategy, with additional improvement provided by the more computationally expensive optimization process.
查看更多>>摘要：Estimating global reservoir evaporation losses is essential for reservoir regulation, operation, and associated water resources management. Estimating globe-scale reservoir evaporation losses remains a gap due to limited accessibility of global long-term continuous reservoir geographic information. Two new datasets, the Global Reservoir Surface Area Dataset and the Global Reservoir and Dam Database, try to address inaccessibility and provide an opportunity to bridge the gap. Here, we used the two datasets to estimate the monthly reservoir evaporation volume of global 7242 large reservoirs from 1985 to 2016. Around 339.8 km(3) of water is estimated to evaporate from these large reservoirs annually during 1985-2016, and the loss amount is near ~& nbsp;73% of the municipal water withdrawal in 2010. From 1985 to 2016, the global reservoir evaporation volume increases significantly at a rate of ~& nbsp;2.0 km(3)/a, and 80% of the increment is contributed by middle-income countries. A surge in reservoir construction in middle-income countries after 1985 triggers the increment. The results can benefit the regulation and operation of reservoirs and realize their role in global water conservation and management.
Tyndall, John C.Morris, Chris J.Koontz, Tomas M.Prokopy, Linda S....
12页
查看更多>>摘要：Decision-support tools (DSTs) are a type of innovation that can facilitate science-based decision-making, including nonpoint source pollution management in agricultural watersheds. However, organizational readiness for adopting innovations is a topic that has received limited attention in the literature. With the goal of filling this knowledge gap, we draw upon the diffusion of innovations (DOI) theory and literature around use of science by agency staff to assess United States Department of Agriculture Natural Resources Conservation Services' (USDANRCS) readiness towards using the Agricultural Conservation Planning Framework (ACPF) - a type of DST. To that end, we conducted 23 semi-structured, in-depth interviews with 27 NRCS staff holding leadership positions to explore how they perceive and use the ACPF, and their perceptions of organizational and structural elements that could enable or hinder NRCS' readiness to adopt the ACPF. Results suggest that NRCS' readiness was an outcome of both organizational- and individual-level factors. Factors such as perceived scientific credibility and the influential role of leaders positively influenced NRCS' readiness; however, factors such as low levels of ACPF knowledge and perceived complexity negatively influenced NRCS' readiness. Overall, our findings suggest that NRCS is in the initial stages of getting ready to adopt the ACPF, and that there is a need for the agency to pilot ACPF in different watersheds and measure social and bio-physical outcomes.
查看更多>>摘要：Sustainable Urban Drainage Systems (SuDS) promote environmental protection and climate resilience. SuDS implementation in cold climates faces concerns of impaired hydrological function due to infiltration-reducing frost. The goal of this research was to assess the seasonal variations in infiltration and how different surface covers prevalent in and near coastal cities respond to frequent rain-on-snow and freeze-thaw cycles. A total of 28 constant head infiltration measurements were conducted over a period of 28 months in Urridaholt in Gardabaer, Iceland (64. 4'18.46 '' N, 21 degrees 54'37.11 '' W) in a grass swale, lupine, and barren terrains. All test locations exhibited infiltration-inhibiting frost in winter, whose severity increased with frequent snow and freeze-thaw cycles. The grass swale resisted structural deformations resulting from frost, which was attributed to the high near-surface porosity within the intertwined root layer and the high drainage capacity of the underlying soil. The sparsely vegetated lupine and the barren area experienced severe frost heaving and cracking, and soil structural collapse which led to bypass flow upon thawing. The non-vegetated site had 30 to 50 times lower infiltration during winter (19 mm h(-1)) compared to the grass swale and lupine field (630- and 890-mm h(-1), respectively), and twenty times lower during summer and fall (45 mm h(-1) vs. similar to 1000 mm h(-1)). The study concludes that frequent warming and cooling renders soils particularly vulnerable to frost. Vegetation plays an instrumental role in maintaining the hydrological functions of SuDS in winter. Therefore, the greening of urban centers is an important step towards climate resiliency. Plant selection and SuDS design criteria need to account for cold climate hydrological performance. In that regard, plants that limit sunlight and fully shed their vegetation in winter, such as the invasive lupine, can potentially contribute to frost formation and increase runoff generation.
查看更多>>摘要：Effective watershed management and protection of water resources from non-point source pollution require identification, prioritization, and targeting of pollutant source areas. Process-based hydrology and water quality models are powerful heuristic tools for land and water resources managers. However, because of their complexity, such models are often under-utilized as management prioritization and planning tools. In this paper, we present a prioritization, interactive visualization, and analysis tool (Pi-VAT) that is programmed to synthesize multi-scenario, multi-watershed outputs from process-based geospatial models. We demonstrate the utility of Pi VAT to examine simulated hydrologic, sediment, and water quality response at the hillslope/hydrologic response unit (HRU) scale. We apply Pi-VAT to output from multiple watersheds and for multiple management scenarios and treatments from two geospatial models for watershed management: Water Erosion Prediction Project (WEPP) and Soil & Water Assessment Tool (SWAT). Pi-VAT was developed using the Shiny web application framework for the R programming language. In a matter of minutes, Pi-VAT can synthesize overwhelming amounts of output from process-based models into information useful for land and water resources managers. We illustrate the use of Pi-VAT to interactively identify, quantify, and visualize areas that are most susceptible to disturbance under different scenarios and provide a synthesis approach based on land use, soil type, and slope steepness. This approach guides land and water resources managers in prioritizing the areas of the watershed that provide the maximum reduction in pollutant loads while treating the least amount of area. Pi-VAT provides a flexible reactive platform for the development of decision support tools based on process-based models intended for watershed management and research applications.
NSTL
Elsevier