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This study assesses the impact of climate change on streamflow characteristics in the Lualaba River Basin (LRB), an important yet ungauged watershed in the Congo River Basin. Two conceptual hydrological models, HBV-MTL and GR4J, were calibrated using the reanalysis datasets and outputs of Generalized Circulation Models (GCMs) under CMIP6 during the historical period. The hydrological models were fed with outputs of GCMs under shared socioeconomic pathways (SSPs) 2-45 and 5-85, moderate- and high-radiative future scenarios. The results demonstrate that hydrological models successfully simulate observed streamflow, but their performance varies significantly with the choice of climate data and model structure. Interannual streamflow (Q) percentiles (10, 50, 90) were used to describe flow conditions under future climate. Q10 is projected to increase by 33% under SSP2-45 and 44% under SSP5-85, suggesting higher flow conditions that are exceeded 90% of the time. Q50 is also expected to rise by almost the same rate. However, a considerably higher Q90 is projected to increase by 56% under the moderate- and 80% under the high-radiative scenario. These indicate the overall higher water availability in this watershed to be used for energy and food production and the need for flood risk management. [ABSTRACT FROM AUTHOR]

In regions characterized by continuous permafrost, hydrological modeling remains a complex activity, primarily due to constraints related to the prevailing climatic conditions and the specific behavior of the active layer. High-latitude regions receive less solar radiation; thus, most creeks are active only during summertime and stay frozen in the winter. To realistically simulate watersheds underlain by continuous permafrost, the heat transfer through the soil needs to be accounted for in the modeling process. In this study, a watershed located in a continuous permafrost zone in Russia is investigated. A model is proposed to integrate this heat transfer into an existing conceptual rain-flow transformation model, Hydrologiska Byråns Vattenbalansavdelning (HBV), to calculate the seasonal thaw depth and determine the components of water balance. The proposed integration is a novelty compared to the standard model, as it enables the physical and thermal properties of the soil to be taken into account. It was found that the proposed model, HBV-Heat, performs better than the stand-alone HBV model. Specifically, the average Nash–Sutcliffe efficiency (NSE) increases by 30% for the whole calibration period. In terms of the water balance components, the results are consistent with previous studies, showing that surface runoff represents 64% of the observed precipitation. [ABSTRACT FROM AUTHOR]

Sewer deterioration, prevalent in municipalities throughout Canada, prompted the Quebec provincial government to implement a 1% renewal rate of the conduit facilities as to meet the goals of the national water plan adopted in 2002. Some of the most affected municipalities are usually the ones already under tight budget constraints, and cannot therefore afford the use of CCTV inspections in assessing the state of their sewage systems. This paper proposes a probabilistic model devised to survey the current conduit deterioration state caused by maintenance and operational conditions. Based on the multinomial logistic regression, this model--successfully applied to a case study in Quebec--shows the temporal deterioration of conduits for different material types. On average, it correctly predicted 54% of outcomes for transition probabilities involving both condition classes 1 (excellent) and 2 (good), and it showed a 59% correct prediction for class 3 condition (fair). This model is a recommended tool--applicable in combination with current exploratory techniques--for an effective prevention of conduits failure. Key words: sewers, deterioration, logistic regression. La plupart des municipalites au Canada font face a des problemes lies a la deterioration des conduites d'assainissement urbain. Le gouvernement du Quebec demande ainsi aux municipalites de pouvoir atteindre un taux de remplacement annuel de 1 % afin de rencontrer les objectifs du plan national de l'eau lance en 2002. Etant donne les contraintes budgetaires, les municipalites ne sont pas toujours en mesure d'effectuer des inspections televisees (CCTV) afin de prevoir le moment d'intervention dans leurs reseaux. De ce fait, il parait tout indique d'elaborer un modele probabiliste devant permettre de determiner le niveau d'operation et d'entretien des conduites. Base sur la regression logistique multinomiale, le modele developpe dans cette etude evalue la deterioration des conduites des differents materiaux en fonction du temps. Ce modele a permis de predire correctement dans 54 % de cas la probabilite de transition impliquant une conduite a l' etat 1 (excellent) et 2 (bon) alors que 59 % des cas ont ete predits avec succes pour les probabilites de transition impliquant une conduite a l'etat 3 (acceptable) pour deux municipalites du Quebec. Cet outil est suggere pour aider les gestionnaires a anticiper le dysfonctionnement des reseaux. Mots-cles: conduites, degradation de la performance des conduites, regression multinomiale. [Traduit par la Redaction], 1. Introduction Numerous Canadian municipalities are experiencing rapid deterioration and sanitary issues due to their aging sewer networks. In Quebec, the situation is so dire that the provincial government put [...]

The non controlled management of runoff stormwater volumes may cause the quality degradation of water tables and water surfaces. An investigation conducted in 2007 on the stormwater management in Quebec shows the existence of certain gaps in the design of the stormwater networks, when more and more expectations are coming from citizens and sustainable development requirements. It becomes therefore urgent to set up in Quebec a new stormwater management approach based on sustainable and integrated solutions. The present paper lists a brief state of the art in Quebec regarding the stormwater issue. Also it analyzes the Best Management Practices (BMP) applicable in Quebec and it describes a strategy to control the stormwater runoff volumes. Eight suggestions for a public action in the context of a sustainable development are developed. A nine-step methodology process is presented to show how professionals involved in environment issues may apply these eight suggestions. Key words: urban drainage, sustainable development, integrated management, quantitative and quality control, best management practices. Le rejet non controle des eaux pluviales est une importante cause de la degradation de la qualite de l'environnement, notamment au niveau de la nappe phreatique, des milieux recepteurs et des habitations. L'analyse de l'eetat actuel de la gestion des eaux pluviales au Quebec montre l'existence de certaines lacunes dans la conception des reseaux de drainage urbain, avec des exigences et des attentes de plus en plus larges de la part des citoyens ainsi que des nouveaux defis associesau developpement durable. Il devient donc urgent de mettre en place une nouvelle approche pour geerer de maniere durable et integree la question du drainage urbain dans le contexte specifique quebeecois. Le present article offre une revue succincte de la litrerature, une analyse exhaustive des pratiques de gestion optimale (PGO) applicables pour le Quebec et une strategie de controle des volumes de ruissellement des eaux pluviales. Il decrit huit propositions d'action publique elaborees pour une gestion durable et integree de ces eaux au Quebec. Une demarche methodologique sommaire en neuf etapes y est egalement presentee pour aider les acteurs du milieu a appliquer les propositions suggerees. Mots-cles: drainage urbain, gestion durable, gestion integree, controle quantitatif et qualitatif, techniques alternatives, pratiques de gestion optimale, developpement durable., 1. Introduction Le rejet non controle des eaux pluviales est une importante cause de la degradation de la qualite de l'environnement sur plusieurs plans : la nappe phreatique, les milieux [...]

Eight suggestions for a public action and a methodology to apply them have been described in a complementary paper, to incite the professionals from Quebec involved in the sustainable stormwater drainage management to target clear objectives. The present paper reports a case study where these eight suggestions were applied in a developing residential sector located in a Quebec municipality, following the proposed methodology. The main objective of this paper is to show the feasibility of some selected Best Management Practices (BMP). The brief economical analysis performed in the study shows that integration of some applicable BMP in Quebec cities seems to be cost effective, when clear objectives are targeted. Nevertheless a deep analysis is still necessary to identify all feasible BMP designed to improve the urban drainage management and to determine the real costs linked to the new techniques investment. Key words: urban drainage, sustainable development, integrated management, quantitative and quality control, best management practices. Pour inciter les professionnels quebecois engages dans la gestion durable et optimale des eaux pluviales a cibler des objectifs clairs, huit propositions d'action publique, de meme qu'une demarche methodologique sommaire pouvant aider a utiliser ces propositions de maniere avisee et responsable, ont ete suggerees dans l'article compleementaire. Le present article traite d'une etude de cas ou les huit propositions ont ete appliqueees dans un secteur en deeveloppement residentiel d'une municipalite queebecoise, en suivant la meethodologie proposeee. L'objectif principal du present article est de montrer la faisabilite d'utiliser de nouvelles pratiques de gestion optimale (PGO) des eaux pluviales au Quebec. L'analyse eeconomique sommaire, deecrite seulement a titre indicatif dans cet article, montre que l'implantation de quelques PGO applicables au Quebec sur la base d'objectifs precis de gestion integree et durable, est realisable et meme rentable. Une analyse technique poussee reste toutefois necessaire pour identifier toutes les PGO susceptibles d'ameliorer les conditions de drainage urbain au Quebec, de meeme qu'une analyse eeconomique approfondie reste indispensable pour preciser les veritables coflts lies a l'investissement dans les nouvelles techniques. Mots-cles: drainage urbain, gestion durable, gestion integree, controle quantitatif et qualitatif, techniques alternatives, pratiques de gestion optimale, deeveloppement durable., 1. Introduction Fuamba et al. (2008) ont effectue une etude analytique et comparative entre la pratique actuelle de la gestion des eaux pluviales au Quebec et celles mises au point [...]

Abstract: Optimal management of power plant units is achieved when the global efficiency of the units and the minimization of the total hydraulic head losses through the water transportation systems [...]

The effects of different variables of closed conduit transient partially pressurized flows on the maximum air pressure are investigated from an energy exchange perspective. It was found that when the air length increases, the maximum pressure decreases because a larger portion of the driving energy will be stored as kinetic energy in the pressurized flow and is dissipated by the friction force. In contrast, when the water depth of the free-surface flow increases, the kinetic energy and dissipating energy of the pressurized flow decrease. Thus, the energy absorbed by the air pocket increases, and the maximum pressure increases. However, after a water depth ratio of 0.8, the maximum pressure decreases even though the kinetic energy and dissipating energy decrease. The reason is that the moving interface receives enough energy, and pressurization of the free-surface flow zone occurs. Note that this pressurization was experimentally observed by Hamam and McCorquodale (1982). [ABSTRACT FROM AUTHOR]

The Low Impact Development (LID) Control module is utilized in the United States Environmental Protection Agency’s Stormwater Management Model (USEPA SWMM) to predict the hydraulic performance of a variety of sustainable stormwater technologies. Data collected in 2019 from the monitoring of a pilot project in Montreal was used to verify the ability of the Bioretention LID Control (which assumes a rectangular cross-section) to accurately simulate outflow from a structure with a trapezoidal cross-section. Two types of LID facility were modeled: one releases captured inflow through a perforated underdrain below the soil layer (bioretention basin; BB); and the other is drained at the surface of the soil layer (vegetated swale; VS). Initially, the modeled LID structures were sized identically to the field surface areas. However, it was necessary to change their model representation to account for the non-rectangular shape of the soil layer. In addition, a sensitivity analysis was completed, and the most influential parameters were identified as the conductivity slope and seepage rate. Both the alteration of the LID structure representation and the parametric calibration greatly improved the simulated outflows from the vegetated swale resulting in an increase of the Nash–Sutcliffe efficiency (NSE) coefficient from −0.6 to 0.64 (NSE >0.5 is acceptable for hydrologic models according to the literature). The bioretention basin calibration did not prove as successful. The evaluated LID Control module presented better predictive capabilities for the basin with a simpler overall design (VS). [ABSTRACT FROM AUTHOR]