Multidisciplinary classification of Canadian river reaches to support the sustainable management of freshwater systems

2020 ◽  
Vol 77 (2) ◽  
pp. 326-341 ◽  
Author(s):  
Camille Ouellet Dallaire ◽  
Bernhard Lehner ◽  
Irena Creed

Climate change is altering the hydrology of Canadian rivers to an unprecedented degree. Consequently, sustainable freshwater management practices need to adapt, which include the development of integrated water resource strategies and environmental flow recommendations. A particular challenge arises for these assessments due to the highly diverse nature of river ecosystems across Canada. This diversity can be addressed by using a classification system to create manageable spatial units. Building upon and adapting the results of a global river reach classification scheme, we present a multidisciplinary K-means clustering approach to categorize all river reaches of Canada into 23 types at fine spatial resolution. The typology is based on classifier variables related to hydrology, mostly derived from modelled long-term means of monthly discharges, physiography, climate, and fluvial geomorphology. Resulting maps provide baseline information for rivers of all size classes, from small headwater streams to very large rivers, across the entire country, including unmonitored regions such as the High Arctic. The classification system also points to some strategic expansion opportunities for the current Canadian monitoring network of river gauging stations.

Koedoe ◽  
2005 ◽  
Vol 48 (1) ◽  
Author(s):  
G. Cleaver ◽  
L.R. Brown ◽  
G.J. Bredenkamp

Long-term conservation ecosystems require a broader understanding of the ecological processes involved. Because ecosystems react differently to different management practices, it is important that a description and classification of the vegetation of an area are completed. A vegetation survey of the valley areas of the Kammanassie Nature Reserve was undertaken as part of a larger research project to assess the environmental impacts of large-scale groundwater abstraction from Table Mountain Group aquifers on ecosystems in the reserve. From a TWFNSPAN classification, refined by Braun-Blanquet procedures, 21 plant communities, which can be grouped into 13 major groups, were identified. A classification and description of these communities, as well as a vegetation map of the different areas are presented. Associated gradients in habitat w ere identified by using an ordination algorithm (DECORANA). The diagnostic species as well as the prominent and less conspicuous species of the tree, shrub, forb and grass strata are outlined. The study also resulted in a total number of 481 species being identified and the discovery of a new Erica species. These vegetation surveys and descriptions provide baseline information for management purposes and that allows monitoring as well as similar surveys to be conducted in future.


2020 ◽  
Author(s):  
Lindsay Johnston ◽  
Dewey Dunnington ◽  
Mark Greenwood ◽  
Barret Kurylyk ◽  
Rob Jamieson

<p>The National Hydrometric Program, operated by the Water Survey of Canada, is the primary source of surface water quantity data in Canada. The network is cost-shared between the federal and provincial governments, and decisions relating to station placement are made according to both federal and provincial interests. Nova Scotia is a small maritime province in Atlantic Canada that is roughly one third the size of England and Wales and has a diverse climate and geology. The Nova Scotia hydrometric monitoring network currently consists of just 31 stations. The overall objective of this study was to determine how well the current network captures the level of hydrologic variability expected in the province using a regional catchment classification scheme. To accomplish this, we developed a combined inductive-deductive catchment classification system and applied it to the province’s active monitoring network and ungauged major watersheds. Initially, hydrologic signatures were used to quantify the catchment function of 47 long-term gauged catchments and to cluster similarly behaving catchments. We identified five generalized flow classes and then attempted to replicate this classification using a deductive-based decision tree framework with physiographic and meteorological explanatory variables. The validated decision tree was used to classify the active hydrometric network and 250+ major watersheds in the province. The network was assessed to determine how well it covered the expected hydrologic variability in the major watersheds across the province. The decision tree proved to be a useful tool for understanding the current network’s coverage and could also be easily applied by practitioners to identify appropriate donor catchments for ungauged watersheds.</p>


1986 ◽  
Vol 18 (4-5) ◽  
pp. 53-61 ◽  
Author(s):  
P. B. Birch ◽  
G. G. Forbes ◽  
N. J. Schofield

Early results from monitoring runoff suggest that the programme to reduce application of superphosphate to farmlands in surrounding catchments has been successful in reducing input of phosphorus to the eutrophic Peel-Harvey estuary. In the estuary this phosphorus fertilizes algae which grow in abundance and accumulate and pollute once clean beaches. The success of the programme has been judged from application of an empirical statistical model, which was derived from 6 years of data from the Harvey Estuary catchment prior to a major change in fertilizer practices in 1984. The model relates concentration of phosphorus with rate of flow and time of year. High phosphorus concentrations were associated with high flow rates and with flows early in the high runoff season (May-July). The model predicted that the distribution of flows in 1984 should have resulted in a flow-weighted concentration of phosphorus near the long-term average; the observed concentration was 25% below the long-term average. This means that the amount of phosphorus discharged into the Harvey Estuary could have been about 2 5% less than expected from the volume of runoff which occurred. However several more years of data are required to confirm this trend.


Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 291
Author(s):  
Ramón Bienes ◽  
Maria Jose Marques ◽  
Blanca Sastre ◽  
Andrés García-Díaz ◽  
Iris Esparza ◽  
...  

Long-term field trials are essential for monitoring the effects of sustainable land management strategies for adaptation and mitigation to climate change. The influence of more than thirty years of different management is analyzed on extensive crops under three tillage systems, conventional tillage (CT), minimum tillage (MT), and no-tillage (NT), and with two crop rotations, monoculture winter-wheat (Triticum aestivum L.) and wheat-vetch (Triticum aestivum L.-Vicia sativa L.), widely present in the center of Spain. The soil under NT experienced the largest change in organic carbon (SOC) sequestration, macroaggregate stability, and bulk density. In the MT and NT treatments, SOC content was still increasing after 32 years, being 26.5 and 32.2 Mg ha−1, respectively, compared to 20.8 Mg ha−1 in CT. The SOC stratification (ratio of SOC at the topsoil/SOC at the layer underneath), an indicator of soil conservation, increased with decreasing tillage intensity (2.32, 1.36, and 1.01 for NT, MT, and CT respectively). Tillage intensity affected the majority of soil parameters, except the water stable aggregates, infiltration, and porosity. The NT treatment increased available water, but only in monocropping. More water was retained at the permanent wilting point in NT treatments, which can be a disadvantage in dry periods of these edaphoclimatic conditions.


Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1474
Author(s):  
Stefan Grasl ◽  
Elisabeth Schmid ◽  
Gregor Heiduschka ◽  
Markus Brunner ◽  
Blažen Marijić ◽  
...  

(1) Objective: To evaluate long-term functional outcome in patients who underwent primary or salvage total laryngectomy (TL), TL with partial (TLPP), or total pharyngectomy (TLTP), and to establish a new scoring system to predict complication rate and long-term functional outcome; (2) Material and Methods: Between 1993 and 2019, 258 patients underwent TL (n = 85), TLPP (n = 101), or TLTP (n = 72). Based on the extent of tumor resection, all patients were stratified to (i) localization I: TL; II: TLPP; III: TLTP and (ii) surgical treatment (A: primary resection; B: salvage surgery). Type and rate of complication and functional outcome, including oral nutrition, G-tube dependence, pharyngeal stenosis, and voice rehabilitation were evaluated in 163 patients with a follow-up ≥ 12 months and absence of recurrent disease; (3) Results: We found 61 IA, 24 IB, 63 IIA, 38 IIB, 37 IIIA, and 35 IIIA patients. Complications and subsequently revision surgeries occurred most frequently in IIIB cases but rarely in IA patients (57.1% vs. 18%; p = 0.001 and 51.4% vs. 14.8%; p = 0.002), respectively. Pharyngocutaneous fistula (PCF) was the most common complication (33%), although it did not significantly differ among cohorts (p = 0.345). Pharyngeal stenosis was found in 27% of cases, with the highest incidence in IIIA (45.5%) and IIIB (72.7%) patients (p < 0.001). Most (91.1%) IA patients achieved complete oral nutrition compared to only 41.7% in class IIIB patients (p < 0.001). Absence of PCF (odds ratio (OR) 3.29; p = 0.003), presence of complications (OR 3.47; p = 0.004), and no need for pharyngeal reconstruction (OR 4.44; p = 0.042) represented independent favorable factors for oral nutrition. Verbal communication was achieved in 69.3% of patients and was accomplished by the insertion of voice prosthesis in 37.4%. Acquisition of esophageal speech was reached in 31.9% of cases. Based on these data, we stratified patients regarding the extent of surgery and previous treatment into subgroups reflecting risk profiles and expectable functional outcome; (4) Conclusions: The extent of resection accompanied by the need for reconstruction and salvage surgery both carry a higher risk of complications and subsequently worse functional outcome. Both factors are reflected in our classification system that can be helpful to better predict patients’ functional outcome.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jianqiang Li ◽  
Qibo Chen ◽  
Zhuang Li ◽  
Bangxiao Peng ◽  
Jianlong Zhang ◽  
...  

AbstractThe carbon (C) pool in forest ecosystems plays a long-term and sustained role in mitigating the impacts of global warming, and the sequestration of C is closely linked to the nitrogen (N) cycle. Accurate estimates C and N storage (SC, SN) of forest can improve our understanding of C and N cycles and help develop sustainable forest management policies in the content of climate change. In this study, the SC and SN of various forest ecosystems dominated respectively by Castanopsis carlesii and Lithocarpus mairei (EB), Pinus yunnanensis (PY), Pinus armandii (PA), Keteleeria evelyniana (KE), and Quercus semecarpifolia (QS) in the central Yunnan Plateau of China, were estimated on the basis of a field inventory to determine the distribution and altitudinal patterns of SC and SN among various forest ecosystems. The results showed that (1) the forest SC ranged from 179.58 ± 20.57 t hm−1 in QS to 365.89 ± 35.03 t hm−1 in EB. Soil, living biomass and litter contributed an average of 64.73%, 31.72% and 2.86% to forest SC, respectively; (2) the forest SN ranged from 4.47 ± 0.94 t ha−1 in PY to 8.91 ± 1.83 t ha−1 in PA. Soil, plants and litter contributed an average of 86.88%, 10.27% and 2.85% to forest SN, respectively; (3) the forest SC and SN decreased apparently with increasing altitude. The result demonstrates that changes in forest types can strongly affect the forest SC and SN. This study provides baseline information for forestland managers regarding forest resource utilization and C management.


Author(s):  
Kardison Lumbanbatu ◽  
Vincent Didiek Wiet Aryanto

Encompassing firms to apply green policy in a holistic management practices are strongly required in order to maintain competitive advantages and experience long-term marketing performance. This current empirical research is aimed to fill the lack of empirical findings and empirical studies on firm's innovative concept. Green-based product innovation, green management practices and green corporate image are presented as the antecedents and postulated as the sources of sustaining firm competitive advantages. A questionnaire-based survey was deployed to collect data from Large Scale Enterprises in Indonesia with Top Management, Operational and Marketing Managers served as respondents. 500 questionnaires were mailed and 388 were valid for further analysis. Data was analyzed by using Confirmatory Factor Analysis (CFA) and Structural Equation Modeling (SEM) via AMOS statistical software. Statistical findings demonstrated that green-based product innovation, green management practices and green corporate image significantly has a positive affect to sustain firm competitive advantages which is led to enhance long term marketing performance. However, green-based product innovation plays insignificant direct relationship on long term marketing performance. This study discusses some managerial implications for enterprises and recommendations on a basis of green implementation.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lisha Hou ◽  
Mier Li ◽  
Ju Wang ◽  
Yawen Li ◽  
Qianwen Zheng ◽  
...  

AbstractThe relationship between exercise and stroke recurrence is controversial. This study was designed to test whether an association exists between exercise and ischemic stroke recurrence in first-ever ischemic stroke survivors. Data were collected from January 2010 to June 2016. Baseline information was obtained during face-to-face interviews, and follow-up phone interviews were conducted every 3 months. Exercise type, frequency, intensity, and duration were recorded. Discrete-time survival analysis was used to determine the relationship between exercise and stroke recurrence. 760 first-ever ischemic stroke survivors who were able to exercise were enrolled. After adjusting for covariates, patients who exercised 3.5–7 h per week and more than 7 h per week had a lower relapse risk than patients who did not exercise (3.5–7: OR 0.415; > 7: OR 0.356). Moreover, if the fluctuation of exercise duration was over 4 h, the patients had a higher risk of stroke recurrence than those with variability of less than 2 h (OR 2.153, P = 0.013). Stroke survivors who engage in long-term regular mild exercise (more than 5 sessions per week and lasting on average 40 min per session) have a lower recurrence rate. Irregular exercise increases the risk of stroke recurrence.


Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 650
Author(s):  
Jesús Aguilera-Huertas ◽  
Beatriz Lozano-García ◽  
Manuel González-Rosado ◽  
Luis Parras-Alcántara

The short- and medium—long-term effects of management and hillside position on soil organic carbon (SOC) changes were studied in a centenary Mediterranean rainfed olive grove. One way to measure these changes is to analyze the soil quality, as it assesses soil degradation degree and attempts to identify management practices for sustainable soil use. In this context, the SOC stratification index (SR-COS) is one of the best indicators of soil quality to assess the degradation degree from SOC content without analyzing other soil properties. The SR-SOC was calculated in soil profiles (horizon-by-horizon) to identify the best soil management practices for sustainable use. The following time periods and soil management combinations were tested: (i) in the medium‒long-term (17 years) from conventional tillage (CT) to no-tillage (NT), (ii) in the short-term (2 years) from CT to no-tillage with cover crops (NT-CC), and (iii) the effect in the short-term (from CT to NT-CC) of different topographic positions along a hillside. The results indicate that the SR-SOC increased with depth for all management practices. The SR-SOC ranged from 1.21 to 1.73 in CT0, from 1.48 to 3.01 in CT1, from 1.15 to 2.48 in CT2, from 1.22 to 2.39 in NT-CC and from 0.98 to 4.16 in NT; therefore, the soil quality from the SR-SOC index was not directly linked to the increase or loss of SOC along the soil profile. This demonstrates the time-variability of SR-SOC and that NT improves soil quality in the long-term.


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