scholarly journals A Case-Study Application of the Experimental Watershed Study Design to Advance Adaptive Management of Contemporary Watersheds

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2355 ◽  
Author(s):  
Jason A. Hubbart ◽  
Elliott Kellner ◽  
Sean J. Zeiger

Land managers are often inadequately informed to make management decisions in contemporary watersheds, in which sources of impairment are simultaneously shifting due to the combined influences of land use change, rapid ongoing human population growth, and changing environmental conditions. There is, thus, a great need for effective collaborative adaptive management (CAM; or derivatives) efforts utilizing an accepted methodological approach that provides data needed to properly identify and address past, present, and future sources of impairment. The experimental watershed study design holds great promise for meeting such needs and facilitating an effective collaborative and adaptive management process. To advance understanding of natural and anthropogenic influences on sources of impairment, and to demonstrate the approach in a contemporary watershed, a nested-scale experimental watershed study design was implemented in a representative, contemporary, mixed-use watershed located in Midwestern USA. Results identify challenges associated with CAM, and how the experimental watershed approach can help to objectively elucidate causal factors, target critical source areas, and provide the science-based information needed to make informed management decisions. Results show urban/suburban development and agriculture are primary drivers of alterations to watershed hydrology, streamflow regimes, transport of multiple water quality constituents, and stream physical habitat. However, several natural processes and watershed characteristics, such as surficial geology and stream system evolution, are likely compounding observed water quality impairment and aquatic habitat degradation. Given the varied and complicated set of factors contributing to such issues in the study watershed and other contemporary watersheds, watershed restoration is likely subject to physical limitations and should be conceptualized in the context of achievable goals/objectives. Overall, results demonstrate the immense, globally transferrable value of the experimental watershed approach and coupled CAM process to address contemporary water resource management challenges.

2018 ◽  
Vol 69 (10) ◽  
pp. 2940-2952 ◽  
Author(s):  
Martina Zelenakova ◽  
Pavol Purcz ◽  
Radu Daniel Pintilii ◽  
Peter Blistan ◽  
Petr Hlustik ◽  
...  

Evaluating trends in water quality indicators is a crucial issue in integrated water resource management in any country. In this study eight chemical and physical water quality indicators were analysed in seven river profiles in the River Laborec in eastern Slovakia. The analysed water quality parameters were biochemical oxygen demand (BOD5), chemical oxygen demand (CODCr), pH, temperature (t), ammonium nitrogen (NH4+-N), nitrite nitrogen (NO2--N), nitrate nitrogen (NO3--N), and total phosphorus (TP). Data from the monitored indicators were provided by the Ko�ice branch of the Slovakian Water Management Company, over a period of 15 years from 1999 to 2013. Mann�Kendall non-parametric statistical test was used for the trend analysis. Biochemical and chemical oxygen demand, ammonium and nitrite nitrogen content exhibit decreasing trends in the River Laborec. Decreasing agricultural activity in the area has had a significant impact on the trends in these parameters. However, NO2--N was the significant parameter of water quality because it mostly exceeds the limit value set in Slovak legislation, Regulation No. 269/2010 Coll. In addition, water temperature revealed an increasing trend which could be caused by global increase in air temperature. These results indicate that human activity significantly impacts the water quality.


1987 ◽  
Vol 19 (9) ◽  
pp. 19-29 ◽  
Author(s):  
Edwin E. Herricks ◽  
Maria I. Braga

Comprehensive river basin management mast move beyond narrowly focused programs dealing with water quantity or water quality. A more comprehensive approach to river basin management recognizes that both flow quantity and water quality can be summarized as habitat measures. A number of well developed physical habitat analysis and prediction procedures are presently available. Several computerized systems available from the U.S.Fish and Wildlife Service (Habitat Suitability Index - HSI and PHysical HABitat SIMulation - PHABSIM) provide macrohabitat definition. We have developed a water quality based habitat component which operates effectively for general analysis. With an emphasis on site specific management in the United States, the macrohabitat definition procedures may not meet all river basin management and planning requirements. This paper reviews the results of research which characterizes microhabitat in streams and rivers and provides a valuable extension to basin management procedures.


2006 ◽  
Vol 54 (11-12) ◽  
pp. 47-55 ◽  
Author(s):  
S.-W. Liao ◽  
J.-Y. Sheu ◽  
J.-J. Chen ◽  
C.-G. Lee

Factor analysis was conducted to explain the characteristics and variation in the quality of water during the disassembly of oyster frames and fishery boxes. The result shows that the most important latent factors in the Tapeng Lagoon are the ocean factor, the primary productivity factor, and the fishery pollution factor. Canonical discriminant analysis is applied to identify the source of pollution in neighbouring rivers outside the Tapeng Lagoon. The two constructed discriminant functions (CDFs) showed a marked contribution to all the discriminant variables, and that total nitrogen, algae, dissolved oxygen, and total phosphate combined in the nutrient effect factor. The recognition capacities in these two CDFs were 95.6% and 4.4%, respectively. The water quality in the Kaoping river most strongly affected the water quality in the Tapeng Lagoon. Disassembling the oyster frames and fishery boxes improved the water quality markedly. However, environmental topographic conditions indicate that strengthening stream pollution prevention and constructing another entrance to the ocean are the best approaches for improving the quality of water in the Tapeng Lagoon by reducing eutrophication. These approaches and results yield useful information concerning habitat recovery and water resource management.


2021 ◽  
Author(s):  
James Harding

<p>Earth Observation (EO) satellites are drawing considerable attention in areas of water resource management, given their potential to provide unprecedented information on the condition of aquatic ecosystems. Despite ocean colours long history; water quality parameter retrievals from shallow and inland waters remains a complex undertaking. Consistent, cross-mission retrievals of the primary optical parameters using state-of-the-art algorithms are limited by the added optical complexity of these waters. Less work has acknowledged their non- or weakly optical parameter counterparts. These can be more informative than their vivid counterparts, their potential covariance would be regionally specific. Here, we introduce a multi-input, multi-output Mixture Density Network (MDN), that largely outperforms existing algorithms when applied across different bio-optical regimes in shallow and inland water bodies. The model is trained and validated using a sizeable historical database in excess of 1,000,000 samples across 38 optical and non-optical parameters, spanning 20 years across 500 surface waters in Scotland. The single network learns to predict concurrently Chlorophyll-a, Colour, Turbidity, pH, Calcium, Total Phosphorous, Total Organic Carbon, Temperature, Dissolved Oxygen and Suspended Solids from real Landsat 7, Landsat 8, and Sentinel 2 spectra. The MDN is found to fully preserve the covariances of the optical and non-optical parameters, while known one-to-many mappings within the non-optical parameters are retained. Initial performance evaluations suggest significant improvements in Chl-a retrievals from existing state-of-the-art algorithms. MDNs characteristically provide a means of quantifying the noise variance around a prediction for a given input, now pertaining to real data under a wide range of atmospheric conditions. We find this to be informative for example in detecting outlier pixels such as clouds, and may similarly be used to guide or inform future work in academic or industrial contexts. </p>


Author(s):  
Michael C. Withers ◽  
Chi Hon Li

Causal identification is an important consideration for organizational researchers as they attempt to develop a theoretical understanding of the causes and effects of organizational phenomena. Without valid causal identification, insights regarding organizational phenomena are challenging given their inherent complexity. In other words, organizational research will be limited in its scientific progression. Randomized controlled experiments are often suggested to provide the ideal study design necessary to address potential confounding effects and isolate true causal relationships. Nevertheless, only a few research questions lend themselves to this study design. In particular, the full randomization of subjects in the treatment and control group may not be possible due to the empirical constraints. Within the strategic management area, for example, scholars often use secondary data to examine research questions related to competitive advantage and firm performance. Natural experiments are increasingly recognized as a viable approach to identify causal relationships without true random assignment. Natural experiments leverage external sources of variation to isolate causal effects and avoid potentially confounding influences that often arise in observational data. Natural experiments require two key assumptions—the as-if random assignment assumption and the stable unit treatment value assumption. When these assumptions are met, natural experiments can be an important methodological approach for advancing causal understanding of organizational phenomena.


Author(s):  

<em>Abstract.</em>—The Willamette River is Oregon’s largest river, with a basin area of 29,800 km<sup>2</sup> and a mean annual discharge of 680 m<sup>3</sup>/s. Beginning in the 1890s, the channel was greatly simplified for navigation. By the 1940s, it was polluted by organic wastes, which resulted in low dissolved oxygen concentrations and floating and benthic sludge deposits that hindered salmon migration and boating. Following basin-wide secondary waste treatment and low-flow augmentation, water quality markedly improved, salmon runs returned, and recreational uses increased. However, water pollution remains a problem as do physical habitat alterations, flow modification, and alien species. Fish assemblages in the main-stem Willamette River were sampled systematically, but with different gear, in the summers of 1945, 1983, and 1999. In the past 53 years, tolerant species occurrences decreased and intolerant species occurrences increased. In the past 20 years, alien fishes have expanded their ranges in the river, and four native fish species have been listed as threatened or endangered. We associate these changes with improved water quality between 1945 and 1983, fish migrations, altered flow regimes and physical habitat structure, and more extensive sampling.


Author(s):  
M. E. Folkoff ◽  
E. A. Venso ◽  
D. W. Harris ◽  
M. F. Frana ◽  
M. S. Scott

This study is only the second to use DNA fingerprinting technology in Maryland to identify fecal coliform sources in order to guide the implementation of water pollution control practices in a watershed with bacterial impairment. By combining the use of digital air photos and GPS with GIS, fieldwork is planned and conducted more efficiently because sample sites can be selected that accurately represent the physical environment of the study area. We can also return to the field and find our sample sites or locate new ones, even in the remotest part of the study area. It is also possible to more accurately map the data directly in the context of its physical environment, greatly increasing the quality of analysis. The integration of DNA fingerprinting techniques with GIS shows great promise for extending our capabilities to identify the controls on water quality and point sources of waterborne health hazards.


Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 914 ◽  
Author(s):  
Guangyi Deng ◽  
Xiaohan Yao ◽  
Haibo Jiang ◽  
Yingyue Cao ◽  
Yang Wen ◽  
...  

Small- and medium-sized rivers are facing a serious degradation of ecological function in water resource-scarce regions of Northern China. Reservoir ecological operation can restore the damaged river ecological environment. Research on reservoir ecological operation and watershed management of urban rivers is limited in cold regions of middle and high latitudes. In this paper, the urban section of the Yitong River was selected as the research object in Changchun, Northern China. The total ecological water demand and reservoir operation water (79.35 × 106 m3 and 15.52 × 106 m3, respectively) were calculated by the ecological water demand method, and a reservoir operation scheme was established to restore the ecological function of the urban section of the river. To examine the scientific basis and rationality of the operation scheme, the water quality of the river and physical habitat after carrying out the scheme were simulated by the MIKE 11 one-dimensional hydrodynamic-water quality model and the Physical Habitat Simulation Model (PHABSIM). The results indicate that the implementation of the operation scheme can improve the ecological environment of the urban section of the Yitong River. A reform scheme was proposed for the management of the Yitong River Basin based on the problems in the process of carrying out the operation schemes, including clarifying department responsibility, improving laws and regulations, strengthening service management, and enhancing public participation.


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