Stochastic Artificial Aeration Control for Regional Drainage Basins

1982 ◽  
Vol 104 (4) ◽  
pp. 337-342
Author(s):  
N. M. Olgac ◽  
R. W. Longman ◽  
C. A. Cooper
Keyword(s):  
Regional Planning ◽  
Drainage Basin ◽  
Measurement Data ◽  
Drainage Basins ◽  
Artificial Aeration ◽  
Stochastic Nature ◽  
Mathematical Mode ◽  
Discrete Nature ◽  
River Drainage Basin ◽  
Quality Measurements

Regional planning for the abatement of pollution in a river drainage basin can profitably include artificial in-stream aeration as a key component in a coordinated abatement effort. This technique compares very favorably, on a capital expense basis, with more traditional abatement methods. A general drainage basin structure containing a river, or rivers, with tributaries in a graphical tree structure is considered. The mathematical mode developed is a general formulation which deals with the arbitrary number of confluences in the basin, tributaries entering the controlled section, the spacially discrete nature of the feedback water quality measurements and of the treatment sites, and the stochastic nature of the measurements and pollution sources. An optimal aeration strategy is determined for each aerator as a function of measurement data throughout the basin, and examples are given to illustrate the results.

scholarly journals Evaluation of Satellite-Derived Products for the Daily Average and Extreme Rainfall in the Mearim River Drainage Basin (Maranhão, Brazil)

2021 ◽  
Vol 13 (21) ◽  
pp. 4393
Author(s):  
Ana Carolina Freitas Xavier ◽  
Anderson Paulo Rudke ◽  
Edivaldo Afonso de Oliveira Serrão ◽  
Paulo Miguel de Bodas Terassi ◽  
Paulo Rógenes Monteiro Pontes
Keyword(s):  
Drainage Basin ◽  
Daily Rainfall ◽  
Extreme Rainfall ◽  
Kendall Test ◽  
Drainage Basins ◽  
Satellite Precipitation ◽  
River Drainage ◽  
Monthly Scale ◽  
Precipitation Estimates ◽  
River Drainage Basin

Satellite precipitation estimates are used as an alternative or as a supplement to the records of the in situ stations. Although some satellite precipitation products have reasonably consistent time series, they are often limited to specific geographic areas. The main objective of this study was to evaluate CHIRPS version 2, MSWEP version 2, and PERSIANN-CDR, compared to gridBR, as daily mean and extreme inputs represented on a monthly scale and their respective seasonal trends of rainfall in the Mearim River Drainage Basin (MDB), Maranhão state, Brazil. Estimates of errors were calculated (relative error, pbias; root mean square error, RMSE, and Willmott concordance index, d), and the chances of precipitation were estimated by remote sensing (RES). In addition, trends in precipitation were estimated by the two-sample Mann–Kendall test. Given the overall performance, the best products for estimating monthly mean daily rainfall in the MDB are CHIRPS and PERSIANN-CDR, especially for rainy months (December to May). For daily extremes on the monthly scale, the best RES is PERSIANN-CDR. There is no general agreement between gridBR and RES methods for the trend signal, even a nonsignificant one, much less a significant one. The use of MSWEP for the MDB region is discouraged by this study because it overestimates monthly averages and extremes. Finally, studies of this kind in drainage basins are essential to improve the information generated for managing territories and developing regionalized climate and hydrological models.

scholarly journals Quantifying landslide frequency and sediment residence time in the Nepal Himalaya

2019 ◽  
Vol 5 (4) ◽  
pp. eaav3482 ◽  
Author(s):  
D. M. Whipp ◽  
T. A. Ehlers
Keyword(s):  
Residence Time ◽  
River Sediment ◽  
Drainage Basin ◽  
Drainage Basins ◽  
Nepal Himalaya ◽  
Stochastic Nature ◽  
Two Samples ◽  
Mountainous Landscapes ◽  
Landslide Frequency ◽  
The Difference

Quantifying how Earth surface processes interact with climate, tectonics, and biota has proven challenging, in part due to the stochastic nature of erosion and sedimentation. Landsliding is a common stochastic erosional process that may account for >50% of the sediment produced in steep mountainous landscapes. Here, we calculate the effects of landsliding and the residence time of sediment in a steep drainage basin in the Nepal Himalaya using a numerical model of landslide erosion combined with published cooling age distributions from two river sediment samples collected several years apart. We find that the difference in the two samples can be explained by landsliding and that the age distributions suggest that the residence time of sediment in the catchment is no greater than 50 years. This sensitivity to landsliding thus offers potential to improve our understanding of stochastic erosional processes, and further suggests that sediment is rapidly evacuated from steep mountainous drainage basins.

scholarly journals Drainage basin checklists and dichotomous keys for inland fishes of Texas

ZooKeys ◽  
2019 ◽  
Vol 874 ◽  
pp. 31-45 ◽  
Author(s):  
Cody Andrew Craig ◽  
Timothy Hallman Bonner
Keyword(s):  
Native Species ◽  
Drainage Basin ◽  
Red River ◽  
Ecological Studies ◽  
Natural Boundary ◽  
Drainage Basins ◽  
As Species ◽  
Native Fishes ◽  
Texas Red ◽  
River Drainage Basin

Species checklists and dichotomous keys are valuable tools that provide many services for ecological studies and management through tracking native and non-native species through time. We developed nine drainage basin checklists and dichotomous keys for 196 inland fishes of Texas, consisting of 171 native fishes and 25 non-native fishes. Our checklists were updated from previous checklists and revised using reports of new established native and non-native fishes in Texas, reports of new fish occurrences among drainages, and changes in species taxonomic nomenclature. We provided the first dichotomous keys for major drainage basins in Texas. Among the 171 native inland fishes, 6 species are considered extinct or extirpated, 13 species are listed as threatened or endangered by U.S. Fish and Wildlife Service, and 59 species are listed as Species of Greatest Conservation Need (SGCN) by the state of Texas. Red River drainage basin was the most speciose with 120 fishes. Rio Grande & Pecos drainage basin had the greatest number of threatened or endangered fishes (N = 7) and the greatest number of SGCN fishes (N = 28). We revised drainage basin occurrences for 77 species. Drainage basin checklists and dichotomous keys provide finer resolution of species distributions within the geopolitical boundaries of Texas and can reduce probability of errors in fish identification errors by removing species not occurring within a natural boundary.

DRAINAGE BASIN AS A COMPLEX SOCIO-NATURAL HIERARCHICAL SYSTEM

2020 ◽  
Vol 42 (3) ◽  
pp. 293-303
Author(s):  
VALERIY BONDAREV
Keyword(s):  
Drainage Basin ◽  
Temporal Analysis ◽  
Large River ◽  
Hierarchical Level ◽  
Effective Management ◽  
Drainage Basins ◽  
Time Intervals ◽  
Natural Systems ◽  
Spatial And Temporal Analysis ◽  
Entire Complex

The theoretical and methodological basis of the systems hierarchical spatial and temporal analysis of a drainage basin, which addresses the problems of effective management in socio-natural systems of different ranks, is considered. It is proposed to distinguish 9 orders of forms that are relevant to the analysis of drainage basins, where the first level is represented by individual aggregates and particles, and the last - by basins of large and the largest rivers. As part of the allocation of geological, historical and modern time intervals, the specificity of the implementation of processes in basins of different scales from changing states, through functioning to evolution is demonstrated. The interrelation of conditions and factors that determine the processes occurring within the drainage basins is revealed. It is shown that a specific combination of conditions and factors that determine processes in the drainage basin is associated with the hierarchy of the objects under consideration, i.e. the choice of a spatial-temporal hierarchical level is crucial for the organization of study within drainage basins. At one hierarchical level, some phenomenon can be considered as a factor, and at another - as a condition. For example, tectonic processes can be considered as an active factor in the evolution of large river basins in the geological perspective, but for small drainage basin, this is already a conservative background condition. It is shown that at the historical time the anthropogenic factor often comes to the fore, with the appearance of which in the functioning of the drainage basin, there is a need to take into account the entire complex of socio-environmental problems that can affect the sustainable state of various territories, especially in the field of water and land use. Hierarchical levels of managing subjects are identified, which are primarily responsible for effective management at the appropriate hierarchical level of the organization of the socio-natural system within the catchment area, starting from an individual to humankind as a whole.

scholarly journals Spatial pattern of geodiversity assessment in the Marrecas River drainage basin, Paraná, Brazil

2021 ◽  
Vol 126 ◽  
pp. 107703
Author(s):  
F.C. Manosso ◽  
Zb. Zwoliński ◽  
A. Najwer ◽  
B.T. Basso ◽  
D.S. Santos ◽  
...  
Keyword(s):  
Spatial Pattern ◽  
Drainage Basin ◽  
River Drainage ◽  
River Drainage Basin
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