The study on the long-perid runoff computation for mountain and river drainage basins(II)

This paper shows that the dendritic patterns formed by low-resistance channels in a river drainage basin are reproducible and can be deduced from a single principle that acts at every step in the development of the pattern: the constrained minimization of global resistance in area-to-point flow. The river basin is modeled as a two-dimensional territory with Darcy flow through a saturated heterogeneous porous medium with uniform flow addition per unit area. From one step to the next, small elements of the porous medium are dislodged and removed in ways that minimize the global flow resistance. The removed elements are replaced by channels with lower flow resistance. The channels form a dendritic pattern that is deterministic, not random. The finest details of this structure are sensitive to internal properties and external forcing, i.e. variations in the local properties of the flow medium, and the manner in which the total area-to-point flow rate varies as the structure develops. Remarkably insensitive to such effects are the basic type and rough size of the flow structure (channels versus no channels, dendrite, number of branches) and the minimized global resistance to flow.

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Propuesta para la reorganización pluridepartamental del Perú

Cuadernos de difusión ◽

10.46631/jefas.2007.v12n22.04 ◽

2007 ◽

Vol 12 (22) ◽

pp. 65-72

Author(s):

Nissim Alcabés ◽

Keyword(s):

Drainage Basins ◽

River Drainage ◽

Alternative Proposal ◽

The Creation ◽

Chamber Of Deputies

This paper discusses the transition from the present single-department regions to a structure of multiple-department regions. It discusses the convenience of creating a pilot region and provides some criteria to create multi-department regions and choose the location of the regional capitals. It also provides guidelines to elect representatives to the Chamber of Deputies and the creation of a Senate. Finally, it outlines eight regions to be created by grouping several departments, and an alternative proposal to create regions based on river drainage basins.

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Geologic and mineral evaluation of the Chitina and Bremner River drainage basins

10.14509/123 ◽

1973 ◽

Author(s):

M. W. Henning ◽

P. L. Dobey

Keyword(s):

Drainage Basins ◽

River Drainage

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

Remote Sensing ◽

10.3390/rs13214393 ◽

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.

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