Guilherme Sobrinho

15 Questions 33 Answers 0 Followers

Questions related from Guilherme Sobrinho

Dear fellows, what models are there available for water stable isotopes in the vadose zone?

I'm aware of Hydrus and Netpath, but are there others? I am highly interested in water stable isotopes in variably saturated and non-equilibrium flow (double porosity/permeability). Any hints...

22 October 2020 9,606 2 View

Dear fellows, how conceptual models for hard-rock fractured aquifers in (semi)arid environments represent "invisible" discharge besides RET?

How discharge is unsually conceptualized for catchments under arid or semiarid environments with no springs and only ephemeral rivers, in a context that could not be explained exclusively by...

28 May 2019 9,927 4 View

Dear fellows, do you know any methods for deriving discharge baseflow constants from groundwater level timeseries?

I am aware of many methods for estimating base-flow recession constants from discharge (due to spring outlets) hydrographs. Unfortunately, in my study case there is no discharge contributing to...

05 June 2018 1,700 3 View

Dear fellows, do you know if intervention analysis (time-series) is used for groundwater recharge assessment?

I apologize if this question has been posed before (if this is the case, please send me the link). It seems reasonable since precipitation is a point event and groundwater level record is a time...

23 May 2017 2,511 8 View

Dear fellows, how should I analyse time-series trend despite missing data?

I have a time-series record of groundwater levels missing c.a. 20% of the data and I want to know if are there suitable methods for assessing monotonic trend.

25 April 2017 1,281 7 View

What are the ratios between "readily available" and "fixed" phases of the soil exchangeable pool for poorly hydrated cations (e.g. Cs+, K+)?

I would like to know what are the average estimates for ratios between readily available (let's say accessible by a single extraction with NH4Ac, or AgTU, or BaCl, or KCl...), and "fixed" poorly...

01 February 2017 469 3 View

Dear fellows, What reviews do you recommend on semiarid hydrogeological modelling?

I'm very interested in understanding the sate of the art on hydrogeological modelling with special concern to semi-arid environments in order to implement a system within FEFLOW software.

30 August 2016 2,738 4 View

Dear fellows, what are the methods for determining the ecological half-life of a given radionuclide?

As biological half-life is a parameter for individuals of a given species, the ecological half-life is a more broad and fuzzy concept, since it consists in a half-life within any given compartment...

29 May 2015 7,039 7 View

Dear fellows, Do you know any comprehensive and relevant, preferentially recent, reviews on the Rhizosphere?

I have only the basics on this topic from college. I would like to know what are the most comprehensive and most read reviews on this concept. Thanks in advance.

27 May 2015 2,338 4 View

Dear fellows, what hysteresis indexes are used for sorption-desorption kinetics of metals in soils?

I am interested in quantify the sorption-desorption hysteresis of 137Cs in soil samples comparing the respective isotherms.

29 April 2015 4,413 4 View

Dear fellows, how can I express the concentration of a "metallorganic" ionic complex in terms of cmolc.L^-1?

I'd like to express the concentration of silver thiourea in aqueous solution [Ag(TU)n]+1 in terms of cmolc.L-1. The protocols for soil CTC using AgTU consider the mass of Ag for calculations and...

28 April 2015 1,250 4 View

What are the problems inherent to the use of linear regression for multimodel selection?

What are the limitations of linear regression methods for choosing one model amongst a group of n candidate models?

18 March 2015 6,877 9 View

Are there any computational codes or models for soil pollutants that use parameters other than linear Kd?

The most widely used parameter for biogeochemical modelling of radionuclides in soils is arguably the Kd. The use of some sort of Kd (e.g. kinetic, parameterized, one-point-Kd) is only possible...

05 November 2014 2,135 1 View

Does any of you know about methods for evaluating the predictive and/or the descriptive power of mathematical models (e.g. sorption isotherms)?

With special concern to multimodel selection, linear regression and theoretic-informational approaches (e.g. AICc).

07 May 2014 948 2 View

Is there any standard soil samples for geochemical studies? Not only for total content analysis?

In theory the successive grinding and milling steps performed during the standardization of reference soil samples would make it unsuitable for partition studies (e.g. sorption-desorption,...

02 October 2013 6,556 23 View