scholarly journals Capacidade de Armazenamento de Água no Solo (CAD) e Características Físicas dos Solos na Avaliação da Distribuição da Água das Chuvas na Alta Bacia do Ribeirão Santo Antônio

2021 ◽  
Vol 14 (6) ◽  
pp. 3635
Author(s):  
Flávio Alves Sousa ◽  
Hildeu Ferreira Da Assunção

O estudo avalia a capacidade de armazenamento de água dos solos (CAD), utiliza como objeto de avaliação os latossolos da alta bacia do ribeirão Santo Antônio no município de Iporá-Goiás. O objetivo do estudo foi avaliar a dinâmica da água da chuva na manutenção do fluxo de água na bacia. Utilizou de dados de umidade dos solos em período de déficit hídrico e de excedente para comparar o comportamento dos solos na retenção de água e na permeabilidade. Utilizou a metodologia padrão na definição do CAD, porém com ajustes específicos na obtenção da umidade e na capacidade de campo (CC) e no ponto de murcha permanente PMP, que aqui foi denominado de ponto de menor umidade residual (PMUR). Informações como dados de chuva do período, balanço hídrico climatológico no período analisado (maio de 2018 a abril de 2019) e valores de vazão obtidos mensalmente no exutório durante o período de referência fizeram parte da análise. Um total de 43,5% da água disponibilizada pela chuva escoam superficialmente, 9,5% escoam em subsuperfície, 47% da água infiltra e/ou permanece retida nos solos. Os solos apresentaram boa drenagem e, cerca de 42% da água das chuvas garantem a perenidade da bacia.    Soil Water Storage Capacity (AWSC) and Physical Characteristics of Soils in the Evaluation of Rainwater Distribution in the High Basin of  Santo Antônio Stream.  A B S T R A C T         The study evaluates the water storage capacity of soils (AWSC). It use like object of evaluation the oxissoils located at the high Santo Antônio basin. The objective of the study was to evaluate the dynamics of rainwater in maintaining the flow of water in the basin through laboratory evaluations, in addition to testing a new methodology to define the destinations of the water that reached the surface. Was used soil moisture data in a period of water deficit and surplus to compare the behavior of soils in water retention and permeability. It used the standard methodology in the definition of the AWSC but with specific adjustments in obtaining the humidity and in the field capacity (FC) and in the permanent wilting point PWP, which here was called the point of lowest residual moisture (PLRM). Information such as rainfall data for the period, climatological water balance in the period analyzed (May 2018 to April 2019) and flow values obtained monthly in the exutory during the reference period were part of the analysis. A total of 43.5% of the water provided by the rain run off superficially, 9.5% seeps in subsurface, 47% of the water seeps and / or remains trapped in the soil. The soils had good drainage and about 42% of the rainwater guarantees the basin's perpetuity.   Keywords: AWSC. Permeability. Moisture. Storage.

2018 ◽  
Author(s):  
Dingbao Wang

Abstract. Following the Budyko framework, soil wetting ratio (the ratio between soil wetting and precipitation) as a function of soil storage index (the ratio between soil wetting capacity and precipitation) is derived from the SCS-CN method and the VIC type of model. For the SCS-CN method, soil wetting ratio approaches one when soil storage index approaches infinity, due to the limitation of the SCS-CN method in which the initial soil moisture condition is not explicitly represented. However, for the VIC type of model, soil wetting ratio equals soil storage index when soil storage index is lower than a certain value, due to the finite upper bound of the power distribution function of storage capacity. In this paper, a new distribution function, supported on a semi-infinite interval x ∈ [0, ∞), is proposed for describing the spatial distribution of storage capacity. From this new distribution function, an equation is derived for the relationship between soil wetting ratio and storage index. In the derived equation, soil wetting ratio approaches zero as storage index approaches zero; when storage index tends to infinity, soil wetting ratio approaches a certain value (≤ 1) depending on the initial storage. Moreover, the derived equation leads to the exact SCS-CN method when initial water storage is zero. Therefore, the new distribution function for soil water storage capacity explains the SCS-CN method as a saturation excess runoff model and unifies the surface runoff modeling of SCS-CN method and VIC type of model.


2021 ◽  
Vol 25 (2) ◽  
pp. 945-956
Author(s):  
Yuan Gao ◽  
Lili Yao ◽  
Ni-Bin Chang ◽  
Dingbao Wang

Abstract. Prediction of mean annual runoff is of great interest but still poses a challenge in ungauged basins. The present work diagnoses the prediction in mean annual runoff affected by the uncertainty in estimated distribution of soil water storage capacity. Based on a distribution function, a water balance model for estimating mean annual runoff is developed, in which the effects of climate variability and the distribution of soil water storage capacity are explicitly represented. As such, the two parameters in the model have explicit physical meanings, and relationships between the parameters and controlling factors on mean annual runoff are established. The estimated parameters from the existing data of watershed characteristics are applied to 35 watersheds. The results showed that the model could capture 88.2 % of the actual mean annual runoff on average across the study watersheds, indicating that the proposed new water balance model is promising for estimating mean annual runoff in ungauged watersheds. The underestimation of mean annual runoff is mainly caused by the underestimation of the area percentage of low soil water storage capacity due to neglecting the effect of land surface and bedrock topography. Higher spatial variability of soil water storage capacity estimated through the height above the nearest drainage (HAND) and topographic wetness index (TWI) indicated that topography plays a crucial role in determining the actual soil water storage capacity. The performance of mean annual runoff prediction in ungauged basins can be improved by employing better estimation of soil water storage capacity including the effects of soil, topography, and bedrock. It leads to better diagnosis of the data requirement for predicting mean annual runoff in ungauged basins based on a newly developed process-based model finally.


2008 ◽  
Vol 12 (5) ◽  
pp. 1189-1200 ◽  
Author(s):  
S. Manfreda ◽  
M. Fiorentino

Abstract. The present paper introduces an analytical approach for the description of the soil water balance dynamics over a schematic river basin. The model is based on a stochastic differential equation where the rainfall forcing is interpreted as an additive noise in the soil water balance. This equation can be solved assuming known the spatial distribution of the soil moisture over the basin transforming the two-dimensional problem in space in a one dimensional one. This assumption is particularly true in the case of humid and semihumid environments, where spatial redistribution becomes dominant producing a well defined soil moisture pattern. The model allowed to derive the probability density function of the saturated portion of a basin and of its relative saturation. This theory is based on the assumption that the soil water storage capacity varies across the basin following a parabolic distribution and the basin has homogeneous soil texture and vegetation cover. The methodology outlined the role played by the soil water storage capacity distribution of the basin on soil water balance. In particular, the resulting probability density functions of the relative basin saturation were found to be strongly controlled by the maximum water storage capacity of the basin, while the probability density functions of the relative saturated portion of the basin are strongly influenced by the spatial heterogeneity of the soil water storage capacity. Moreover, the saturated areas reach their maximum variability when the mean rainfall rate is almost equal to the soil water loss coefficient given by the sum of the maximum rate of evapotranspiration and leakage loss in the soil water balance. The model was tested using the results of a continuous numerical simulation performed with a semi-distributed model in order to validate the proposed theoretical distributions.


2020 ◽  
Author(s):  
Xiaojing Zhang ◽  
Pan Liu ◽  
Chong-Yu Xu

<p>The intensification of climate change and human activities can lead to non-stationarity of hydrological model parameters, which in turn affects the correctness of model simulation results. Previous studies mainly focus on impacts of climate change, while catchment hydrological responses to human activities require detailed investigation for sustainable water management. This study evaluates anthropogenic impacts on soil water storage capacity of the upper Yangtze River Basin by representing hydrological parameters as functions of human activity indicators. The Xinanjiang (XAJ) model is used since its parameter WM accounts for soil water storage capacity. In this study, time-variations of WM are identified by the split-sample calibration based on dynamic programming (SSC-DP). The variations are further related to ten indicators of human activities from five aspects: population, gross domestic product, farming, irrigation and reservoir construction. Then, the proposed WM functional form is selected by comparing the performance of a set of parameter functions of the identified human activity indicators during the validation period. The study shows that WM increases in 1976-2000, while a relatively high relationship is detected between WM and some indicators such as agricultural acreage, population and reservoir construction. It is further demonstrated that agricultural population has the greatest impact on soil water storage capacity and its linear functional form for WM is validated to be effective in 2001-2010 with best streamflow simulation, especially for low streamflow. These results can help understand the hydrological response to the increasing human development and contribute to adaptive development strategies for future water resource management.</p>


2013 ◽  
Vol 6 (3-4) ◽  
pp. 457-466 ◽  
Author(s):  
Peter M. Kammer ◽  
Christian Schöb ◽  
Gabriel Eberhard ◽  
Renzo Gallina ◽  
Remo Meyer ◽  
...  

2020 ◽  
Author(s):  
Yuan Gao ◽  
Lili Yao ◽  
Ni-Bin Chang ◽  
Dingbao Wang

Abstract. The present work diagnoses the prediction in mean annual runoff affected by the uncertainty in estimated distribution of soil water storage capacity. Based on a distribution function, a water balance model for estimating mean annual runoff is developed, in which the effects of climate variability and the distribution of soil water storage capacity are explicitly represented. As such, the two parameters in the model have explicit physical meanings, and relationships between the parameters and controlling factors on mean annual runoff are established. The estimated parameters from the existing data of watershed characteristics are applied to 35 watersheds. The results showed that the model could capture 88.2 % of the actual runoff on average, indicating that the proposed new water balance model is promising for estimating mean annual runoff in ungauged watersheds. The underestimation of runoff is mainly caused by the underestimation of the spatial heterogeneity of soil storage capacity due to neglecting the effect of land surface and bedrock topography. A higher spatial variability of soil storage capacity estimated through the Height Above the Nearest Drainage (HAND) indicated that topography plays a crucial role in determining the actual soil water storage capacity. The performance of mean annual runoff prediction in ungauged basins can be improved by employing better estimation of soil water storage capacity including the effects of soil, topography and bedrock. The purpose of this study is to diagnose the data requirement for predicting mean annual runoff in ungauged basins based on a newly developed process-based model.


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