Validation of Soil Moisture Simulation and Water Balance Analysis in a Citrus Orchard in Jiangxi Province, China

Author(s):  
Yuanshu Jing ◽  
Alexander Thimm
2008 ◽  
Vol 6 (2) ◽  
Author(s):  
Baina Afkril

<p>Area studi terletak di bagian tenggara Dataran Tinggi Blackwood, Australia Barat mencakup 71 km<sup>2</sup>. Akifer Yarragadee di daerah studi utamanya tersusun oleh batu pasir yang mengandung lapisan-lapisan batu lempung dan liat. Akifer ini merupakan akifer tak-tertekan karena muncul dipermukaan sepanjang alur Sungai Blackwood pada daerah hilir di Nannup dan merupakan sumber airtanah yang keluar ke sungai. Sungai Blackwood mengalir melintasi Dataran Tinggi Blackwood. Selama musim kering, aliran permukaan ke dalam Sungai Blackwood dapat diabaikan, namun aliran dasar dari airtanah menjadi sumber utama bagi aliran sungai. Neraca air pada daerah studi dilakukan dengan menggunakan analisa jaring-aliran dan kesetimbangan air guna mengevaluasi masukan airtanah dari akifer Yarragadee ke dalam Sungai Blackwood. Mayoritas sel-sel jaring-aliran adalah sel-sel keluaran dan kebanyakan aliran airtanah masuk ke dalam Sungai Blackwood di daerah studi. Curah hujan rata-rata tahunan area studi sekitar 6.7 x 10<sup>7</sup> m<sup>3</sup> a<sup>-1</sup>. Sekitar 9 % dari total curah hujan rata-rata tahunan ini masuk ke dalam tanah sebagai sumber bagi air tanah dan 91 % hilang melalui proses evapotranspirasi. Volume total airtanah yang masuk ke dalam Sungai Blackwood antara stasiun Darradup dan Layman Flat yang dihitung menggunakan analisis jarring-aliran dan kesetimbangan air sekitar 8.1 GL a<sup>-1</sup>.  </p>


2021 ◽  
Vol 29 (7) ◽  
pp. 2411-2428
Author(s):  
Robin K. Weatherl ◽  
Maria J. Henao Salgado ◽  
Maximilian Ramgraber ◽  
Christian Moeck ◽  
Mario Schirmer

AbstractLand-use changes often have significant impact on the water cycle, including changing groundwater/surface-water interactions, modifying groundwater recharge zones, and increasing risk of contamination. Surface runoff in particular is significantly impacted by land cover. As surface runoff can act as a carrier for contaminants found at the surface, it is important to characterize runoff dynamics in anthropogenic environments. In this study, the relationship between surface runoff and groundwater recharge in urban areas is explored using a top-down water balance approach. Two empirical models were used to estimate runoff: (1) an updated, advanced method based on curve number, followed by (2) bivariate hydrograph separation. Modifications were added to each method in an attempt to better capture continuous soil-moisture processes and explicitly account for runoff from impervious surfaces. Differences between the resulting runoff estimates shed light on the complexity of the rainfall–runoff relationship, and highlight the importance of understanding soil-moisture dynamics and their control on hydro(geo)logical responses. These results were then used as input in a water balance to calculate groundwater recharge. Two approaches were used to assess the accuracy of these groundwater balance estimates: (1) comparison to calculations of groundwater recharge using the calibrated conceptual HBV Light model, and (2) comparison to groundwater recharge estimates from physically similar catchments in Switzerland that are found in the literature. In all cases, recharge is estimated at approximately 40–45% of annual precipitation. These conditions were found to closely echo those results from Swiss catchments of similar characteristics.


2021 ◽  
Vol 36 ◽  
pp. 100837
Author(s):  
Mou Leong Tan ◽  
Yi Lin Tew ◽  
Kwok Pan Chun ◽  
Narimah Samat ◽  
Shazlyn Milleana Shaharudin ◽  
...  

2018 ◽  
Vol 22 (6) ◽  
pp. 3229-3243 ◽  
Author(s):  
Maoya Bassiouni ◽  
Chad W. Higgins ◽  
Christopher J. Still ◽  
Stephen P. Good

Abstract. Vegetation controls on soil moisture dynamics are challenging to measure and translate into scale- and site-specific ecohydrological parameters for simple soil water balance models. We hypothesize that empirical probability density functions (pdfs) of relative soil moisture or soil saturation encode sufficient information to determine these ecohydrological parameters. Further, these parameters can be estimated through inverse modeling of the analytical equation for soil saturation pdfs, derived from the commonly used stochastic soil water balance framework. We developed a generalizable Bayesian inference framework to estimate ecohydrological parameters consistent with empirical soil saturation pdfs derived from observations at point, footprint, and satellite scales. We applied the inference method to four sites with different land cover and climate assuming (i) an annual rainfall pattern and (ii) a wet season rainfall pattern with a dry season of negligible rainfall. The Nash–Sutcliffe efficiencies of the analytical model's fit to soil observations ranged from 0.89 to 0.99. The coefficient of variation of posterior parameter distributions ranged from < 1 to 15 %. The parameter identifiability was not significantly improved in the more complex seasonal model; however, small differences in parameter values indicate that the annual model may have absorbed dry season dynamics. Parameter estimates were most constrained for scales and locations at which soil water dynamics are more sensitive to the fitted ecohydrological parameters of interest. In these cases, model inversion converged more slowly but ultimately provided better goodness of fit and lower uncertainty. Results were robust using as few as 100 daily observations randomly sampled from the full records, demonstrating the advantage of analyzing soil saturation pdfs instead of time series to estimate ecohydrological parameters from sparse records. Our work combines modeling and empirical approaches in ecohydrology and provides a simple framework to obtain scale- and site-specific analytical descriptions of soil moisture dynamics consistent with soil moisture observations.


Author(s):  
Cong WANG ◽  
Shuai WANG ◽  
Bojie FU ◽  
Lu ZHANG ◽  
Nan LU ◽  
...  

ABSTRACTSoil moisture is a key factor in the ecohydrological cycle in water-limited ecosystems, and it integrates the effects of climate, soil, and vegetation. The water balance and the hydrological cycle are significantly important for vegetation restoration in water-limited regions, and these dynamics are still poorly understood. In this study, the soil moisture and water balance were modelled with the stochastic soil water balance model in the Loess Plateau, China. This model was verified by monitoring soil moisture data of black locust plantations in the Yangjuangou catchment in the Loess Plateau. The influences of a rainfall regime change on soil moisture and water balance were also explored. Three meteorological stations were selected (Yulin, Yan'an, and Luochuan) along the precipitation gradient to detect the effects of rainfall spatial variability on the soil moisture and water balance. The results showed that soil moisture tended to be more frequent at low levels with decreasing precipitation, and the ratio of evapotranspiration under stress in response to rainfall also changed from 74.0% in Yulin to 52.3% in Luochuan. In addition, the effects of a temporal change in rainfall regime on soil moisture and water balance were explored at Yan'an. The soil moisture probability density function moved to high soil moisture in the wet period compared to the dry period of Yan'an, and the evapotranspiration under stress increased from 59.5% to 72% from the wet period to the dry period. The results of this study prove the applicability of the stochastic model in the Loess Plateau and reveal its potential for guiding the vegetation restoration in the next stage.


2019 ◽  
Vol 34 (02) ◽  
Author(s):  
R. K. Jaiswal ◽  
T. Thomas ◽  
Jyoti P Patil ◽  
Meeta Gupta ◽  
V. C. Goyal

It is a well-known fact that it is not all possible to avoid droughts, but droughts can be managed to minimise the hardships of the local population. For this purpose, understanding of the supply-demand scenario is of utmost importance to understand the overall hydrology and planning needs of any watershed. It is in this direction, the comprehensive water balance analysis has been performed for the Sajnam watershed in Lalitpur district of Bundelkhand which is susceptible to regular and continuous droughts. The detailed water balance has been carried out after identification of important components and their quantification using the advance tools of Remote Sensing and GIS alongwith standard estimation techniques of individual components. It was observed that the runoff at the outlet of Sajnam basin is influenced by the water storage in the irrigation project located on the main river. The higher surface runoff of 668.53 MCM, 406.17 MCM, 343.46 MCM and 214.00 MCM is generated only during 2013-14, 2008-09, 2012-13 and 2010-11 respectively. During the remaining years, the runoff varied between 89.35 MCM and 209.81 MCM. Efforts can be initiated towards exploring the possibility of more water harvesting structures onthe lower order tributaries as well as artificial recharge measures depending on the hydro-geology of the watershed..


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