scholarly journals Laboratory model test study of the hydrological effect on granite residual soil slopes considering different vegetation types

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jie Chen ◽  
Xue-wen Lei ◽  
Han-lin Zhang ◽  
Zhi Lin ◽  
Hui Wang ◽  
...  

AbstractThe problems caused by the interaction between slopes and hydrologic environment in traffic civil engineering are very serious in the granite residual soil area of China, especially in Guangdong Province. Against the background of two heavy rainfall events occurring during a short period due to a typhoon making landfall twice or even two typhoons consecutively making landfall, laboratory model tests were carried out on the hydrological effects of the granite residual soil slope considering three vegetation types under artificial rainfall. The variation in slope surface runoff, soil moisture content and rain seepage over time was recorded during the tests. The results indicate that surface vegetation first effectively reduces the splash erosion impact of rainwater on slopes and then influences the slope hydrological effect through rainwater forms adjustment. (1) The exposed slope has weak resistance to two consecutive heavy rains, the degree of slope scouring and soil erosion damage will increase greatly during the second rainfall. (2) The multiple hindrances of the stem leaf of Zoysia japonica plays a leading role in regulating the hydrological effect of slope, the root system has little effect on the permeability and water storage capacity of slope soil, but improves the erosion resistance of it. (3) Both the stem leaf and root system of Nephrolepis cordifolia have important roles on the hydrological effect. The stem leaf can stabilize the infiltration of rainwater, and successfully inhibit the surface runoff under continuous secondary heavy rainfall. The root system significantly enhances the water storage capacity of the slope, and greatly increases the permeability of the slope soil in the second rainfall, which is totally different from that of the exposed and Zoysia japonica slopes. (4) Zoysia is a suitable vegetation species in terms of slope protection because of its comprehensive slope protection effect. Nephrolepis cordifolia should be cautiously planted as slope protection vegetation. Only on slopes with no stability issues should Nephrolepis cordifolia be considered to preserve soil and water.

2021 ◽  
Author(s):  
Harro Joseph Jongen ◽  
Gert-Jan Steeneveld ◽  
Jason Beringer ◽  
Andreas Christen ◽  
Krzysztof Fortuniak ◽  
...  

2021 ◽  
Author(s):  
Harro Jongen ◽  
Gert-Jan Steeneveld ◽  
Jason Beringer ◽  
Krzysztof Fortuniak ◽  
Jinkyu Hong ◽  
...  

<p>The amount and dynamics of urban water storage play an important role in mitigating urban flooding and heat. Assessment of the capacity of cities to store water remains challenging due to the extreme heterogeneity of the urban surface. Evapotranspiration (ET) recession after rainfall events during the period without precipitation, over which the amount of stored water gradually decreases, can provide insight on the water storage capacity of urban surfaces. Assuming ET is the only outgoing flux, the water storage capacity can be estimated based on the timescale and intercept of its recession. In this paper, we test the proposed approach to estimate the water storage capacity at neighborhood scale with latent heat flux data collected by eddy covariance flux towers in eleven contrasting urban sites with different local climate zones, vegetation cover and characteristics and background climates (Amsterdam, Arnhem, Basel, Berlin, Helsinki, Łódź, Melbourne, Mexico City, Seoul, Singapore, Vancouver). Water storage capacities ranging between 1 and 12 mm were found. These values correspond to e-folding timescales lasting from 2 to 10 days, which translate to half-lives of 1.5 to 7 days. We find ET at the start of a drydown to be positively related to vegetation fraction, and long timescales and large storage capacities to be associated with higher vegetation fractions. According to our results, urban water storage capacity is at least one order of magnitude smaller than the known water storage capacity in natural forests and grassland.</p>


Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1674
Author(s):  
Anna Ilek ◽  
Małgorzata Szostek ◽  
Anna Mikołajczyk ◽  
Marta Rajtar

During the last decade, tree species mixing has been widely supported as a silvicultural approach to reduce drought stress. However, little is known on the influence of tree species mixing on physical properties and the water storage capacity of forest soils (including the forest floor). Thus, the study aimed to analyze the effect of mixing pine needles and oak leaves and mixing fir needles and beech leaves on hydro-physical properties of the litter layer during laboratory tests. We used fir-beech and pine-oak litter containing various shares of conifer needles (i.e., 0, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100%) to determine the influence of the needle admixture on bulk density, total porosity, macroporosity, water storage capacity, the amount of water stored in pores between organic debris and the degree of saturation of mixed litter compared to broadleaf litter (oak or beech). We found that the admixture of fir needles increased the bulk density of litter from 7.9% with a 5% share of needles to 55.5% with a 50% share (compared to pure beech litter), while the share of pine needles < 40% caused a decrease in bulk density by an average of 3.0–11.0% (compared to pure oak litter). Pine needles decreased the water storage capacity of litter by about 13–14% with the share of needles up to 10% and on average by 28% with the 40 and 50% shares of pine needles in the litter layer. Both conifer admixtures reduced the amount of water stored in the pores between organic debris (pine needles more than fir needles).


FLORESTA ◽  
2013 ◽  
Vol 43 (2) ◽  
pp. 205
Author(s):  
Richardson Guenther Schechi ◽  
Rita De Cássia Bianchi ◽  
Rafael Zoboli Guimarães ◽  
Nivaldo Eduardo Rizzi

 O presente trabalho demonstra a capacidade potencial de armazenamento de água da bacia hidrográfica do rio Pequeno, São José dos Pinhais, PR, que é uma região de crescente expansão urbana e industrial da Região Metropolitana de Curitiba. Com a análise da capacidade potencial de armazenamento de água da bacia hidrográfica, podem ser identificadas áreas com maior ou menor capacidade de recarga de aquíferos, auxiliando, dessa maneira, na implementação de políticas de desenvolvimento socioeconômicas. Para tanto, foi aplicada a metodologia de avaliação da capacidade potencial de armazenamento de água proposta por Chiaranda (2002), que consiste na análise e cruzamento, em ambiente de Sistemas de Informações Geográficas (SIG), de informações temáticas como geologia, geomorfologia, solo, cobertura vegetal original e usos dos solos nos anos de 1986, 1996 e 2007. No ano de 1986, a bacia apresentou 79,39; 49,38 e 1,68%, e em 2007 a bacia apresentou 74,10; 47,73 e 8,62% de sua área enquadrada nas classes de alta, média e baixa capacidade de armazenamento, respectivamente. Verificou-se que os usos da terra modificaram as características da capacidade potencial de armazenamento da bacia do rio Pequeno.Palavras-chave: Recursos hídricos; capacidade de armazenamento; hidrologia florestal. AbstractEvaluation of potential water storage capacity in the Rio Pequeno watershed, São José dos Pinhais, PR. This work demonstrates the potential water storage capacity of Rio Pequeno watershed, located in the municipality of São José dos Pinhais, in Paraná State, Brazil. The city is part of Curitiba Metropolitan Area and presents high urban and industrial development.The analysis of the Rio Pequeno watershed potential water storage capacity can identify areas of aquifers with higher or lower capacity to recharge, due to implementation of socioeconomic development policies. In order to that, it was applied the methodology of assessment of potential water storage capacity proposed by Chiaranda (2002). It consists in a Geographical Information System (GIS) analysis combined to different sources of information, such as geology, soil type, original plant cover and land uses. The methodology was applied to the years of 1986, 1996, and 2007. In 1986 the basin presented 79.39, 49.38, and 1.68%, in 2007 the basin presented 74.10, 47.73, and 8.62% of its framed area in classes of high, medium and low storage capacity, respectively. According to that, it was observed that land uses have changed the characteristics of potential water storage capacity of Rio Pequeno watershed. Keywords: Water resources; storage capacity; forest hydrology.


2020 ◽  
Vol 12 (8) ◽  
pp. 3112 ◽  
Author(s):  
Yanpei Li ◽  
Mingan Shao ◽  
Jiao Wang ◽  
Tongchuan Li

Earthworm cast is a common bio-organic fertiliser, which can effectively improve soil fertility and structure. However, only a few studies have focused on the effect of earthworm cast on soil water movement. In this study, loess soil was used to determine the effects of earthworm cast application on soil evaporation. The effects on water storage capacity and capillary upward movement were also investigated. A laboratory-based soil column experiment using earthworm cast with different particle sizes (1–3 × 1–2 cm and 3–5 × 2–4 cm) and three application doses (5%, 7.5%, and 10%) was carried out. The daily evaporation and volume of capillary ascension were monitored. The addition of earthworm cast clearly affected the soil evaporation by changing soil water storage capacity and capillary water upward movement. Compared with control soil, the application of 5% small-particle cast reduced the soil cumulative evaporation by 5.13%, while the cumulative evaporation was higher in all large-particle cast treatments. The upward capillary water movement increased with increasing dose of earthworm cast, but decreased with increasing particle size. Overall, the addition of earthworm cast clearly enhanced the water storage capacity of the soil, with the small-particle cast having greater effects than the large-particle cast. We concluded that the application of 5% small-particle earthworm cast can enhance soil water retention and reduce soil evaporation.


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