scholarly journals Temporary Confined Water-Induced Landslide in the Binary Structure of a Gentle Slope: A Case Study of the Fanshantou Landslide

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 596
Author(s):  
Lei Wang ◽  
Yuequan Shang ◽  
Jun Zheng ◽  
Yingqiu Zhang
Keyword(s):  
Water Table ◽  
Water Permeability ◽  
Rainfall Intensity ◽  
Soil Layer ◽  
Confined Water ◽  
Mountainous Areas ◽  
Initial Water ◽  
Southeast China ◽  
Gentle Slope ◽  
Water Table Level

With the increase in rainfall, landslides occur on many gentle slopes in the mountainous areas of southeast China. Gentle slopes have a particular dual geological structure, i.e., the lower part is a gravel soil layer with good water permeability, and the surface layer is clay soil with relatively poor water permeability. Under conditions of heavy rainfall, a gentle slope with this structure is likely to collect temporary confined water. The intermittent creep of the upper slope is caused by the floating force of the temporary confined water, which causes landslide disasters. The conditions that bring about temporary confined water are related not only to the stratum structure, but also to the rainfall intensity and the initial height of the water table level. On the basis of the characteristics of the stratum of the gentle slope landslide on the front of Fanshantou Mountain, we constructed a hydrological model in GEO-STUDIO. We investigated the effect of different rainfall intensities and initial water table levels on confined water under continuous rainfall conditions and conducted a corresponding stability analysis. The results show that when both the initial water table level and the rainfall intensity are high, temporary confined water is formed rapidly, increasing the chance of a landslide disaster. The research results provide a theoretical basis for the treatment of landslides on similar gentle slopes in the mountainous areas of southeast China.

scholarly journals The effects of rainfall on the stability of soil slopes in Khanh Vinh district, Khanh Hoa province

2016 ◽  
Vol 19 (1) ◽  
pp. 45-58
Author(s):  
Danh Thanh Nguyen ◽  
Ngo Van Dau ◽  
Dung Quoc Ta
Keyword(s):  
Water Table ◽  
Safety Factor ◽  
Rainfall Intensity ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Failure Surface ◽  
Residual Soils ◽  
Soil Permeability ◽  
Initial Water ◽  
The Stability

This study presents a procedure for calculating the change of the safety factor for unsaturated slopes of homogenous, residual soils suffering from rainfall infiltration within Khanh Vinh district, Khanh Hòa province. Rainfall is supposed as a main trigger caused failure of the potential sliding slopes. Rainwater into the slope due to infiltration caused an increase in moisture content and negative pore water pressure; a decrease in matric suction and in shear strength on the failure surface. Thus, slopes are reduced stability and can be failed. Soil permeability and rainfall intensity were found to be the primary factors controlling the instability of slopes due to rainfall, while the initial water table location and slope geometry only played a secondary role. A numerical model of analysis coupled seepage-stability used to simulate the seepage and slope stability under conditions of specific environment such as soil permeability, rainfall intensity, water table location and slope geometry in the study area. The relationships between safety factor and rainfall intensity, soil permeability, angle slope, high slope were identified to provide a good indication for the management of landslide hazards under the effects of rainfall.

Measurements and Determinants of Multidimensional Poverty: Evidence from Mountainous Areas of Southeast China

2021 ◽  
pp. 1-19
Author(s):  
Chengchao Wang ◽  
Benxiang Zeng ◽  
Dongshen Luo ◽  
Yuan Wang ◽  
Ying Tian ◽  
...  
Keyword(s):  
Multidimensional Poverty ◽  
Mountainous Areas ◽  
Southeast China

The biology of two species of Engaeus (Decapoda : Parastacidae) in Tasmania. III. Habitat, food, associated fauna and distribution

1977 ◽  
Vol 28 (1) ◽  
pp. 95 ◽  
Author(s):  
PJ Suter ◽  
AMM Richardson
Keyword(s):  
Dissolved Oxygen ◽  
Geographical Distribution ◽  
Water Table ◽  
Freshwater Crayfish ◽  
Associated Fauna ◽  
Water Table Level ◽  
Burrow Structure ◽  
Study Sites ◽  
North Western ◽  
Temperature Water

The habitats of two apparently sympatric freshwater crayfish, Engaeus cisternarius and E. fossor, in north-western Tasmania were compared. At two study sites data on rainfall, temperature, water table level, dissolved oxygen and pH were collected. E. fossor occupies regions below the water table, whilst E. cisternarius occupies drier areas above the water table. The burrow structure, burrow fauna, ectofauna and food were compared. The geographical distribution of each species is discussed.

scholarly journals PRODUÇÃO DE MATÉRIA SECA E EVAPOTRANSPIRAÇÃO REAL DA AVEIA PRETA (Avena strigosa S.) EM SEIS NÍVEIS FREÁTICOS

Irriga ◽  
2001 ◽  
Vol 6 (2) ◽  
pp. 62-68
Author(s):  
Marcos Henrique Sias Silveira ◽  
Antonio Evaldo Klar
Keyword(s):  
Water Level ◽  
Water Table ◽  
Dry Matter ◽  
Soil Surface ◽  
Dry Matter Production ◽  
Progressive Decrease ◽  
Surface Level ◽  
Water Table Level ◽  
Avena Strigosa ◽  
Matter Production

PRODUÇÃO DE MATÉRIA SECA E EVAPOTRANSPIRAÇÃO REAL DA AVEIA PRETA (Avena strigosa S.) EM SEIS NÍVEIS FREÁTICOS  Marcos Henrique Dias SilveiraAntonio Evaldo KlarDepartamento de Engenharia Rural –  Faculdade de Ciências Agronômicas – UnespBotucatu – SP  Cep: 18603-970Fone: (0xx14) 6802-7165 – [email protected]  1  RESUMO Para avaliar os efeitos de seis diferentes níveis freáticos na produção de matéria seca e na evapotranspiração real ou de cultura da aveia preta (Avena strigosa S.) foi conduzido um experimento em casa de vegetação, no Departamento de Engenharia Rural da FCA - Campus de Botucatu - UNESP.  Foram semeadas 21 sementes de aveia por vaso, construído de anéis de PVC, com diâmetro nominal de 0,15m x 0,07m de comprimento e alturas totais variando entre 0,21m e 0,91m, de modo a simular os efeitos de níveis freáticos de 0,17m, 0,31m, 0,45m, 0,59m, 0,73m e 0,87m de profundidade.  Após a emergência das plântulas procedeu-se ao desbaste,  deixando-se 8 plantas por vaso, com 06 repetições (seis vasos) para cada nível freático, totalizando 36 vasos em delineamento inteiramente casualizado.  Dados de evapotranspiração real foram coletados diariamente e computados semanalmente.  As plantas foram cortadas rente ao solo ao final da 12.ª semana após a semeadura.  Foram avaliadas as produções de matéria seca da parte aérea e do sistema radicular em cada nível freático.  Os resultados mostraram maior produção de matéria seca para o nível freático mais superficial (0,17m), com queda gradativa à medida que o nível freático se aprofundava. A evapotranspiração da cultura  mostrou a mesma tendência, variando entre 591,6 mm  no tratamento com nível freático a 0,17m de profundidade e 215,4 mm para o de 0,87m de profundidade. UNITERMOS: evapotranspiração, níveis freáticos, aveia preta.  SILVEIRA, M. H. D., KLAR, A. E.  DRY MATTER PRODUCTION AND EVAPOTRANSPIRATION OF OAT         ( Avena strigosa S.) UNDER  SEVERAL TABLE LEVELS.  2  ABSTRACT The aim of this study was to evaluate the influence of six different water table levels on yield and evapotranspiration of oat (Avena strigosa S.) .  21 seeds were sowed  per  pot, which was built with PVC rings (0.15m nominal diameter x 0.07m lenght).  6 water table levels were used: 0.17; 0.31; 0.45; 0.59; 0.73; and 0.87 m measured from the soil surface replicated  6  times.  The completely randomised design was used.  After seedling emergency, 8 plants were maintained  per  pot.  The evapotranspiration were daily measured from reservoirs connected to the pots.  The plants were cut at the soil surface level after 12 weeks from the sowing.The results showed greater dry matter production at the most superficial water table level with progressive decrease with water level distance from the soil surface.  The  evapotranspiration  showed  the  same tendency: the higher values occurred on the 0.17m water table (591.6 mm) until 0.87m water table (215.4 mm). KEYWORDS:  water table, evapotranspiration, Avena strigosa S.

scholarly journals Spontaneous revegetation of a peatland in Manitoba after peat extraction: diversity of plant assemblages and restoration perspectives

Botany ◽  
2018 ◽  
Vol 96 (11) ◽  
pp. 779-791 ◽  
Author(s):  
Félix Gagnon ◽  
Line Rochefort ◽  
Claude Lavoie
Keyword(s):  
Water Table ◽  
Plant Cover ◽  
High Water ◽  
Point Of View ◽  
Water Table Level ◽  
Peat Extraction ◽  
Peatland Restoration ◽  
Water Ph ◽  
Plant Assemblages ◽  
A Site

There are very few studies on the spontaneous revegetation of cutover fens or bogs from which peat has been extracted to the minerotrophic layers. Most peatlands with fen-type residual peat have problems regenerating a plant cover satisfactorily from a restoration point of view. We nevertheless found a site (Moss Spur, Manitoba, Canada) presenting a substantial and diversified spontaneous plant cover. We estimated that the site would provide insights about natural revegetation processes operating in peatlands. Vegetation assemblages and environmental conditions were surveyed 19 years after extraction activities ceased. Moss Spur has densely revegetated (163 plant species, vegetation cover of 94%) with minimal human assistance. However, the composition of plant assemblages varies considerably across the site, depending on certain abiotic variables, particularly water pH, water table level, and the thickness of the residual peat layer. Moss Spur was remarkably wet considering the past peat extraction activities and the absence of active rewetting procedures. The high water table level may in part explain the successful revegetation. However, plant assemblages were not of equal quality from a restoration perspective. Some assemblages were highly diversified, and especially those dominated by Scirpus cyperinus, a species that should be further considered in peatland restoration projects to direct the recovery of the peatland towards a natural fen species composition.

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