scholarly journals Water Level and the Potentials for Wetland Formation and Sustainability in Lower Ogun River Floodplain, Nigeria

2020 ◽  
Vol 24 (6) ◽  
pp. 1041-1044
Author(s):  
I.A. Ogunyemi ◽  
O. Oguntoke ◽  
C.O. Adeofun
Keyword(s):  
Surface Water ◽  
Ground Water ◽  
Water Table ◽  
Rainy Season ◽  
Soil Depth ◽  
Wetland Management ◽  
Water Levels ◽  
Groundwater Levels ◽  
One Year ◽  
Ogun River

Identification, delineation and monitoring of wetlands which requires the understanding and application of their ecological characteristics are critical factors in wetland management and conservation. This study assessed the potentials of wetland formation and sustainability in the lower Ogun river basin by determining the levels of surface and ground water. The study area was divided into 1 km2 grids of 67 units using 0.052 %  sampling intensity for the assessments in dry and wet seasons. Monthly water table levels were assessed in 50 cm soil pit while inundation levels were measured during the flooding event using staff gauge. Assessment was carried out for one year during which frequency and periodicity of water table and inundation events were recorded. Results revealed that low water table level ranged from 5 to 45cm of soil depth and occurred between August and September within 6 grids. Water table and surface water was recorded within a period of 2 – 10 weeks during the rainy season. The peak of water levels coincided with the peak of precipitation (> 200 mm) ranging from 30 to 280 cm between September and October while covering 28.75 km2. Conclusively, surface and groundwater levels were recorded during the rainy season having direct variation with the volume of  precipitation for a duration that is long enough to support the formation of wetland hydrophytes and hydric soil. Keywords: Wetlands; Hydrology; Ground water; Surface water; Inundation; Precipitation

scholarly journals Hydrogeology of Brahmaputra Basin, India

2003 ◽  
Vol 28 ◽  
Author(s):  
Barendra Purkait
Keyword(s):  
Ground Water ◽  
Water Table ◽  
Land Surface ◽  
Flood Plain ◽  
Water Levels ◽  
The South ◽  
Drainage Pattern ◽  
The North ◽  
The World ◽  
Brahmaputra Basin

The Ganga-Brahmaputra river system together forms one of the largest deltas in the world comprising some 59570 sq km. The waterpower resources of the Brahmaputra have been presumed to be the fourth biggest in the world being 19.83 x 103 m3s1. The entire lower portion of the Brahmaputra consists of a vast network of distributary channels, which are dry in the cold season but are inundated during monsoon. The catchment area of the entire river is about 580,000 sq km, out of which 195,000 sq km lies in India. The maximum discharge as measured at Pandu in 1962 was of the order of 72800 m3 s-1 while the minimum was 1750 m3 s-1 in 1968. The drainage pattern in the valley is of antecedent type while the yazoo drainage pattern is most significant over the composite flood plain to the south of the Brahmaputra. The Brahmaputra valley is covered by Recent alluvium throughout its stretch except a few isolated sedimentary hills in the upper Assam, inselbergs/bornhardt of gneissic hills in the Darrang, Kamrup and Goalpara districts and a few inlying patches of Older Alluvium in the Darrang and Goalpara districts. The basin is very unstable. The present configuration of the basin is the result of uplift and subsidence of the Precambrian crystalline landmasses. Four geotectonic provinces can be delineated in the N-E India through which the Brahmaputra flows. These are bounded by major tectonic lineaments such as the basement E-W trending Dauki fault, a NE-SW trending structural feature of imbricate thrusts known as 'belt of Schuppen' and the NW-SE trending Mishmi thrust. Hydrogeologically, the Brahmaputra basin can be divided into two distinct categories, viz(a) dissected alluvial plain and (b) the inselberg zone. The first category is rep resented in the flood plain extending from the south of Sub-Himalayan piedmont fan zone in the north to right upto the main rock promontory of Garo Hills and Shillong Plateau. The inselberg zone is characterized by fractured, jointed and weathered ancient crystalline rocks with interhill narrow valley plains, consisting of thin to occasionally thick piles of assorted sediments. From the subsurface lithological data, two broad groups of aquifers are identified. These are i) shallow water table and ii) deeper water table or confined ones, separated by a system of aquicludes. The shallow aquifer materials, in general, consist of white to greyish white, fine grained micaceous sand and the thickness ranges from 1.2 to 10.3 m. The sand and clay ratio varies from 1: 2.5 to 1:26. The bedrock occurs at depth ranges of 30.4 to 39.5 m. The materials of the deeper aquifers comprise grey to greyish white, fine to medium grained sand. The sand and clay ratio varies from 1:2 to 1:7. The effective size of the aquifer materials varies from 0.125 to 0.062 mm with uniformity co-efficient around 4.00, porosity 38 to 42%, co-efficient of permeability 304 to 390 galls per day/0.3m2. The ground water is mildly alkaline with pH value 6.5 to 8.5, chloride 10 to 40 ppm, bi-carbonate 50 to 350 ppm, iron content ranges from a fraction of a ppm to 50 ppm. Total dissolved solids are low, hardness as CaCo3 50 to 300 ppm, specific conductance at 25 °C 150 to 650 mhos/cm. The yield from shallow aquifers is 1440 litres to 33750 litres/hour and for deeper aquifers ~ 1700 litres/hour at a drawdown of 13.41 m, specific capacity 21 litres/minute. The temperatures of ground water are 23°-25° C during winter, 24°-26° C during pre-monsoon and 27°- 28° C during peak monsoon. The general hydraulic gradient in the north bank is 1:800 whereas in the south bank it is 1: 300-400 The Tertiary sediments yield a range of water from 200 to 300 l.p.m whereas the yield from the Older Alluvium is 500 to 700 1.p.m. The estimated transmissibility and co-efficient of storage is of the order of ~ 800 1.p.m/ m and 8.2 x 10-3 respectively. Depths to water levels range from 5.3 to 10m below land surface (b.l.s). In the Younger or Newer Alluvium, ground water occurs both under water table and confined conditions. Depths to water levels vary from ground level to 10 m b.l.s. Depth to water ranges from 6 m b.l.s. to 2 m above land surface. The yield of the deep tubewells ranges from 2 to 4 kl/minute for a drawdown of 3 m to 6 m. The transmissibility of the aquifers varies from 69 to 1600 l.p.m/m and the storage co-fficient is of the order of 3.52 x 10-2.

scholarly journals Assessing the Potential Impacts of the Grand Ethiopian Renaissance Dam on Water Resources and Soil Salinity in the Nile Delta, Egypt

2019 ◽  
Vol 11 (24) ◽  
pp. 7050 ◽  
Author(s):  
Sherien Abdel Aziz ◽  
Martina Zeleňáková ◽  
Peter Mésároš ◽  
Pavol Purcz ◽  
Hany Abd-Elhamid
Keyword(s):  
Surface Water ◽  
Water Resources ◽  
Soil Salinity ◽  
Crop Yields ◽  
Nile Delta ◽  
National Income ◽  
Water Levels ◽  
Groundwater Levels ◽  
Deep Aquifers

Several studies have reported that the construction of the Grand Ethiopian Renaissance Dam (GERD) could have severe effects on the water resources in downstream countries, especially Egypt. These effects include changes in surface water level, groundwater levels in shallow and deep aquifers, saltwater intrusion, and increases in soil salinity, which could affect crop yields. This paper assesses the potential impacts of the GERD on the Nile Delta, Egypt. It includes the effects of reducing surface water levels (SWL) and changing the crop patterns at the groundwater levels (GWL), in addition to the effect of cultivating crops that consume less water on soil salinity. A pilot area is selected in the east of the Nile Delta for the assessment. The results of the study revealed that GWL is directly proportional to SWL. Comparing the case study of 2012, when SWL was reduced by 50%, the GWL decreased from 5.0 m to 2.0 m. After adjustment, the crop patterns from rice to other crops decreased the GWL to 1.30 m. Additionally, the results showed that there is a significant relationship between soil salinity and crop patterns. Soil salinity increased during the cultivation of the Delta with non-rice crops, such as grapes. Salinity increased from 0.45 S/m after 10 years of simulation to 0.48 S/m. This estimation highlights the undesirable effects of the GERD on Egypt’s water resources, soil salinity, crop yields, and national income.

Groundwater levels under climate change in the Gnangara system, Western Australia

2013 ◽  
Vol 4 (1) ◽  
pp. 52-62 ◽  
Author(s):  
Adrian H. Gallardo
Keyword(s):  
Climate Change ◽  
Water Table ◽  
Western Australia ◽  
Water Levels ◽  
Good Correspondence ◽  
Groundwater Levels ◽  
Aquifer Systems ◽  
The Status ◽  
Rainfall Reduction ◽  
The Impact

The Gnangara system is the main source of freshwater for Perth, Western Australia. However, aquifers in the region are under severe stress due to a drying climate, intensive pumping and changes in land use. The aim of this study is to apply the mean rainfall cumulative deviation and Mann-Kendall analyses at 77 monitoring bores to investigate the response of the water table to key recharge components. This information is critical for setting new allocation limits and reviewing current policies in the region. Results show that overall there is a good correspondence between water levels and rainfall fluctuations. Areas of groundwater recharge are highly sensitive to climate change and have been severely affected by reduction in rainfall rates in recent years. Further, removal of pine plantations correlated well with a rise in groundwater levels although the effect seems to be temporary. The impact of pumping is mainly observed in vicinities of public-supply borefields. Elsewhere, water table trends show a relative stabilisation indicating that storage still exceeds the influence of rainfall reduction in areas dominated by through flow or groundwater discharge. The study contributes to update the status of the Gnangara groundwater resource, and provides new insights for the sustainable management of one of the main aquifer systems in Australia.

scholarly journals Analisis Pengaruh Penyekatan Kanal Untuk Untuk Pembahasan Lahan Gambut Tropis

2020 ◽  
Vol 14 (2) ◽  
pp. 129-135
Author(s):  
Gina Khusnul Khotimah ◽  
◽  
Sigit Sutikno ◽  
Indradi Wijatmiko ◽  
◽  
...  
Keyword(s):  
Ground Water ◽  
Water Level ◽  
Good Effect ◽  
Fire Prevention ◽  
Emission Rates ◽  
Groundwater Levels ◽  
Peatland Restoration ◽  
Peatland Rewetting ◽  
One Year ◽  
The Impact

Peatlands rewetting for hydrological restoration plays an important role for fire prevention and peatland restoration of degraded peatland. One of the methods for the rewetting is canal blocking. The impact of canal blocking for peatland rewetting is further analyzed in this research. This study focused in Pulau Tebing Tinggi peatland hydrological unit (PHU), which is located in Kepulauan Meranti Regency, Riau Province. To analysis the rewetting impact, 15 dipwells were installed with the distance of 1 m, 51 m, 101 m, 201 and 301 m from the canal for each transect of the three transects. A transect was set in the downstream and two transects were set in the upstream of canal block. The ground water level (GWL) in the 15 dipwells was recorded using water-loggers for one year. This research found that canal blocking has a good effect on maintaining groundwater levels and keeping peatlands in always wet or humid conditions up to a distance of 201 m perpendicular to the canal if the rise in water level in the canal due to canal blocking is more than 0.6 m. It is able to maintain the ground water depth in peatlands around 0.4 m, where the peatlands become low risk to the fire, emission rates and subsidence.

scholarly journals Applying MODFLOW to wet grassland in-field habitats: a casestudy from the Pevensey Levels, UK

2003 ◽  
Vol 7 (1) ◽  
pp. 43-55 ◽  
Author(s):  
R. B. Bradford ◽  
M. C. Acreman
Keyword(s):  
Groundwater Flow ◽  
Water Table ◽  
Hydrological Regime ◽  
Water Levels ◽  
Management Technique ◽  
Low Permeability ◽  
Groundwater Levels ◽  
Depth To Water Table ◽  
Wet Grasslands ◽  
Vertical Leakage

Abstract. Historical drainage improvements have created complex hydrological regimes in many low-lying, wet coastal grassland areas. The manipulation of ditch water levels is a common management technique to maintain important in-stream and in-field habitats in such areas. However, in wet grasslands with low soil conductivities the water table in the centre of each field is not closely coupled to variations in ditch stage. Consequently rainfall and evaporation have a greater influence on the depth to water table and water table fluctuations within each field. In-field micro-topographic variations also lead to subtle variations in the hydrological regime and depth to water table that create a mosaic of different wetness conditions and habitats. The depth, duration, timing and frequency of flooding from accumulated rainfall, surface water and standing groundwater also influence the availability of suitable in-field habitats. Land drainage models are often used for studies of wet grasslands, but tend to be more complex and require more field variables than saturated zone models. This paper applies a 3D groundwater flow model, MODFLOW, to simulate groundwater levels within a single field in a wet coastal grassland underlain by a low permeability sequence and located in the central part of Pevensey Levels, Sussex, UK. At this scale, the influence of vertical leakage and regional groundwater flow within the deeper, more permeable part of the sequence is likely to be small. Whilst available data were not sufficient to attempt a full calibration, it was found that the sequence could be represented as a single, unconfined sequence having uniform hydraulic properties. The model also confirmed that evaporation and rainfall are the dominant components of the water balance. Provided certain information requirements are met, a distributed groundwater model, such as MODFLOW, can benefit situations where greater hydrological detail in space and time is required to represent complex and subtle changes influencing the in-field habitats in wet grasslands with low permeability soils. Keywords: wetlands, hydrology,groundwater, MODFLOW

scholarly journals ASSESSING GROUNDWATER POTENTIAL USE FOR EXPANDING IRRIGATION IN THE BURITI VERMELHO WATERSHED

Irriga ◽  
2015 ◽  
Vol 1 (2) ◽  
pp. 81-94 ◽  
Author(s):  
Doris Elise Wendt ◽  
Lineu Neiva Rodrigues ◽  
Roel Dijksma ◽  
Jos C Van Dam
Keyword(s):  
Surface Water ◽  
The Netherlands ◽  
Water Balance ◽  
Agricultural Production ◽  
Groundwater Potential ◽  
Water Levels ◽  
Groundwater Levels ◽  
Management Group ◽  
Irrigated Area ◽  
Potential Use

ASSESSING GROUNDWATER POTENTIAL USE FOR EXPANDING IRRIGATION IN THE BURITI VERMELHO WATERSHED  DORIS ELISE WENDT1; LINEU NEIVA RODRIGUES2; ROEL DIJKSMA3; JOS C VAN DAM4 [1] Wageningen University, the Netherlands. [email protected];2Embrapa Cerrados, BR020, km18, CEP 73310970, Planaltina, DF.  [email protected];3 Hydrology and Quantative Water Management Group, Wageningen University, the Netherlands. [email protected];4 Soil Physics and Land Management Group, Wageningen University, the Netherlands. [email protected];  1 ABSTRACT In Brazil, the increasing middle class has raised food demand substantially. The Brazilian Savannah (Cerrados) is one of the rare places where agriculture can expand and address this new demand without jeopardizing the environment. Cerrados has a strictly divided dry and wet season. The dry season lasts from May to September. This long period contributes to various problems such as water shortages, conflicts and insecure food production. Without irrigation, only two crops can be grown per year in this region. Production suffers with a recurrent drought. Because agricultural production is uncertain, irrigation has an important role in this context, but its expansion is limited by water availability. Water conflicts have already occurred in some watersheds, which may jeopardize agriculture and decrease the livelihood of rural communities. In general, water for irrigation is limited to surface water. Therefore, it is important to investigate alternative sources of water, like groundwater. The purpose of this study is to assess the groundwater potential for expanding the irrigated area in a small-scale catchment (Buriti Vermelho, DF, Brazil). The current water demand was investigated and simulated by an Irrigation Strategies Simulation Model (MSEI). A daily water balance was computed, which quantified catchment storage over time. In addition, groundwater behavior and availability were investigated by recession curve analysis. The irrigated area was changed using two scenarios that showed different effects in both catchment surface water balance and groundwater levels. A decline in groundwater levels is seen in all scenarios one year after the beginning of extra extraction. With time, water levels may decline beyond the natural recovery capacity, which will certainly penalize poorer farmers and result in areas being taken out of agricultural production. Keywords: Base flow Recession, Catchment Hydrology, Hydrogeology, Crop Water Productivity  WENDT, D.E.; RODRIGUES, L.N.; DIJKSMA, R.; DAM, J.C. VANAVALIAÇÃO DO POTENCIAL DE USO DA ÁGUA SUBTERRÂNEA PARA EXPANSÃO DA IRRIGAÇÃO NA BACIA DO BURITI VERMELHO   2 RESUMO A demanda por alimentos no Brasil cresceu substancialmente devido, entre outras coisas, ao aumento da classe média. O Cerrado brasileiro é um dos poucos lugares no país onde a agricultura ainda pode expandir e atender a essa nova demanda, sem comprometer o meio ambiente. A região do Cerrado possui duas estações climáticas bem definidas, uma seca e outra chuvosa. O longo período da estação seca, que vai de maio a setembro, contribui para o surgimento de vários problemas, entre eles restrições hídricas, conflitos e insegurança na produção de alimentos. Sem irrigação, apenas dois plantios podem ser feitos por ano. Os cultivos sofrem com os veranicos e a produção é incerta. A irrigação é de fundamental importância nesse contexto, mas sua expansão é limitada pela disponibilidade de água. Em algumas bacias hidrográficas já se observam a ocorrência de conflitos, que podem comprometer a agricultura irrigada e a qualidade de vida das comunidades rurais. De maneira geral, a água para irrigação é de superfície. Desta forma, é importante investigar fontes alternativas de água, com vista ao crescimento da irrigação, tais como a água subterrânea. O Objetivo deste trabalho é avaliar a viabilidade de se utilizar água subterrânea para expandir a agricultura irrigada na bacia hidrográfica do Buriti Vermelho, DF, Brasil. A demanda atual de água foi estimada por meio de um modelo de simulação de estratégias de irrigação (MSEI). Um balanço diário da água no solo foi realizado. O comportamento e a disponibilidade de água subterrânea foram avaliados por meio de uma análise da curva de recessão. Para fins da análise, foram utilizados três cenários de área irrigada, que indicaram diferentes efeitos tanto no perfil do balanço de água no solo quanto no nível do lençol freático. Nos três cenários avaliados, em apenas um ano após a expansão da área irrigada, verificou-se um rebaixamento do lençol freático, que pode atingir níveis abaixo da sua capacidade natural de recuperação. Esse rebaixamento penalizará principalmente os agricultores menores. Em alguns casos haverá necessidade de interromper a produção em algumas áreas. Palavras-chave: Curva de recessão, hidrologia, hidrogeologia, produtividade do uso da água

EFEKTIVITAS PENGELOLAAN IRIGASI DENGAN SUMUR POMPA GUNA MENINGKATKAN POLA TANAM DI KECAMATAN NEGARA, KABUPATEN JEMBRANA

1970 ◽  
Vol 4 (1) ◽  
Author(s):  
Agus Gede Putra Wiryawan ◽  
I N Norken ◽  
IBN Purbawijaya
Keyword(s):  
Surface Water ◽  
Ground Water ◽  
Rainy Season ◽  
River Flow ◽  
Irrigation Management ◽  
Likert Scale ◽  
Generating Set ◽  
Purposive Sampling ◽  
Descriptive Qualitative

Abstrack : Jembrana Regency especially Negara District have two river caracteristics such as the river which located in western Melaya River only flow when the rainy season and the rivers located between western Klatakan river and eastern Pulukan river flow every years with low discharge. it caused failing of harvest. So the ground water used to supply the surface water needs. But, complaint comes from the farmer caused by the expensive cost of operational generating set. The approach doing by study and research directly to the well pump which located in Negara district. Purposive sampling used  to determine the respondents in this quisionaires. Likert scale used to measure attitudes, opinon and perceptions from the respondents on data analyzed by descriptive qualitative. The research showed resource, subak organization, operational and maintenance generating set, pump, and financial. Work on 82% reaching effectiveness of irrigation management with pump well in Negara district. And, based on result of double linier regression simultaneous and partial, showed that the significant effect to effectiveness of irrigation management with pump well in Negara district, Jembrana regency.

scholarly journals Impacts of groundwater extraction on groundwater flow and arsenic distribution in the western Hetao Basin, Inner Mongolia, China

2019 ◽  
Vol 98 ◽  
pp. 09037
Author(s):  
Zhuo Zhang ◽  
Huaming Guo ◽  
Weiguang Zhao ◽  
Haicheng Weng
Keyword(s):  
Surface Water ◽  
Groundwater Flow ◽  
Flow Direction ◽  
Temporal Variations ◽  
Water Levels ◽  
Labile Organic Matter ◽  
Near Surface ◽  
Groundwater Levels ◽  
Arsenic Distribution ◽  
Geochemical Parameters

Temporal variations in water levels are crucial for understanding As behaviour in groundwater systems. Groundwater levels were recorded in irrigation wells in non-irrigation and irrigation seasons. Groundwater samples were collected yearly in irrigation wells from 2014 to 2016 and in a multilevel well from 2015 to 2016 for analysing geochemical parameters. Results showed that groundwater flow direction was reversed due to groundwater pumping. The change of groundwater flow led to the surface water, as a new groundwater recharge source, which flushed the near-surface sediments enriched in soluble components and increased groundwater TDS. The labile organic matter introduced by the surface water recharge fueled dissimilatory reduction of Fe(III) oxides and further increased groundwater As concentration.

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