scholarly journals Geostatistics-based spatial variation characteristics of groundwater levels in a wastewater irrigation area, northern China

2017 ◽  
Vol 17 (5) ◽  
pp. 1479-1489 ◽  
Author(s):  
Shiyang Yin ◽  
Xiaomin Gu ◽  
Yong Xiao ◽  
Wenyong Wu ◽  
Xingyao Pan ◽  
...  
Keyword(s):  
Groundwater Recharge ◽  
Urban Areas ◽  
Large Scale ◽  
Northern China ◽  
Temporal Variations ◽  
Wastewater Irrigation ◽  
Geostatistical Model ◽  
Groundwater Exploitation ◽  
Irrigation Area ◽  
Groundwater Levels

Although wastewater reuse in agriculture can ease water scarcity, this practice also alters the variation of groundwater recharge and groundwater levels. This study employed a geostatistical method to systematically investigate the spatio-temporal variations and storage fluctuations of groundwater in a wastewater irrigation area in a southeastern suburb of Beijing. Specifically, we generated an optimal geostatistical model for measuring groundwater levels. Furthermore, we proposed that universal kriging is a suitable method for examining groundwater spatial variations, whereas a raster-based model can provide high accuracy for studying groundwater fluctuations; the nugget effect value of groundwater levels increases with increasing exploitation intensity. Our results indicated that groundwater levels increased overall in the early stages of wastewater irrigation development, followed by local increases in some pockets in the middle stages of development, large-scale increases in the late stages and an increasing variation of magnitude over time. The results also showed that groundwater level declined less on farmlands than that in urban areas, suggesting that wastewater irrigation facilitates groundwater conservation by reducing groundwater exploitation and enhancing groundwater recharge. Our results are conducive to developing an effective groundwater management plan and for improving the accuracy of groundwater resource assessments.

scholarly journals Potential of Shallow Groundwater for Household Level Irrigation Practices in Tahtay Koraro Woreda, Tigray, Northern Ethiopia

2021 ◽  
Vol 13 (1) ◽  
pp. 43-66
Author(s):  
Ermias Hagos ◽  
Amare Girmay ◽  
Tesfamichael Gebreyohannes
Keyword(s):  
Groundwater Recharge ◽  
Large Scale ◽  
Potential Evapotranspiration ◽  
Shallow Groundwater ◽  
Northern Ethiopia ◽  
Groundwater Abstraction ◽  
Groundwater Levels ◽  
Household Level ◽  
Average Value ◽  
Dug Wells

This paper deals with the results of a pilot study conducted to estimate the shallow groundwater resource potential and irrigation capacity at the household level in Tahtay Koraro Woreda, northwestern zone of Tigray, Ethiopia. The potential evapotranspiration and actual evapotranspiration of the study area are estimated to be 1484 mm/year and 814 mm/year respectively. The runoff is approximately calculated to be 280 mm/year and the annual groundwater recharge is estimated to be 29 mm/year. The total annual groundwater abstraction for human, livestock, and irrigation is estimated to be 25 mm/year. It should be noted that the groundwater recharge rate is expected to remain constant while the total annual groundwater discharge is expected to increase from year to year. This relation when projected over a long period may result in a negative groundwater budget which can result in depletion of groundwater (lowering of groundwater levels), reduced baseflow to streams, and deterioration of water quality.  The computed values for hydraulic conductivity of the aquifers range from 1.63 m/day to 7.27 m/day with an average value of 4.9 m/day and transmissivity from 48.9 m2/day to 218.1 m2/day with an average value of 147.14 m2/day. The aquifers in the highly weathered basalt and highly weathered siltstone – sandstone intercalation have transmissivity values ranging from 99 m2/day to 218.1 m2/day with an average value of 157 m2/day and are grouped into the moderate potentiality aquifers category. The aquifers in the slightly weathered and fractured metavolcanics grouped under low potentiality based on the lower transmissivity values (<50 m2/day). The study area has low to moderate groundwater potentiality, hence, large-scale groundwater pumping is not possible. Therefore, the current activity of using hand dug wells for household-level irrigation is the best way of using groundwater for irrigation and other uses as well. Increasing the depth of the existing hand dug wells that are constructed in highly weathered basalt and highly weathered siltstone – sandstone intercalation can also enhance the yield of the hand dug wells. It is recommended to use water-saving irrigation technologies rather than increasing the number of wells. This will also help in increasing the irrigation area. Groundwater recharge enhancement structures such as trenches, percolation ponds, and check dams be constructed in scientifically selected localities to further enhance the groundwater potential.

Investigating of River-Aquifer Interactions using Sub-Surface Hydrological Model and Remote Sensing Inputs in an agriculturally Dominated Kosi River Basin, India.

2021 ◽  
Author(s):  
Naga Venkata Satish Laveti ◽  
Suresh A. Kartha ◽  
Subashisa Dutta
Keyword(s):  
Remote Sensing ◽  
Groundwater Recharge ◽  
River Basin ◽  
Hydrological Model ◽  
Temporal Variations ◽  
Interaction Process ◽  
Groundwater Levels ◽  
Physically Based ◽  
Spatio Temporal ◽  
Exchange Flux

&lt;p&gt;River-Aquifer Interaction is a natural and complex phenomenon for understanding its physical dynamic processes. These interactions highly vary with time and space and are to be investigated at river reach scale. The present study aims to understand and quantify the spatio-temporal variations of river-aquifer interaction process in Kosi river basin, India. This basin is majorly dominated with agricultural lands and irrigation requirement of the crops are mostly met by groundwater. In order to quantify the river-aquifer exchange flux at reach scale, a physically based sub-surface hydrological model has been carried for the study area. For this purpose, high resolution remotely sensed evapotranspiration data and groundwater recharge (estimated using soil water budget method method) along with other aquifer parameters were utilized for simulating the monthly groundwater levels as well as exchange flux between river and aquifer. The model results showed that simulated groundwater levels were well calibrated and validated with measured groundwater levels. Further, this calibrated groundwater flow model has been used to quantify the river-aquifer exchange flux. Based on the obtained exchange flux values, three different interaction zones were identified from upstream (Kosi barrage) to downstream (confluence point with Ganga river) in the study reach. It is observed that the river mostly loses water to the aquifer (as influent) in Zone I (80km from upstream) and the river mostly gains water from the aquifer (as effluent) in Zone III (40 km above downstream to confluence point). Whereas, the river has a combination of both losing and gaining natures in Zone II (between Zone I and III). From this study, it can be concluded that use of satellite remote sensing inputs (groundwater recharge and evapotranspiration) in the sub-surface hydrological model, facilitated to improve the assessment and understanding river-aquifer interaction process in an alluvial River basin.&lt;/p&gt;

scholarly journals Groundwater Policy and Ground Water Dependencies: Reflecting on the Evolving Socio-Environmental Dynamics in Peri-Urban Kathmandu Valley

2019 ◽  
Vol 6 (1) ◽  
pp. 32-51
Author(s):  
Anushiya Shrestha
Keyword(s):  
Ground Water ◽  
Urban Areas ◽  
Urban Spaces ◽  
Kathmandu Valley ◽  
Negative Consequences ◽  
Groundwater Exploitation ◽  
Groundwater Use ◽  
Groundwater Levels ◽  
Urban Dynamics ◽  
Groundwater Policy

Groundwater is an increasingly important source of water supply in Kathmandu Valley, ‘the hub of Nepal’s urbanisation’. Past studies have revealed that groundwater extraction in Kathmandu Valley exceeds its recharge, thus having negative consequences like drying of traditional water sources, decreasing yield of wells, and declining groundwater levels. The groundwater policy 2012 was formulated with the aim of managing groundwater use in the valley. Yet, with rapid urban growth, groundwater exploitation has continued increasing in the city and the peri-urban areas in Kathmandu Valley. But little is known regarding how urbanisation shapes increasing groundwater exploitation in the peri-urban settings. This study unfolds the underexplored socio-environmental dynamics underlying groundwater exploitation in peri-urban areas of Kathmandu Valley. The findings from the case study using qualitative research methods, conducted in peri-urban locations of Kathmandu Valley show increasing competition for water and growing use of as well as dependence on groundwater in these rapidly evolving peri-urban spaces, despite growing protests and worries about its consequences. However, the existing groundwater policy lacks attention to peri-urban dynamics of change and growth and does little to address the increasing groundwater use in peri-urban locations in the valley. The polarised views and local conflicts around groundwater exploitation emerging in peri-urban spaces are the outcome of multiple entanglements: sectoral divides and overlapping responsibilities in water institutions, weak governance and management; socio-economic transformations in peri-urban spaces, the invisibility of groundwater and ambiguity in the hydrological dynamics of conjunctive water use. Based on my findings, I stress on the need for addressing the existing macro-micro gaps (ground)water management by improving the understanding of local hydro-geological  complexities and paying critical attention to the socio-economic, political and institutional drivers of increasing groundwater use.

Underreporting of Births and Infant Deaths in Rural China: Evidence from Field Research in One County of Northern China

1998 ◽  
Vol 155 ◽  
pp. 637-655 ◽  
Author(s):  
M. Giovanna Merli
Keyword(s):  
Population Growth ◽  
Rural Areas ◽  
Urban Areas ◽  
Birth Rate ◽  
Large Scale ◽  
Crude Birth Rate ◽  
Field Research ◽  
Northern China ◽  
Natural Increase ◽  
Human Reproduction

Between the beginning of the 1950s and the early 1970s, China, like many other countries in Asia, Africa and Latin America, experienced rapid population growth. This was due mainly to a dramatic mortality decline not offset by any decline in the birth rate. In 1970, China had a crude birth rate of 33.43 (per 1,000), a crude death rate of 7.60 (per 1,000) and a rate of natural increase of 25.83. “Population growth” was identified as a fundamental obstacle to economic development, and the stage was set for large-scale state interventions in the process of human reproduction. The apotheosis of this intervention was the introduction, in 1979, of the One Child Policy, which was successfully implemented in the urban areas. In rural areas, policies promoting later marriage, one child – maximum two – per couple, and greater spacing of those births that are permitted contributed to the swift fertility decline witnessed over the last three decades. In 1996 China's birth and death rates were reported at 16.98 per 1,000 and 6.56 per 1,000 respectively and the population was growing at 10.42 per 1,000.

Clustering of Groundwater Wells and Spatial Variation of Groundwater Recharge in Sina Basin, India

2020 ◽  
Vol 17 (4) ◽  
pp. 11-21
Author(s):  
Thendiyath Roshni ◽  
Jesu V. Nayahi ◽  
Madan K. Jha ◽  
Mandal Nehar ◽  
Choudhary Sourav ◽  
...  
Keyword(s):  
Spatial Analysis ◽  
Groundwater Recharge ◽  
Numerical Models ◽  
Regional Scale ◽  
Groundwater Exploitation ◽  
Groundwater Levels ◽  
Expectation Maximisation ◽  
Eras Model ◽  
Recharge Estimation ◽  
Selection Of

A spatial and temporal analysis of groundwater levels, topography, and precipitation is required to properly manage the groundwater resource. The present paper explains it in two parts: (1) spatial analysis of groundwater levels and selection of suitable clustering approach for selection of representative wells and (2) spatial and temporal variations of groundwater recharge calculated by three numerical models: Chaturvedi model, Amritsar model and ERAS model. Four clustering techniques including K-Means clustering algorithm, Hierarchical clustering technique, canopy and expectation maximisation (EM) were used for the clustering of groundwater levels. Among these, the canopy technique presents more reliable results compared to the other techniques for the spatial analysis of groundwater levels and the formation of representative wells in the Sina basin. For the groundwater recharge estimation, Chaturvedi model and ERAS model values were found very close. The recharge values show consistency with the precipitation data and found that 15% of precipitation contributes to annual groundwater recharge. Spatio-temporal variation of groundwater recharge correlated with precipitation is also carried out for the selected basin. The results show a drastic decline in the groundwater recharge from the year 1990 to 2008. An empirical expression is also developed for groundwater recharge estimation in terms of groundwater level. This provides regional scale information about the basin and helps to understand the groundwater exploitation scenario for instance.

Study of groundwater vulnerability in three unconfined aquifers in Slovenia

2020 ◽  
Author(s):  
Miha Curk ◽  
Matjaž Glavan ◽  
Joseph Adu-Gyamfi ◽  
Janine Halder ◽  
Sonja Cerar ◽  
...  
Keyword(s):  
Land Use ◽  
Groundwater Recharge ◽  
Urban Areas ◽  
Agricultural Land ◽  
Shallow Groundwater ◽  
Nitrate Pollution ◽  
Soil Types ◽  
Nitrate Sources ◽  
Groundwater Levels ◽  
Unconfined Aquifers

&lt;p&gt;Groundwater is the main source of drinking water in Slovenia, but nitrate pollution originating from agriculture and urban areas is threatening its quality in several areas of the country. The aim of this study is to assess the vulnerability of three different unconfined aquifers in Slovenia (Ljubljansko polje, Dravsko-ptujsko polje and Kr&amp;#353;ko-bre&amp;#382;i&amp;#353;ko polje). All three study areas are located on alluvial plains with shallow groundwater levels and similar soil types, but different ratios of urban and agricultural land use. Soil types and land use were analyzed in each area as they contribute strongly to leaching of nitrate. Along with this we performed the analysis of stable isotopes of O, H and N to determine the origin of groundwater recharge and trace the possible sources of nitrate pollution. Results will give us an overview of nitrate pollution pathways through better understanding of nitrate sources, vulnerable areas, and groundwater recharge characteristics.&lt;/p&gt;

scholarly journals Atmospheric wet and dry deposition of trace elements at ten sites in Northern China

2014 ◽  
Vol 14 (14) ◽  
pp. 20647-20676 ◽  
Author(s):  
Y. P. Pan ◽  
Y. S. Wang
Keyword(s):  
Trace Elements ◽  
Atmospheric Deposition ◽  
Dry Deposition ◽  
Urban Areas ◽  
Wet Deposition ◽  
Northern China ◽  
Temporal Variations ◽  
Deposition Flux ◽  
Forest Site ◽  
Wet And Dry Deposition

Abstract. Atmospheric deposition is considered to be a major process that removes pollutants from the atmosphere and an important source of nutrients and contaminants for ecosystems. Trace elements (TEs), especially toxic metals deposited on plants and into soil and water, can cause substantial damage to the environment and human health due to their transfer and accumulation in food chains. Despite public concerns, quantitative knowledge of metal deposition from the atmosphere to ecosystems remains scarce. To advance our understanding of the spatio-temporal variations in the magnitudes, pathways, compositions and impacts of atmospherically deposited TEs, precipitation (rain and snow) and dry-deposited particles were collected simultaneously at ten sites in Northern China from December 2007 to November 2010. The measurements showed that the wet and dry depositions of TEs in the target areas were orders of magnitude higher than previous observations within and outside China, generating great concern over the potential risks. The spatial distribution of the total (wet plus dry) deposition flux was consistent with that of the dry deposition, with a significant decrease from industrial and urban areas to suburban, agricultural and rural sites. In contrast, the wet deposition exhibited less spatial variation. The seasonal variation of wet deposition was also different from that of dry deposition, although they were both governed by the precipitation and emission patterns. For the majority of TEs that exist as coarse particles, dry deposition dominated the total flux at each site. This was not the case for K, Ni, As, Pb, Zn, Cd, Se, Ag and Tl, for which the relative importance between wet and dry deposition fluxes varied by site. Whether wet deposition is the major atmospheric cleansing mechanism for the TEs depends on the size distribution and solubility of the particles. We found that atmospheric inputs of Cu, Pb, Zn, Cd, As and Se were of the same magnitude as their increases in the topsoil of agricultural systems. In addition, the total deposition flux of Pb observed at a forest site in this study was twice that of the critical load (7.0 mg m−2 yr−1) calculated for temperate forest ecosystems in Europe. These findings provide baseline data needed for future targeting policies to protect various ecosystems from long-term heavy metal input via atmospheric deposition.

scholarly journals Study on the Exploitation Scheme of Groundwater under Well-Canal Conjunctive Irrigation in Seasonally Freezing-Thawing Agricultural Areas

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1384
Author(s):  
Yang Yang ◽  
Yan Zhu ◽  
Wei Mao ◽  
Heng Dai ◽  
Ming Ye ◽  
...  
Keyword(s):  
Northern China ◽  
Empirical Method ◽  
Irrigation District ◽  
Groundwater Exploitation ◽  
Irrigation Area ◽  
Irrigated Area ◽  
Single Well ◽  
Local Grid ◽  
Process Prediction ◽  
Agricultural Areas

The suitable groundwater exploitation scheme in freezing-thawing agricultural areas under the well-canal conjunctive irrigation conditions is confronted with two major challenges, which are computationally expensive local grid refinements along wells, and the model suitability problem in the freezing-thawing period. In this study, an empirical method for groundwater level prediction in the freezing-thawing period was developed and integrated with the local grid refinement groundwater model MODFLOW-LGR for the groundwater process prediction. The model was then applied to estimate the suitable groundwater exploitation scheme, including the size of well-irrigated area and the irrigation area of single well. The results showed that suitable size of well-irrigated area should be smaller than 15 × 106 m2, and the recommended irrigation area of single well as 15 × 104 m2 to 19 × 104 m2. The recommended layout parameters of groundwater exploitation were further used to plan the well-canal conjunctive irrigation scheme in Yongji irrigation district located in northern China. This study provides an important pilot example of the conjunctive use of groundwater and surface water in arid irrigation areas with a seasonal freezing-thawing period.

Engineering in the time of cholera: overcoming institutional and political challenges to rebuild Zimbabwe's water and sanitation infrastructure in the aftermath of the 2008 cholera epidemic

2013 ◽  
Vol 3 (2) ◽  
pp. 222-229 ◽  
Author(s):  
Clarissa Brocklehurst ◽  
Murtaza Malik ◽  
Kiwe Sebunya ◽  
Peter Salama
Keyword(s):  
Urban Areas ◽  
Large Scale ◽  
Humanitarian Aid ◽  
Urban Systems ◽  
Political Crisis ◽  
Rapid Improvement ◽  
Cholera Epidemic ◽  
Rapid Action ◽  
Water And Sanitation Infrastructure ◽  
Urban Rehabilitation

A devastating cholera epidemic swept Zimbabwe in 2008, causing over 90,000 cases, and leaving more than 4,000 dead. The epidemic raged predominantly in urban areas, and the cause could be traced to the slow deterioration of Zimbabwe's water and sewerage utilities during the economic and political crisis that had gripped the country since the late 1990s. Rapid improvement was needed if the country was to avoid another cholera outbreak. In this context, donors, development agencies and government departments joined forces to work in a unique partnership, and to implement a programme of swift improvements that went beyond emergency humanitarian aid but did not require the time or massive investment associated with full-scale urban rehabilitation. The interventions ranged from supply of water treatment chemicals and sewer rods to advocacy and policy advice. The authors analyse the factors that made the programme effective and the challenges that partners faced. The case of Zimbabwe offers valuable lessons for other countries transitioning from emergency to development, and particularly those that need to take rapid action to upgrade failing urban systems. It illustrates that there is a ‘middle path’ between short-term humanitarian aid delivered in urban areas and large-scale urban rehabilitation, which can provide timely and highly effective results.

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