نتایج جستجو برای: groundwater decline

تعداد نتایج: 118576  

2000
Gayatri Acharya Edward B. Barbier

This study applies a production function approach to value the groundwater recharge function of the Hadejia-Nguru wetlands in northern Nigeria. The groundwater recharge function supports dry season agricultural production which is dependent on groundwater abstraction for irrigation. Using survey data this paper first carries out an economic valuation of agricultural production, per hectare of i...

Journal: :Environmental pollution 2012
D J Lapworth N Baran M E Stuart R S Ward

Emerging organic contaminants (EOCs) detected in groundwater may have adverse effects on human health and aquatic ecosystems. This paper reviews the existing occurrence data in groundwater for a range of EOCs including pharmaceutical, personal care, 'life-style' and selected industrial compounds. The main sources and pathways for organic EOCs in groundwater are reviewed, with occurrence data fo...

2007
K. P. Chen

Local groundwater in coastal aquifers in Shenzhen has experienced heavy pumping since the 1980s when it began to expand very quickly from a fishing village to a modern city. Meanwhile, large-scale land reclamation was carried out to meet the needs of various urbanization projects. In this paper we analyzed the groundwater from a coastal aquifer system in Shenzhen and examined the evolution of g...

Journal: :Environmental science & technology 2012
Peter S K Knappett Larry D McKay Alice Layton Daniel E Williams Md J Alam Md R Huq Jacob Mey John E Feighery Patricia J Culligan Brian J Mailloux Jie Zhuang Veronica Escamilla Michael Emch Edmund Perfect Gary S Sayler Kazi M Ahmed Alexander van Geen

Ponds receiving latrine effluents may serve as sources of fecal contamination to shallow aquifers tapped by millions of tube-wells in Bangladesh. To test this hypothesis, transects of monitoring wells radiating away from four ponds were installed in a shallow sandy aquifer underlying a densely populated village and monitored for 14 months. Two of the ponds extended to medium sand. Another pond ...

Journal: :Journal of environmental quality 2012
Casey A Schmidt Mark W Clark

Denitrification walls have significantly reduced nitrogen concentrations in groundwater for at least 15 yr. This has spurred interest in developing methods to efficiently increase capture volume to reduce N loads in larger watersheds. The objective of this study was to maximize treatment volume by locating a wall where a large groundwatershed was funneled toward seepage slope headwaters. Nitrog...

2007
V. J. Bidwell

Papers published in Hydrology and Earth System Sciences Discussions are under open-access review for the journal Hydrology and Earth System Sciences Abstract The proportion and origin of groundwater contribution to streamflow from agricultural catchments is relevant to estimation of the effects of nitrate leached from the soil on the quality of surface waters. This study addresses the partition...

2014
S. M. Shrestha K. Rijal M. R. Pokhrel

A study was conducted in forty-one deep groundwater and twenty shallow groundwater wells of Kathmandu Valley, Nepal to assess arsenic contamination (shallow and deep groundwater) and spatial and seasonal variation in deep groundwater. The depths of the wells were ranged from 9 to 304 m. Groundwater samples were collected during pre monsoon and post monsoon in 2012. Atomic Absorption Spectromete...

Journal: :Water science and technology : a journal of the International Association on Water Pollution Research 2005
T Shah

At less than 1000 km3/year, the world's annual use of groundwater is 1.5% of renewable water resource but contributes a lion's share of water-induced human welfare. Global groundwater use however has increased manifold in the past 50 years; and the human race has never had to manage groundwater use on such a large scale. Sustaining the massive welfare gains groundwater development has created w...

2015
Xianbo Li Rui Zuo Yanguo Teng Jinsheng Wang Bin Wang Andrew C Singer

Increasing pressure on water supply worldwide, especially in arid areas, has resulted in groundwater overexploitation and contamination, and subsequent deterioration of the groundwater quality and threats to public health. Environmental risk assessment of regional groundwater is an important tool for groundwater protection. This study presents a new approach for assessing the environmental risk...

2017
Menglin Zhang Litang Hu Lili Yao Wenjie Yin

Overexploitation of groundwater resources has caused groundwater-related problems all over the world. Effective groundwater governance is a favorable guarantee for its protection and sustainable utilization. Accurate prediction of groundwater level (GWL) or depth to groundwater (GWD) plays an important role in groundwater resource management. Due to the limitations and complexity of numerical m...

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