generally, alluvial basins of arid and semiarid zones are the places with excessive groundwater withdrawal, and also they have a high potential for land subsidence. excessive groundwater withdrawals have caused severe land subsidence in tehran, iran. at present, the maximum land subsidence rate is 36 cm/year, covering an area of nearly 530 km2. in the 2000s, as a result of economic and populati...

This study examines the effect of pumping, hydrogeology, and pesticide characteristics on pesticide concentrations in production wells using a reactive transport model in two conceptual hydrogeologic systems; a layered aquifer with and without a stream present. The pumping rate can significantly affect the pesticide breakthrough time and maximum concentration at the well. The effect of the pump...

Mean groundwater levels of a multi-layered coastal leaky aquifer system are considered. The system consists of an unconfined aquifer, a confined aquifer and a semi-permeable layer between them. Both exact asymptotic solutions and approximate perturbation solutions are derived for multi-sinusoidal-component sea tide. At inland places far from the coastline, the perturbation solutions show a good...

A three-dimensional (3D) texture model was developed to help characterize the aquifer system of Central Valley, California (USA), for a groundwater flow model. The 52,000-km Central Valley aquifer system consists of heterogeneous valley-fill deposits. The texture model was developed by compiling and analyzing approximately 8,500 drillers’ logs, describing lithologies up to 950m below land surfa...

DOI 10.1007/s10040-002-0225-5 Abstract Suzhou City, located at the lower reaches of the Yangtze River in southeastern Jiangsu Province, is one of the few cities in China which suffer from severe ground settlement. A research project was carried out to investigate this problem. Geological and hydrogeological studies show that there is a multi-layered aquifer system with three distinct, soft mud ...

This study presents a semi-analytical solution for the problem of leakage in an unconfined aquifer bounded below by an aquitard of finite or semi-infinite extent. The homogeneous anisotropic unconfined aquifer of infinite radial extent is pumped continuously at a constant rate from a well of infinitesimal radius. The aquitard is also homogeneous , anisotropic and of infinite radial extent. Flow...

Groundwater flow is affected by heterogeneity in the anisotropy. Our investigations started with some simple numerical experiments consisting of one or two homogeneous anisotropic blocks. Three-dimensional pathlines in such models have the shape of spirals; bundles of spiralling pathlines were termed 'groundwater whirls'. The present research also deals with hypothetical models of stratified aq...

Generally, alluvial basins of arid and semiarid zones are the places with excessive groundwater withdrawal, and also they have a high potential for land subsidence. Excessive groundwater withdrawals have caused severe land subsidence in Tehran, Iran. At present, the maximum land subsidence rate is 36 cm/year, covering an area of nearly 530 km2. In the 2000s, as a result of economic and populati...