Catálogo de publicaciones - libros

A water-saturated biological denitrification system was employed to remove selected pesticides and nitrate from drinking waters. In the study, approximately 99% nitrate removal was observed, but most of the samples included nitrite. Up to 95% removal of pesticides was also observed. The lowest removal efficiency of nitrate (63%) was observed when the temperature dropped sharply from 18 °C to 14 °C. Despite such oscillations, high removal efficiencies for trifluralin, fenitrothion and endosulfan (α+ β) were observed and the highest nitrite concentration was 16 mg/l in the effluent of the reactor.

The Tbilisi reservoir (Georgia) represents an important water supply for the city of Tbilisi, but has suffered considerable problems over the past 50 years. Initially the problems related to leakage of stored water via the schistose bedrock. It contains soluble gypsum and is highly sensitive to particulate removal by the process of suffusion. To some extent the leakage problems were ameliorated by the construction of vertical grout curtains but they have never been fully resolved. In recent times, an additional problem has appeared related to the inflow of saline groundwater from the bedrock host during times when reservoir levels are low. This groundwater locally contains as much as 16,000 mg/l total dissolved solids due primarily to gypsum dissolution. This release of groundwater to the reservoir has impaired reservoir water quality, increasing total dissolved solids from about 250 mg/l in 1988 to almost 500 mg/l in 2002. This has important implications for the long-term viability of the reservoir as a supply of potable water for the city.

Buildings in the Varkethili ‘Sleeping District’ of Tbilisi are often affected by subsidence. They are underlain by the extensive third left bank terrace of the River Mtkvari, formed by products of erosion of the flat-lying slopes above and cut by natural drainage channels. Geotechnical and chemical analyses of the sediments suggests that the main reasons for subsidence are chemical and pore water pressure changes in the reactive sediments brought about in part by changes in the recharge regime which in turn was the result of urbanization.

Bridging the gap between a need for preserving unique historic cities and a requirement for modern infrastructure development is one of the major challenges for sustainability of urban areas. Many historic cities around the world have complicated ground conditions, commonly represented by weak soils and a high groundwater table. Natural, or historically formed, hydrogeological conditions need to be maintained carefully in such ground conditions, since even insignificant variations of groundwater level and gradient may affect valuable historic buildings. This paper discusses an integrated evaluation program for the assessment of causes and consequences of variations in hydrogeological parameters within urban historic environments. An analytical quantitative method based on hierarchy structures is used for the program. Some examples of the potential use of the assessment program in Hamburg and St.Petersburg are given.

Investigations were carried out on hydrothermal resource exploitation in the Tbilisi hydrothermal reservoir, Georgia, using a multidisciplinary approach involving geophysical, geological, and hydrogeological techniques. Highresolution monitoring of temperature and pressure in several boreholes was carried out over a long period of time using an innovative geophysical tool. The system was numerically modelled, being calibrated against both the hydraulic and thermal monitoring data. It was found that the oil and thermal fields are connected hydraulically, that the thermal resource is of the order of 2-4 x 10 m/day, and that the hydraulic system responds to the stresses associated with seismic events.

In a number of cities in Uzbekistan, infiltration from irrigation and surface drainage structures, leakage from water supply pipelines and sewers, and discharges of waste water all contribute to rising groundwater levels. To prevent damage to buildings, well fields have been installed to act as vertical drainage systems. These vertical drainage systems need to be managed properly if they are to achieve their purpose. This paper presents a calculation scheme for estimating the requirements for basic materials and other resources for urban areas where drainage by well systems is necessary. The scheme takes into account many different types of pumping failure, and is supported by empirical relationships developed from a large data set collected across the country. The principles of the approach could be adapted for other management issues concerned with urban water development.

This study describes the hydrogeological conditions of the coastal urban areas of Poti and Batumi, Georgia. A clear hydrogeological zonation can be mapped out. The hydrological influence of the rivers Rioni and Chorokhi on the environment of Poti and Batumi is evaluated. Infilling of the coastal zone with inert material has proven to be, and will remain, the most effective method of rehabilitation of the areas where coastal erosion is occurring.

Based on a literature review, the paper analyses groundwater management problems in the urban and the agricultural setting in the developing world. It is argued that in both settings groundwater rights can neither be established nor enforced. Groundwater rights are based on land rights and the economic capacity of the user to follow the falling groundwater table. The connection of groundwater access rights to land rights and economic capacity may cause social instability and could lead to further depletion of the resource.

This paper presents an economic approach towards urban groundwater in the context of a fast growing metropolis. It attempts to understand the current role of groundwater in the urban water supply for the city of Delhi, India, and proposes possible scenarios of future evolution. The main insight of this paper is that in spite of the public neglect of groundwater as a resource for urban water supply, groundwater plays a central role in meeting urban needs through a variety of private and uncontrolled systems. The potential role of these systems in the future and their impact on urban sustainability is questioned.

This paper concerns the bringing together of the science of hydrology and the socio-economics of water supply in order to deliver a high degree of human security to those people who have diminished, or complete loss of access to their water supply. Human security is measured in a number of ways, but one underlying factor for all humanity is access to adequate water (quality and quantity) at an affordable cost. In Azerbaijan there are over 50 secondary towns with populations in the range 10,000 - 100,000. While the larger towns had a well developed industrial and infrastructure base during the former Soviet Union, with its collapse and shut down of industry in the early 1990s, the town infrastructure has significantly deteriorated and water supply and sanitation systems are anticipated to collapse by the middle of this century. The situation in the smaller towns, where the economic base was more fragile, having been founded on agriculture and processing of agricultural products, the situation is no less dire. For a combined population of 1.45 million in secondary towns, the systems originally designed to a capacity of 179.6 Mm/y, actually delivers only 48.2 Mm/y. As a consequence, the population resident in these towns suffers considerable hardships incurring high personal costs, thus further impacting their incomes, and reinforcing widespread poverty. The water related health and environmental problems add to the burden, trapping some people into a vicious cycle of poverty.