Nonconventional water resources

If conventional resources are not usually available to cover excess or peak demands, non-conventional resources are employed. Among natural non-conventional water resources several possibilities are considered, but the usual ones are runoff water, natural brackish water, or desalinated seawater (Georgopoulou et al. 2001). Non-conventional water resources coming from the anthropic water cycle can also be used reclaimed wastewater will be considered (Asano & Levine 1998). In the Mediterranean...

Weather generation using LARSWG

At present, output from GCMs is of insufficient spatial and temporal resolution and reliability to be used directly in hydrologic models. A stochastic weather generator, however, can serve as a computationally inexpensive tool to produce multiple-year climate change scenarios at the daily time scale, which incorporates changes in both mean climate and climate variability (Semenov & Barrow 1997). Stochastic weather ensures that daily values of variables are realistic, consistent,...

Spectral analysis

The statistical technique used to find cyclic components in a time series is known as spectral analysis (Jenkins & Watts 1968 Yevjevich 1972 Bras & Rodriguez-Iturbe 1985). The signal component represents the structured part of the time series, made up of a small number of embedded Fig. 3. Representative time fluctuations of piezometric levels in the aquifer showing an increase of the irregular data (a-d). Levels are in metres above sea level (masl). Fig. 3. Representative time...

The case of Arad

The ruins of the ancient city of Arad are located on the southern semi-arid flanks of the Hebron Mountains. The average annual precipitation is about 200 mm, and there is no perennial water source in the region. The bedrock is composed of chalks of Eocene age (Avedat Group) overlain by loess of Late Pleistocene age (Issar & Bruins 1983). The chalks are mostly impervious, enabling the ancient and present inhabitants to dig cisterns for collecting rainwater flowing along the hillslopes. At the...

General characteristics of karst basins in Bulgaria

Due to the complex geological structure and variable relief in Bulgaria, numerous karst basins are formed. According to Boyadjiev (1964) there are more than 170 karst basins. Each of them is characterized according to its location, recharge and drainage conditions, with inherent regime and different vulnerability to human impacts. In Figure 1 the main outcropping karst collectors in the country are presented in a light grey colour. The dots in the figure locate the karst springs that will be...

Recharge studies in Jalore Rajasthan

Jalore district (Fig. 7) is situated adjacent to Barmer in the SW part of Rajasthan. An environmental isotope investigation was undertaken to understand the groundwater recharge mechanism at the study area (Fig. 8). The region receives a mean annual rainfall of c. 380 mm and is drained by Sukri river, a tributary of the Luni river system, which is ephemeral in nature. The younger alluvium which is present along the river course is unconso-lidated to semi-consolidated coarse to fine sand and...

Groundwater regime variability during the 19821994 drought period

The orographical, climatic and hydrological conditions influence groundwater occurrence, recharge intensity and regime. Our previous studies concerning the drought period in Bulgaria confirmed the sensitivity of karst springs and shallow groundwater to climate variability (Orehova & Bojilova 2001 Gerassimov et al. 2004a). For these studies the examples of springs and observational wells from the NHGN were used. The impact of the 1982-1994 drought period on groundwater was observed all over...

References

C. & Wei, M. 2004a. Groundwater and climate change a sensitivity analysis for the Grand Forks aquifer, southern British Columbia. Hydrogeology Journal, 12, 270-290. Allen, D. M., Scibek, J., Whitfield, P. & Wei, M. 2004b. Climate Change and Groundwater Summary Report. Natural Resources Canada, Climate Change Action Fund. Bredehoeft, J. D., Papadopulos, S. S. & Cooper, H. H., jr. 1982. Groundwater the water-budget myth. In Scientific Basis of Water-resource...

Adaptive methods for sustaining groundwater regime techniques adopted for artificial recharge

There are several important techniques (Athavale 2003 Sharma 1998) used for artificial recharge as described below. In the water spreading technique, surface water from perennial rivers streams is allowed to spread over a large area for a sufficiently long period so that it percolates to recharge the aquifers. With recharge basin and percolation tanks ponds, the concept is to maximize the contact area and time of surface water with soil so that surface water percolates down to recharge...

Groundwater availability and role of climate change

Main characteristics of selected aquifers The effects of recent climate variations on ground-water availability are evaluated considering five wide hydrogeological structures (HSs). In each HS the shallow or outcropping aquifer is considered three are porous, two are constituted by carbonate rocks, all are coastal aquifers. The Apulian Tableland HS, Tavoliere HS, consists of a shallow and large porous aquifer within a conglomerate sandy-silty succession, less than 60 m deep, with a clayey...

Southern Italy

CNR - IRPI, Department of Bari, Via Amendola 122 I, 70126 Bari, Italy (e-mail m.polemio ba.irpi.cnr.it) Abstract Data for the period 1821 to 2003 from 126 rain gauges, 41 temperature gauges, eight river discharge gauges and 239 wells, located in southern Italy, have been analysed to characterize the effect of recent climate change on availability of water resources, focusing on groundwater resources. Regular data are available from 1921 to 2001. Many analysis methods are used principal...

Groundwater recharge in a limestone belt

The limestone belt of Jodhpur-Nagaur district of Rajasthan extends from Bilara (SE of Jodhpur) to Fig. 13. Plot of 14C versus S18O for all samples collected from Barmer area. 72 Fig. 14. Sample location map in the limestone belt of Jodhpur-Nagaur district of Rajasthan. 72 Fig. 14. Sample location map in the limestone belt of Jodhpur-Nagaur district of Rajasthan. Phalodi (north of Jodhpur) shown in Figure 14. In the southern part of the study area a controlling fault has channelized the flow of...

GCM climate predictions

For many climate change studies, scenarios of climate change derived directly from global climate models (GCMs) are of insufficient spatial and temporal resolution. Spatial downscaling techniques (Hewitson & Crane 1996 Wilby & Wigley 1997) are used to derive finer resolution climate information from coarser resolution GCM output. The fundamental assumption behind all these methods is that the statistical relationships, linking observed time series to GCM variables, will remain valid under...

Environmental isotope studies along an identified palaeochannel

Interpretation of satellite imagery of the western parts of the Jaisalmer district (western Rajasthan) 'revealed' the buried course of a river orientated in the NE-SW direction (Kar 1986 Bakliwal & Grover 1988) (Fig. 2a). In spite of the highly arid condition of the region, comparatively good quality groundwater is available along the course below 30 m depth. The aquifer consists of medium to fine sand with very little clay. A few dug wells do not dry up even in summer and the tube wells do...

Hydrologic modelling

In order to model the interaction between groundwater and surface water in the valley, stage elevations are required as a function of time for each river node in the groundwater flow model for each climate scenario. The challenges in constructing the model were firstly, balancing the discharge volume in the valley, given that hydrometric stations are located outside the valley and have different periods of record secondly, modelling basin-scale discharge from downscaled GCM outputs and thirdly,...

Isotope investigation of dynamic changes due to longterm exploitation of groundwater

The Bhadka-Bheemda area in Barmer district is situated in the SW part of Rajasthan. At the request of the Groundwater Department, Rajasthan, environmental isotope investigations were undertaken in the 1980s to understand the recharge processes and dynamics of groundwater in these areas. A fresh look at the isotopic and chemical characteristics of groundwater was attempted subsequently in order to understand their response to large-scale exploitation of groundwater. Figure 10 shows the geology...

General characteristics of chosen karst springs

For the purposes of this study, some typical karstic springs were selected. The springs are chosen to represent the main hydrological zones of Bulgaria. The location of the springs is represented in Figure 1. The numbering of the chosen springs is in accordance with the system used in NHGN. This spring is one of the largest in Bulgaria. It drains the main part of the so-called Zlatna Panega karst basin (according to Antonov & Danchev 1980). The karst basin is built from Upper Jurassic...

Recharge modelling

There are many methods for recharge modelling (York et al. 2002), but the methodology presented here generates spatially distributed and temporally varying recharge zonation using a GIS linked to the one-dimensional software HELP (US EPA Hydrologie Evaluation of Landfill Performance model) (Schroeder et al. 1994). The program WHI UnSat Suite Plus (Waterloo Hydrogeologic Inc. 1999), which includes the sub-code Visual HELP, is used to estimate recharge to the Grand Forks aquifer. HELP is a...

Study of sustaining groundwater resources through percolation ponds during droughts in India

The vagaries of climate change are already being felt in many countries including India. Droughts and floods have perhaps become more common. The time series of rainfall data for c. 100 years in a semi-arid region of India shows (Fig. 1) that every fourth year is a drought year and every seventh year is a year of surplus water causing floods. Thus it becomes imperative for a country like India, situated in the monsoon region (other monsoon countries include Korea, Philippines, China, Japan,...