Water-table contours, maps

FIGURE 3.17 Example of water table contour map and hydrogeologic cross section showing two groundwater flow regimes. 

Before a volume determination can be estimated, a corrected water table contour map is prepared that depicts the configuration of the water table excluding the... 

Water table levels mark, in most cases, a high in the water table contour map. 

Figure 4. Water table contour map near the plant site...

Maps showing groundwater contours are compiled when there are a sufficient number of observation wells to determine the configuration of the water table (Fig. 4.3). Data on surface water levels in reservoirs and streams that have free connection with the water table also should be used in the production of such maps. These maps usually are compiled for the periods of the maximum, minimum and mean annual positions of the water table. A water table contour map is most useful for studies of unconfined groundwater. 

Depth to water table maps show the depth to water from the ground surface. They are prepared by overlaying a water table contour map on a topographical map of the same area and scale, and recording the values at the points where the two types of contours intersect. Depth to water contours are then interpolated in relation to these points. A map indicating the depth to the water table also can provide an indication of areas of recharge and discharge. Both are most likely to occur where the water table approaches the surface. 

Figure 1. Maps showing water-table contours for Fields 1-5 and locations of monitoring wells, irrigation wells, and multilevel samplers ...

Figure 2. Map showing location of Fields 6 and 7 relative to Field 4, water-table contours and positions of monitoring wells, irrigation wells and multilevel samplers.

A water table piezometric surface contour map is presented in Figure 12.18. The elevation of this surface varies from 10 to 40 ft below sea level across the facility. Groundwater occurring under water table conditions is first encountered between 30 and 60 ft in depth. The regional direction of flow of shallow groundwater is toward a depression in the piezometric surface of the Gage aquifer located about... 

FIGURE 12.18 Corrected water table piezometer surface contour map showing regional hydrogeologic gradient toward the southwest. Note the impact of recovery systems within their area of influence or capture zones. (After Testa et al., 1989.)... 

Water table maps consist of equipotential lines—contours of equal water table altitudes. The contours are drawn to fit measured water table altitudes, as shown in Fig. 4.4. An immediate outcome is the deduction of the dominant direction of groundwater flow (Fig. 4.4b). 

Fig. 4.12 Extracting flow gradients from a water table map (contours in masl). Ah, from B to A, is 300.0m — 298.0m = 2.0m, and the distance (read from the map) is 3.7 km. Hence the gradient between B and A is 0.54m/km. The gradient from B to C is Om/km.

Flc. 6.12. Contour maps of the electronic charge density for the staggered and eclipsed conformers of ethane (a) and for the bent and linear conformers of water (b). The outermost contour ha.s the value 0.001 au. The remaining contours increase in value according to the scale given in the Appendix (Table A2). The bond paths, the interatomic surfaces, and the bond critical... 

A map of total iron concentrations based on analyses of 180 well waters (30) is shown in Figure 9. Also indicated in the figure are locations of 12 wells which were sampled and their waters chemically analyzed in December 1969 (Table III). A comparison of Figures 8 and 9 shows that total iron contours parallel pH contours. The latter figure shows that total iron concentrations increase rapidly to a maximum and... 

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