with approximate analysis, such rough or fuzzy 

![0_image_0.png](0_image_0.png) facets. 

Before balancing step between SOM and RST, we use a checkpoint based on granulation level, or possible best emerged granules, is assessed by setting of threshold dependency factor. In figure 5, we haven't given up the real world (as here hard granules part) and dashed arrow keeps on linkage with upper level if and only if SORST-R couldn't gratify the pre-defined constraints. Next part of this study show how these algorithms complete not1-1 mapping levels. 

## 4. Practical Example

In this part of our study, we pursue a practical example, which covers a comprehensive data set from lugeon test in Shivashan dam. 

4.1. *Permeability assessment in Shivashan dam* site-Iran Shivashan hydroelectric earth dam is located 45km north of Sardasht city in northwestern of Iran. 

Geological investigation for the site selection of the Shivashan hydroelectric power plant was made within an area of about 3 square kilometer. The width of the V-shaped valley with similarly sloping flanks, at the elevation of *1185m and 1310m* with respect to sea level are 38m and *467m*, respectively. 

At the site area, the rock type indicates generally signs of metamorphisms, which are formed by low temperature metamorphic rocks, overlain by quaternary alluvial deposits. The bedrocks consist of two types of low temperature metamorphic rocks, namely, slates and phyllites. Indeed, slate is the breadline between metamorphic and sedimentary rocks also known as a weakly metamorphosed rock. Figure 7 shows overall view of dam site. Totally, 20 boreholes have been drilled and consequently about 789 objects were resulted. Water Pressure Test (WPT) has used for determination of this area's permeability. WPT is an effective method for widely determination of rock mass permeability.

The Lugeon unit is not stated as a ratio of permeability, but to get a sense of proportion, it might be related such that: *1Lugeon=1.3*10-5 cm/s.*
In practice, usually, the Lugeon test is utilized before grouting to determine quantitatively the volume of water take per unit of time [13]. 

A general pattern from five chief attributes of the boreholes, namely: Z=elevation of the test, L: length of the tested section, RQD and Type of the Weathering Rock Type (*T.W.R*) - see table 1- has been shown in figure 3. 

![0_image_1.png](0_image_1.png)

To evaluate the permeability due to the lugeon values we follow two situations: 1) utilizing of SONFIS and SORST on the five chief attributes(figure8); 2) direct application of RST and NFIS on the local coordinates of dam site (as conditional attributes) and lugeon values (as decision part) to depict 3D Iso-surfaces of lugeon variations diagrams. 

Analysis of first situation is started off by setting number of close-open iteration and maximum number of rules equal to 10 and 4 in SONFIS-R, 
respectively. The error measure criterion in 