Geomorphology and hydrology of Nee Soon 
37 
Legend 
Catchment boundary 
SOIL ON ALLUVIUM, on Recent Alluvium Tengah (TgJ Sell 
SOIL ON ALLUVIUM, on Recent Alluvium. Junonfl 5en« (Jfl 
SOIL ON IGNEOUS ROCK, m Granite. Rengam Senas (Run) Son 
High gtnuntl 
Street 
A 
Legend 
-&s™*t 
- Streim 
* We* Soon to rest boun^ar, 
^ CilcWwi i h j rt Mw i iy 
Fig. 2. (a) Major soil types in the Nee Soon Catchment (based on Ives, 1977). Locations of 
the soil pits in the upper and lower catchment are indicated with circles. Locations of cores 
collected in the mid and lower catchment are indicated with crosses, (b) Stream network and 
the hydrological “operational units” (based on Murphy, 1997) within the Nee Soon Catchment. 
concentrations are not associated with contamination). Further, higher concentrations 
of many elements to depths below 6 m in the lower pit, compared with the upper pit, 
support this interpretation (shown for Cr in Fig. 3b). 
With respect to anthropogenic disturbance, we find very high concentrations of 
some elements, which are associated with human disturbance, in the lower part of the 
catchment—i.e., military lands (ML) or variably disturbed lands (VDL) containing 
roads and golf courses. For example, maximum values of some elements greatly 
exceed those measured on lands in the forested upper catchment: As (252 versus 70 
ppm); Cr (224 versus 55 ppm); Cu (632 versus 16 ppm); Fe (17.32 versus 3.35%); Mn 
(1362 versus 110 ppm); Na (1.32 versus 0.16%); Pb (>10,000 versus 188 ppm); Sn 
(21.5 versus 8 ppm); Sr (336 versus 11 ppm); Ti (3.83 versus 0.45%); V (521 versus 
65 ppm); and Zn (431 versus 55 ppm). 
The general similarity between the Nee Soon forested upper catchment and 
forested lower catchment soil chemistry and concentrations determined in the nearby 
MacRitchie Catchment give support to the reliability of the values we have determined 
in Nee Soon, despite the wide range found within such a small area (Table 1). Further, 
the maximum values associated with disturbed lands at Nee Soon (372, 679, and 1926 
