1 appendix; 2 figs; 1 map; 7 tables Available from Technical Information Office, Water and Soil Division, Ministry of Works and Development, PO Box 12041, Wellington

The Ministry of Works has established a network of experimental basins to study the hydrological characteristics of important soil-vegetation complexes of New Zealand. The effect of cultural changes on these characteristics has also been studied. The Purukohukohu Basin is situated 10.5 km due west of Reporoa, 40 km south of Rotorua and 40 km north of Taupo. Although the basin slopes gently to the east, the relief is extensively dissected to produce steep-sided valleys with narrrow ridges and a few strongly rolling interfluves. The objects of the project were, (a) to carry out research to aid in understanding natural hydrological processes on the soil-vegetation complexes - yellow-brown pumice soils/pines, and yellow-brown pumice soils/podocarp-hardwood forest, (b) to find the effect of a change in land use (grass versus pines or indigerous forest) on the hydrological regimen, (c) to provide data for a mathematical model of catchments for the generation of information on the effect of landuse/land management on the hydrology of typical soil-vegetation complexes, (d) to improve techniques of observingand/or analysing data