SOIL EROSION STUDY

Press, Volume LXXVII, Issue 23352, 11 June 1941, Page 6

SOIL EROSION STUDY

• HINDRANCE SEEN IN ' LACK OF DATA Lack of topogi .-hie maps and an inadequate number of automatic rain gauges are hampering the study of soil erosion and the application of remedial action in the Dominion, according to Mr K. B. Cumberland, lecturer in geography at Canterbury University College, who gave ah address to the ■Geographical Association, Canterbury, last evening. His address, illustrated with slides, was mainly on the differing forms of erosion. • ’ Though constructive use of the Do-: minion’s resources had received con-;, siderable publicity, he said, destruc-. tive aspects- had not been so depicted and publicised. Only three official publications An soil erosion had appeared in New Zealand, and they were not easily accessible to the public. None of them had a wide appeal or they were not written in popular language. It was no wonder that nationwide soil losses were ignored, and that palliatives, such as controlling floods by building still more stopbanks, were suggested, when- the only real cure of flooding was to clothe catchment basins in effective covers of vegetation. “In view of this it is all the more encouraging to hear the recently-an-nounced amendments to the proposed river erosion bill,” he added. “In the widening of its scope to envisage soil ■ conservation we have the first delayed sign of progress—-the first gleam of hope that something, however little, might be done.” , ' - ' Individual Problems Soil erosion, he said, was essentially geographic. Each region required different solutions of its individual 1 problems, . Conservation had to-be approached regionally, and in full knowledge of the inter-relation .of v physical and cultural conditions under which soil dissipation had been tened in different regions. s Among physical factors conducive of . accelerated soil wastage in New Zealand were the phenomenal relief of New Zealand’s surface, soils which often had. high credibility; frequent.- - frosts in the South Island, and strong . winds generally. ■ . The nature of the rainfall—the extraordinary intensity—was also important, but this factor had not received the attention it deserved. “The soil erosion problem cannot be tackled in many parts of New Zealand until we know more about the., rainfall—until, that is, we have automatic rain gauge recordings,” Mr Cumberland said. “The number of .automatic gauges in New Zealand is hopelessly inadequate. “And there is another thing that Is going to prevent worth-while study of soil erosion and the application of remedial action, and that, is the lack of topographic maps. There are no contoured maps of areas badly damaged, and until there are we shall remain ignorant of the shape of the surface and of . the nature of the slopes, and be-unable to map the incidence of accelerated soil losses. By providing automatic rain gauges and hastening the production of topographic maps of those areas seriously tortured by soil destruction, fundamental preliminaries could be accomplished.”