Physical Sciences and Mathematics Commons^™

Increasing Groundwater Salinity In The Northern Wheatbelt, R J. Mcgowan

Journal of the Department of Agriculture, Western Australia, Series 4

Every farmer in western Australia's northern wheatbelt will know of a groundwater supply, be it bore, well or soak. that has become increasingly saline. The groundwater may have become more saline over a period of 15 years or more, or have been noticed only recently. Inevitably, the bore will lie within an area cleared for agriculture. This increase in groundwater salinity may be associated with soil salinisation. Although researchers have some understanding of the processes causing salinisation of groundwater in the wheatbelt and the extent of the problem, little is known about the rates of salinisation and groundwater rise. A …

Dam Site Selection In The North-Eastern Wheatbelt, J L. Frith

Journal of the Department of Agriculture, Western Australia, Series 4

Western Australia's wheatbelt farm dams are dug three to eight metres deep and are generally sited in soils which either are inherently impermeable or can be made so during construction.

In the eastern and north-eastern wheatbelt, however, only a small proportion of the soils meets these criteria. Dam site selection in these areas therefore depends on a good knowledge ofwhich soils aresuitable and on our being able to locate them efficiently by using surface indications such as surface soil, natural vegetation or topographic features.

Northern Wheatbelt Water Supply Study, I A F Laing, R. M. Pridham

Journal of the Department of Agriculture, Western Australia, Series 4

Department of Agriculture surveys have shown that many farms in Western australia's northern wheatbelt have inadequate water supplies. More than 80 per cent of all farms in that area depend soley on groundwater for watering livestock, a much higher percentage than for most other farming areas. Because groundwater salinities have increased in recent years, concern is held for the long-term future of this recource.

In contrast to more southern agricultural areas, farm dams in the northern wheatbelt are relatively uncommon. Only 30 per cent of the existing dams in the northern wheatbelt constitute effective water supplies. More than half of …

Sandplain Hardpan : A Different Dam Construction Material, A F. Mccrea

Journal of the Department of Agriculture, Western Australia, Series 4

Before 1980, the Department of Agriculture did not believe that suitable farm dam materials could be found in light land soils. However Beacon earthmoving contractor, V> J> Pavlinovich, has demonstrated that where suitable cemented subsoils or 'hardpan' existed, a succcessful dam site could be found.

This material should not be confused with compaction or traffic hardpans ehich are dense layers of soil found near the surface. Traffic hardpans result from compaction of soil materials with the passage of vehicles and farm machinery. Rather, the hardpan referred to here is a natural subsoil layer that has been cemented by silica and …

Underground Water Supplies In The Wheatbelt, T T. Bestow

Journal of the Department of Agriculture, Western Australia, Series 4

Underground water originates from rainfall. The size of the underground recource in any region is broadly related to the amount of rainfall. However, rainfall intensity and seasonal distribution are just as importent as the quality. A relatively small annual fall which consists of a series of heasvy showers or storms close together, may be a more effective source of recharge to underground water than a larger fall that is more evenly distributed over a longer period.

A large annual rainfall, however, is no guarantee that underground water supplies will be readily available. This is because soils and the underlying rocks …