adminFeature Saul Gwakuba Ndlovu
ZIMBABWE’S Meteorological Services recently predicted a poor rainy season for the 2015-16 period for the country. If it will be as foreseen, it will be one of many such weather experiences since the country’s independence in 1980, resulting in a drought. Zimbabwe is one of several Sothern African nations that occasionally have droughts that cause a great deal of loss of livestock and crop failure.
The landlocked country is situated between two large rivers, the Zambezi and the Limpopo, both of which carry larger quantities of rain water to the Indian Ocean especially in summer but also throughout the year.
The country rises gradually from each of those waterways, the Limpopo in the south and the Zambezi in the north, to a high plateau in more or less its central region.
Its physical features, referred to as velds, are the lowveld, the middleveld and the highveld.
The highveld receives large relief rains because of hills, mountains and generally high attitude that deflect moisture laden wind upwards where it condenses and precipitation occurs. The highveld receives generally more rain than the middle and low velds both of which get convectional and/or cyclonic rain.
About 80 percent of the country’s 14 million-plus population live in rural areas where they depend on agriculture for their livelihood. Whenever a drought occurs, its devastating effects are felt mostly by those people, the majority of whom are in the middle and lowveld.
The Government deals with each drought when it occurs by distributing food to the people. It is not economically possible for the Government to provide the affected regions with stockfeed, as a result, a large number of cattle die each time a drought is experienced.
We can rightly describe droughts as a recurring series of meteorological disease that occurs in many parts of Zimbabwe, causing massive economic and social disaster to life in general.
It is in this context that it must be dealt with, beginning with its prevention and ending with the cure of its terrible effects. Preventive or prophylactic measures would involve a correct reading and “milking” of the clouds, as it were.
There are four types of clouds: nimbus, cumulus, stratus and cirrus. With the exception of the cirrus, the first three comprise water droplets. Rain can be induced to form in and fall from them if the right nuclei is applied on them.
A combination of two of those cloud types results in hybrid clouds such as cumulo-nimbus or strato-cumulus.
One or the other of two kinds of nuclei may be used in cloud seeding, silver iodide crystals or dust, with the former being regarded as far better than the latter.
Drought-prone regions need to invest heavily in water harvesting, water storage and water reticulation infrastructures. That is particularly so for the agricultural sector in those regions.
In addition to “milking” the clouds by means of seeding, it is possible to lessen drought effects by developing and utilising underground water.
Geologists and hydrologists tell us that underground aquifers flow in the same direction as surface rivers. That simply means that subterranean streams rise mostly on the highveld and flow towards the lowveld.
The lowveld has, therefore, more underground water resources than the high and the idle velds, as a general rule since it is the lowest region from where water will not flow in any direction except just to sink.
However, in spite of all this one locality may show hydrological characteristics different from another because of its unique geological formation as reflected by its kind of prevailing rocks.
Some type of rocks retain water much better than others. There are, in fact, three types of rocks: sedimentary, igneous and metamorphic.
Sedimentary (umkhumece, vuvubgwe) is sandy and porous, and does not hold water for long periods.
Igneous and metamorphic rocks have a higher water retention capacity than sedimentary rocks.
Subterranean water is, however, not as suitable for human and livestock consumption as surface water because of its higher salt content.
Some countries such as Namibia have found it impossible to use underground water from some regions of its desert because of its extremely high salinity content.
Libya faced the same problem but used its oil revenue to desalinise the water to make it potable and industrially usable. That may not be the case with most of Zimbabwe’s underground water as the country has only a few localities known to have sodium chloride.
We are discussing here the possibility of investing in underground water resources in drought-prone areas such as both Matabeleland North and Matabeleland South, as well as Masvingo Province, the Midlands and parts of Manicaland.
While cloud seeding is carried out in order to prevent a drought, underground water extraction’s aim is to counteract drought effects. One is prophylactic and the other curative, or preventive and the other corrective.
The need for the Government to invest in water resources development is as important for industrialisation as is the need for energy development.
Lack of water or the inaccessibility of it is one of the causes many people desert rural areas for urban centres. Development of rural areas must prioritise the availability and accessibility of water for people and their livestock in every village.
It is no more excusable to suffer or die from an immunisable disease than it is to suffer or die from drought at this day and age.
Saul Gwakuba Ndlovu is a retired, Bulawayo-based journalist. He can be contacted on cell 0734 328 136 or through email. [email protected]
Bongani Ndlovu
Online Reporter