A network of consultants in: water resources, hydrology, hydraulics, hydrogeology and water quality

Lakes

Dramatic short-term changes in climate or over-exploitation of the resource can produce major changes in lake regime with corresponding effects on other environmental and ecological variables. The sharp rise in Lake Victoria in the early 1960s, which took many years to subside, and the continual fall in level of the Dead Sea due to potash extraction, are examples of major changes that can occur.

Water Resource Associates has experience of a range of these issues. Each study should be based on a thorough understanding of the resource balance of the lake and the historical evidence of seasonal and longer term natural fluctuations. The lack of historical rainfall data over large lakes is a serious problem in accounting for lake behaviour, and it is helpful to compare implied lake rainfall with records from shore stations.

Stochastic models defined from the historical data can give indications of likely future behaviour, against which planned measures can be tested for control or exploitation of the water resource.

Botswana
Review of proposed engineering works in the Okavango Delta based on hydrological modelling including the conjunctive development of surface and groundwater resources and the impact of development on the riparian population.

Chad
Hydrological modelling and forecasting of inflows to Lake Chad for strategic planning of resource development.

Turkey
Study of the environmental impact of sewerage schemes and tourism on Lake Köycegiz and Dalyan Beach in southern Turkey. Preliminary water balance studies showed that there is a net inflow from the sea each summer and that the ecology of the lake is finely balanced.

Jordan
A study of the hydrology of the Dead Sea based on rainfall records over the past century showed that abstraction of water from the river Jordan basin has caused sea levels to fall in recent decades. However, a much greater impact is due to the evaporation of brines for potash production.

Prediction of future sea levels was based on stochastic models of rainfall fitted to historic data and used to generate a large number of future sequences. These were transposed into series of sea level change allowing for modern developments. Thus, the probability of sea levels falling to specified ranges could be estimated.

Thailand
Study of the hydrology of the Songkhla Lake basin in southern Thailand and the development of parallel time series of river flows in all the rivers entering the lake.

E Africa
An extensive study of the hydrology of Lake Victoria included a review of the basic data back to 1900, synthesis of river inflows for the ungauged periods, and development of a water balance of the lake able to explain the dramatic rise of lake levels in 1961/64. The writings of early explorers and evidence from lake shore sediments were used in conjunction with stochastic models of lake and basin rainfall to estimate the likelihood of similar events in future.