engleski

Determination of Optimal Water Storages in the Accumulation for the Irrigation Requirements

The disposal of suitable water quantities is the main pre-requisite of the irrigation system intended to make up for possible water shortages in agriculture. As such pre-condition is not often existing in the natural hydrological regime, the accumulation’ s construction can make up for the required water storage. There are several methods developed basing on climatologic parameters, and particularly on the data on precipitations in the vegetation periods determining irrigation water requirements. The lower the precipitation amounts, the higher are the irrigation water demands. The fact that precipitation’ s nature is of stochastic character points at the probabilistic approach for determination of needed irrigation water requirements. The construction of accumulation for water storage involves certain annual expenses, e.g. the annual investment, maintenance and usage expenses rising with the needed water which is going to be accumulated. On the other hand, the agricultural researches indicated that the specific crops increase of irrigated agricultural items per used water unit is the lower the more we satisfy 100% the irrigation water requirements. This fact and the stochastic character of the precipitations impose the issue of comparison of accumulation’ s annual expenses and the benefits from the irrigation at different supplying degrees, e.g. with different water storage amounts for irrigation requirements. The paper describes a probabilistic procedure of determining the optimal degree of water storage for the irrigation based on economic criteria. The paper also addresses the issues referring to determination of optimal construction size of multipurpose accumulations taking into account current water management trends of multipurpose accumulations construction.

irrigation, evapotranspiration, precipitations, irrigation norm, water storage, accumulation, safety degree, annual expenses, irrigation benefits

Rad je vezan uz znanstveni projekt 082-1780692-2164 u toliko što se istraživanja erozije tla vrše na slivu višenamjenske akumulacije Botonega u Istri, koja je među inim predviđena i kao zališnik vode za navodnjavanje poljoprivrednih površina u dolini rijeke Mirne. Neke spoznaje do kojih se došlo tijekom istraživanja u okviru projekta 082-1780692-2164 korištene su prilikom izrade ovog rada.