Regionalized Flow Duration for Philippines

A regionalization technique is employed to obtain estimates of water availability at ungaged potential small hydropower sites in the Philippines. The flow duration characteristics at representative locations across the country were first parameterized to permit numerical interpolation. Then the geographic variation of one of the parameters was mapped to span the whole archipelago. Using regression, another parameter was expressed as a function of the drainage area. The regionalized map and the regression equation may then be used to synthesize a flow duration curve at an ungaged site. Future modifications of the procedure are suggested as additional data become available.