CONTENTS

中　　文

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PREFACE

Taiwan is located in the subtropics with average annual precipitation of 2,515 millimeters. However, the rainfall pattern has been distributed unevenly in terms of time and space which results in great difference in rainfall abundance and scarcity during flood and dry period. Occasionally flood and drought took turns to occur reciprocally in the same year. In addition, the special natural feature of the island, characterized by its short river and steep slope, has caused a restriction on water resources development; this situation leads to the limited available water in spite of abundant rainfall. From now on, how to make use of water resources reasonably and efficient1y to meet the future demand and free from water shortage through practical measurements of highly effective operation, management, and planning.

Accuracy in hydrological data is the basis for the management and planning of water resource. The evaluation and selection of the water conservancy projects find their basis on all the results achieved through the collection, investigation, sorting, analysis, and appraisal of the relevant hydrological data. The collection of hydrological data in Taiwan has begun since long time ago, but because there were many different units that were not well integrated in charge of the collection, the data were varied and not regulated properly, and, therefore, can not be used practically. The first edition of “Hydrological Year Book of Taiwan, Republic of China” was published in l972 by the former Water Resources Planning Commission, Ministry of Economic Affairs, with its contents that incorporated the overall hydrological conditions, daily discharge and the practical record of suspended sediment measurement. The Year Book has been published annually. The compilation of each publication has also been updated in the subsequent years. It includes in recent years the information of river quality, surface water quality at intakes of water supply work and the groundwater quality of Taipei basin. The database system is also established to make the distribution and change of the data more convenient so the units concerned and the public can use the data more efficiently.

The Bureau has finished the edition and printing of “Hydrological Year Book of Taiwan, Republic of China, 1999” for the use of the public. We have also established the Management System of Hydrological Database, all the information collected can be processed by computer in the future and, as a result, the efficiency of editing and printing the data can be promoted, the time for publishing the periodical can be shortened, and the information of hydrological conditions can be provided to units and individuals concerned in the shortest time period. Any suggestion to further improve the Year Book will be greatly welcomed and appreciated.

Shiang-Kueen Hsu,Dr.

Director General

October, 2000