Geographical Features -- Penghu Islands

As introduced by the Yearbook of the Republic of China:

Introduction

Lying between 119°18'03"and 119°42'54"E longitude and 23°09'40"and 23°45'41"N latitude, the Penghu Islands (the Pescadores) consist of 64 islets situated in the Taiwan Strait, midway between China and Taiwan. They form a natural demarcation between the East China Sea and the South China Sea. In the past, they were a key stop for ships sailing throughout the Far East and crossing the Pacific. Penghu is the only county that is an archipelago.

Only 20 of the islands comprising Penghu are inhabited. Two of the three main islands, Yuwong and Baisha, are connected by two causeways, and the Cross-sea Bridge, with its 76 spans, is the longest inter-island bridge in the Far East.

The total area of the islands is 126.86 sq. km. Penghu, the largest island of the archipelago, accounts for half of the total area and is home to 70 percent of the population.

The islands were formed by a mass of basalt rising from the sea through volcanic action. Due to long-term underwater erosion, the islands have a relatively flat terrain. Their highest elevation, located on Mao Island (Greater Cat Islet), is only 79 meters above sea level. There is some arable land on the three main islands, with altitudes varying from three to five meters above sea level. The islands have no rivers and are marked by winding coastlines forming numerous natural harbors. The shallow, warm water around the Penghu Islands favors the growth of coral, with numerous reefs sheltering the coral from sea waves.

Climate

The Penghu Archipelago's climate is characterized by hot summers, cold winters, and strong winds. From October to March, the northeasterly wind (known as the northeast monsoon) blows at a high velocity of nine meters per second. This often brings sea water to the islands in the form of "salty rain." From June to October, the southwesterly wind is mild. Typhoons frequently hit the islands during the summer.

Annual rainfall in Penghu County is about 1,000 mm, only half the rainfall of the plains of Taiwan. Moreover, the strong monsoon winds result in a high rate of evaporation. Over 1,800 mm of water, or 1.8 times the annual rainfall, evaporate every year. Maintaining water supplies is a high priority, therefore. At present, there are five reservoirs in the Penghu area: Chenggong, Singren, Dongwei, Baisha Chihkan (an underground reservoir with a capacity of 1,761,774 cubic meters), and Si-an. Virtually every household has its own private well.