HUANG SHENG-CHANG
1. The water supply of Sian had been successfully satisfied in various ways through all its history, yet as far as water conservancy was concerned, there were ups and downs. In the Han Dynasty, the Kun-Ming-Chih reservoir was the regulation centre with 3 ditches distributing water over the urbanized area. One of them passed by the Palace Chien-Zhang-Gong and supplied the need of that part of the capital. The second ditch crossed the city proper and the third one turned around the south of the city before entering the Wei-ho, The conservancy work in the Sui and the Tang Dynasties was comparatively expanded. For the citizens' use, 3 ditches led respectively the 3 neigh，bouring rivers, viz., the Ch'an-Shui, the Zü-Shui and the Chiao-Shui, so that they might well supply the city, the palaces, and the Imperial Garden. For the purpose of transportation, 2 canals were built: one flowing W-Earound the north of the city was mainly for cereal, grains and other commodities; the other ran S-N, floating firewood and other kinds of timber from the mountains. For the purpose of recreation, the Dai-Yi-Yü river was conducted by the Huang- and other ditches which emptied into the then famous Qü-Chiang pool. During the Five Dynasties, the city was much neglected (no longer the capital) and the ditches of the preceding periods were abandoned. However, in the subsequent Song Dynasty, that ditch which led the neghbouring Ch'an-Shui was re-dredged, as was that leading the Zü-Shui in middle Wing Dynasty. Then for a long time, these 2 ditches and their distributions met the demands respectively for the E and W portions of the city, until in the mid-Ching Dynasty when the Ch'an Shui ditch first went abandoned before the Zü-shui ditch followed suit in late Ching Dynasty, 2. With the experience of the past, the water conservancy work in the future may be furthered场including the following points: ( I ) the redredging and expansion of the Oü-Chiang pool into a large reservoir; (2) the full utilization of both the Ch'an-Shui and the Zü-Shui partly for the purpose of recreation and partly for draining the sewage water; (3) the reclamation of the S-N flowing streams and ditches, which were once regulated.
