Acta Geographica Sinica ›› 2013, Vol. 68 ›› Issue (7): 966-974.

### Temporal and spatial changes of river systems in Hangzhou-Jiaxing-Huzhou Plain during 1960s-2000s

XU Guanglai1,2, XU Youpeng2, WANG Liuyan2

1. 1. College of Territorial Resources and Tourism, Anhui Normal University, Wuhu 241000, Anhui, China;
2. School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210093, China
• Received:2013-02-04 Revised:2013-03-28 Online:2013-07-27 Published:2013-07-27
• Supported by:
National Natural Science Foundation of China, No.40730635; Public Project of the Ministry of Water Resources, No.200901042; No.201301075

Abstract: Based on the topographic map data in 1960s, 1980s and 2000s, the temporal and spatial changes of river networks of Hangzhou-Jiaxing-Huzhou Plain region were analyzed from aspects of the river density (DR), rate of water area (WP), development coefficient of the river network (Kω), the ratio of area-length of main river (RAL) and box dimension (D0) etc. The results showed that: (1) DR and WP presented a decline trend during the 1960s-2000s with river length decreased by 11023.33 km (about 38.67%) and water area decreased by 151.58 km2 (about 18.83%), and the trend was still intensifying. (2) Kω also showed a decline trend with K2 decreasing from 1.41 to 1.35 (a decrease of 3.9%) during the 1960s-1980s and to 0.15 during the period of 1980s-2000s (decreased by 88.6% ). And the main rivers were gradually dominant in river network in the process of urbanization. (3) The spatial variation of the river network was obvious, the southern regions with an intensive river network was the most dramatic. (4) Each river system has its characteristics under different underlying surface conditions. Wp was smaller with 4.9%-9.4% in city regions. The DR and WP had decreased since the 1960s. Some river channel projects for dredging and urban flood control were implemented in the process of urbanization. In the regions of intensive river network (DR was 2.1-5.3 km/km2), there was a significantly decreasing trend of tributary rivers, and an increasing trend of main rivers. In the lake regions with bigger WP (about 17.8%-19.7%), there were no significant changes of river system pattern.