A historical perspective of river basin management in the Pearl River Delta of China

Abstract

Three innovations in water and soil conservancy technology in the Pearl River Delta of South China, i.e., dike building, land reclamation, and dike–pond systems, were examined from a historical perspective. They were found to best reflect local farmers’ efforts to cope with the challenges of various water disasters and to build a harmonious relationship with the changed environment. These technologies were critical to the agricultural success and sustainability over the past 2000 years, and reflected local farmers’ wisdom in balancing land use and environmental conservation. Imprudent use of a new agricultural technology could damage the environment, and could disturb the human–environment relationship, as evidenced by the more frequent flooding that followed inappropriate dike building and premature reclamation. It is suggested that as the urbanization and industrialization process in the delta region continues, the kind of thinking that made the water and soil conservancy sustainable needs to be incorporated into the design of similar technologies for water use and river basin management today.

Introduction

The Pearl River (“Zhujiang” in Chinese) Delta, China, is located between latitudes 21°40′N and 23°N, and longitudes 112°E and 113°20′E (Fig. 1). It is the third largest river delta in the nation (next to the Yangtze and Yellow River Deltas), with an area of 17,200 km². The delta has a subtropical climate with an average annual temperature between 21 and 23 °C, and an average precipitation from 1600 to 2600 mm. Because of the impact of the East Asian Moonsoonal circulation, about 80% of the rainfall comes in the period of April–September with a concentration in the months of May–July, when flooding is prone to occur (Ditu Chubanshe, 1977). Another hazard is typhoons, which occur most frequently from June to October. Since 1978, when the economic reform and open-door policy was implemented, a dramatic social, economic, and spatial transformation has occurred in China. This is particularly true in the coastal regions such as the Pearl River Delta, where economic growth has exhibited a two-digit rate over the past two decades and which has appeared as one of the most advanced regions in the nation (Xu and Li, 1990; Lin, 1997; Weng, 1998). The urbanization process has been speeded up due to accelerated economic development. Massive parcels of agricultural land are disappearing each year for urban or related uses. Because of the lack of appropriate land use planning and measures for sustainable development, rampant urban growth has created severe environmental consequences (Weng, 2001a, Weng, 2001b, Weng, 2002). The field surveys the author conducted in the summers of 1998 and 2001, sponsored by the National Geographic Society, witnessed the deteriorating environment. Fieldworks were carried out in different parts of the delta to provide “ground truth” data on current land use and land cover, and first-hand data on environmental changes induced by urbanization. Interviews with city planning officers, visits to contaminated sites, and literature and document surveys were also conducted.

Nothing was more important than water in shaping the civilization in the delta over the past 2000 years. The fertile alluvial deposits, the subtropical climate, and millenniums of exploitation have nurtured the region into one of the most diversified agricultural areas in China. Its paddy cultivation, sugarcane and fruit horticulture, and dike–pond agriculture–aquaculture have long been known to the nation and to the world. Innovations in water and soil conservation technology were crucial to these agricultural accomplishments. Recent environmental, socioeconomic, and demographic changes in the delta region urge us to re-examine the significance of these technological innovations from a historical perspective, in order to understand better the emerging relationship between the people and the environment.

The objective of this paper is to examine the history of the formation and development of three water and soil conservancy technologies, namely, dike building, land reclamation, and dike–pond systems, and their impacts on the delta's evolution in the Holocene period. Field survey data were applied in addition to the literature and documents in government gazetteers (di fang zhi), archeological discovery, agricultural history, geology, and geography. These data and materials were analyzed to demonstrate that the innovation of dike building, land reclamation, and dike–pond agriculture–aquaculture systems was a result of the dynamics of people and the environment and their interplay in the Holocene era. A major argument is that these water and soil conservation technologies were elegant in that they showed a great understanding of the people–environment interactions, and provided a good lesson for today's water resources and river basin management in the delta as well as in other areas of similar settings in the world.