Landscape and Ecological Water Requirement of Ancient Town River: An example of Lijiang World Heritage City

Lijiang is the first city in China to be designated by the United Nations as a world cultural heritage site. The cultural accumulation of the city is deep and the water culture is an important part of the heritage. However, the hydrology in the region has changed in recent years, where continuous drought has led to the decrease of river runoff, and seriously affected the image of Lijiang as a world cultural heritage. A recent example is when the Heilongtan River went dry for a few days in December of 2012. In this paper, the landscape ecological water demand was computed based on golden section method and applied to assess the unique water demand of Lijiang ancient city. Using the latest knowledge of the river form and the history of the hydro-geological transformation process to determine the appropriate landscape ecological water level, it has been calculated that the average annual ecological water demand is 103.56 million m³. These results were verified using the Tennant method, and the calculated average runoff for many years can be demonstrated to be appropriate and rational.