Identification of Potential Distribution Areas of Rice-Growing Cultural Landscape in the Han River Basin

Under the background of the rural revitalization strategy, it is very important to explore and protect agricultural landscape. Agricultural landscape is a kind of cultural landscape featuring continuous evolution and mutual adaptation between farming activities and natural geographical environment. The rice-growing cultural landscape is a kind of agricultural landscape that is rooted in the rice-growing agricultural production activities and demonstrates a harmonious symbiotic relationship with nature. This research aims to improve and break through the previous approach of using geographical environmental factors as the basis and method for spatial distribution identification. This approach incorporates considerations on the impact of farming cultural activities on the environment, and aims to provide reference for the identification, survey and management of potential cultural landscape.

This research screens identification factors based on the OUV (outstanding universal value) evaluation criteria for agricultural landscapes. In combination with the biological and cultural characteristics of the rice-growing cultural landscape included in the the World Heritage List and the listed important rice-growing agricultural heritages in China, a method for identifying the potential distribution areas of rice-growing cultural landscape is developed at the county level from the perspectives of geographical environment (biological factors) and historical culture (cultural factors). The geographical environment identification factors are climate, topography, soil and hydrology, and the maximum entropy model is used for simulation of these factors; the historical and cultural identification factors are farming history, farming culture, traditional villages and historical water conservancy facilities, and ArcGIS is used for overlay analysis of these factors.

Most areas of the Han River Basin have terrain and climate conditions suitable for rice growth, and have abundant water resources suitable for paddy field irrigation. In addition, the Han River Basin has rich historical and cultural value of rice farming, where Neolithic rice-growing relics have been discovered. As a major north-south transportation route, the Han River Basin has witnessed frequent population migration activities, which have promoted agricultural exchanges between the north and south regions of China and also the spread of rice culture. The identification results show that from the perspectiove of geographical environment, there are potential distribution areas of rice-growing cultural landscape in the upper, middle and lower reaches of the Han River. Soil type, annual precipitation, precipitation in the driest month and elevation are the main environmental factors affecting the distribution of rice-growing agricultural cultural heritage. In terms of history and culture, the overall scores of the upper and lower reaches of the Han River are relatively high, and the area with the highest score is Chenggu County in Hanzhong City. In terms of the distribution of rice-growing cultural landscape, high-potential areas are those with high scores in both geographical environment and historical culture, distributed in Hanbin District, Shiquan County, and Hanyin County in Ankang City in the upper reaches of the river, and Jingshan, Zhongxiang, Tianmen and Qianjiang in the lower reaches, with Hanyin County and Jingshan City serving as home to important rice-growing cultural landscapes in China; general potential areas are those with a score greater than 0.75 in geographical environment while a lower score in historical culture, including Xixiang County in Hanzhong City, Laohekou City, Zaoyang City, Yicheng City, Xiangzhou District, Baokang County in Xiangyang City, and Dongbao District in Jingmen City; other districts and counties with a score below 0.75 in geographical environment are considered non-potential areas. In order to clarify the biocultural characteristics of high-potential areas, the research extracts the scores of each factor and divides the high-potential rice-growing agricultural landscape in the Han River Basin into such types as mountainous, plain-hilly, and plain rice-growing cultural landscape by combining topographic and geomorphic characteristics. Different landscape types form the cultural landscape patterns of “mountain – forest – village – farmland”, “valley – slope – farmland – village”, and “lake – embankment – farmland – village”.

It is found that the rice-growing cultural landscape is a complete system of change due to the comprehensive influence of geographical environment and historical culture factors. This research identifies potential distribution areas of rice-growing cultural landscape from the perspective of bio-cultural integration. This method is helpful to judge the background resource condition of the rice-growing cultural landscape from the regional level, and promote the protection and sustainable development of the cultural landscape in the basin.