JOURNAL OF NATURAL RESOURCES ›› 2020, Vol. 35 ›› Issue (1): 106-118.doi: 10.31497/zrzyxb.20200110

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The debris flow disaster land use and ecological restoration measures in Wenchuan earthquake hard-hit disaster areas: A case study in the small watershed of Duba River

HUANG Hai1,2, YANG Shun1,2, TIAN You1,2, XIE Zhong-sheng1,2   

  1. 1. Institute of Exploration Technology, CAGS, Chengdu 611734, China;
    2. Technical Center for Geological Hazard Prevention and Control, CGS, Chengdu 611734, China
  • Received:2019-06-21 Revised:2019-10-08 Online:2020-01-28 Published:2020-01-28

Abstract:

Abundant debris flows and disaster lands have been induced by the Wenchuan earthquake in Longmen Mountain area, Southwest China. The disaster land use and ecological restoration are the most important aspects of the mountain industrial reconstruction. By focusing on the Duba River Basin of Beichuan county as an object, through investigating the conditions of disaster land, characteristics of debris flow and demand of land resource, taking the analysis methods of multi-factor coupling and the key limiting factor, this paper explores how the disaster and development influence the land use and ecological restoration. The results were as follows: The new sources of land supply in Duba River Basin are mainly debris flow disaster lands, and the utilization of disaster land confronts three great limiting conditions, such as the risk of high-frequency debris flow, dynamic settlements, and industrial structure. Through spatial and temporal variation analysis and geo-hazard characteristics, we identify three types of disaster land, such as deposited type, gully erosion type and gully bank erosion type, which shows that there are significant differences in the fertility, safety and traffic conditions. Therefore, based on the following four principles, which contains to divide land use areas according to disaster risks, to give the first priority to the cultivated land in land use, to take into account the needs of industrial development in land utilization, and to improve human settlement environment by ecological restoration, with hazards prevention and evaluation, this paper proposed an idea of the debris flow ecological restoration and built debris flow hazard ecological restoration mode, and applied it to Yangjia gully as an example. In the Yangjia gully watershed, the types of land use were ecological forest land, industrial forest land, and high-quality cultivated land, accounting for 28.5%, 56.3%, and 15.2%, respectively. The ecological restoration measures are mainly taken to improve the vegetation coverage of forest land and to enhance the function of soil and water conservation of cultivated land. The land use and ecological restoration model established in this study, which is based on disaster risk and industrial development, can effectively coordinate the contradiction between human and land, develop the green economy and enhance the environment of human settlements.

Key words: debris flow, symbiotic mechanism, ecological restoration, earthquake-stricken area, disaster land