Implementation of a landscape ecological use pattern model: Debris flow waste-shoal land use in the Yeyatang Basin, Yunnan Province, China

Highlights

• Demonstration project of land use in debris flow waste-shoal land.

• Intensive agriculture generated more income per hectare than local slope farms.

• Forest and grass cover increased in the study area.

• The demonstration project stimulated agricultural tourism and provided employment.

Abstract

Debris flow waste-shoal land (DFWSL) is a significant and potential land resource that is largely ignored in ecologically fragile mountainous areas. Yeyatang Basin, in Yunnan Province, China, is a typical mountainous debris flow area with a large amount of DFWSL. In order to achieve efficient use of DFWSL in this area, we built a demonstration plot and implemented a landscape ecological use pattern (LEUP) model for the DFWSL, with which we analyzed the economic, ecological, and social benefits. The results showed that the LEUP significantly improved incomes and vegetation coverage, and it reduced soil and water loss, controlled the debris flow, and ensured the safety of residents. To some extent, the LEUP alleviated the conflict between socioeconomic development and environmental protection and increased local employment opportunities, which could help to resolve the socioeconomic issues associated with rural hollow villages and left-behind children. The model demonstration results will provide a “road map” to wasteland use and serve as an important information resource for policymakers. Leaders should consider shifting their perspectives toward exploring land resources that had previously been deemed unavailable and pay more attention to the management and development of DFWSL, which could potentially enable the sustainable development of mountain ecosystems and economies, and enhance the prevention and control of natural disasters in mountainous regions.

Introduction

Currently, approximately one billion people reside in mountainous regions.² Ecosystem services from mountainous regions, including those involving food, energy, water, carbon sequestration, biodiversity, living spaces, and cultural services, are closely related to human welfare (Xu et al., 2011, 2015; Benton et al., 2018). Nonetheless, due to global climate change and destructive human activities, land degradation and pollution have aggravated the conflict among social development, scarce land resource utilization, and the preservation of ecological health in mountainous area. Globally, 4.9 billion ha of land are devoted to agriculture (approximately 38% of the total global land area), and it is predicted that by 2050, the food supply may need to increase by 60% (Alexandratos and Bruinsma, 2012), which would necessitate an increase in agricultural (arable) land by 10–26% (Schmitz et al., 2014). To overcome extreme limitations, an increase of 42% in farmland and 15% in rangeland will be required (Bajželj et al., 2014). Although the total area under cultivation is fixed, the demand for such land resources is increasing, and this is being driven by both population growth and economic development. Thus, it is likely that additional agricultural land development in mountainous regions will occur.

Available land resources in ecologically fragile areas are decreasing as a result of intensive human activities and natural disasters. In these areas, large populations need to survive and improve their quality of life, even at the expense of the environment, which means that it is difficult to balance the need for environmental protection with the need for local populations to earn a livelihood (Tallis et al., 2008; Cao et al., 2009; Zhong et al., 2013; Oort et al., 2015). Many researchers have attempted to develop strategies to ensure harmony between environmental protection and human development needs in ecologically fragile areas, and examples include the successful management and utilization of desert land in northwest China (Cao et al., 2018), reuse of mining wasteland (Liu et al., 2016), exploitation and utilization of karst land (Chen et al., 2017), and rational combination of mountain torrent areas and land resources in arid and semi-arid areas (Zhang et al., 2018). These successful case studies provide a “road map” to managing marginal land, which could be applicable to the use of debris flow waste-shoal land (DFWSL) in China.

As a country with a large population, China is facing land resource scarcity and rapid growth in societal demands (e.g., products and capital). The scarcity of land resources is prominent in mountainous regions, especially in disaster-stricken areas, where development occurs in a cycle of environmental degradation and poverty; specifically, the scarcity of land resources causes poverty, which results in excess land reclamation that causes soil degradation and further poverty (Yan and Qian, 2004; Cao et al., 2018). In addition, China often has debris-flow disasters, but these debris flows create DFWSL. Debris flow waste-shoal land has good photothermal conditions for plant growth, gentle topography (a gradient of approximately 5°), convenient transportation access points, ease of access to irrigation, and positive development and construction potential (Cui et al., 2009), with great possibilities for resolving land scarcity issues. People living in mountainous areas use DFWSL for crop cultivation; furthermore, such land can even be used for suburban-like, constructions, and rural tourism (Okunishi and Suwa, 2001; Sancho et al., 2008). These measures could potentially bring tangible benefits to the local populations in these areas. However, several major factors currently limit the development of DFWSL, such as disordered patterns of development and sand-petrochemical petrification, which have resulted in a gap between investments in development and financial returns. Priorities for these areas include curbing petrification, optimizing spatial layouts, establishing efficient development models, enhancing safety, and improving environmental protections during land exploitation, which will contribute to the proper allocation of resources (Yin et al., 1995; Antoine et al., 1997; Lambin, 1999).

In order to transform a wasteland into usable land, this study applied a landscape ecological use pattern (LEUP) model for the development of DFWSL in the Yeyatang Basin, Yunnan Province, China. This model used optimal spatial arrangements and followed basic patterns of landscape ecology consistent with the patch-corridor-matrix model, and the model promoted material and energy recycling, increases in the area of cultivated land and protection of the natural environment. The objectives of this study were to explore new paths for the development and use of marginal land resources and to find new ways to accelerate the transition to sustainable development in ecologically fragile mountainous regions (Future Earth, 2014). On the one hand, these measures could help to control the degree of exploitation in mountainous regions; on the other hand, they could improve the efficiency of land use in ecologically fragile areas, optimize the development and management of wasteland, ensure a minimum area of arable land, and finally, achieve sustainable use of marginal land resources in mountainous areas (He et al., 2018). Besides, this study also aimed to solve the discrepancy between the need for the protection of natural environmental resources and the need to increase rural farmers’ income through comprehensive management of a small basin.