基于多主体模型的典型区域退耕还林工程实施空间模拟

Spatial simulation of "Grain to Green Program" implementation in a typical region based on agent-based model

土地利用变化是全球变化的重要驱动力,模拟是研究土地变化重要的方法。退耕还林是中国山区土地利用变化的重要原因。当前退耕还林模拟在综合社会与空间途径方面的不足限制了退耕还林模拟的空间精度及后续社会效益研究。结合社会和空间途径精确模拟退耕还林的空间过程可为该工程实施提供科学依据。本文以云南省东川区铜都镇为研究区,基于人口普查数据、地理环境数据、实地调研数据,综合考虑农民、农户和政府3类主体,基于多主体模型构建了退耕还林工程实施的空间模型,模拟了2010—2015年铜都镇具有空间特征的农户年收入、农户/政府退耕意愿和退耕还林工程空间实施过程。研究发现退耕还林工程实施主要与坡度、交通和农户收入有关,与土壤肥力相关性较小,坡度25°~30°的耕地占了81.47%,离道路0~2 km交通条件较好的地段占56.37%,农户年收入较低的区域退耕还林比例较高,且退耕还林工程的实施显著提高了铜都镇收入,2010—2015年户均收入提高了1475元。本文模拟结果空间精度为91.12%。本文构建的退耕还林工程实施空间模拟方法可为其它区域提供方法借鉴,以期为中国生态保护和精准扶贫等工程实施提供科学支撑。

Landuse change is an essential driving force of global climate change. Dynamic simulations are helpful for understanding and explaining the changing rules and characteristics of the land system. The "Grain to Green Program"(GTGP) is a critical contributing factor to landuse change in China’s mountainous areas. Presently, the deficiency of integrated social and spatial approaches in the simulation of the "GTGP" limits the spatial accuracy of the social benefits simulation and its subsequent research. The accurate simulation of the "GTGP", by combining social and spatial approaches, can provide scientific evidence for the completion of this project. Taking Tongdu Town, Dongchuan district in Yunnan province as the research area,this study identified three kinds of agents: farmers, farmer households, and the government based on census, geographical information and field survey data. In addition, this research constructed a regional spatial simulation of the "GTGP" implementation based on agent-based model. It conducted spatial simulations of Tongdu Town from 2011 to 2015, including the annual income of farmer households, the willingness of farmer households and the government towards the program, and the spatial processes implementation of the "GTGP". The results showed that the implementation of the "GTGP" was mainly related to the slope, the traffic, and the income of farmer households. Specifically, 81.47% of the "GTGP" program conducted in this areas was on slopes of 25°-30°, and 56.37% of them was 0-2 km away from the road with convenient traffic conditions, and the proportion of the "GTGP" areas with low annual income of farmers was relatively high. The correlation between "GTGP" areas and soil fertility was low. The implementation of the project significantly enhanced the revenue of the study area,with an average household income increase of 1475 yuan from 2010 to 2015. The spatial accuracy of the simulation results was 91.12%. The spatial simulation methods constructed in this study can provide references for the implementation of the "GTGP" in other regions, which can contribute to applications of ecological protection and targeted poverty alleviation programs in China.