Landscape Planning Method for Sustainable Rainwater-greening in Semi-arid Human Settlements of Loess Plateau

The semi-arid regions in Loess Plateau in northwest China are important in terms of ecology, culture and economy. However, over the past thousands of years, the original verdant forests had been severely destroyed due to natural and human causes; "lacking water and green landscape" has become the core problem in the degradation of the human settlements in this region. On the basis of Trilism of "human settlements context - human settlements activities - human settlements construction", this paper, taking the human settlements in semi-arid region of the east part of the loess plateau as the research subject, tries to analyze the challenges on human settlement context brought by climate change all over the globe by combining the local natural and human settlements context so as to create a trial of methods in water catchment and green landscape construction and green environment planning with landscaping as the major means. (1) From the perspective of human settlements, the various elements that affect the water catchment and green landscape construction are analyzed, and these elements include natural elements such as precipitation, gradient, slope direction, slope position, rivers, springs and human-made elements like towns, roads and reservoirs. The ratings of the various elements are made and the relevant impact factors are also ranked; (2) With GIS technology, the data is processed and rated so as to rank the zones that can be used for water catchment and green landscape construction in a comprehensive way, i.e. through suitability degree analysis; the "nodes" and "pathways" for rainwater catchment and green landscape construction will be identified; (3) the space and network for water catchment and green landscape construction will be identified; researches demonstrate that in the water sensitive areas in the semi-arid regions in loess plateau, the rainwater catchment and green landscape construction space and network established through "base-node-pathway" can provide for the requirements of human settlements. In the planning analysis of Huan County, the forest coverage rate can be enhanced from 6.8% to 19.40% in the initial planning, and on a larger scope and from a long-term perspective, it is expected that the regional human settlements will be gradually improved by means of landscape architecture so that the semi-arid area of the loess plateau can have the win-win results in harmonious symbiosis of "water-green-human".