Integrated benefit of rainwater harvesting in small watershed on the Loess Plateau of China

Rainwater harvesting is an effective measure for solving water resources shortage and eco-environmental rehabilitation in the semi-arid land of Loess Plateau in China. Research on rainwater harvesting using integrated benefit evaluation is a core problem concerning development of dryland agriculture, soil and water environment protection as well as coordinated economic and eco-environmental development. Nowadays the assessment models and indicators system of rainwater harvesting mostly use economic benefit maximum as optimized objection function, regardless of social benefit and eco-environmental benefit. Especially research on rainwater harvesting using integrated benefit in Loess Plateau is inadequate. Based on the current situation of rainwater harvesting and the characteristic of converting rainwater into rainwater resources, applying analytic hierarchy process theory, this paper establishes the mathematical model and indicators system for integrated benefit evaluation of rainwater harvesting by taking small watershed as research unit and rainwater resources as research object. The assessment indicators system is proposed based on characteristics and principles of scientific, practical realities. These indicator systems include three aspects such as economic benefit! social benefit and eco-environmental benefit. These indicator systems systematically reflect rainwater harvesting features in small watershed. Because of the complex relation of indicator factors synthetically benefit evaluation includes quantitative and qualitative aspects. The assessment model and indicator systems are applied to evaluate synthetically the status of rainwater harvesting in Nihegou watershed in Shaanxi Province. The assessment model played an important role in the evaluation and management of rainwater resources for sustainable utilization and eco-environment construction in the semi-arid land of Loess Plateau in China.