The proposed research will investigate the climate effects of Zhangye Oasis, an irrigated agricultural oasis in Northwest China. As an artificial oasis located in an arid environment, Zhangye is a typical case of dryland agricultural system, and studying the implication of its intensive irrigation to the surrounding climate is of broad significance.
The research aims to quantify the influence of the oasis to its local climate (defined as oasis effect), and to explain its mechanism. Specifically, it asks if the oasis effect in Zhangye has increased due to agricultural intensification or expansion of cropland, and it examines if irrigation is the main driver for such climate effect. In the research, three possible factors, including irrigation intensity, crop type and background climate change will be explored, and their contribution to local scale climate change will be determined. Based on such analysis, the research will try to yield a conclusion on the mechanism of oasis effect in Zhangye, and give a prediction of its future trend.
As for methodology, this research will mainly analyze data from remote sensing, and will also include climate station data, interviews and agricultural records. By comparing their time series and utilizing statistical tools, each factor’s contribution to the oasis effect will be determined. Modelling methods will help further research into various hypothetical future agricultural and climate scenarios. The flux data collected from recent observation projects will be used to justify the modelling.
The research is among the first attempts to investigate the long-term trend of how an artificial oasis affects its local climate. Around 30 years of data will be analyzed, and with the help of remote sensing, the study area covers the major part of the oasis and its surrounding desert area. Results in existing literature, including short term trend modelling and field measurement, will be verified in greater temporal and spatial scales. Meanwhile, it will attempt to explain oasis effect with historical data, attribute the effect to various factors, and propose a mechanism, which is lacking in previous research.
The output of this research will hopefully provide insights in oasis climate and guidance for sustainable crop and water management. It will not only benefit the study area, but also serve as a reference for similar irrigated cultivated areas in arid climate around the world.