绿洲适宜规模的不确定性研究

Recently the oases of Xinjiang, especially of south rim of Tarim Basin, is expanding greatly. Thus it is becoming urgent question that how large oasis scale is suitable and sustainable. Uncertainty theory and algorithms get rapid development in recent 10 years, and it make us to re-examine our study area and need us to pay more attention on its inherent uncertainty characteristics. The oasis's development is constrained by the water supply and utilization, and also effected by the goverment policies in large degree. It can be found that uncertainty characteristics exist in every aspect above, thus the final suitable oasis scale must display uncertainty traits. However, what are these uncertainty characteristics and how to show these uncertainty to researchers? In this study, we selected the Cele Oasis located south rim of Tarim Basin as typical research area. Firstly, we comprehensively analysize the nature and human factors influencing oasis development from multi-discipline and multi-angle. Secondly, we analysize these factor's uncertainty through modeling and parameterizing factors methods. Last, we will build a concept modle about identifying oasis suitable scale after data assimilation and modification, and then the MCMC algorithm will be mainly used to identify the uncertainty of suitable oasis scale based on the uncertainty analysises of factors. These results will be firstly used to identify whether present oasis scale is suitable, and then will be used to predict future suitable oasis scale, and also can be used to provide suitable management suggestions in the situation that oasis scale has be determined by goverment. Thus this research will finally provide scientific advices to local government about oasis expanding, and then support oasis ecological safty and sustainable development. Using uncertainty theory and methods in the oasis research, not only can reflect oasis evolution direction effectively, but also enrich research content of oasis ecology.

目前新疆尤其是塔里木盆地南缘绿洲的高速扩张，为绿洲适宜规模研究提供迫切的现实诉求。而当前不确定性思想、理论与方法的日趋完善与广泛应用，也促使我们重新审视研究对象并重视其内在的不确定性。绿洲发展严重受水资源约束，更受政策导向影响，无论哪方面都充斥着不确定性，故其适宜规模也必体现出不确定性特征，但这些特征如何体现？本研究以塔南策勒绿洲为典型研究区，以水为媒从多视角、多学科角度，全面解构影响绿洲发展的各自然、人为模块；并通过模型模拟或因素参数化等数理手段，分析诸模块的不确定性特征；最后在绿洲适宜规模概念模型的构建、同化改进基础上，利用MCMC为主的贝叶斯理论，推导各模块不确定性下绿洲适宜规模的不确定性分布范围。研究结果用于判别当前绿洲规模是否合理的同时，对将来绿洲适宜规模进行预测；并基于可能出现规模提供相关管理措施建议。不确定性理论的运用，客观反映绿洲演化规律的同时，也丰富绿洲生态学的研究内容。

目前新疆尤其是塔里木盆地南缘绿洲的高速扩张，为绿洲适宜规模研究提供迫切的现实诉求。而当前不确定性思想、理论与方法的日趋完善与广泛应用，也促使我们重新审视研究对象并重视其内在的不确定性。绿洲发展严重受水资源约束，更受政策导向影响，无论哪方面都充斥着不确定性，故其适宜规模也必体现出不确定性特征，但这些特征如何体现，绿洲如何实现可持续发展，都是目前迫切需要回答的问题。.本项目以塔南策勒绿洲为典型研究区，首先从理论上阐述了绿洲适宜规模及其不确定性的研究内涵并构建其概念模型；其次全面分析影响绿洲规模的各自然、人为模块的不确定性特征，包括地表径流补给不确定性特征、地下水动态变化及其不确定性特征，主要作物水分利用效率变化特征；最后，利用贝叶斯理论，在充分考虑社会经济和政策人为影响下，全面分析策勒绿洲适宜发展规模及其可行性路径。.通过4年研究，我们：1）从理论上阐明了干旱区、极端干旱区绿洲化与荒漠化的辩证关系，明确提出在干旱区正视绿洲化的过程是维持绿洲可持续发展及破解荒漠化的关键，而明确绿洲适宜规模及其不确定特征又是破解绿洲化的关键。2）构建了绿洲适宜规模及其不确定性分析的概念模型，确定了模型结构和主要参数；揭示了当前绿洲耕地面积较1970年增长了78.5%，绿洲农业扩张态势令人担忧；模型重建并模拟了策勒河径流补给的不确定性特征，揭示了绿洲地下水动态变化及其不确定特征，显示当前地下水利用已接近极限但仍然安全；回答了当前农业主要作物棉花、红枣、核桃的耗水特征，以及绿洲年生态环境需水量在高、中、低的需水量分别为0.752×108， 0.619×108，0.516×108。3）构建离散型、连续型、参与式贝叶斯网络，全面模拟不同管理情境下的水资源配置方案和建议。4）当前策勒绿洲规模总体安全，但需要优化种植结构和实施农民补偿方式增加天然绿洲面积，最大不确定性来自于政府决策。.本项目发表论文23篇，不仅拓展了绿洲科学研究内容，更对绿洲可持续发展和管理提供支持。