基于非称量蒸渗仪梭梭个体和林分蒸散机理及其蒸散量耦合模拟

蒸散在土壤—植物—大气连续体水分运动过程中占有极为重要的地位，对节水农业发展、水资源集约管理、水分利用效率和生物产量模拟预测均具有重要意义和作用。目前，称重式蒸渗仪作为农田作物蒸散测定的标准仪器已被大量使用，但由于容积称重的局限性，应用领域受到一定的限制。非称量蒸渗仪通过扩容改造，可在乔灌木植物林分尺度上进行蒸散耗水定位观测。项目利用民勤建成的非称量蒸渗仪及其自动化监测系统，以固沙先锋树种梭梭为研究对象，依据水分平衡原理开展梭梭个体和林分蒸散定位监测，总结梭梭蒸散耗水规律，分析梭梭个体与林分蒸散及其与气候、水分、植物因子的响应机理，构建梭梭个体和林分蒸散量之间的耦合关系，并进行梭梭林分蒸散模型模拟，为梭梭林分蒸散尺度外推及其林分密度选择和生态用水量的确定奠定理论基础。

The evapotranspiration plays an extremely important role in the process of water movement of soil-plant-atmosphere system and its research has significantrole to the development on water-saving agriculture, intensive management of water resources, water use efficiency and simulating and forecasting of biomass. At present, though the weighting lysimeter has greatly used as a stand and instrument of determining field crop evapotranspiration, it has interdicted from application fields for limitations of its'expansion. Through the expansion and renovation of non-weighing lysimeter, evapotranspiration of trees and shrubs can be positioned and observed on the stand scale. Base on none-weighed lysimeter and its automatic monitoring system in Minqin, Haloxylon ammodendron of the fixing pioneer species is used as the subject investigated and according to the principle of water balance, the positioning monitoring of evapotranspiration for individual Haloxylon ammodendron and its stand will be arranged to sum up evaporation and water consumption laws of the individual and its stand，to analyze response mechanism of individual and stand evapotranspiration and climate, water and plant factors, to establish the evapotranspirational coupling relationship of Haloxylon ammodendron on the individual and its stand scale, and to simulate the evapotranspirational model of Haloxylon ammodendron on stand scale. It is to provide a theoretical basis for extrapolation transpiration measure, selecting desert planting density and defining the ecological wate for Haloxylon ammodendron froest.