适用于强土壤背景噪声的荒漠植被多层辐射传导模型的构建及机理性光谱指数开发

Retrieval of vegetation biophysical and biochemical parameters from hyperspectral information is one of the highlights in current remote sensing applications. However, such researches in arid land are dramatically lagging behind other regions because of specific drought-adapted structure properties of vegetation and strong background disturbances. The proposed study aims to develop a new multi-layer radiative transfer model, which is able to embrace such drought-adapted specifics and strong background noisy to clarify radiative transfer mechanisms based on newly set-up database made of long term synchronous measurements of biochemical, biophysical, environmental and soil parameters and in situ hyperspectral reflectance at different scales, as well as data from various controlled experiments, over two represent desert species, Haloxylon spp. and Tamarix spp. The new RTM will be applied to separate different contribution to canopy reflectance from vegetation and soil, to investigate sensitivity of reflectance to each parameter, and to provide a base for developing specific sensitive vegetation indices for every parameters. The study targets to avail a new precise way of retrieving vegetation parameters in arid land, which is a key requirement for understanding the response of arid ecosystems to climate change.

高光谱遥感反演植被生化和物理参数是目前遥感技术应用的热点，但由于荒漠植被特殊结构以及强土壤背景噪声干扰，导致该类研究在干旱荒漠地区应用十分困难。准确观测荒漠植被的结构与光谱特征，发展新型适用荒漠植被的冠层辐射传导模型将是了解荒漠植被遥感机理的唯一途径。本研究拟选择典型荒漠植被柽柳和梭梭，通过对生化参数、结构参数、环境参数、土壤参数及各层光谱信息的长期同步监测，结合相关控制实验，构建高光谱遥感反演基础数据平台。基于现有叶片、冠层和土壤辐射传导模型，发展适用荒漠植被特殊结构和强土壤背景的新型多层辐射传导模型，揭示荒漠植被辐射传导机理，分离混合光谱中植被和土壤信息，分析各参数含量及其动态对光谱的影响，开发具广适性并对各参数特异敏感的光谱指数，最终形成可以推广应用的干旱地区稀疏荒漠植被各参数的高精度定量反演模式，为干旱地区气候变化研究提供技术支持，并为干旱荒漠生态安全与生态服务提供科学理论依据。

高光谱遥感反演植被生化和物理参数是目前遥感技术应用的热点，但由于荒漠植被特殊结构以及强土壤背景噪声干扰，导致该类研究在干旱荒漠地区应用十分困难。.本研究以典型荒漠植被梭梭和柽柳为研究对象，开展荒漠植被生理生化参数与环境参数及光谱的同步观测与控制实验，旨在发展能够较准确模拟荒漠植被辐射传导过程的辐射传导模型，结合辐射传导模型和统计方法，建立高效、快捷估算植被和土壤关键参数的高光谱遥感反演方法，为干旱地区气候变化研究提供技术支持，并为干旱荒漠生态安全与稳定的应用提供科学理论依据。.通过四年的研究，本项目（1）掌握了荒漠植被的物理结构，生理生化等参数和高光谱信息变化特征；（2）发展了适用于荒漠植被的辐射传导模型；（3）基于辐射传导模型，结合控制实验，分析了荒漠植被的辐射传导机制；（4）探求了荒漠植被冠层物理结构、生理生化及土壤水盐含量各参数的高光谱指数。