基于RS和GIS的甘南草地生产力估测模型构建及其降水量空间分布模式的确立

利用遥感（Remote Sensing)、地理信息系统(Geographic Information System)并结合植被生态学基本原理，以甘南藏簇自治州高寒草甸生态系统为研究对象，进行了草地生产力估测模型构建与降水量空间分布模式确立的方法研究。以归一化植被指数NDVI和降水数据库为例，具体论述了草地GIS数据库的形成过程。通过遥感气象卫星NOAA数据在ERDAS图像软件中进行处理，提取了甘南全州的NDVI值，并结合实际采样点的植物地上部分生物量鲜重实测数据，进行统计回归分析（线性回归和指数回归），建立了生产力估测模型，证实了NDVI值与地面初级生产力之间的正相关关系。利用甘南全州及周围共61个气象站和水文站的多年平均降水资料，形成了甘南多年平均降水等值线图。在分析降水数据时，采用了SPLINE、IDW、TREND、KRIGING4种插值法，对4种插值方法进行分析，发现SPLINE方法比较适合甘南降水资料的插值模拟。

The establishment of grassland productive assessment model and the determination of precipitation resource distribution pattern of Gannan tibetan autonomous prefecture based on RS and GIS

This paper discusses the methods of grassland ecology based on RS and GIS technologies. Meanwhile, by applying the technologies and the theory of plant ecology to establish grassland productive assessment model and precipitation resource distribution pattern of the Gannan tibetan autonomous prefecture. The framework of grassland GIS databases is put forward. The establishing process of GIS databases are illustrated by NDVI (normailized vegetation index ) and precipitation database. By using RS and GIS technologies and statistical methods, the NDVI of Gannan prefecture is extracted and a regression model is built up by sampling data in the study area. It is proved that positive correlation exists between the NDVI and the primary biomass. According to the data of 61 hydrologic and meterologic stations, the Gannan precipitation isogram is made. Four kind of methods (SPLINE, IDW, TREND and KRIGING ) are used to analyze the precipitation data and we find that the SPLINE is a better method for Gannan tibetan autonomous prefecture.