基于北斗终端时空轨迹和遥感的天然草地利用评估方法研究

天然草地是放牧畜牧业生产赖以存在的物质基础。科学评估天然草地利用情况，为畜牧管理部门实施天然草地建设提供决策依据，对促进放牧畜牧业可持续发展有重要的研究和应用价值。 本项目提出"天然草地利用过程是放牧行为和植被生长相互作用的过程"的观点，研究融合放牧行为与草地植被生长的天然草地利用评估方法。本项目基于北斗终端轨迹数据来分析放牧行为，通过研究轨迹计算算法，从轨迹数据中获取放牧行为的时空演变模式，并估算出畜群的理论采食量分布；选取天然草地的遥感数据来刻画植被生长，通过现有遥感估测模型估算出天然草地的产草量分布；然后畜群的理论采食量分布和天然草地的产草量分布进行叠加，评估天然草地利用情况。并揭示天然草地产草量遥感估测模型和放牧行为的时空演变模式之间存在着互验证关系，即借助天然草地产草量遥感估测模型来验证放牧行为的合理性，并将放牧过程作为自主采集地面实测数据的途径，以验证产草量遥感估测模型的精度。

The natural grassland is the material basis for the existence of grazing livestock husbandry. Scientific assessment of the utilization of natural grassland can provide decision making for livestock management department to implement the natural grassland construction projects, and promote the sustainable development of the grazing livestock husbandry. In this project, we propose that the process of natural grassland utilization is a interaction process between grazing behavior and vegetation growth. We study the evaluation method of the utilization of natural grassland which takes grazing behavior and grassland vegetation growth into account at the same time. Firstly, trajectory data acquired from Beidou terminals are used to analyze the grazing behavior, and we design the Beidou terminal trajectory computing algorithms to acquire the space-time evolution mode of the grazing behavior, which can be used to estimate the theoretical distribution of feed intake of the herd. Secondly, we use remote sensing data to characterize the natural grassland vegetation growth, and exploit the existing remote sensing estimation model to estimate the grass production distribution of the natural grassland. Thirdly, we overlay the grass production distribution of the natural grassland with the theoretical distribution of feed intake of the herd, and evaluate the utilization of natural grassland.Furthermore, we reveal the mutual authentication relationship existing between the remote sensing estimation model and the space-time evolution mode of the grazing behavior, namely, using the grass production remote sensing model of natural grassland to verify the reasonableness of the grazing behavior, and using the the grazing process as an independent way to collect ground truth data to verify the accuracy of the remote sensing estimation model of grass production.