基于遥感数据的内蒙古呼伦贝尔草原草畜平衡时空动态研究

利用2000~2018年的MODIS13Q1遥感数据、地面样方调查数据建立最优估算模型,反演地上生物量,计算牧草产量的月动态系数;结合牧业统计数据中的牧业年度和日历年度资料,计算家畜月动态系数;综合分析内蒙古呼伦贝尔市陈巴尔虎旗、鄂温克族自治旗、新巴尔虎左旗、新巴尔虎右旗等4个牧业旗2000~2016年月尺度草畜平衡的时空动态。结果表明:呼伦贝尔4个牧业旗模拟产草量与NDVI值关系以幂函数模拟效果较好。从年尺度来看,呼伦贝尔市4个牧业旗2000~2018年各年份的草地产草量分布具有明显的空间异质性,均呈现由东向西逐渐递减的趋势,草畜平衡状况与产草量分布呈现相同的空间异质性;从月尺度来看,呼伦贝尔市4个牧业旗在每年的7月、8月产草量相继达到最高峰,月草畜平衡状况也均在6月、7月、8月最好,但不同年份季节性超载月份略有不同,以新巴尔虎左旗为例产草量丰年草畜平衡主要集中在4~10月,平年主要集中在3~10月,歉年则主要集中在3~11月。建议呼伦贝尔草原根据草畜平衡状况在不同水热条件年份适当控制牲畜数量,调整牲畜结构,使草原生态环境达到良性循环。

Study on the Spatiotemporal Dynamics of Forage-Livestock Balance in Hulunbuir Grassland of Inner Mongolia Based on Remote Sensing Data

In this study,the optimized estimation model was established to retrieve the aboveground biomass and calculate the monthly dynamic coefficient of grass yield,Basing on the MODIS13Q1 remote sensing data and ground sample survey data of Hulunbuir grassland from 2000 to 2018.Combined with the date of animal husbandry year and calendar year in animal husbandry statistical data,the monthly dynamic coefficient of livestock was calculated,and the spatiotemporal dynamics of forage-livestock balance in four animal husbandry banners of Hulunbuir city from 2000 to 2016 were comprehensively analyzed,including Chenbaerhu banner,Evenk Autonomous banner,Xin Barag Zuoqi and Xin Barag Youqi.The results showed that:(1)The power function could well simulate the correlation between grass yield and its corresponding NDVI value for the four animal husbandry banners.(2)From the perspective of annual scale,the distribution of grass yield in Hulunbuir city’s four animal husbandry banners from 2000 to 2018 has obvious spatial heterogeneity,showing a decreasing trend from east to west,as well as the forage-livestock balance and the distribution of grass yield showed the same spatial heterogeneity.(3)From the perspective of monthly scale,the grass yield of Hulunbuir city’s four animal husbandry banners reached the peak in July and August each year,the monthly forage-livestock balance was the best in June,July and August.However,due to different seasonal overloaded months in different years,the forage-livestock balance can be observed mainly from April to October in high grass yield year;and from March to October in normal and from March to November in poor grass yield year at Xin Barag Zuoqi.It is suggested that the quantity of livestock in Hulunbuir grassland should be controlled and the structure of livestock should be adjusted according to forage-livestock balance in different years of water and heat conditions,so that the grassland ecological environment can reach a virtuous cycle.