CAJ | 학술논문

草地地上生物量监测是草地资源空间格局动态研究的重要内容,也是草畜平衡综合分析的基础.利用2006-2008年甘南牧区草地调查资料和Terra/MODIS每日地表反射率产品MOD09GA,建立了草地地上生物量遥感反演模型,模拟分析了甘南州及各县市草地资源在2001-2008年期间的各旬、月和年的生物量及理论载畜量变化动态.研究结果表明, MODIS增强型植被指数EVI的乘幂函数可以较好地模拟甘南牧区草地地上的生物量鲜重,拟合模型平均估产精度为76.7%,可很好地模拟牧草生长状况较好时期(5-10月)的草地地上生物量变化动态.甘南牧区草地生长主要集中在5月上旬-10月下旬期间,草地旬最大地上生物量数字图像可以较客观地反映草地植被生长发育的总体规律.但是,个别旬生物量受大范围长时间阴雨多云天气状况及放牧家畜数量有较大变动情况的严重影响.2001-2008年不同草地类型的月最大生物量动态变化曲线均呈单峰抛物线形式,全州平均最大生物量均出现在7月,但不同年份产量达到最大值的月份有所变化,主要集中在7-8月.甘南州草地地上总生物量年度之间存在较大的差异.全州8年平均总地上生物量为109.31亿kg.2005年全州草地植被年总生物量最高,达129.1亿kg,其次为2006,2007和2002年,分别为113.2,110.7和109.0亿kg.由于气候条件和不同县市草地面积及生长状况等存在较大差异,其理论载畜量也存在显著差别.
초지지상생물량감측시초지자원공간격국동태연구적중요내용,야시초축평형종합분석적기출.이용2006-2008년감남목구초지조사자료화Terra/MODIS매일지표반사솔산품MOD09GA,건립료초지지상생물량요감반연모형,모의분석료감남주급각현시초지자원재2001-2008년기간적각순、월화년적생물량급이론재축량변화동태.연구결과표명, MODIS증강형식피지수EVI적승멱함수가이교호지모의감남목구초지지상적생물량선중,의합모형평균고산정도위76.7%,가흔호지모의목초생장상황교호시기(5-10월)적초지지상생물량변화동태.감남목구초지생장주요집중재5월상순-10월하순기간,초지순최대지상생물량수자도상가이교객관지반영초지식피생장발육적총체규률.단시,개별순생물량수대범위장시간음우다운천기상황급방목가축수량유교대변동정황적엄중영향.2001-2008년불동초지류형적월최대생물량동태변화곡선균정단봉포물선형식,전주평균최대생물량균출현재7월,단불동년빈산량체도최대치적월빈유소변화,주요집중재7-8월.감남주초지지상총생물량년도지간존재교대적차이.전주8년평균총지상생물량위109.31억kg.2005년전주초지식피년총생물량최고,체129.1억kg,기차위2006,2007화2002년,분별위113.2,110.7화109.0억kg.유우기후조건화불동현시초지면적급생장상황등존재교대차이,기이론재축량야존재현저차별.
Monitoring grassland aboveground biomass (GAB) is not only an important content for the research of spatial patterns of grassland resources, but is also a basis for the integration analysis of the balance between grassland forage supply and livestock demand. Grassland investigation data from 2006-2008 and Terra/MODIS (Moderate-resolution Imaging Spectroradiometer) daily surface reflectance product of MOD09GA in Gannan pastoral area, were used to establish both a monitoring model of GAB, and the 10-day, monthly and yearly dynamics of biomass and theoretical livestock carrying capacity during 2001-2008 in Gannan Prefecture. And each county was simulated and analyzed. Results suggested that the power function of MODIS-EVI (Enhanced Vegetation Index) can best simulate the green yield of GAB in Gannan pastoral area. The mean precision of the monitoring model was 76.7%, which might simulate the GAB dynamics in the period from May to October when the grassland was at a good growing stage. It mainly concentrated in the period from the first 10-days of May to the third 10-days of October during the grassland growth time. During this period digital images of the maximum GAB in a 10-day period may objectively reflect the general rule of grassland growth, but a few of the digital images of the maximum GAB were severely affected by rainy or cloudy weather condition which lasted a long time and covered a large scale, with a considerable change in the quantity of grazing livestock. The dynamic curve of the monthly maximum GAB for each grassland type during 2001-2008 was characterized by a unimodal parabola form. The average maximum GAB appeared in July, but the month that the GAB reached the maximum value varied from year to year, mainly in the period from July to August. There were great differences in the overall biomasses in different years in the Gannan pastoral area. The average overall biomass during those years in the overall Prefecture was 109.31×10~8 kg. The highest value appeared in 2005 (129.1×10~8 kg), followed by 2006 and 2007, which reached 113.2×10~8, 110.7×10~8, and 109.0×10~8 kg, respectively. Due to the differences of weather condition, grassland area and growth situation, there was a significant difference for the theoretical livestock carrying capacity in each county.