古浪县草原资源及其温性草原植被覆盖及生产力评价

Evaluation of vegetation coverage and productivity of temperate steppe in Gulang County

将3S技术与地面调查相结合,通过决策树分类、像元二分模型和二元回归模型,分别对古浪县草原资源、温性草原植被覆盖及其生产力情况进行了研究。结果表明,古浪县总草原面积22.41万hm^2,其中高寒草甸、山地草甸、温性草原、温性荒漠和温性荒漠草原分别占1.68%、1.66%、32.55%、24.02%和40.08%;正常年景古浪县温性草原以20%<FVC<40%植被盖度为主,近10年温性草原FVC出现逐步改善的趋势;温性草原平均鲜草产量为1 042.70kg/hm^2,以500~1 000kg/hm^2产量草原所占面积较大,占温性草原总面积的50.01%,其次为1 000~500kg/hm^2草地,占41.87%,全县7.29万hm^2温性草原总鲜草产量7.61万t,可承载3.65万个羊单位。

3S technology and ground survey were used to evaluate the natural grassland resource,the vegetation coverage and productivity of temperate steppe in Gulang County through decision tree classification,dimidiate pixel model and binary regression model.The results showed that the total grassland area was 224 100 ha,the alpine meadow,mountain meadow,temperate steppe,temperate desert and temperate desert grassland accounted for 1.68%,1.66%,32.55%,24.02%,40.08% respectively.The vegetation coverage of temperate steppe（FVC）mainly ranged in 20% 〈FVC 〈40% and the FVC increased in recent 10 years.The avaerage freash yeild of temperate steppe was 1042.70kg/ha,the steppe area with yeild from 500nkg/ha to 1 000kg/ha was the largest,which accounted for 50.01% of total steppe area,and followed by the steppe with yeild from 1000kg/ha to 1 500kg/ha,which accounted for 41.87%.The total fresh yeild of 72 900 ha temperate steppe was 76100 tand the carrying capacity was 36 500 sheep units.