摘要
基于AVHRR-GIMMS和SPOT-VEGETATION两种NDVI数据计算西北干旱区生长季植被覆盖度指数（fc）,根据该指数划分阈值范围确定荒漠植被面积,并在塔里木盆地进行适用性验证。通过荒漠植被面积和参考作物蒸散量（ET0）,采用潜水蒸发模型,计算西北干旱区1982—2010年荒漠植被生态需水量,以期为今后西北干旱区水资源利用和管理提供科学依据。结果表明：根据fc确定荒漠植被面积,在西北干旱区阈值范围设为0.1~0.35较为合理;1982—2010年西北干旱区荒漠植被面积总体上变化不大,呈现增-减-增的波动趋势。高、低覆盖度荒漠植被面积多年平均值分别为234.3和448.2万hm2;西北干旱区ET0空间分布总体为南疆大于北疆、东部大于西部,其中南疆、北疆及河西地区ET0多年平均值分别为1066.9、975.6和1171.6 mm。根据ET0数据拟合分析计算西北干旱区荒漠植被潜水蒸发量,其中南疆、北疆和河西地区低覆盖度荒漠植被潜水蒸发量多年平均值分别为75、64和82 mm,高覆盖度荒漠植被分别为275、233和299 mm;1982—2010年西北干旱区荒漠植被生态需水量呈减少趋势,以0.1063亿m3·a-1的速率减少,多年平均生态需水量为134.13亿m3。其中高覆盖度荒漠植被需水量多年平均为91.64亿m3,以0.3034亿m3·a-1的速率减少;低覆盖度荒漠植被需水量多年平均为42.49亿m3,以0.1972亿m3·a-1的速率增加。
In this paper, we calculated the fractional vegetation cover （f：） within growing season in the arid region of Northwest China based on two kinds of NDVI data （AVHRR-GIMMS and SPOT-VEGETATION）. The desert vegetation area was determined according to the thresholds of vegetation cover, and which was validated in the Tarim River Basin. The ecological water require- ment of desert vegetation in the arid region of Northwest China was calculated using the phreatic evaporation model with the area of desert vegetation and the reference crop evapotranspiration （ETo） during 1982-2010. The results were expected to provide evidence for water use manage- ment in this area in future. Results showed that the thresholds of f were reasonable to be 0.1- 0.35 to determine the desert vegetation area in this area. There was no drastic change in area of desert vegetation during 1982-2010, which showed an increase-decrease-increase trend. The mean areas of high vegetation cover and low vegetation cover were 2.343 million and 4.482 mil- lion hm2, respectively. The annual ETo in the Tarim River Basin was hiher than that in Northern Xinjiang, and the ETo in eastern part was larger values in Tarim River Basin, Northern Xinjiang than that in western part. The mean annual ETo and Qilian-Hexi area were 1066.9, 975.6, and 1171.6 mm, respectively. Phreatic evaporation of the desert vegetation in the arid region of Northwest China was calculated according to the data fitting of the ETo. In the Tarim River Basin, Northern Xinjiang and Qilian-Hexi area, the mean annual phreatic evaporation values of the low- cover desert vegetation were 75, 64 and 82 mm, respectively; the mean annual phreatic evapora- tion values of the high-cover desert vegetation were 275, and 233 and 299 mm, respectively. The mean annual ecological water requirement of desert vegetation was 13.413 billion m3 in the arid region of Northwest China, with a reduced rate of 10.63 million m3 · a-1 during 1982-2010. In area with high vegetation cover, the mean annual eco
出处
《生态学杂志》
CAS
CSCD
北大核心
2015年第3期670-680,共11页
Chinese Journal of Ecology
基金
国家重点基础研究发展计划项目(2010CB951003)资助
关键词
西北干旱区
荒漠植被
生态需水量
潜水蒸发模型
the arid region of Northwest China
desert vegetation
ecological water requirement
phreatic evaporation model.
