近30年来中国气候湿润程度变化的空间差异及其对生态系统脆弱性的影响

Spatial Diversity of Humidification and Its Impact on Ecosystem Venerability in China during the Last 30 Years

论文利用近30 a中国756个气象站点日观测数据计算中国陆地表层潜在蒸散和湿润指数现状及变化趋势,然后划分湿润程度变化对不同自然地带生态系统脆弱性影响的等级,并应用于农田、林地和草地三大生态系统脆弱性变化分析,结果显示:近30 a中国陆地表层平均年潜在蒸散为754 mm,平均湿润指数为-5.6,湿润指数平均变化率为-4.4/10 a,反映中国陆地表层湿润程度总体具有下降趋势。近30 a中国陆地表层气候湿润程度变化导致生态系统脆弱性增加的面积约占中国陆地面积的43.7%,主要集中在东北地区西南部、华北地区、西北地区东部,以及青藏高原的西部、北部和东部。总体上,近30 a中国陆地表层气候湿润程度变化对农田、林地和草地生态系统脆弱性具有不利影响。其中草地生态系统脆弱性增加的面积最大,约占草地生态系统总面积的63.2%;其次为农田生态系统,约占31.6%;林地生态系统脆弱性受影响面积最小,约占17.7%。

In this study we calculated potential evapotranspiration and moisture index status and trends of China territory using daily observation data from 756 meteorological stations of China during the last 30 years.Then we divided the vulnerability tendency grades of China territory according to the impact of humidification variation on ecosystems in different climatic zones,and applied this vulnerability tendency grades to cropland,woodland and grassland ecosystems.The results showed that during the last 30 years the average annual potential evapotranspiration was 754 mm;the average moisture index was-5.6;the average rate of moist index change was-4.4/10 a,reflecting a whole downward trend of humidification of China territory.Caused by humidification variation in the last 30 years,the ecosystem vulnerability increase areas concentrated in the southwestern part of Northeast China,North China,eastern part of Northwest China and western,northern and eastern part of Tibet Plateau,which occupied approximately 43.7% of China territory.The main appearances of ecosystem vulnerability tendency were slight,small and moderate increase.Totally,humidification variation had negative effects on cropland,woodland and grassland ecosystem vulnerability tendency in China.Grassland ecosystem had the largest vulnerability increase area,63.2% of the total grassland area.And the next was cropland ecosystem,31.6% of the total cropland area.Woodland ecosystem vulnerability was minimally affected,17.7% of the total forestland area.