基于MOD16和地面降水数据的大别山区农业干旱与气象干旱响应关系

Response relationship between agricultural drought and meteorological drought in Dabie Mountains based on MOD16 and surface precipitation data

利用2000—2020年大别山区气象观测资料和MODIS16A2资料,计算降水距平百分率(PA)和作物缺水指数(CWSI),研究农业干旱与气象干旱的时空分布特征,利用滞后相关分析探究二者的响应关系。结果表明:(1)大别山区降水存在显著时空分布不均匀性,西北少、东南多,且旱涝年的降水量差异大(最高达875 mm)。(2)大别山区东南部发生气象干旱事件的频率偏高(最高为66.67%),但干旱程度较轻;北部发生干旱频率较低(最低为38.1%),但易发生严重干旱。(3)大别山区农业干旱具有秋冬春季容易发生、北部更容易发生、海拔低处更容易发生的特征。(4)大别山区南部农业干旱对气象干旱在次月和第3个月响应程度最高,农业干旱比气象干旱更容易发生,持续时间更久,影响更大。

Using meteorological observations of Dabie Mountain area and MODIS16A2 data from 2000 to 2020,the precipitation distance level percentage(PA)and crop water stress index(CWSI)were calculated to study the spatial and temporal distribution characteristics of agricultural drought and meteorological drought,and the response relationship between the two was explored using lag correlation analysis.The results showed that:(1)there was a significant spatial and temporal unevenness in precipitation distribution in the Dabie Mountain area,with less in the northwest and more in the southeast,and the difference in precipitation between drought and flood years was large(up to 875 mm).(2)The frequency of meteorological drought events in the southeastern part of the Dabie Mountain area was high(up to 66.67%)but the drought intensity was less severe,and in the northern part of the area,the frequency of drought events was low(up to 38.1%),but it was susceptible to severe droughts.(3)Agricultural drought in the Dabie Mountain area had the characteristics of being easy to occur in the fall,winter,and spring,in the north,and at lower elevations.(4)In general,the response of agricultural drought to meteorological drought in the southern Dabie Mountain area was the largest in the next month and the third month.Agricultural drought is more prone to occur,lasts longer,and has a greater impact than meteorological drought.