民勤春小麦NDVI与产量的关系及其对气候变暖的响应

Relation between NDVI and Spring Wheat Yields and Their Response to Climate Warming in Minqin,Gansu

应用1982—2003年的GIMMS NDVI时间序列遥感数据集和民勤站气象资料以及1985—2000年民勤作物物候期观测和产量资料,借助于GIS技术,在识别春小麦种植区的基础上,分析了其生长季平均NDVI与产量的相关关系,并采用时滞互相关法对月际尺度的平均气温、最高气温、最低气温、降水和日照时数与春小麦NDVI的相互关系进行研究,建立了春小麦生长季平均NDVI对气候因子的响应关系模型。结果显示,民勤县春小麦生长季平均NDVI与单产产量极度相关;月际尺度上,春小麦NDVI与平均气温、最高气温、最低气温和降水相互作用同步,而滞后于日照时数1个月,且气温和降水对春小麦NDVI影响时效为1个月,日照时数为2个月;近年来,日照时数延长和降水增多有利于春小麦NDVI的增加及产量的提高。应用1982—2003年的GIMMS NDVI时间序列遥感数据集和民勤站气象资料以及1985—2000年民勤作物物候期观测和产量资料,借助于GIS技术,在识别春小麦种植区的基础上,分析了其生长季平均NDVI与产量的相关关系,并采用时滞互相关法对月际尺度的平均气温、最高气温、最低气温、降水和日照时数与春小麦NDVI的相互关系进行研究,建立了春小麦生长季平均NDVI对气候因子的响应关系模型。结果显示,民勤县春小麦生长季平均NDVI与单产产量极度相关;月际尺度上,春小麦NDVI与平均气温、最高气温、最低气温和降水相互作用同步,而滞后于日照时数1个月,且气温和降水对春小麦NDVI影响时效为1个月,日照时数为2个月;近年来,日照时数延长和降水增多有利于春小麦NDVI的增加及产量的提高。

Based on GIMMS NDVI data set at a spatial resolution of 8 km and 15-day interval from 1982 to 2003,meteorological data from 1982 to 2003,and observational data of growing periods and yields of spring wheat from 1985 to 2000 in Minqin of Gansu,the planting regions of spring wheat were firstly identified by RS and GIS,and relationship between yields of spring wheat and mean NDVI in growing periods was analyzed.The relations of NDVI of spring wheat with monthly mean,maximal and minimal air temperature,precipitation,and sunshine duration were examined via lag cross-correlation analysis,based on which a responding model of mean NDVI of spring wheat to climatic factors was established.The results showed that the relationship between the yields and the mean NDVI in growing periods was very significant.The responding of NDVI of spring wheat to monthly mean temperature,maximum temperature,minimum temperature and precipitation are synchronous,and one-month late than sunshine.Furthermore,the time effects of temperature and precipitation factors are one month,and that of sunshine is two months.The status that sunshine duration and precipitation increase recently is beneficial to increasing of NDVI and yields of spring wheat.