Drought Monitoring of Winter Wheat in Henan Province Based on Improved Crop Water Scarcity Index
Drought monitoring based on the agricultural drought remote sensing monitoring index is a relatively simple and effective method.The crop water stress index(CWSI)has been widely applied in agricultural drought monitoring via reflecting vegetation water supply status,but it shows a lag in promptly reflecting actual vegetation water conditions.To address this limitation,an improved crop water stress in-dex,CWSIIMP,is constructed on the basis of CWSI by adding LAI variation term to characterize crop morphology changes due to drought,so as to reflect the actual crop water status and the degree of drought-affected crops.The results show that CWSIIMP values in winter wheat fields in Henan Province are gener-ally lower than CWSI values,indicating milder agricultural drought conditions that align more closely with observation.The coefficient of determination(R2)between CWSIIMP and 20 cm relative soil moisture is 0.856,highlighting a stronger correlation for CWSIIMP compared to the R2 value of 0.803 between CWSI and 20 cm relative soil moisture.Empirical models are used to transform drought grade classifications based on 20 cm relative soil moisture into classifications based on both CWSI and CWSIIMP.Regional analysis demonstrates that using the CWSIIMP index for monitoring agricultural drought grades in winter wheat areas of Henan Province is more reliable and scientific than using CWSI alone.This approach can provide a robust basis for large-scale farmland drought monitoring,evaluation and irrigation management.
万方数据
维普
