Remote sensing monitoring on regional crop water productivity in the Haihe River Basin

Crop water productivity (CWP) is one of the important indicators for sustainable agricultural development in water scarcity area. There is serious conflict between water supply and requirement in the Haihe River Basin. CWP of winter wheat and summer maize from 2003 to 2007 in the Haihe River Basin is estimated based on large-scale evapotranspiration (ET) and crop yield obtained by remote sensing technology. Spatial and temporal distribution of CWP of winter wheat and summer maize is investigated in this study. Results show that CWP of winter wheat in most parts of the study area varies from 1.02 kg/m³ to 1.53 kg/m³, and CWP of summer maize varies from 1.31 kg/m³ to 2.03 kg/m³. Multi-year averaged CWP of winter wheat and summer maize in the study area is about 1.19 kg/m³ and 1.59 kg/m³. CWP results show certain promotion potential to alleviate the water shortage in the Haihe River Basin. Correlation analysis of CWP, crop yield and ET shows that there is great potential for crop yield promotion without the growth in irrigation water. Large-scale CWP estimated by remote sensing technology in this study shows spatial distribution features, which could be used to real-time agricultural water resource management combined with crop yield and ET.