Evapotranspiration is an important variable in the terrestrial water cycle, and is extremely critical to the planning and management of agricultural water resources and global environmental change. This course mainly introduces commonly used regional and global evapotranspiration products, and explains the methods of downloading, processing, visualization, and numerical statistics of evapotranspiration data products; the verification method, accuracy evaluation, and uncertainty evaluation of evapotranspiration products; various evapotranspiration products fusion method, etc.
This content mainly introduces the commonly used regional and global ET products, and explains the methods of downloading, processing, visualization, and numerical statistics of ET data products; the verification method, accuracy evaluation, and uncertainty evaluation of ET products; various ET products fusion method, etc.
https://mp.weixin.qq.com/s?__biz=MzU5NTkyMzcxNw==&mid=2247531211&idx=6&sn=5fdb6015370aeecb670811608c635193&chksm=fe68bca1c91f35b7204b54cd3ced8130aa1ca997f7761fad3e46fc651b781db803b0b0cc1690&token=1245295760&lang=zh_CN# rd[Method]: Video tutorial + permanent review + long-term assistance of Q&A group + full set of courseware materials
【Introduction】:
Topic 1. " Evapotranspiration Remote Sensing Product Information Extraction ":
- Download, processing and information extraction of commonly used evapotranspiration products
At present, there are nearly dozens of surface evapotranspiration products in the world. This course selects 9 commonly used surface evapotranspiration products, and explains the download of these products in detail, and uses Python programs to extract, visualize, and collect information from remote sensing information.
Topic 2, "Verification and Evaluation of Evapotranspiration Products":
- Verification and evaluation of evapotranspiration products
This section mainly includes three parts: site verification, basin water balance verification, and regional relative error verification.
- site verification
Surface observation data are often used as "true values" to evaluate the performance of surface evapotranspiration algorithms and the accuracy of products. The ground observation data of evapotranspiration are quite diverse, mainly including: lysimeter system, Bowen ratio system, eddy correlation system, scintillator, airborne eddy correlation system, etc. Among them, eddy related instruments are the most popular and widely used. The observation data of eddy-related instruments can be downloaded from observation networks such as FLUXNET2015, Ameriflux, and CERN.
- Download and processing of site data
Explain the downloading and processing of the observation data of the eddy correlation system.
There is a problem of energy closure in the observation data of the eddy correlation system, for example: Rn-G>H+LE
Therefore, this course will explain data processing operations such as energy closure correction of eddy-related systems, and interpolation of missing data on soil heat flux .
- Site data verification method practice
Use the processed observation data to evaluate the overall accuracy of evapotranspiration products, analyze the time trend, etc.
- &bsp; Basin Water Balance Verification
Water balance verification is a method of verifying multiple evapotranspiration products on a multi-year scale (without data on changes in total land water storage) and on a monthly scale (with data on changes in total land water storage) using a watershed or sub-basin as a verification unit.
- Data preparation for each component of water balance
Data preparation for each component of the water balance method, including: precipitation, runoff, etc.; ET=PR-△S
- Water balance verification method and practice
The water balance method is used to conduct the overall verification and analysis of the surface evapotranspiration in the watershed.
- Regional Relative Error Validation
- Spatial matching and resampling of multi-source remote sensing data
Carry out spatial scale matching and resampling for multi-source remote sensing data products.
- Cap Method and Evapotranspiration Area Evaluation
In the absence of "true value", the hat method is used to evaluate the relative errors of various remote sensing products pixel by pixel.
Topic 3. " The Integration of Evapotranspiration Products ":
- Bayesian Fusion Principles and Practice
Explain the principle of Bayesian fusion, and use the Bayesian method to carry out the practical operation of fusion of various data products to obtain higher-precision evapotranspiration data sets.
- Introduction to Bayesian Principles
- Multiple product fusion based on Bayesian principle
Two product fusion methods:
Multiple product integration weights: