# Evaluation and Prediction of Ecological Benefits in Song-Liao River Basin
## 2 Materials and Methods
### Data Description  
In this study, several open-source satellite data sets were used to assess and predict the ecological benefits of Song-Liao River Basin. In order to analyze the response of environmental factors to ecosystem services and ecological quality, the spatial distribution characteristics of temperature, precipitation, NDVI and NPP are presented in Figure 2.  
The Delta spatial downscaling scheme was used in China to create the temperature data set. The worldwide high-resolution climate data set published by World-Clim ([[https://worldclim.org/](https://worldclim.org/)]([https://worldclim.org/](https://worldclim.org/)), accessed on 28 February 2023) and the global climate data set of 0.5 \({}^{\circ}\)supplied by CRU (Climatic Research Unit, research-portal.uea.ac.uk) serve as the foundation for this data set. Additionally, 496 meteorological observation sites have validated this data set, and the verification results are reliable [21]. The China National Qinghai-Tibet Plateau Scientific Data Center is the source of the precipitation data set. The global high-resolution data set from World-Clim and the global 0.5 \({}^{\circ}\)climate data set from CRU serve as the foundation for this data set. This data collection covers 1901-2022, has a 1000 \(\times\) 1000 m geographic resolution, and has 12 periods of precipitation data annually [22]. Based on medium-resolution satellite data sets, MODIS offers GPP and NPP-related data products with spatial resolutions of 500 \(\times\) 500 m and 1000 \(\times\) 1000 m. This data set provides the yearly net primary productivity at a 500 m pixel resolution [23]. The total of all 8-day net photosynthesis (PSN) products (MOD17A2H) in a particular year yields the annual net primary productivity. The United States Geological Survey provided the data sets of the Normalized Difference Vegetation Index (NDVI) [24]. The first is the Normalized Difference Vegetation Index (NDVI), also known as the continuity index to the current NDVI generated from the  
Figure 1: Study area. Note: (**a**) indicates that Song-Liao River Basin is located in the northeast of China, and (**b**) shows that the administrative divisions of Song-Liao River Basin mainly include Jilin, Liaoning, Heilongjiang, the eastern part of Inner Mongolia Autonomous Region and the northern section of Hebei. The China Academy of Sciences' Data Center of Resources and Environmental Science is the source of the land use cover change (LUCC) data set. The Landsat-MSS, Landsat-TM/ETM, and Landsat 8 data sets form the majority of the data set. 6 I-class and 25 II-class land types--including Cropland, Grassland, Woodland, Water, Residence, and Barren--make up the categories of land use types [25]. Figure 2: Spatiotemporal characteristics of Data Set in SRB during 1990–2020. Note: (**a–d**) are the spatial distribution characteristics of Temperature in SRB in 1990, 2000, 2010, and 2020, respectively; (**e–h**) is the spatial distribution characteristics of Precipitation in SRB in 1990, 2000, 2010, and 2020, respectively; (**i–l**) are the spatial distribution characteristics of Normalized Difference Vegetation Index (NDVI) in SRB in 1990, 2000, 2010, and 2020, respectively. (**m–p**) is the spatial distribution characteristics of Net Primary Production (NPP) in SRB in 1990, 2000, 2010, and 2020, respectively. The Food and Agriculture Organization of the United Nations (FAOUN) maintains the Harmonized World Soil Database, which served as the study's source of soil data. With an emphasis on a 1 km resolution, the Harmonized World Soil Database version 2.0 (HWSD v2.0) is an extensive worldwide soil inventory that provides in-depth insights into soil qualities, including their morphology, chemistry, and physical characteristics [26]. After all the data sets are collected and preprocessed, the ecological benefit assessment system is constructed according to the steps in Figure 3. This assessment system mainly includes macro-ecosystem structure, Ecosystem service index (ESI), and ecological quality index (EQI).