关键词: 引水工程, NDVI, LUCC, 残差分析

Abstract: Water diversion project is one of the effective ecological projects to alleviate desertification, reduce ice flood, and promote vegetation growth. In order to understand the impacts of water diversion project on vegetation in the northern edge of the Kubuqi Desert, based on Landsat 7/8, GF_1/2, project water diversion amount and temperature and precipitation data, we analyzed the land cover types and vegetation spatiotemporal variations of the northern edge of the Kubuqi Desert with and without water diversion engineering measures using Sen’s slope, residual analysis, and two sample T test. We further discussed the contribution of temperature, precipitation and water diversion projects to NDVI changes. The results showed that annual maximum value of NDVI increased in the past 10 years. The NDVI value of 55% of the pixels showed an upward trend before 2015, while the number of pixels that showed an upward trend after 2015increased to 73%. After the implementation of water diversion project in 2015, grassland area increased from 25 km² to 41.31 km², and sandy land area reduced from 65.95 km² to 17.73 km². Results of the residual analysis showed that the area where human activities promoted NDVI accounted for 52.92%. The area with significant NDVI changes after human activities accounted for 78.00%. Precipitation before 2015 was the main driving force of NDVI changes, whereas water diversion projects were the dominant factor driving NDVI changes after 2015.

Key words: water diversion project, NDVI, LUCC, residual analysis.