Analysis of changes in the actual irrigated area of the Tarim River Basin and its impact on terrestrial water reserves
The Tarim River Basin is a typical arid oasis agricultural area,and clarifying the impact of the growth of irrigated agricultural areas on water storage in the basin was particularly important for maintaining the stability of the ecological environment and sustainable development of the region.In this study,we constructed a remote sensing monitoring method for actual irrigated area based on crop growth,deciphered the actual irrigated area in the Tarim River Basin from 2003 to 2022,and used the correlation coefficient and decoupling index to evaluate the correlation and dependence of the change in actual irrigated area and water storage in the basin.The results of the study showed that:(1)the growth of irrigated and non-irrigated vegetation in the arid zone differed significantly,and the rapid extraction of the actual irrigated area over a wide range of years could be realized by using the maximum vegetation index(NDVI)during the crop reproductive period calculated from satellite remote sensing imagery as a classification index,and using a random forest classifier supplemented with a certain number of samples;(2)the actual irrigated area of the Tarim Basin during the period of 2003-2022 increased from 29,890 square kilometers.The largest increase among the five prefectures was in Aksu,with a total increase of 9.26 million mu,or 87.94％,followed by Kashgar,with a total increase of 6.68 million mu,or 77.44％;(3)The correlation coefficient between the actual irrigated area and the land water reserve in the Tarim Basin during the period of 2003-2022 was 0.74,with the highest correlation of 0.96 in Aksu and the smallest of 0.56 in Kezhou among the five prefectures.(4)From the decoupling coefficient,the growth of irrigated area in the whole basin was strongly dependent on the depletion of water reserves,and the degree of dependence had been reduced in recent years,but it had not reached the decoupling status.From a spatial perspective,Kashgar,Kezhou,Bazhou,and Aksu were strongly dependent,while Hotan was decoupled.The above results indicated that for most areas in the Tarim River Basin,it was no longer appropriate to continue expanding the irrigated area unless irrigation efficiency was significantly im-proved.The results of this study can provide a reference for water resources management and sustainable develop-ment in the Tarim River Basin.
Tarim River Basinactual irrigated areaspatial and temporal variabilityterrestrial water storagedecoupling indexrandom forest classification
万方数据
维普
