中国科学院新疆生态与地理研究所陈曦和周成虎的团队，合作报道了咸海盆地液体和固体水的四波段指数及其应用。2024年2月23日出版的《中国科学：地球科学》杂志发表了这项最新的研究成果。

研究首先确定了ASB、Syr和Amu流域及其上、中、下游的边界。然后，针对经典水指数分类错误的问题，提出了一种同时适用于液态水和固态水的四波段指数(ILSW)。ILSW是将归一化差水指数(NDWI)和地表温度(LST)结合，对绿、红、近红外和热红外波段的反射率值进行计算得到的。验证结果表明，到目前为止，ILSW水指数在咸海盆地具有最高的精度。结果表明，咸海南部水域的年平均水覆盖面积减少了963平方千米，而咸海北部面积变化不大。与此同时，ASB上游的永久冰雪已明显消退。

阿姆河流域(UARB)和锡尔河流域(USRB)的永久冰雪年退缩率分别为6223和3841平方千米。主要原因之一为ASB的气候变暖。气候变化引发了严重的水资源短缺问题。自20世纪90年代以来，水资源亏缺呈增加趋势，年平均增幅为37.78亿立方米。2010年代，整个ASB全区平均总亏水量为769.67亿立方米。而作为ASB组成部分的锡尔河流域上游供水量为254.61亿立方米。这些结论对于制定ASB的可持续发展战略具有重要意义。

据介绍，前人已经对咸海和咸海盆地的水域面积进行了各种调查分析。然而，调查存在较大的不确定性，并且所使用的水指数存在分类错误的问题，导致不同研究组得出的结果不同。

附：英文原文

Title: A four-band index for both liquid and solid water and its applications in the Aral Sea Basin

Author: Bing YUE, Xi CHEN, Saibo LI, Zhengping DU, John WILSON, Junhui YANG, Yimen JIAO, Shuangyan HUANG, Chenghu ZHOU

Issue&Volume: 2024/02/23

Abstract: Various investigations have been conducted to analyze the water-coverage area of the Aral Sea and the Aral Sea Basin (ASB). However, the investigations incorporated considerable uncertainty and the used water indices had misclassification problem, which made different research groups present different results. Thus we first ascertain the boundaries of the ASB, the Syr and Amu river basins as well as their upper, middle and lower reaches. Then a four-band index for both liquid and solid water (ILSW) is proposed to address the misclassification problems of the classic water indices. ILSW is calculated by using the reflectance values of the green, red, near infrared, and thermal infrared bands, which combines the normalized difference water index (NDWI) and land surface temperature (LST) together. Validation results show that the ILSW water index has the highest accuracy by far in the Aral Sea Basin. Our results indicate that annual average decline of the water-coverage area was 963km² in the southern Aral Sea, whereas the northern Aral Sea has experienced little change. In the meanwhile, permanent ice and snow in upper reach of ASB has retreated considerably. Annual retreating rates of the permanent ice and snow were respectively 6233 and 3841km² in upper reaches of Amu river basin (UARB) and Syr river basin (USRB). One of major reasons is that climate has become warmer in ASB. The climate change has caused serious water deficit problem. The water deficit had an increasing trend since the 1990s and its increasing rates was 3.778 billion m³ yearly on average. The total water deficit was 76.967 billion m³ on average in the whole area of ASB in the 2010s. However, up reaches of Syr river basin (USRB), a component area of ASB, had water surplus of 25.461 billion m³. These conclusions are useful for setting out a sustainable development strategy in ASB.

DOI: 10.1007/s11430-023-1252-9

Source: https://www.sciengine.com/10.1007/s11430-023-1252-9