Irrigation-Induced Environmental Changes around the Aral Sea: An Integrated View from Multiple Satellite Observations

Abstract

Abstract:The Aral Sea basin (ASB) is one of the most environmentally vulnerable regions to climate change and human activities. During the past 60 years, irrigation has greatly changed the water distribution and caused severe environmental issues in the ASB. Using remote sensing data, this study investigated the environmental changes induced by irrigation activities in this region. The results show that, in the past decade, land water storage has significantly increased in the irrigated upstream regions (13 km 3 year −1 ) but decreased in the downstream regions (−27 km 3 year −1 ) of the Amu Darya River basin, causing a water storage decrease in the whole basin (−20 km 3 year −1 ). As a result, the water surface area of the Aral Sea has decreased from 32,000 in 2000 to 10,000 km 2 in 2015. The shrinking Aral Sea exposed a large portion of the lake bottom to the air, increasing (decreasing) the daytime (nighttime) temperatures by about 1 • C year −1 (0.5 • C year −1 ). Moreover, there were other potential environmental changes, including drier soil, less vegetation, decreasing cloud and precipitation, and more severe and frequent dust storms. Possible biases in the remote sensing data due to the neglect of the shrinking water surface area of the Aral Sea were identified. These findings highlight the severe environmental threats caused by irrigation in Central Asia and call attention to sustainable water use in such dryland regions.

High Summertime Aerosol Loadings Over the Arabian Sea and Their Transport Pathways

“…MERRAero uses a static dust source map of Ginoux et al (). However, dust source can change significantly with time due to climate change, such as drought (Kaskaoutis et al, ) and drying of lakes (Jin et al, ). These new dust sources are not emphasized in the dust source map of Ginoux et al (), and thus are not included in MERRAero.…”

Potential use of lakes as a component of small retention in Wielkopolska

“…Based on the adopted methodology, in the case of increasing the water level in the existing lakes through damming by 0.2 m, the obtained increase in water volume, in the scope of retention volume, could amount to 31 million m 3 . Increasing water level by 0.5 m could permit obtaining an increase in water resources amounting to 78 million m 3 . The values can be also treated as the flood volume that would increase flood protection in the Oder River catchment.…”

“…This involves the use of, among others, artificial water reservoirs, ponds, lakes, or wetlands in which the maximum obtained useful volume does not exceed 5 million m 3 . The objective of the paper is to present the state of hydrotechnical infrastructure in the Wielkopolskie Province with particular consideration of lakes, and evaluation of further possibilities of water retention as a result of its damming.…”

“…Water was accumulated in situations of deficits or its flow was accelerated in places of its excess. Cases of unfavourable impact of human activity evidently leading to the impoverishment of the hydrosphere are known both in Poland and around the globe [1][2][3].…”

The Spatial and Temporal Land Cover Patterns of the Qazaly Irrigation Zone in 2003–2018: The Case of Syrdarya River’s Lower Reaches, Kazakhstan

“…The area is mostly occupied by the Qazaly irrigation zone and is surrounded with sands, such as the vast Qyzylqum desert and the recently formed Aralqum desert. It is a flat land with an elevation below 100 m and with arid climatic conditions, where annual precipitation is lower than 200 mm [35]. The vegetation period starts in March and ends in October.…”