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[Display omitted] • Grassland degradation is the main reason for the decline in carbon storage. • The carbon storage of farmland has increased significantly. • The risk of carbon storage reduction in the future is still high. The carbon storage of terrestrial ecosystems is closely related to global climate change. Therefore, assessing the impact of land-use changes on carbon storage is instructive to reduce global carbon emissions. Taking an arid region in northwest China as an example, this paper analyzed the land-use changes in arid region from 1980 to 2015. It used the CA-Markov model to predict the land-use pattern from 2020 to 2050, the carbon storage and sequestration module in Integrated Valuation of Ecosystem Services and Tradeoffs (Invest) mode to assess and predict ecosystem carbon storage over the past 35 years and in the next 30 years and discusses the impact of land-use changes on the carbon storage of terrestrial ecosystems. The results showed that: (1) The high-value areas of carbon storage in arid region were primarily concentrated in grassland, forests and farmland, and the low-value areas of carbon storage were mainly in desert areas. (2) The carbon storage in arid region showed a downward trend. From 1980 to 2015, the carbon reserves of terrestrial ecosystems in arid region decreased by 90.95 Tg, and the net loss of carbon reserves from 2020 to 2050 was 14.72 Tg. Grassland degradation was the main reason for the reduction of carbon storage in arid region. (3) The carbon storage of farmland had increased significantly, but the expansion of farmland dominated by high carbon density grassland, wetland and forest, had reduced the overall carbon storage of the arid region. [ABSTRACT FROM AUTHOR]

[Display omitted] • Reservoir is the main place for changes of hydro chemical characteristics. • Artificial channels and reservoir systems have changed the temporal and spatial distribution of surface water chemistry. • Rock lithology and evaporate crystallization are decisive factors for surface water hydro chemistry. Reservoirs provide more than 90% of water for agricultural, municipal, and environmental flows in arid regions. Yet, these resources may be compromised if the effects of reservoirs on water chemistry are not considered. This manuscript summarizes water chemistry data collected from May 2014 to October 2018 in the Shiyang Basin, an endorheic basin in arid North-Central China, where samples were collected from a chain of reservoirs, including headwater (mountain), mid-reach (oasis), and lower (desert) reservoirs. All samples consisted of a mixture of Ca-HCO 3 , Ca (Mg)-HCO 3 , and Na-SO 4 (Cl), with concentrations increasing at lower elevations. Stable isotopes indicate that most evaporation occurs in reservoirs, rather than in stream channels. Rock lithology is the primary factor influencing water chemistry in the headwater and mid-reach reservoirs, with the additional influence of imported water from the Yellow River in the mid-reach reservoir. Water quality in the desert reservoir was primarily influenced by evaporative crystallization. We show that these reservoirs are the primary source of hydrochemical transformation in this endorheic basin, affecting both the temporal and spatial variation of water chemistry. [ABSTRACT FROM AUTHOR]