Search

Water scarcity is a critical threat in arid regions in China due to dry climate and rising human water demand. The sustainability of a recent wetter trend and its impact on future water security remain uncertain. This case study focuses on a hotspot region, the North Slope of the Tianshan Mountains (NSTM), to assess water scarcity in the coming decades (2030–2050) under two climate scenarios. To this end, we developed an integrated agro‐hydrological model to simulate historical and future hydrological processes and crop water dynamics in arid regions. Our results indicate nonsignificant increases in precipitation (around 3%) and evident rising temperatures (0.9–1.5°C) in the NSTM compared to the present‐day (2011–2020) climate. This translates to a projected increase in water availability (5.6%–11.2%) during 2030–2050, with slightly larger increases (6.3%–14%) in glacier runoff. However, the spatial mismatch between precipitation increases and water demand makes this potential gain largely offset by rising irrigation water demand (over 7%) if cropland remains constant from 2020 onwards. As a result, the current annual water deficit (3.3 km3) is likely to increase by 5%–11%, with 32% of NSTM basins facing persistent water scarcity. Most croplands are at high risk of groundwater depletion and 17%–34% of basins will experience intensified water scarcity. These findings highlight the urgent need for comprehensive water management strategies, including improved irrigation efficiency and exploration of alternative water sources, to ensure water security and sustainable development in arid China facing a changing climate. Plain Language Summary: Dry regions in China face a water shortage due to low rainfall and rising water use. Recently, even though more rainfall was observed in some arid regions, scientists aren't sure if this will continue. We focus on the hotspot region, the North Slope of the Tianshan Mountains (NSTM), to see how future climate change might affect water scarcity. We found slightly more rain and warmer temperatures in the coming decades (2030–2050) in the NSTM. This could lead to a small increase in available water. However, the need for irrigation water is expected to offset these gains. The current water deficit is likely to worsen, with some areas facing even greater scarcity and increased risk of groundwater depletion. This highlights the need for better irrigation practices and exploring alternative water sources to ensure water security and sustainable development in these regions under a changing climate. Key Points: Slight increases in precipitation and water availability are projected in the NSTMWater scarcity persists due to the spatial mismatch between increased water availability and high irrigation demandThe water deficit is likely to increase by 5%–11% from the current level of 3.3 km3 per year [ABSTRACT FROM AUTHOR]

We assessed how climate change may impact net primary production (NPP) and reference evapotranspiration (ET0) from the Zagros region of western Iran covered extensively by oak, -Quercus branti Lindl. forests. The daily meteorological parameters of temperature (T), precipitation (P), relative humidity (RH), wind speed (WS), and sunshine hours were obtained from 20 meteorological stations throughout the region over a 30-year period (1988-2017). Net primary production and ET0 were estimated by the synthetic and the FAO Penman-Monteith models, respectively. A non-dimensional relative sensitivity coefficient was used to examine the sensitivity of NPP and ET0 to changes in the meteorological parameters. The sensitivity analyses were carried out for T, P, and WS within a possible range of ± 10%, ± 30%, and ± 10%, respectively, from the long-term mean. Except for the P with no notable trend, other meteorological parameters exhibited upward or downward trends. The mean NPP and ET0 values were estimated to be 6.5 t ha-1 y-1 and 3.9 mm d-1 across the Zagros region, respectively. Net primary production was found to be more sensitive to precipitation with a sensitivity coefficient of 0.66 and less sensitive to temperature with a sensitivity coefficient of 0.40. The ET0 sensitivity coefficients in response to T changes doubled relative to WS (0.33 against 0.63). Identifying the contributing factors in NPP and ET0 trends is important for understanding the relative impacts of climate change and human activities in arid and semi-arid regions. [ABSTRACT FROM AUTHOR]