Hydrological responses to climate change conditioned by historic alterations of land-use and water-use
Hydrological responses to climate change conditioned by historic alterations of land-use and water-use
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DOI：
10.5194/hess-16-1335-2012
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发表时间：
2012-01-01
影响因子：
6.3
通讯作者：
Destouni, G.
中科院分区：
文献类型：
--
作者：
Jarsjo, J.;Asokan, S. M.;Destouni, G.
本文量化和条件预期的水文响应咸海流域（ASDB，占地球陆地表面的1.3%），中亚，在该地区的气候变化的多模式预测从20个大气环流模型（GCM）。其目的是研究未来气候变化的不确定性如何与历史上人类重新分配土地灌溉用水的影响相互作用，以影响未来的水通量和水资源。到目前为止，历史上的灌溉变化大大放大了水分蒸发损失（ET）在ASDB，而20世纪世纪的气候变化并没有太大的影响区域净水分流失到大气中。结果表明，温度（T）和降水量（P）从单一的GCM的误差有很大的影响，预测的变化趋势（2010-2039年）的河流径流量（R），即使ASDB是空间上很好地解决了当前的GCM。相比之下，观测到的GCM集合平均结果的偏差对预计的R变化趋势的影响相对较小。平均结果表明，预测的未来气候变化将大大增加大气中的净水分损失。此外，ET响应强度的任何未来T变化将进一步增加保持（或增加）灌溉的做法，这表明如何气候变化和用水量的变化可以相互作用，修改ET（和R）。在维持灌溉做法的情况下，R可能会减少到接近完全耗尽，并有可能在灌溉土地地区下游的水生生态系统中发生级联生态制度变化。在没有灌溉的情况下，锡尔河流域的主要农业地区在产生与目前灌溉做法相同的消耗性ET增加和相关R减少之前，可以维持50%的T增加（2.3 A摄氏度，而不是2010-2039年预测的1.5 A摄氏度）。
This paper quantifies and conditions expected hydrological responses in the Aral Sea Drainage Basin (ASDB; occupying 1.3% of the earth's land surface), Central Asia, to multi-model projections of climate change in the region from 20 general circulation models (GCMs). The aim is to investigate how uncertainties of future climate change interact with the effects of historic human re-distributions of water for land irrigation to influence future water fluxes and water resources. So far, historic irrigation changes have greatly amplified water losses by evapotranspiration (ET) in the ASDB, whereas 20th century climate change has not much affected the regional net water loss to the atmosphere. Results show that errors in temperature (T) and precipitation (P) from single GCMs have large influence on projected change trends (for the period 2010-2039) of river runoff (R), even though the ASDB is spatially well resolved by current GCMs. By contrast, observed biases in GCM ensemble mean results have relatively small influence on projected R change trends. Ensemble mean results show that projected future climate change will considerably increase the net water loss to the atmosphere. Furthermore, the ET response strength to any future T change will be further increased by maintained (or increased) irrigation practices, which shows how climate change and water use change can interact in modifying ET (and R). With maintained irrigation practices, R is likely to decrease to near-total depletion, with risk for cascading ecological regime shifts in aquatic ecosystems downstream of irrigated land areas. Without irrigation, the agricultural areas of the principal Syr Darya river basin could sustain a 50% higher T increase (of 2.3 A degrees C instead of the projected 1.5 A degrees C until 2010-2039) before yielding the same consumptive ET increase and associated R decrease as with the present irrigation practices.