基于气象水文因子的呼伦湖湿地消长综合模型研究

利用1961-2005年呼伦湖湿地的气象及水文资料, 基于水量平衡方程, 以湿地各年水量盈亏累积量(∑ΔW)为因子, 建立了呼伦湖湿地水域面积和水位高程的消长对气象及水文因子协同作用的响应模型, 分析了湿地水域面积和水位高程的消长对影响因子的响应特征.结果表明:呼伦湖湿地消长对气象及水文因子的年代际变化有很好的响应.年平均气温每增加1 ℃, 湿地水域面积和水位高程分别减少134.5 km²和93.44 cm; 年降水量每增加10 mm, 二者分别增加10.2 km²和7.1 cm; 年蒸发量每增加10 mm, 二者分别减少1.1 km²和0.9 cm; 年径流量每增加1×10⁸m³, 二者分别增加4.8 km²和3.3 cm. 年平均气温的升高和年降水量的减少变化对湿地消减的贡献率分别为13.6%和86.4%, 当前降水量的变化在湿地消长中占主导作用.如果不考虑人类活动的影响, 根据未来较低排放(SRES-B2)情景下气候预测, 初步估算2040、 2070和2100年湿地水域面积将分别减少275.8 km²、 442.8 km²和583.6 km², 水位高程分别下降191.6 cm、 307.6 cm和405.4 cm, 未来气温的变化在湿地消长中占主导作用.呼伦湖湿地在未来暖干化趋势下, 湿地水资源短缺加剧, 湿地水域面积萎缩和水位高程下降将加快.

Integrated Model Describing the Growth and Decline of the Hulun Lake Wetland Based on Meteorological and Hydrological Factors

With meteorological and hydrological data from 1961 to 2005 in Hunlun Lake wetland, based on water balance equation, taking the yearly cumulative sum of water balance as a factor, the response model about growth and decline of water area and rise and fall of water level in Hulun Lake wetland was developed in respect of meteorological and hydrological factors, The response characteristics about growth and decline of water area and rise and fall of water level were analyzed with the influencing factors, in order to protect, recover and utilize the Hunlun Lake wetland. It is found that: 1) the growth and decline of water area has good response to the interdecadal change of meteorological and hydrological factors in the wetland. Water area and water level in the wetland will decrease 134.5 km² and 93.44 cm, respectively, if average yearly air temperature increases 1 ℃. They will increase 10.2 km² and 7.1 cm, respectively, if yearly precipitation increases 10 mm. They will decrease 1.1 km² and 0.9 cm, respectively, if yearly evaporation increases 10 mm. They will increase 4.8 km² and 3.3 cm, respectively, if yearly runoff increases 1×10⁸ m³. 2) Yearly average air temperature increase and yearly precipitation decrease have different contribution rates to decline of the wetland. The former is 13.6% and the later is 86.4%. The later is a dominant factor. 3) If human active effect can be ignored, according to a future climatic prediction, for the lower discharge(Scenario B2), it is preliminary assessed that wetland water area will decrease 275.8 km², 442.8 km² and 583.6 km², respectively, and water level will decrease 191.6 cm, 307.6 cm and 405.4 cm respectively, in 2040, 2070 and 2100. Air temperature change will be the leading factor for the wetland growth and decline in future. Looking forward to the future, the wetland will be warmer and dryer, and then shortage of water resources will intensify, and water area shrinking and water level lowering will accelerate.