中国西北地区城市经济发展对降水趋势的影响

利用西北地区136 个气象站1961-2012 年的降水量、降水日数、降水强度、日最大降水量、城市与经济发展等数据,研究了西北地区降水各要素的趋势变化特征及人为活动影响。结果表明,西北降水量在1980 年以后呈增加趋势,但东西部趋势相反,中西部地区增加,而东部地区减少。经济快速期(1979-2012 年)与慢速期(1961-1978 年)降水量的趋势差表明,人为活动密集的东部地区降水下降趋势明显减缓;而中西部区域的化工区、城市及其下风区的降水量、降水日数、降水强度和日最大降水量都有明显增加。省会城市和化工城市对降水各指标的正贡献总体在10%~60%之间,其中化工城市对降水的影响最为显著。多元回归表明,社会固定资产投资、工业产值和服务业产值对西北降水有显著影响。

The Impact of Urban Economic Development on Precipitation Changing Trends over Northwestern China

On the basis of 136 stations with annual precipitation amount, rainy days, precipitation intensity, the maximum daily precipitation amount records, and city and economic developmental data during 1961-2012 over northwestern China, the paper mainly studied the precipitation changing trends characteristics and artificial impact on them. The results showed that the precipitation of northwestern China has risen after 1980 in the mass; however the precipitation changing trends of eastern and western parts were opposite to each other and the central-western part has an upward trend, but downward trend for the eastern. In contrast to 1961-1978, the downward trend during 1979-2012 in the eastern part of northwestern China was noticeably declining, which formed a practice that the east developed region had an effect on increasing precipitation. Moreover, the changing trends during 1979-2012 for annual precipitation amount, rainy days, precipitation intensity, the maximum daily precipitation amount in other cities, petrochemical areas, and their downwind areas have increased markedly during 1961-1978. The contributions of urbanization, economic and petrochemical development to precipitation indexes are 10%-60% generally, and the petrochemical development has the most significant effect among them on raising precipitation. The multiple stepwise regressions indicated that social investment, industrial output value and services output value were the important economic indexes to significantly improved precipitation.