1951-2010年洮河流域水文气象要素变化的时空特征

采用M-K检验、小波分析和Sen斜率等方法, 对1951-2010年60 a来洮河流域不同地理-生态区间水文气象要素变化的时空特征进行了综合研究.结果表明: 洮河流域水文气象要素呈现多种周期不同尺度的振荡特性, 气温、降水和径流的年代际变化周期以9~13 a和2~5 a最为常见.气温从1990年代中期开始明显上升, 突变的时间北部略早于南部, 西部明显迟于东部;除上游草原牧区外, 降水总体于1990年代初期开始减少;受降水变化影响, 流域河川径流量1990年代发生明显减少.过去60 a, 洮河流域气温以0.18 ℃·(10a)^-1的速率增温;降水以0.03 mm·(10a)^-1的速率减少;河川径流量以11.36 mm·(10a)^-1的速率减小;近30 a来洮河流域以0.63 ℃·(10a)^-1的速率增温, 降水以8.86 mm·(10a)^-1的速率减少, 径流以21.00 mm·(10a)^-1的速率减少.降水和径流变化在不同时期和不同生态-地理区间差异明显, 与区域气候和下垫面因素变化所致的流域能水通量过程的变异有关.

Spatial and Temporal Variation of Main Hydrologic Meteorological Elements in the Taohe River Basin from 1951 to 2010

The purpose of this paper is to comprehensively detect the spatial and temporal characteristics of the hydrologic meteorologicalchanges from 1951 to 2010 in the four geographic-ecological sections in the Taohe River basin by using multiple methods including wavelet analysis, M-K test and the Sen's slope. It was found that the hydrologic meteorologicaloscillation over the basin presented a variety in time scales. Annual variations of air temperature, precipitation and runoff were mostly in time periods of 9-13 years and 2-5 years over the basin. Air temperature has increased since the middle 1990s with an abrupt change in the north earlier than in the south and in the west later than in the east. Precipitation has decreased overall since the early 1990s over the basin, except for the prairie pastoral areas in the upper reaches of the river, as a result, runoff has obviously decreased. Over the 60 years, temperature had averagely increased at a rate of 0.18 ℃·(10a)^-1while precipitation had decreased at a rate of 0.03 mm·(10a)^-1;runoff had decreased with a rate of 11.36 mm·(10a)^-1. In the latest 30 years, the hydrologic meteorologicalchange over the basin has become more severe;air temperature has increased with a rate of 0.63 ℃·(10a)^-1;precipitation has decreased with a rate of 8.86 mm·(10a)^-1;runoff has decreased with a rate of 21.00 mm·(10a)^-1. Amounts and amplitudes of the hydrologic meteorologicalelements changes are different among the four geographic-ecological sections, depending on the water-energy variations due to the changes in regional climate and underlying surface shift.