【作者】 许宝荣；

【导师】 刘勇；

【作者基本信息】 兰州大学 ， 地图学与地理信息系统， 2015， 博士

【摘要】 陆-气系统水文循环密切联系大气水、地表水与生态水,其变化深刻影响到全球水资源系统与生态演变,开展变化环境下流域尺度陆-气系统水文循环研究成为当前发展趋势。水资源先天性短缺的干旱半干旱区,经济与生态可持续发展对水资源双重依赖。黑河流域具备内陆河流域独特的区域水文功能差异与典型的地表水文循环过程,区域人类活动历史悠久,伴随社会经济的飞跃发展,区域经济活动用水与生态环境用水矛盾突出。全面认识黑河流域的水汽分布、水汽输送、水汽收支与降水量时空分布特征,深刻理解黑河流域文循环过程及特征,对实现内陆河流域的区域水资源开发利用和合理配置,以及干旱区水文-生态-经济的可持续发展均具有十分重要的意义。论文以黑河流域高分辨率区域气候模式输出的1980-2010年期间11个标准等压面3km×3km分辨率的6小时大气温度、比湿、经向风和纬向风数据为主要数据,基于环流背景场理论与地形抬升降水效应理论构建基于物理机制的分布式降水模型,详细分析了陆-气系统水文循环中包括区域上空水汽含量、水汽输送、和水汽收支等大气水文过程与降水的时空分布特征,结合区域的实际蒸散发量与径流量等,探讨了黑河流域上中下游及全流域陆-气系统水文循环的基本特征,主要研究结论如下：(1)流域上空整层水汽含量低值区位于上游,高值区位于下游,尽管季节性差异明显,但其基本分布格局基本不变。全流域多年年均水汽含量介于31.73～125.62mm之间,平均为101.08mm,上中下游年均水汽含量分别为59.24mm、107.05mm和112mm。冬季1月全流域水汽含量最小,介于0.88-4.00mm之间,平均为3.21mm,上中下游的水汽含量分别为1.62mm、3.34mm和3.67mm；夏季7月水汽含量达到最大,全流域水汽含量介于6.26～23.00mm之间,平均为18.70mm,上中下游的平均水汽含量分别为11.37mm、19.50mm和20.74mm。秋季10月月均水汽含量高于4月份的月均水汽含量。(2)流域上空纬向西风输送和经向北风输送为主,在1、4、7和10月的季节代表月份中,上游与下游仅7月水汽收支为正；而中游的水汽收支均为正值。流域上空多年年均水汽输送通量为3039.97～7392.36g/(cm·s),冬季1月月均水汽输送通量最小,约为420.95～133.08g/(cm·s);夏季7月水汽输送量最大,其值为928.44～395.92g/(cm·s);秋季的水汽输送量大于春季。流域各区全年、冬季1月、春季4月和秋季10月的纬向水汽输出量大于纬向水汽输入量,水汽净收支为负,纬向水汽输送不仅作为“过境水”方式越过区域上空,同时带走了大量区域蒸发水汽,造成水汽亏损；夏季7月,纬向输送为中下游带来了大量水汽,净水汽收支为正。经向水汽输入与水汽输出所占比例较小,但成为区域水汽盈余的主要来源；夏季上游山区中东部地区及流域东部边缘出现南风水汽输送。全流域全年净水汽收支为255.32亿m3,在4个季节代表性月份中,仅夏季7月的水汽净收支为正,达到125.14亿m3,其他季节代表性月份水汽净收支为负。与全流域一样,上游和下游在季节性代表月份中仅夏季水汽收支为正,其他水汽净收支均为负值。上游全年水汽收支量为23.73亿m3,其中夏季7月的水汽净收支达21.58亿m3；下游全年水汽收支量为11.54亿m3,夏季7月的水汽净收支达43.32亿m3。中游在四季代表性月份的水汽净收支都为正,夏季7月的水汽净收支最大,达61.94亿m3,全年净水汽收支量达225.73亿m3。(3)因地形抬升降水效应引发的流域降水空间分布特征呈现与其上空水汽含量、水汽通量分布相反的格局,上游为降水量高值区、下游为降水量低值区,境外输入水汽与区域本地蒸发对降水的贡献因季节而异。1月境外输入水汽对各区降水的贡献最高,7月份最低；区域本地蒸发对降水的贡献则相反。环流背景场年均理论降水介于0.07384-98.79mm之间,降水高值区以张掖、临泽及金塔为中心分布在中游,上游与下游的理论降水较少,降水低值区在下游连片分布。地形抬升降水效应主要发生在上游山区,其区域地形降水效应介于-19.41～20.92mm之间。冬季1月最小,夏季7月最大。受来自各季节不同方向大气环流的影响,地形抬升理论降水的空间分布不同,冬季1月、春季4月与秋季10月上游山区地形降水效应的低值区与高值区成对出现,呈现犬牙交错分布；而夏季7月上游成为降水高值区。全流域年均降水量为139mm,其中90%的降水量来源于境外输入水汽,10%来源于区域蒸发水汽；上游年均降水量为425mm,其中90%的降水量来源于境外输入水汽,10%来源于区域蒸发水汽；中游年均降水量为147mm,其中93%的降水量来源于境外输入水汽,7%来源于区域蒸发水汽；下游年均降水量为46mm,95%的降水量来源于境外输入水汽,5%来源于区域蒸发水汽。上中下游及全流域冬季1月境外输入水汽的贡献分别达到97%、99%、99%和98%,区域蒸发水汽对降水的贡献分别达到3%、1%、1%和2%；而夏季7月区域蒸发量对降水的贡献增多,上中下游及全流域降水分别为14%、11%、9%和15%。(4)上游的水文外循环和水文循环较弱,但水文内循环较强,水汽交换频繁,水汽滞留时间最短,转化效率最高,与上游降水量最多的事实一致。中游的水文外循环最高,但水文循环不高,水汽的滞留较长,转化效率低。而下游的水文循环最高,水文内循环最低,水文外循环较低,水汽很难形成降水,水汽不活跃,转化效率最低,与区域干旱少雨现象一致。水文循环特征在各区高温高湿的夏季7月份表现最为活跃,而在干冷的冬季1月表现较弱。水文外循环系数运用区域上空水汽净收入量转化为降水的次数,衡量境外水汽参与降水的活跃程度,全流域的水文外循环系数为1.52,上中下游的水文外循环系数分别为0.24、6.27和0.34。水文内循环系数表示区域蒸发量对区域降水的贡献,反映区域内部水循环的活跃程度,全流域的水文内循环系数为10%,上中下游的水文内循环系数分别为18%、5%和3%。水文循环系数表示境外水对区域降水的贡献,上中下游及全流域的水文循环系数分别是90%、93%、99%和90%。水汽滞留时间表示区域上空水汽含量完全转化为降水所需天数,水汽滞留时间越短,水汽转化为降水的效率越高。上中下游及全流域的水汽滞留时间分别是4.24、22.15、74.20和22.12,水汽转化效率则与水汽滞留时间相反。流域各区夏季7月的水文循环系数和水文内循环系数均达到最大值。上中下游及全流域夏季7月的水文循环系数分别为1.14、7.9、4.39和3.41次,水文内循环系数分别为25%、10%、9%和18%；冬季1月,除中游水文循环系数升高至9.37外,其他均达到最低值；上游、下游和全流域冬季1月的水文循环系数均接近0,水文内循环系数分别为2%、2%、1%和2%。在各区的水汽滞留时间中,仅上游在春季4月,夏季7月,秋季10月和年均水汽滞留时间少于10天,分别为6.85、4.23、6.81和4.24天,以夏季7月的滞留时间最短,水汽转化效率最高。中游在各季节代表性月份的水汽滞留时间均小于下游。更多还原

【Abstract】 The land-atmosphere hydrologic cycles in them closely related the atmospheric water, surface water and ecological water, and the changes in them profoundly influenced on the water resources and the ecological evolution all over the world. It has becoming the current developing trend to carry out the study on the land-atmosphere hydrologic cycles in watersheds under rapidly changing environment. The natural severe scarcity of the water resources was the remarkable characteristics of the arid and semi-arid regions and became the double dependence of the sustainable development for its economy and ecological environment in them. Heihe River Basin had the unique characteristics with the different hydrological functions in each region and typical hydrologic cycle processes, and the conflict between ecological water demand and economic water utilization had becoming serious due to the intensive human activities for a long time. To realize the reasonably utilization and the rational disposition of regional water resources and the sustainable development for their hydrology-ecology-economy, the spatial-temporal distributions of the water vapor content, water vapor flux, water vapor budget and the precipitation should be comprehensively recognized, and the processes of the hydrologic cycles in inland watershed should be deeply understood.Using the data from the high resolution regional climate model, which contains atmospheric temperature, specific humidity, meridional and zonal wind at 11 standard isobaric in Heihe River Basin during 1980-2010, as the main data, the distributed water vapor content and the water vapor flux were analyzed, and the physical-based distributed precipitation in the region were estimated based on the theory of the circulation background field and the topographical uplifting theory. The atmospheric hydrology process in the land-atmosphere hydrologic cycle including the water vapor content, the water vapor budget from the water vapor flux over the Heihe River Basin, and the hydrologic cycle characteristics of land-atmosphere in upstream, middle-stream, down-stream and the whole basin were studied, combining with the detailed-distributed precipitation, the actual evapotranspiration and runoff in each region. The results showed as followed.(1) The low values of the whole water vapor content over the Heihe River Basin located in upstream and the high values of it located in down-stream. Although the seasonal difference between the water vapour contents was remarkable, the distribution pattern of it in Heihe River Basin remained unchanged. Annual average water vapor content was in the range of 31.73～125.62mm, and those in the up-stream, middle-stream, down-stream and the whole basin was 59.24mm,107.05mm,112mm and 101.08mm, respectively. The average water vapor content in January was in the range of 0.88～4.00mm to a minimum, and those in the up-stream, middle-stream, down-stream and the whole basin was 1.62mm,3.34mm, 3.67mm and 3.21mm, respectively. And the average water vapor content in July was in the range of 6.26～23.00mm to the maximum, and those in the up-stream, middle-stream, down-stream and the whole basin was 11.37mm,19.50mm,112mm,20.74mm and 18.70mm, respectively. The average water vapor contents in each region in October were more than those in April.(2) The west wind in zonal direction and the north wind in meridional direction were the major driver of the water transportation over the Heihe River Basin. Among the representative months of each season, the water vapor budget of the up-stream, dowm-stream in July were positive, but negative in the other months. The water vapor budgets of the middle-stream in all months were positive, and the water vapor had a lot of surplus.The annual average water vapor flux over the basin was about 3039.97～7392.36 g/(cm·s). The average water vapor flux in January was about 420.95～133.08 g/(cm·s) to the minimum, and the one in July was about 928.44～395.92 g/(cm·s) to the maximum. The average water vapor flux in October was more than that in April.The water vapor outputs in each region were more than the inputs in zonal direction and the water vapor budget is negative in January, July and October, the water vapor transportation not only crossed over the regions as "transit water", but also took away a large amount of regional water vapor, resulting in water vapor losses. Only in July, because the water vapor transportation brought a lot of water vapor into them, the middle-stream and down-stream had a positive net water vapor budget. The water vapor inputs and the outputs in meridional direction of each region were a minority, but became the main source of the water surplus in them. Only in July, there were the water vapor transportations by south wind and it appeared in the middle and east part of up-stream and the eastern edge of the basin. The annual average net water vapor budget over the whole basin was about 255.32×108 m3, and it was 125.14×108 m3 in July, only a month with surplus water budget among the representative months of the seasons in a year. The monthly average net water vapor budget over the up-stream and down-stream were positive in July, but negative in other representative months of seasons. The annual net water vapor budget over the up-stream was 23.73×108m3, among which the ones in July was about21.58×108m3; The annual net water vapor budget over the down-stream was 11.54×108m3, among which the ones in July was about43.32×108m3; The annual net water vapor budget was 225.73 × 108m3, and the monthly net water vapor budgets over the middle-stream in all representative months of the seasons were positive, among which the ones in July was 61.94×108m3 to the maximum.(3) The spatial distribution of the precipitation resulted from topographical uplifting effect showed that the high values located in up-stream and and low values located in down-stream, opposite to the spatial patterns of the water vapor content and the water vapor flux over the basin. In January the contributions of the total water vapor input abroad to the precipitations in up-stream, middle-stream, down-stream and all the basin in January was 97%,99%,99% and 98%, respectively, and in July, the rate of the precipitations from the evapotranspiration was 3%,1%,1% and 2%; while the rate of the precipitations from the evapotranspiration of the up-stream, middle-stream, down-stream and all the basin reached 14%,11%,9% and 15%,respectively.The theoretical precipitation under the circulation background field was in the range of 0.07384-98.79mm, and the high precipitation values located around Zhangye, Linze and Jinta in middle-stream, while the low values distributed in up-stream and down-stream, became continuous distribution in down-stream. The effect of the orographic uplift mainly happened in the mountains of up-stream and the spatial distribution of it was different from each other because of different influence in unique atmospheric circulation from each season. The effect of the orographic uplift was to the minimum in January and to the maximum in July. In January the high values and the low values from the effect of orographic uplift in the mountainous up-stream, and April and October appeared in pairs showing the condition of being indented, while disappeared in July, instead of continuous region of high precipitation in July, with the range of -19.41～20.92mm in whole basin.The annual average precipitation of the whole basin was about 139mm,90% of which from water vapor input abroad and 10% from the local evapotranspiration. The annual average precipitation of the up-stream was about 425mm,90% of which from water vapor input abroad and 10% from the local evapotranspiration. The annual average precipitation of the middle-stream was about 147mm,93% of which from water vapor input abroad and 7% from the local evapotranspiration. The annual average precipitation of the down-stream was about 46mm,95% of which from water vapor input abroad and 5% from the local evapotranspiration.The contribution of water vapor input abroad and local evapotranspiration to precipitation differed from each season. The contribution of water vapor input abroad was the most in January and the least in July, and the ones in October were more than those in April. Of all the basin,98% of precipitation was from water vapor input abroad in January while 85% in July. In the up-stream,97% of precipitation was from water vapor input abroad in January while 86% in July. In the middle-stream,99% of precipitation was from water vapor input abroad in January while 89% in July. In the down-stream,99% of precipitation was from water vapor input abroad in January while 91% in July. Correspondingly, the contribution of local evapotranspiration to precipitation was to the minimum in January and to the maximum in July.2% of precipitation was from local evapotranspiration in January while 15% in July in the whole basin, while 3% and 14% in the up-stream,1% and 11% in the middle-stream, and 1% and 9% in the down-stream.(4) In the up-stream, the external cycle and the hydrologic cycle were weaker, but the internal cycle was stronger. The water exchange in it was active and the water vapor retention in it was shortest in up-stream, showing the highest precipitation efficiency. The result was consistent with the fact that the up-stream had the most precipitation in the whole basin. In the middle-stream, the external cycle in was the strongest, but the hydrologic cycle was lower, the water vapor retention in it was longer, and the precipitation efficiency was lower. In the down-stream, the hydrologic cycle was the strongest, but the internal cycle was lower, the water vapor was not active, thus the water vapor in it was difficult to form the precipitation, and the precipitation efficiency was lowest, consistent with the phenomenon of little precipitation in it. All kinds of the hydrologic cycles performed most actively in July with high air temperature and high humidity, while weakest in cold and dry climate of January.The external cycle coefficient measured the degree of involving the precipitation of the water vapor abroad using the times converted from the net water vapor budget. The external cycle coefficient in the whole basin was 1.52, and those in the up-stream, middle-stream and the down-stream were 0.24,6.27 and 0.34, respectively. The internal cycle coefficient showed the contribution of the local evapotranspiration to the precipitation, reflecting the activity of the local water vapor. The internal cycle coefficient in the whole basin was 10%, and those in the up-stream, middle-stream and the down-stream were 18%,5% and 3%, respectively. The hydrologic cycle coefficient reflected the contribution of the water vapor abroad to the precipitation and those were 90%,93%,99% and 90% in the up-stream, middle-stream, down-stream and the whole basin, respectively. The water vapor retention coefficient indicated the days needed converting the water content over the region to the precipitation completely. The shorter the water vapor retention, the higher the precipitation efficiency. The water vapor retention coefficients in the up-stream, middle-stream, down-stream and the whole basin were 4.24,22.15,74.20 and 22.12 days, respectively.The coefficients of hydrologic cycle and the internal cycle in each region reached the maximum in July. The hydrologic cycle coefficients in the up-stream, middle-stream, down-stream and the whole basin were 1.14,7.9,4.39 and 3.41, and the internal coefficients in those were 25%,10%,9% and 18%, respectively. Except for the hydrologic cycle coefficient in middle-stream increased to 9.37, the coefficients of hydrologic cycle and the internal cycle in each region reached the minimum in January. The hydrologic cycle coefficients in the up-stream, down-stream and the whole basin were near to zero, and the internal coefficients in those were 2%,2%,1% and 2%, respectively. Among the water vapor retention in each region, only those of the up-stream in April, July, and October and that in a year were shorter than 10 days. They were 6.85,4.23,6.81 and 4.24 days, respectively, and that in July was shortest, representing the highest precipitation efficiency. The water vapor retentions coefficents of the middle-stream in each presenting months of the seasons were shorter than those in down-stream.更多还原