由于气候变化和人类活动引起的土地利用/覆盖变化（LUCC）对陆地生态水文过程的影响日益深刻，要求我们及时把握变化环境下的水资源形成与演化规律，保障水资源安全，实现水资源的可持续利用。近几十年来，在气候变化和人类活动的双重影响下，原本脆弱的生态环境进一步恶化，需要迫切地研究气候变化和LUCC对流域水循环和水资源的影响。本研究采用实验、调查、遥感和模型（SWAT模型）相结合的方法，探讨了气候变化和LUCC对泾河流域生态水文过程的影响。在年和月的时间尺度上量化了1970~2006年泾河流域气候变化和LUCC对径流和蒸散发的影响及其贡献率。在此基础上，进一步分析了“退耕还林（草）”对流域生态水文过程的影响，取得了以下主要结果：(1) SWAT模型能够在年和月时间尺度上较准确地模拟泾河流域的径流量，可以做为流域水资源评价的重要手段和工具。(2) 过去几十年来，泾河流域的多年平均气温、最高温度和最低温度呈逐年上升趋势，流域多年平均降雨量总体呈减少趋势。上世纪70年代(1970~1979)～80(1980~1989)年代，气温呈微弱上升趋势；80年代(1980~1989)～90(1990~1999)年代，气温呈现明显增温趋势，流域多年平均最高气温升温最明显；1990～2005年，流域气温仍保持明显增温趋势，多年平均最低气温升温最明显。上世纪70～80年代，降雨量年际变化不大，月际变化较大，5-6月份降雨量增加较明显；上世纪80～90年代，流域总降水量减少，下游减少较明显；1990～2005年，总降水量有所增加，中、下游增加显著。综合分析，上世纪80~90年代，流域气候呈暖干化特征，1990～2005年，流域气候呈现暖湿化特征。(3)对比1979、1989、1999和2006 年泾河流域4期土地利用分类结果，可以看出耕地和低覆盖草地始终是流域最主要的土地利用类型。几十年来，林地面积持续减少，城镇用地的面积持续增加，未利用地的面积增减变化比较剧烈。与1979年相比，1989年时流域植被覆盖度整体上呈降低趋势：林地和高覆盖草地面积分别减少了4.55%和2.44%，未利用地和低覆盖草地面积分别增加了3.61%和4.17%，耕地面积减少较小；到1999年，与1989年相比，流域植被覆盖度仍呈降低趋势：耕地面积增加了2.57%，未利用地面积增加了5.70%，高、低覆盖草地面积减少共减少了7.32%，林地面积减少了0.93%；到了2006年，与1999年相比，流域植被覆盖情况有所改善：高覆盖草地、未利用地、耕地面积变化最显著，高覆盖草地增加了4.60%，未利用地减少了9.78%，耕地增加了5.11%，林地增加面积和低覆盖草地减少面积非常小。(4) 上世纪70~80年代，在气候变化和LUCC共同作用下，流域年和月径流都呈现增加趋势，年径流量共增加了29.75 m3s-1。其中气候变化使得年均径流增加了26.07 m3s-1；对径流影响的贡献率为+87.62%；LUCC使得年径流增加了2.30 m3s-1，对径流影响的贡献率为+7.73%。其它因素的贡献率为+4.64%。在气候变化和LUCC共同作用下，流域月蒸散量都呈现出减少趋势，年蒸散量共减少了78.39 mm，其中气候变化使得年均蒸散量减少了30.03 mm，对蒸散量影响的贡献率为-38.31%；LUCC使得年蒸散量减少了37.93 mm，对蒸散量影响的贡献率为-48.39%。其它因素的影响为-13.31%。上世纪80 ~90年代，在气候和LUCC共同作用下，流域年、月径流量都呈现出减少趋势，年径流量减少了12.59 m3s-1。其中气候变化使得年均径流减少了7.04 m3s-1，对径流减少的贡献率为-55.92%；LUCC使得年径流减少了6.83 m3s-1，对径流影响的贡献率为-54.25%。其它因素的影响为+10.17%。在气候变化和LUCC共同作用下，流域年、月蒸散量都是增加的，年蒸散量共增加了72.53 mm，其中气候变化使得年均蒸散量增加了47.19 mm，对蒸散量影响的贡献率为+65.06%；LUCC使得年蒸散量增加了33.46 mm，对蒸散量影响的贡献率为+46.13%。其它因素的影响为-11.21%。上世纪90年代到现在，在气候变化和LUCC共同作用下，流域年、月径流量都在减少。年径流量共减少了15.65 m3s-1，其中气候变化使得年均径流减少了6.59 m3s-1；对径流影响的贡献率为-42.11%；LUCC使得年径流减少了11.06 m3s-1，对径流影响的贡献率为-70.67%。其它因素的影响为+12.18%。同期，在气候和LUCC共同作用下，流域年、月蒸散量都是增加的，年蒸散量共增加了34.15 mm，其中气候变化使得年均蒸散量增加了37.01mm，对蒸散量影响的贡献率为+108.37%；LUCC使得年蒸散量减少了10.09 mm，对蒸散量影响的贡献率为-29.55%。其它因素影响+21.18%。(5) 泾河流域自90年代末“退耕还草”措施实施以来，流域部分坡耕地逐渐退耕恢复为草地。流域上游坡耕地主要恢复为低密度草地，流域中、下游由于气候条件较为优越，坡耕地主要恢复为高覆盖草地。研究结果表明，退耕还草后流域上游的径流总量和土壤含水量增加，而蒸散发量和地表径流量减少。主要原因可能是流域坡耕地恢复为低、高覆盖草地后，减少了坡面地表径流和土壤侵蚀，增加了土壤下渗量，起到了涵养水源、保持水土的作用。

As the increasing affections of climate change and land use/cover change (LUCC) to terrestrial eco-hydrology processes, it is necessary to understanding mechnisims of water resources formations under new conditions, which would be important to guarantee the security of water resource. The trendency of clmate warming and drying is obvious in Jinghe River basin over the past decades. Affected by both the climate change and LUCC, the fragiled condition of ecological environment has changed to more deterioration. Researches on the effects of climate change and LUCC on basin’s water circulation and water resources are urgently demanded. By using laboratory experiment, field investigation, GIS technology and eco-hydrological model (SWAT), we explored the effects of climate change and LUCC to eco-hydrology process of Jinghe river basin. In yearly and monthly scale, this paper calculated the ratioes of climate change and LUCC contributions to the basins runoff and evapotranspiration from 1970 to 2006 respectively. Then, further analysis the effect of “returning farmland to grass”policy to the eco-hydrology process of Jinghe river basin.The main outcomes were following: (1) In yearly and monthly scale, SWAT model can better simulate the runoff change of Jinghe river basin after parameters calibration and certification, and can be an improtent means and tool to evaluation water resources. (2) The annual average temperature, mean annual maximum and minimum temperature of Jinghe river basin was increased and precipitation was decreases over the past decades.1970s (1970~1979) ~1980s1980s (1980~1989), temperature increased very slowly, but turbulenced between years and months. 1980s1980s (1980~1989)~1990s1990s (1990~1999), temperature increased very significantly, especially the annual average temperature. 1990~2005, the temperature also contained increase trend, especially the mean annual minimum temperature. 1970s1970s~1980s1980s, basin precipitation increased not obvious, but various hardly in month, especially in month 5~6.1980s ~1990s, precipitation represented decreased trend. 1990~2005, precipitation increased again, especially the middle and down stream of Jinghe river basin.(3) Comparing four years land use classification image of 1979, 1989, 1999 and 2006, can finded out: farmland and low covered grassland were always two land use types in Jinghe river basin from 1970 to 2006. And Forest was only land use type whose area continuous decreased, while town area was only land use type whose area continuous increased. Comparized with 1979’s and 1989’s land use types, the land use tendency of Jinghe river basin was degenerated: forest, high covered grassland was decreased 55%, 2.44% respectively. While, unutilized land and low covered grassland was increased 3.61%, 4.17% respectively. Comparized with 1989’s and 1999’s land use types, the land use tendency of Jinghe river basin was degenerated more severe: farmland and unutilized land increased 2.57%, 5.70% respectively. Grassland and forest decreased reduced 7.32%, 0.93% respectively.Comparized with 1999’s and 2006’s land usetypes, vegetation condition began to recovery: high covered grassland increased 4.60%, and unutilized land decreased 9.78%. However, farmland still increased 5.11%. (4) 1970s ~1980s, under the interaction of climate change and LUCC, Jinghe river basin yearly and monthly runoff were all increased. Mean annual runoff increased 29.75 m3s-1. And climate change made it increased 26.07 m3s-1, and is the +87.62% of all affection that climate and land-use change to the basin’s mean annual runoff. The LUCC made it increased 2.30 m3s-1, and is the +7.73% of the affection. Others factor affection occupied +4.64%. On the other hand, under the interaction of climate change and LUCC, Jinghe river basin yearly and monthly evapotranspiration were all decreased. Mean annual evapotranspiration decreased 78.39mm. And climate change made it decreased 30.03mm, and is the -38.31% of all affection that climate and land-use change to the basin’s mean annual evapotranspiration. The LUCC made it decreased 37.93mm, and is the -48.38% of the affection. Others factor affection occupied -13.31%.1980s~1990s, under the interaction of climate change and LUCC, Jinghe river basin yearly and monthly runoff were all decreased. Mean annual runoff decreased 12.59 m3s-1. And climate change made it decreased 7.04 m3s-1, and is the -55.92% of all affection that climate and land-use change to the basin’s mean annual runoff. The LUCC made it decreased 6.83 m3s-1, and is the -54.25% of the affection. Others factor affection occupied +10.17%.On the other hand, under the interaction of climate change and LUCC, Jinghe river basin yearly and monthly evapotranspiration were all increased. Mean annual evapotranspiration increased 72.53mm. And climate change made it increased 47.19mm, and is the +65.06% of all affection that climate and land-use change to the basin’s mean annual evapotranspiration. The LUCC made it increased 33.46mm, and is the +46.13% of the affection. Others factor affection occupied -11.21%.1990~1999, under the interaction of climate change and LUCC, Jinghe river basin yearly and monthly runoff were all decreased. Mean annual runoff decreased 15.65 m3s-1. And climate change made it decreased 6.59 m3s-1, and is the -42.11% of all affection that climate and land-use change to the basin’s mean annual runoff. The LUCC made it decreased 11.06 m3s-1, and is the -70.67% of the affection. Others factor affection occupied +12.18%. On the other hand, under the interaction of climate change and LUCC, Jinghe river basin yearly and monthly evapotranspiration were all increased. Mean annual evapotranspiration increased 34.15 mm. And climate change made it increased 37.01mm, and is the +108.37% of all affection that climate and land-use change to the basin’s mean annual evapotranspiration. The LUCC made it decreased 10.09 mm, and is the -29.55% of the affection. Others factor affection occupied +21.18%.(5) After the policy of returning farmland to forest and grass carried out in Jinghe river basin, part of farmland transformed to high or low covered grassland. All these vegetation restoration measures made the soil water content, runoff increased, evapotranspiration decreased, and ecological environment were protected. In the future, the policy of returning farmland to forest and grass should be deeply insisting on.