【作者】 郑江坤；

【导师】 余新晓；

【作者基本信息】 北京林业大学 ， 水土保持与荒漠化防治， 2011， 博士

【摘要】 在全球气候变化和强烈人类活动的影响下,世界各国均不同程度上面临着水问题与水危机。潮白河流域做为北京(严重缺水的特大城市)唯一的地表水水源地,具有重要的战略意义。本研究以土门、半城子、红门川、怀河和潮白河上游流域为研究对象,通过收集和处理大量土地利用和水文气象数据,采用相关数理统计方法分别对土地利用和水文气象进行趋势变化和突变检验,在此基础上,采用CA-MARCAV模型和未来气候变化模式分别对土地利用、气温和降水进行预测。同时利用AWY模型、水文分析法和二元水循环理论分别评估径流、泥沙和水质变化成因。最后耦合SWAT模型、水库控制模块、未来土地利用变化模型和未来气候变化模型,应用分段连续模拟方式和分离判别手段定量评估历史时期或未来沟道库坝、森林植被、土地利用和气候变化对径流、泥沙和水质的影响。主要结果如下：(1)土门流域土地利用变化发生在林缘交接处,期际变化甚微；半城子流域农地期际转化较频繁,阔叶林和水域逐期分别呈增加和减少趋势；红门川流域各土地利用类型逐期呈波状变化,变化幅度小；怀河流域年变化率起伏较大,各土地利用类型转化强度呈逐期递增趋势。潮白河上游各土地利用类型年变化较小,呈双向高速转换的平衡状态。预测潮白河上游2020年和2030年的林地、耕地、未利用地面积较2008年有所减少,而水域、草地和居民工矿用地较2008年明显增加。家庭联产承包责任制和京津风沙源治理工程是潮白河流域土地利用变化和转移的主要驱动。(2)潮白河流域年降水和潜在蒸散发在1956—2009年间没有显著变化,气温则呈显著上升趋势且在1990年发生突变。潮白河流域径流和输沙量呈显著下降趋势,突变发生在1978年左右。白河流域(辛庄桥监测站)除氯化物、溶解氧、高锰酸盐指数、硝酸盐氮和氛的浓度变异系数小于潮河(大关桥监测站)外,其他水质指标变异系数均大于潮河。预测潮白河2020年和2030年平均地表温度较1961-1990年分别增加1.2℃和1.65℃,夏季降水则分别增加0.21mm和0.05mm。(3)通过敏感性分析,得到潮白河流域林地对月径流深有影响显著,其次为耕地、草地和居民工矿用地,水域和未利用地影响不显著。1980-1989年间,潮河流域和白河流域土地利用对径流变化的贡献率分别达到40.7%和6.5%。人类活动在1974-1997年和1998-2007年期间对潮白河流域泥沙变化的贡献率分别达到78.5%和71.9%。非点源污染分别占COD、TN和TP排放总量的74%、91%和73%,点源污染中生活来源部分所占份额远大于工业来源部分。(4)20世纪80年代沟道库坝工程对潮河和白河径流的贡献率分别达到95%和83%,对输沙的影响则较小,贡献率分别为41%和40%。以工程措施为背景,利用SWAT模型得出潮河和白河土地利用对径流变化的贡献率分别为42%和24%,对泥沙变化的贡献率则为40%和49%。应用“皆伐”还原法得出潮白河各嵌套流域森林植被约减少60%～70%的径流量。(5)基于土地利用和气候因子的预测数据,利用国家气象站资料重新建立SWAT模型并对其校准和验证,以1991-2000年为基准期,2001-2010年、2011-2020年和2021-2030年为评价期：模拟得到评价期3个阶段土地利用对潮河流域径流变化的贡献率分别为23%、43%和25%,白河流域则分别为35%、36%和23%,其它部分则是由气候变化引起。对比分析可知潮白河流域2011-2020年人类活动对径流的影响最为强烈。研究多重环境因子和水文过程相互影响和反馈机制,可为该区水资源可持续利用和土地利用优化配置提供理论依据。更多还原

【Abstract】 Water problems and water crisis are of widespread concern around the world under the background of climate change and intense human activities. As the only source of drinking water in Beijing which is confronted with severe water shortage, the role of Chaobai River Basin is extraordinarily significant in Beijing. In the present study, the five watersheds of Tumen, Banchengzi, Hongmenchuan, Huaihe and the upper Chaobai River were chosen as research areas. The changes of land uses and hydro-meteorological factors during the research period were analyzed based on long time series of land use and hydro-meteorological data, furthermore, the inflection years were revealed through non-parameter test; then land use, temperature and precipitation were predicted by use of CA-MARCAV and future climate scenarios respectively; subsequently the reasons for runoff, sediment and water quality changes were assessed through using AWY model, hydrological analysis method and binary cycle theory. Besides SWAT model was used in the study to simulate and forecast the impacts of reservoir establishment, forest vegetation, land use and climate change on runoff, sediment and water quality, and quantifying each contribution to each hydrological factor. The main results were as follows:(1) Land use changes in Tumen watershed mainly occurred in the edge junction of forestry, and it was found that it produced few changes between different periods; Agricultural land in Banchengzi watershed transformed frequently during the research period, the areas of broad-leaved forest and water body presented the uptrend an downtrend respectively; land uses in Hongmenchuan watershed did not change largely, and had a state of wavelike form among different terms of land uses; Land uses have taken place lots of changes in Huaihe watershed, and it was further observed that speeds of land uses changes became larger as time went; as regards the upper Chaobai River Basin, it did not produce large changes. Land uses in Chaobai River Basin were forecasted in the future, the results showed that forest, cultivated land and unused land would reduce in 2020 and 2030, while water body, grassland and built up increase obviously compared with the present situation. It was analyzed that Household contract responsibility system and Beijing and Tianjin sandstorm source control project may be the main driving force of land use change in Chaobai River Basin.(2) Annual precipitation and potential evapotranspiration in 1956-2009 did not change significantly in Chaobai River Basin, while air temperature climbed evidently, and an inflection point (in 1990) was identified through visual observation. With regard to annual runoff and sediment yield, they both took on a rapid decline during the research, and the change point was in 1978. The variation coefficients of water quality indicators in Bai River Basin (Daguanqiao station)were greater than that in Chao River Basin (Xinzhuangqiao station) except chloride, dissolved oxygen, permanganate index, nitrate nitrogen and the atomic. It was predicted that annual average surface temperature would increased 1.2℃and 1.65℃in 2020 and 2030 respectively compared with the period of 1961-1990. Meanwhile, average rainfall increased 0.21mm and 0.05mm respectively in summer.(3) In Chaobai River Basin, forest land markedly influenced on monthly runoff by sensitivity analysis, then was farmland, grassland and built up, and water body and unused land was not observed to have clear impact on runoff. In 1980-1989, the contribution rate of land use to runoff change reached 40.7% in Chao River Basin and 6.5% in White River Basin. Moreover, human activities contributed 78.5% and 71.9% to sediment yield change in 1974-1997 and 1998-2007 respectively in Chaobai River Basin. Non-point source pollution accounted for 74%,91% and 73% of total COD, TN and TP output. The output of domestic waste is much larger than that of industrial waste in point source pollution.(4) Channel and Dam projects in Chao River Basin and White River Basin played a key role in reducing runoff in the 1980s, and it contributed 95% and 83% to runoff reduction in the two watershed respectively; however, it did not bring great impact on sediment transport, and the contribution rates were 41% and 40% respectively. Take Channel and Dam projects as research background, SWAT model was used to calculate the effect of land use on runoff change in the two watersheds, the results indicated that the contributions were 42% in Chao River Basin and 24% in White River Basin, correspondingly 40% and 49% to sediment change in the two watersheds. In order to understand the effect of forest on runoff, "clear cutting" method was adopted in Chaobai River Basin and its nest watersheds, and it was found that different forest cover influenced about 60%-70% of runoff reduction.(5) Based on the forecast results of land uses and climatic factors, SWAT model was calibrated and validated in the watershed. The period of 1991-2000 was taken as basal period, and 2001-2010, 2011-2020 and 2021-2030 as evaluation period; It was simulated that the contributions of land uses to runoff changes were 23%,43% and 25% in the three evaluation stages respectively in Chao River Basin, while correspondingly 35%,36% and 23% in Bai River basin; the rest of runoff change may be caused by climate change. It can be concluded that human activities may intensively affect runoff process in 2011-2020.In conclusion, the present study provides some support on the sustainable water resources management and land use optimization through researching the Land-cover/climate changes and their impacts on hydrological processes.更多还原