塔里木河下游断流河道最小生态流量研究

以塔里木河下游断流河道作为研究区域,进行河道最小生态流量的研究．根据第五次和第六次应急输水过程获得的河道内3个控制断面的几何形态特征数据,选择湿周法中的曲率法推求河道最小生态流量,以及此流量对应的水面宽、平均水深和平均流速等指标．结果显示,英苏、阿拉干和依干布及麻断面所在河道的最小生态流量分别为2．85,3．76和1．76m^3·S^-1,分别占推算的多年平均流量的9．7％,14．0％和6．9％．在排除塔里木河流域的枯水期后,求得不考虑蒸发和渗漏条件下的河道年生态需水量为0．79×10^8m^3。采用多种方法对计算结果进行验证分析认为,研究结果符合实际情况,可以作为塔里木河下游水资源调配的依据．     

塔里木河下游输水后地下水动态变化及天然植被的生态响应

通过总结自2000年开始的对塔里木河下游生态输水后的地下水和天然植被的详细调查资料,从输水后地下水的时空变化和天然植被对地下水动态变化的响应差异上展开了针对性的分析,结果显示:生态输水后塔里木河下游沿河一定区域的地下水受输水影响出现了明显的响应,其抬升和回落存在着明显的时空差异,而正是这种水位的时空差异导致了地表植被在时间和空间响应上的明显不同;在空间上表现为从上到下的差异和距河由近而远的差异,从时间上表现为随输水持续时间的增长而响应的越来越明显的特点．同时,根据输水后地下水和植被响应的关系以及输水对塔里木河下游天然植被的保护和恢复进行了讨论,目的是为塔里木河流域的生态治理工程提供植被保护和恢复的理论依据,同时为其他地区开展类似的生态工程提供可供参考的科学依据．     

塔里木河下游生态输水对当地经济影响实证研究

文章采用随机抽样问卷调查、入户访问和统计资料相结合方法,塔里木河对下游输水后农牧民经济收入和当地经济变化进行研究。调查结果表明：90％以上的被调查者赞同生态输水带来了明显的经济利益,至少76％的农户家庭收入在输水后得到不同程度的增加,农牧民家庭收入增加更显著。随着输水后放牧数量增加193％,平均家庭收入相应增加了近2倍,人均收入提高了181％;96％的居民认为地方经济发展与生态输水有关。输水后两团场农林牧渔业生产年平均产值提高了141％,实际播种面积也增加18％。问卷调查的民意结果充分说明生态输水在改善生态环境的同时,给当地农牧民带来了可观的经济收入,并在一定程度上促进了当地经济的发展,突现出塔里木河下游生态输水的社会经济效益。     

新疆塔里木河下游河道生态输水对植被生理的影响研究

通过对2000～2002年塔里木河下游生态输水过程中地下水位变化的动态监测和24个样地的胡杨、柽柳、芦苇等主要植物叶片的脯氨酸(PRO),超氧化物歧化酶(SOD)和过氧化物酶(POD)等生理指标的测试分析,探讨了塔里木河下游断流河道输水后地下水位抬升变化以及地表植被的生理响应过程. 监测研究表明,随着塔里木河下游生态输水工程的实施,河道附近地下水位呈逐级抬升过程, 由输水前的5～8?m抬升至2.5～5?m;塔里木河下游天然植物的生长与地下水位变化有着密切的关系,随着地下水位的抬升,植被生长状况得到改善,胡杨、柽柳、芦苇等植物的各生理指标对地下水位变化响应敏感,对不同地下水位条件下植物的PRO累积过程、POD和SOD酶活性的变化分析推测,芦苇、柽柳、胡杨的胁迫地下水位分别为 3.5,5和4.5?m.     

塔里木河下游数字地下水埋深模型的构建

根据数字地面模型的概念,利用航空拍摄的地面高程数据和地下水观测孔观测得到的地下水水位数据,建立了塔里木河下游地区的数字高程模型和数字地下水水位模型,并在这两个数字模型的基础上得到了塔里木河下游的数字地下水埋深模型．从数字地下水埋深模型获得的地下水埋深分布状况可知,地下水埋深大于10m的面积占统计面积的65％．     

塔里木河下游输水条件下浅层地下水化学特征变化与合理生态水位探讨

结合2000—2005年塔里木河下游间歇性输水过程中地下水化学与地下水位变化的监测资料的分析发现：地下水化学特征对间歇性生态输水的响应表现出明显的阶段性；在地下水化学特征对输水响应的不同阶段，地下水化矿化度和主要离子含量的变化量与采样点距输水河道距离有较强相关性，而地下水埋深的变化是地下水化学特征阶段性变化的直接影响因素；地下水埋深在5m左右时主要离子含量和矿化度最小，水质状况最佳，植被盖度远大于荒漠化临界盖度.在该埋深条件下既能满足生态恢复的需要，又能避免水分的过度蒸发浪费.因此间歇性生态输水条件下，能维持较好水质并抑制荒漠化发展的合理生态水位为5m.     

生态输水工程对塔里木河中下游地区地下水循环特征的影响

利用环境同位素技术结合水化学特征,对塔里木河中下游地区生态输水影响下地下水循环规律进行监测分析。结果显示:塔里木河中下游各断面地下水p H值变化不大,矿化度和各离子差异明显,地下水水样以Na+、Cl+占绝对优势;矿化度较低的断面其离子浓度变化较小,反之,矿化度高的断面其离子浓度变化幅度较大;塔里木河中游δ2H和δ18O变化趋势基本一致,随着距河道距离的增大,δ18O的值呈增大趋势,下游H、O同位素变化波动较大,下游各样点距河道最近处(即50m处)H、O同位素最小,随着距河道距离的增大,H、O同位素亦呈增大趋势变化;塔里木河中下游地下水、地表水中δ2H和δ18O之间均呈明显的线性关系,中游地表水补给是地下水的主要来源;下游地下水中H、O同位素则普遍高于地表水,说明水体受到严重的蒸发作用,导致同位素富集外,也说明存在地下水对河水的补给。     

塔里木河流域下游绿洲演变对生态输水的响应

参考前人对绿洲的定义和分类方法,对塔里木河下游人工绿洲、天然绿洲进行提取,分析生态输水前后人工绿洲和天然绿洲的面积变化特征、转化过程、重心迁移情况以及扩张与退缩的空间变化。结果表明:1990—2015年,塔里木河下游绿洲总面积先下降、后上升,人工绿洲不断扩张,10 a平均增长量为46.78 km~2,天然绿洲面积不断缩减,在2000年后有所上升。生态输水前(1990—2000年),塔里木河下游来水量减少,导致大面积草地退化,天然绿洲面积减少;生态输水后(2000—2015年),部分未利用土地得到了利用,变成河渠、水库、湖泊、灌木林和高覆盖度草地,塔里木河下游生态有所恢复。下游绿洲重心先往西北,再往南方,最后又往东南方向迁移。绿洲主要向西北和东南方向扩张,1990—2000年的扩张区域主要集中于英苏上游区域;2000—2010年期间,台特玛湖地区绿洲面积增加明显;绿洲缩减区域分布广而零星。     

不同水分处理对激活土壤种子库的影响——以塔里木河下游为例

萌发法是目前国内外研究土壤种子库恢复潜力时普遍采用的方法.但以往的研究往往是在实验室内同一水分处理下进行.而同一水分条件很难满足所有种子在水分需求上处于最佳状态,并且种子在实验室萌发与自然环境中具有很大的差异.针对该方法的不足之处,采用不同水分处理在野外进行了激活土壤种子库实验.研究结果表明:(1) 随着供给水量的减少,土壤种子库萌出的幼苗种类和数量逐渐降低,但个别物种最高出苗率并不在土壤含水量最高的水分处.(2) 不同的物种具有不同的萌发特征.在萌发速度上,不同物种表现为速萌型和迟缓型;各物种均存在各自的萌发高峰期,随着水分供给量减少,各物种萌发高峰期向后推迟了2—3d.因此,水分选择对于萌发实验至关重要,研究种子库特征和针对某一物种开展研究时,在水分选择上应区别对待;对于塔里木河下游土壤种子库的研究,理论上土壤含水量介于23%—28%最宜;在萌发高峰期(自浇水日9—15d)应加强对幼苗的保育.     

地下水污染模型的特征有限元解法──以佳木斯为例

特征有限元法是求解对流─弥散方程的一种有效方法，特别是将该法用于求解对流项占优的溶质运移问题时，其优越性尤为突出，解决了使用其它数值方法求解时所不可避免的数值弥散问题。本文首先介绍了这种方法的基本原理，提出了特征有限元法求解时确定运动质点所属单元的方法，随后以佳木斯地区为例，介绍了这一方法在求解地下水污染问题时的具体运用。     

Analysis on water potential of Populus euphratica oliv and its meaning in the lower reaches of Tarim River, Xinjiang

Combined with materials measured on leaves water potential of Populus euphratica ofiv in the process of ecological water delivery in the lower reaches of Tarim River, the influence of ground-water depths and soil salinity on leaves water potential of P. euphratica was analyzed. We found that there was evident negative correlation between the leaves water potential of P. euphratica and ground-water depths. The deeper the ground-water depths were, the lower the leaves water potential of P. euphratica was, the more serious drought stress P. euphratica suffered from. Besides, there was evident negative correlation between the soil salinity and the leaves water potential of P. euphratica. The bigger the soil salinity was, the lower the leaves water potential of P. euphratica was, the more serious drought stress was indicated from which P. euphratica suffered. For sections rather distant for Daxihaizi Reservoir as well as for those places of wells rather distant from the river course, ground-water depths and the soil salinity were high; the leaves water potential of P. euphratica was low. The leaves water potential of P. euphratica can reflect the degree at which P. euphratica suffers from drought and salt stress, and has an important reference meaning in analyzing proper ground-water depths for the survival and growth of P. euphratic in the lower reaches of Tarim River.     

Analysis on water potential of Populus euphratica oliv and its meaning in the lower reaches of Tarim River,Xinjiang

Combined with materials measured on leaves water potential of Populus euphratica oliv in the process of ecological water delivery in the lower reaches of Tarim River, the influence of ground-water depths and soil salinity on leaves water potential of P. euphratica was analyzed. We found that there was evident negative correlation between the leaves water potential of P. euphratica and ground-water depths. The deeper the ground-water depths were, the lower the leaves water potential of P. euphratica was, the more serious drought stress P. euphratica suffered from. Besides, there was evident negative correlation between the soil salinity and the leaves water potential of P. euphratica. The bigger the soil salinity was, the lower the leaves water potential of P euphratica was, the more serious drought stress was indicated from which P. euphratica suffered. For sections rather distant for Daxihaizi Reservoir as well as for those places of wells rather distant from the river course, ground-water depths and the soil salinity were high; the leaves water potential of P. euphratica was low. The leaves water potential of P. euphratica can reflect the degree at which P. euphratica suffers from drought and salt stress, and has an important reference meaning in analyzing proper ground-water depths for the survival and growth of P. euphratic in the lower reaches of Tarim River.     

西安市渭滨傍河水源地地下水质变化预测

西安市渭滨水源地位于渭河南岸,属于傍河集中地下水源地,开采量约为９８１００ｍ＾３／ｄ。目前,渭河水已受污染,但渭滨水源地地下水潜水未受污染,承压水质良好。运用地下水污染物数值模型对未来地下水质进行了预测,结果表明,当可水为三类水时,到２０１０年渭滨水源地地下水质仍符合饮用水质标准。但从长远来看,保护该水源地的关键是治理渭河水污染。     

Corridor effect of the spatial changes of landscape patterns in arid areas:A case study of the river corridor areas in the middle and lower reaches of Tarim River

The river corridor areas in the middle and lower reaches of the Tarim River are dominated by the traditional green corridors along the river section from the Qara Reservoir in Yuli County to the Taitema Lake in Ruoqiang County, which plays an important role in the social and economic development in the Tarim River Watershed with a extremely significant ecological functions. The buffer zones perpendicular to the watercourse were defined along both riversides at a 5-km interval beginning from the watercourse (10 km wider) using the method of the buffer zone analysis. The landscape pattern indexes of each buffer zone were calculated, and the indexes of the main landscape patterns were analyzed so as to reveal the radiative effect and the characteristics of the river corridors on landscape and patch levels. The results show that the radiative width is generally 30 km in the study area, and can be up to 50-70 km in sub- region FG1 because the study area is located in two drainage basins, with an ecological interstitial zone between them. The landscapes of woodlands and wetlands are generally distributed within the 10 km buffer zone (it means that the buffer zone is 5 km away from the watercourse; the same hereafter) along both riversides. Moreover, the closer the buffer zone is to the watercourse, the higher the patch density and the largest patch index are. In the ecological and environmental regeneration for the study area, the extent of ecological effect of the river corridors must be fully considered, and the projects must be scientifically and rationally planned and designed.     

长江上游主要河流鱼类多样性与流域特征关系

对长江上游12 条主要河流鱼类种类数与流域特征进行了回归分析和主成分分析. 相关回归分析结果显示: 特有种类数目与全部种类数目呈极显著正相关; 全部种类数目的绝对数与流域面积、干流长度、流量呈显著或极显著正相关, 与比降呈显著负相关; 单位流域面积( 或单位干流长度) 全部种类数与干流长度( 或流域面积) 、流量呈显著或极显著的负相关, 与比降、径流深呈极显著正相关; 特有种类数目的绝对数与流域面积、干流长度、流量呈显著或极显著正相关; 单位流域面积特有种类数与干流长度、流量呈显著或极显著负相关, 与比降、径流深呈极显著正相关; 单位干流长度特有种类数与流域面积呈显著负相关, 与比降、径流深呈极显著正相关. 主成分分析得到的第一和第二主成分分别综合反映了河流鱼类的相对种类数和绝对种类数与流域特征因子之间的关系.     

Assessment of waterrecharging based on ecological features of riparian forest in the lower reaches of Tarim River

The occurrence and development of riparian forests which are mainly dominated by mesophytes species relate closely with surface water. Since there is no water discharge to the lower reaches of Tarim River in past 5 decade years, the riparian forests degrade severely. Based on the analyses of the monitored data of Yingsu, Argan and Luobuzhuang in 2002 and 2003, the effect of water-recharging is discussed. The water-recharging project neglects the fact that that it is flooding that controls the process of Populus euphratica colonizing on the bare surface, but focuses on groundwater influence on vegetation. The flooding control deviates Inherent laws of riparian forests development, so the natural regeneration of riparian forests is checked. The response scope of riparian plants on groundwater uplift is extremely narrow, and most riparian communities have not been optimized. No seedlings of dominant species are found in flooding areas because their physio-ecological characteristics are ignored. The vegetation changes in vicinities of stream only reflect the demand of mesophytes species on the shallow groundwater, however, the water-recharging fails to provide suitable habitats for the seedlings establishment of riparian plants. The present water-recharging scheme is difficult to realize vegetation restoration.     

Assessment of water-recharging based on ecological features of riparian forest in the lower reaches of Tarim River

The occurrence and development of riparian forests which are mainly dominated by mesophytes species relate closely with surface water. Since there is no water discharge to the lower reaches of Tarim River in past 5 decade years, the riparian forests degrade severely. Based on the analyses of the monitored data of Yingsu, Argan and Luobuzhuang in 2002 and 2003, the effect of water-recharging is discussed. The water-recharging project neglects the fact that that it is flooding that controls the process of Populus euphratica colonizing on the bare surface, but focuses on groundwater influence on vegetation. The flooding control deviates Inherent laws of riparian forests development, so the natural regeneration of riparian forests is checked. The response scope of riparian plants on groundwater uplift is extremely narrow, and most riparian communities have not been optimized. No seedlings of dominant species are found in flooding areas because their physio-ecological characteristics are ignored. The vegetation changes in vicinities of stream only reflect the demand of mesophytes species on the shallow groundwater, however, the water-recharging fails to provide suitable habitats for the seedlings establishment of riparian plants. The present water-recharging scheme is difficult to realize vegetation restoration.     

盐旱胁迫对塔里木河下游三种植物幼苗根系解剖结构的影响

文章以塔里木河下游荒漠环境中三种豆科植物的幼苗为研究对象,观测盐旱胁迫对铃铛刺、疏叶骆驼刺、胀果甘草生长的影响,并采用石蜡切片法观察了盐旱胁迫后幼苗根解剖结构的变化。结果表明：盐旱胁迫下3种豆科植物的株高呈递减变化,根解剖结构中皮层厚度变薄、维管柱变厚。综合评价3种豆科植物的耐盐抗旱能力：甘草＞铃铛刺＞骆驼刺。作为塔里木下游荒漠植物优势种,可为塔里木河下游生态恢复植物耐盐抗旱能力的研究提供理论基础。     

塔里木河下游胡杨径向生长与水文的响应

借助树木水文学的方法,文章以对塔里木河下游主要建群植物胡杨年轮的生长量变化进行深入分析。结果显示：（1）塔里木河下游生态输水后,胡杨样枝年轮生长量变化明显,说明输水对胡杨生长量的影响是显著的和积极的;并表现出明显的时空动态变化规律;（3）胡杨样枝的中部和底部年轮径向生长量之间的相关性显著,主枝顶部和侧枝顶部以及主枝中部和侧枝中部之间的相关性显著;（4）随着输水时间的延续,样枝胡杨主枝和侧枝径向生长量呈上升趋势;而且胡杨样枝不同部位径向生长量年际变化规律呈上升趋势,这充分说明塔里木河下游实施的生态输水工程对胡杨生长量的影响是显著的和积极的。