Evaluating actual evapotranspiration and impacts of groundwater storage change in the North China Plain   总被引：2，自引：0，他引：2       下载免费PDF全文

Guoliang Cao  Dongmei Han  Xianfang Song 《水文研究》2014,28(4):1797-1808

As a critical water discharge term in basin‐scale water balance, accurate estimation of evapotranspiration (ET) is therefore important for sustainable water resources management. The understanding of the relationship between ET and groundwater storage change can improve our knowledge on the hydrological cycle in such regions with intensive agricultural land usage. Since the 1960s, the North China Plain (NCP) has experienced groundwater depletion because of overexploitation of groundwater for agriculture and urban development. Using meteorological data from 23 stations, the complementary relationship areal evapotranspiration model is evaluated against estimates of ET derived from regional water balance in the NCP during the period 1993–2008. The discrepancies between calculated ET and that derived by basin water balance indicate seasonal and interannual variations in model parameters. The monthly actual ET variations during the period from 1960 to 2008 are investigated by the calibrated model and then are used to derive groundwater storage change. The estimated actual ET is positively correlated with precipitation, and the general higher ET than precipitation indicates the contributions of groundwater irrigation to the total water supply. The long term decreasing trend in the actual ET can be explained by declining in precipitation, sunshine duration and wind speed. Over the past ~50 years, the calculated average annual water storage change, represented by the difference between actual ET and precipitation, was approximately 36 mm, or 4.8 km³; and the cumulative groundwater storage depletion was approximately 1700 mm, or 220 km³ in the NCP. The significantly groundwater storage depletion conversely affects the seasonal and interannual variations of ET. Irrigation especially during spring cause a marked increase in seasonal ET, whereas the rapid increasing of agricultural coverage over the NCP reduces the annual ET and is the primary control factor of the strong linear relationship between actual and potential ET. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Analysis of water stable isotopes fingerprinting to inform conservation management: Lake Urema Wetland System,Mozambique     

《Physics and Chemistry of the Earth》2014

The present study focusses on the analysis of water stable isotopes to contribute to understanding the hydrology of the Lake Urema wetland system in central Mozambique towards conservation management.Lake Urema Wetland is located in the Gorongosa National Park at the southernmost extent of the East African Rift System and is situated entirely within the Urema catchment. Of particular concern to the park’s management is the understanding of hydrological processes as these may trigger transformations of ecosystems, habitat losses and wildlife migrations. Concerns over the Lake Urema wetland’s drying up and the trapping of sediments in the floodplain have been raised for some time by conservationists.Water samples were collected for stable water isotope analyses during the wet and the dry seasons for the period 2006–2010 from springs, boreholes, rivers, and Lake Urema. In addition monthly composite precipitation was collected at two rain gauges.The results show that Lake Urema is maintained throughout the dry season merely from water generated during the wet season. It receives water from wet season precipitation and the runoff generated from this precipitation. The water source areas of the lake are the Gorongosa Mountain and the Barue Basement geomorphological units. Consequently, the source of the sediments which have been trapped into the lake and the floodplain has to be identified in these two catchment areas and urgent action is required to rescue the lake. This water body constitutes a groundwater buffer system which supports a unique wetland landscape. The annual inundations’ processes leading to the recharge-drainage cycle in the floodplain are most sensitive to the deposition of sediments, changing hydraulic gradients, and reducing wet season inflows and increasing drainage rates.  相似文献   

Fluctuation of Cadmium Load on a Tide‐Influenced Waterfront Lake in the Middle‐Lower Reaches of the Yangtze River          下载免费PDF全文

Hua Wang  Yiyi Zhou  Yong Pang  Xianmin Wang 《洁净——土壤、空气、水》2014,42(10):1402-1408

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Reply to the comment by F. Gharbi on “Multiple dating of varved sediments from Lake Łazduny,northern Poland: Toward an improved chronology for the last 150 years”     

《Quaternary Geochronology》2014

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黑龙江省三江平原垦区中心城市选择     

李欣  张平宇  李静 《地理科学》2014,34(6):681-686

黑龙江省三江平原垦区是中国耕地规模最大的连片农垦区和第三大区际商品粮供应基地。近年来,随着这一地区工业化和城镇化进程的加快,如何科学的选择和建设区域的中心城市成为该区完善区域城镇体系和推进城镇化进程的紧迫任务和现实课题。基于此,应用改进的引力模型来计算县级单位与农场间的空间联系强度,界定出各县级单位的腹地范围,明确三江平原垦区的中心城市;以各农垦分局为研究单元,研究各农垦分局的碎化程度;通过明确县级单位拥有农场腹地数目,确定各农垦分局的中心城市;结果发现建三江、虎林、富锦、友谊和密山等宜作为三江平原垦区的中心城市;提出通过壮大中心城市的综合实力、推动场县共建和深化对外合作等措施来推动三江平原垦区城镇化进程。  相似文献   

查干湖湿地水环境演变特征分析   总被引：1，自引：0，他引：1  

李然然  章光新  魏晓鸿  刘艳  张蕾  孙爽 《地理科学》2014,34(6):762-768

查干湖湿地是吉林西部重要的生态屏障,分析其水环境演变特征,可为保障其水环境安全提供科学依据。利用1982~2011年的水位资料和1985~2011年的水质资料分析其水环境演变特征,采用卡尔森指数法和模糊综合评价法对查干湖湿地进行综合营养状态和水质状况评价。结果显示引松工程通水后湿地水位得以恢复并稳定在129.8~130.3 m;20世纪80年代末湿地水环境大幅改善,水体盐碱化、富营养化、有机污染得以缓解,但2006年以来水质碱化和有机污染加剧,水质由Ⅲ类演变为IV类。现阶段农田退水缓解了主湖区的碱化且暂未加剧其水体富营养化。查干湖水受流域陆源排放、湖泊内源释放及水文情势等多重因素的交互作用,呈以磷素为限制的中营养状态,应控制区域生活污水和畜禽粪便的污染以保护其水环境健康。  相似文献   

洞庭湖区生态承载力系统耦合协调度时空分异   总被引：11，自引：0，他引：11  

熊建新  陈端吕  彭保发  邓素婷  谢雪梅 《地理科学》2014,34(9):1108-1116

不同时空尺度下,生态承载力系统耦合协调度呈现不同差异和变化。在阐述耦合协调发展作用机理的基础上,构建了耦合协调度评价指标体系,利用容量耦合模型对洞庭湖区生态承载力系统耦合协调度进行时空分析。结果表明：① 时序变化上,2001~2012年洞庭湖区生态承载力系统耦合度和耦合协调度变化趋势基本趋同,大致呈现同步稳定上升态势,耦合度均值达0.499,处于拮抗阶段;耦合协调度均值达0.463,处于中度耦合协调阶段;年均增长率上,耦合度达3.35%,大于耦合协调度的3.05%。表明生态承载力内部系统耦合作用和协同效应明显,并且耦合作用的强度大于内部协调性。② 空间分异上,17个县域的耦合度出现了低水平耦合、拮抗阶段和磨合阶段3种状态,3种耦合状态的县域个数和区间变化呈现不同的差异。耦合协调度出现了低度耦合协调、中度耦合协调和高度耦合协调3种状态,其变化状况基本上与耦合度类似,但从协调状态的县域个数和区间变化来看,耦合协调度的变化稍滞后于耦合度的变化,空间分布与耦合度分布特征基本相似,高、低值区的空间分布由西南向东北大致呈现较低-高-低-高-较低的“M”型基本格局。③ 空间组合上,17个县域出现了低耦合低协调区、中耦合低协调区、中耦合中协调区、高耦合中协调区和高耦合高协调区5种空间组合类型,其基本空间格局是,低耦合低协调区集中分布在洞庭湖区中部和西南部,高耦合高协调区则沿京广线、石长线和常岳高速三线呈“三足鼎立”布局,其它不同组合类型则集中于高耦合高协调区外围呈“零星状”分布。  相似文献   

三江平原垦区基础设施建设对区域城镇化的影响     

谭俊涛  张平宇  李静 《地理研究》2014,33(3):501-508

通过构建三江平原垦区基础设施和城镇化评价指标体系,运用主成分分析法,建立垦区基础设施评价函数和城镇化评价函数,分析了垦区的基础设施和城镇化发展现状。结果显示,垦区的基础设施水平和城镇化水平自2000年起呈现波动上升趋势,并且二者的协调性不断提高,最终围绕平衡状态上下波动。为检验垦区基础设施建设对城镇化的影响,将研究区域划分为基础设施建设超前型和滞后型,并对两组样本的基础设施水平和城镇化水平进行回归分析,发现垦区的基础设施对城镇化有较大的推动作用,并且基础设施超前型区域的推动效果更强。最后从基础设施建设的角度提出促进三江平原垦区城镇化发展的具体对策。  相似文献   

洞庭湖周边地区第四纪红土粒度特征及环境意义   总被引：4，自引：1，他引：3  

朱丽东  谷喜吉  叶玮  李凤全  金莉丹  陈渠  詹文娟  刘名瑜 《地理科学进展》2014,33(1):13-22

第四纪风成红土广泛分布于中国南方,与北方的黄土同为反映第四纪古环境的重要载体。基于洞庭湖周边地区10 处剖面122 个红土样品的粒度分析,对该区红土沉积特征及其反映的环境意义进行探讨。结果显示：①样品均以粉砂（4~63 μm）为优势粒级,其次为粘粒（<4 μm）,砂含量很少,并富集“风尘基本粒级”（10~50 μm）,含量达33.23%~42.23%,粒度特征与典型的黄土、下蜀黄土、加积型红土样品相似,显著不同于湘潭洪冲积红土,也区别于本区砂岩风化壳红土,表明洞庭湖西、南、东缘丘陵岗地存在风成堆积成因的中亚热带风成加积型红土。② 黄棕色土、网纹黄棕色土、均质红土、网纹红土等4 类样品的粘粒含量由高到低的排序是网纹红土 >均质红土 >网纹黄棕色土>黄棕色土;粉砂含量由高到低的排序正好相反。结合粒度参数推测,黄棕色土发育时期,沉积作用增强,粒度变粗,分选性较好;网纹红土发育时期,沉积作用较弱,风化成壤作用强,细颗粒含量增多,分选性相对较差。这可能反映了洞庭湖地区中更新世至晚更新世冬季风加强,风化减弱的气候变化过程。③ 沿冬季风主导风向（偏北风）,洞庭湖周边地区红土的M_φ、Md值（φ值）自北向南增大（变细）,风成组分（10~63 μm）百分含量随之减少,<2 μm组分百分含量自北向南略有增加。这种趋势提供了组成该地区加积型红土的粉尘由偏北向南传输的风成证据和母质风化程度向南增强的环境信息。  相似文献   

下辽河平原浅层地下水环境风险评价及空间关联特征     

孙才志  朱静 《地理科学进展》2014,33(2):270-279

以下辽河平原浅层地下水为研究对象,将自然灾害风险理论引入地下水环境风险评价,从脆弱性、功能性、胁迫性、适应性4个方面选取指标,构建地下水环境风险评价指标体系和模型。运用GIS空间分析方法对地下水环境风险进行评价,并对风险值进行空间关联特征研究。结果表明：① 研究区内地下水环境中度以上风险区占整个研究区面积的63.12%,其中高风险区占6.79%,较高风险区占18.96%,中等风险区占37.37%;较低风险区占21.98%,低风险区占14.90%。② 地下水环境风险最高的地区主要位于下辽河平原中部的新民市东北部、灯塔市、辽中县西部、黑山县部分地区及凌海市东南部。③ 研究区内地下水环境风险呈现较高的正相关性,相似性高的区域主要分布在中东和中西部风险高值区,以及东北和东南部风险低值区。研究成果丰富了地下水环境风险理论,对下辽河平原地下水环境保护实践具有一定的理论和实践意义。  相似文献