土地覆被和气候变化对拉萨河流域径流量的影响

以拉萨水文站上游流域为研究对象,利用分布式水文模型SWAT对拉萨河流域水文过程进行模拟,分别用1995～2000和2003～2006年两个时间段的实测数据对模型进行校准和验证。结果显示月径流模拟相关系数和模拟效率系数分别为0.88和0.84。在此基础上通过建立情景模拟,探讨拉萨河流域气候波动和土地覆被变化对径流产流量的影响。结果表明:气候变化对年径流量影响显著,在各种模拟假设情景中最多可以使径流量增加89%。土地覆被变化相对于气候变化对径流量的年际影响较弱,但对径流量的季节变化影响显著。     

东江流域土地覆被变化的水文响应模拟研究

采用近年来快速发展的水文模型模拟手段,应用HSPF模型模拟东江流域不同下垫面条件下的径流影响变化情况,定量地评估了东江流域土地覆被变化对径流深、年内径流分配的影响。结果表明,随着流域内城镇化进程的加快,流域调蓄能力下降,因而产流能力增强;从年内分配的情况来看,汛期影响最为明显,这显然与土地利用变化影响到流域调蓄能力有关。     

土地利用/土地覆被变化的水文效应模拟

通过SWAT模型数据库的建立、参数敏感性分析、率定、验证,模拟了泾河流域1992—2001年的月流量过程,并将构建的5种不同土地利用/土地覆被情景分别输入SWAT模型,模拟土地利用/土地覆被变化的水文效应。结果表明:随着草地和林地面积的增加,年均流量减小;地表裸露无植被时,年均流量比模拟期增大20.36%;地表全部为林地草地时,年均流量比模拟期减小7.68%;退耕还林和土地进一步退化时,年均流量均有所增大,但增幅不大。     

拉萨河流域径流对土地利用和气候变化的响应分析

拉萨河流域处青藏高原中南部,因其独特的地理位置是对气候变化较为敏感的区域之一,同时也是青藏高原人口和耕地较为密集区域.在建立SWAT模型对拉萨河流域水循环过程进行模拟的基础上,通过设置不同气候情景与土地利用状况,分析近30 a来拉萨河流域径流变化的成因,并研究径流对气候因子变化的敏感性.结果表明:①气候变化与土地利用对...     

基于SWAT模型的秦淮河流域气候变化水文响应研究

为了解气候变化对水文水资源的影响机理,以秦淮河流域为研究区构建SWAT模型,使用SWAT-CUP对模型进行参数敏感性分析、率定及验证,并采用任意假设法设计未来气候情景,分析温度及降雨变化对流域径流及实际蒸散发量的影响。结果表明:模型在月径流模拟中具有较高的精度,适用于秦淮河流域气候变化下的水文响应研究;气温降低或降雨量上升都会引起流域径流量增加,反之则减少;实际蒸散发量与降雨量正相关,而实际蒸散发量对气温变化的响应不明显;平水年径流量对降雨量变化的响应较强,枯水年径流量对温度变化的响应较强;枯水年实际蒸散发量对降雨量变化的响应较强。     

气候变化对北江流域径流影响的模拟研究

通过构建北江流域SWAT分布式水文模型,以北江流域13个雨量站10年逐月降水量及北江流域干流石角水文站同步逐月流量数据为输入条件进行水文模型参数率定,应用气候情景设置方法研究了北江流域在降水和气温等不同气候变化条件下径流量的变化规律。研究表明:气温变化1℃对年径流量及其年内分配的影响变化均在1%以内。降水量变化对年径流量影响十分显著,降水量变化10%对年径流量的影响变化可达到15%,而对径流年内分配的影响变化在1%以内,影响较小。随着气温下降和降水量的增加,枯季径流量占年内分配比例均有所上升,枯水期来水量提高,有利于流域城乡供水安全和生态用水安全。     

基于SWAT模型的诺敏河流域径流对土地利用/覆被变化的响应模拟研究

土地利用/覆被变化直接反映了人类活动的影响程度,对于流域水文循环过程影响显著。本文以诺敏河流域为研究区,基于1976和2000年两期土地利用数据,结合SWAT模型定量评价了径流对土地利用/覆被变化的响应。研究结果表明:SWAT模型可以较好地模拟诺敏河流域的月径流变化过程,在研究区具有一定的适用性;相对于1976年的土地利用条件,2000年土地利用变化主要表现为林地和草地面积减小,耕地面积增加。1976-2000年间诺敏河流域土地利用变化导致年均地表径流增加了17.78%,且空间差异显著,尤其是下游的莫力达瓦达斡尔族自治旗和阿荣旗等地地表径流增加趋势更为明显,增加幅度超过20 mm。模拟研究对于诺敏河流域合理规划土地利用格局具有重要意义。     

长江上游及清江流域土地覆被变化分析

随着长江上游电站及清江流域电站开工、投产发电,其控制的流域成为重要敏感性区域。利用国家基础地理信息中心于2014年研制的2000,2010 年两期30 m分辨率土地覆被数据产品GlobeLand30,对2000~2010年长江上游及清江流域土地覆被的空间分布格局、变化幅度、区域差异及主要土地覆被类型的变化原因进行了综合分析。研究发现,总体上2010年较2000年,长江上游及清江流域耕地、森林变化率较低,分别为-0.09%,0.31%;冰川及永久积雪、人造地表、湿地、水体变化率较高,分别为-7.25%,22.9%,10.60%,2.87%。分析结果客观反映了气候变暖、城市扩张、水电站建设等活动对流域的影响,可为长江上游及清江流域调查、生态评价提供依据。     

SWAT模型在流域LUCC水文效应研究中的应用

土地利用/覆被变化（LUCC）的水文效应是GLP研究的热点。分布式水文模型SWAT是目前被广泛应用于LUCC水文效应研究的水文模型之一。论文首先概述了SWAT模型的发展历程和最新版本SWAT 2005的功能,其次就模型在不同土地覆被条件下水文效应应用中的几个方面进行了总结和分析：流域径流模拟,区域水量平衡分析和非点源污染的模拟及其对BMP评价研究的贡献。最后,归纳探讨模型应用中存在的一些问题,通过合理的情境设计以及关键参数的实测等方法,可以实现模型在流域LUCC水文效应研究中的高效应用。     

南水北调中线工程水源区水文循环过程对气候变化的响应

以南水北调中线工程水源区为研究流域,基于数字高程模型、土地利用和土壤类型等资料,采用1980—1990年日资料进行模型参数率定和检验,研究了SWAT模型在该流域的适用性;根据联合国政府间气候变化专业委员会第四次评估报告中大气环流模型多模式输出结果,分析了特别排放情景下21世纪降水、气温、径流、蒸发的响应过程。结果表明:与基准期相比,南水北调中线工程水源区21世纪气温将持续增高,年降水量将增加,径流量较基准期将出现先减少后增大的趋势,21世纪40年代年径流量开始较基准期增加,预示着水源区的水资源在21世纪前期将出现减少,21世纪中后期将增加。未来气候变化对南水北调中线工程水源区径流变化影响不大,总体来看有利于南水北调中线工程的调水。     

黄河三角洲湿地蒸发蒸腾及其对土地利用/覆被变化的响应特征研究

以黄河三角洲为研究区,基于1986年6月5日和2009年6月4日的Landsat TM影像进行土地利用/覆被分类及变化特征研究,同时,基于SEBAL模型估算区域蒸发蒸腾量,进而分析湿地蒸发蒸腾的数量特征、空间格局特征及其对土地利用/覆被变化的响应特征。结果表明:23年间,58.74%的区域土地利用/覆盖类型发生了变化,未利用地大幅减少,水体和建设用地大幅增加,显著的土地垦殖与耕地荒废则同时存在;蒸发蒸腾强度大小按土地利用/覆被类型排序依次为水体>滩涂>苇地>林草地>耕地>建设用地>未利用地,研究区未利用土地变为水体和耕地是导致区域蒸发蒸腾整体提高的主导原因,而耕地流失则是导致区域蒸发蒸腾整体下降的主要原因,但23年间实际变化以前一种情形占优势,因而区域蒸发蒸腾总体呈现为增加趋势。研究结果对区域土地利用规划和水资源管理有重要的理论和实践指导意义。     

Modelling Impacts of Land Cover Change on Critical Water Resources in the Motueka River Catchment, New Zealand

After the SWAT (Soil and Water Assessment Tool) model was calibrated and validated to historic flow records for the current land use conditions, two additional land cover scenarios (a prehistoric land cover and a potential maximum plantation pine cover) were used to evaluate the impacts of land cover change on total water yields, groundwater flow, and quick flow in the Motueka River catchment, New Zealand. Low-flow characteristics and their potential impacts on availability for water abstraction and for support of in-stream habitat values were focused on. The results showed that the annual total water yields, quick flow and baseflow decreased moderately in the two scenarios when compared with the current actual land use. The annual water balance for the pine potential land cover scenario did not differ substantially from the prehistoric scenario for the catchment as whole. However, there were more notable differences among individual tributary catchments, which could be attributed to the relative area of land cover altered and location of those catchments. Simulated low flows for the prehistoric and potential pine land cover scenarios were both significantly lower than the low flows for the current land use. In summary, under the current land use conditions, both annual water yield and low flow are higher than was the case before human intervention in the area or in a maximum commercial reforestation scenario.     

The effects of climate change on the water resources of the Geumho River Basin,Republic of Korea

Assessments of the variation and vulnerability of water resources due to climate change are essential for future planning in agriculture. In this study, the impacts and uncertainty associated with climate change on water resources in the Geumho River Basin were measured based on the relative change in the mean annual runoff and the aridity index. Statistically adjusted and downscaled multi-ensemble General Circulation Model (GCM) predicted rainfall and temperature data for three representative concentration pathways (RCPs) (RCP2.6, 4.5 and 8.5) were applied to two lumped parameter conceptual rainfall runoff models. The results revealed considerable uncertainty in the projected temperature, rainfall, potential evapotranspiration (PET), runoff and aridity index (AI). Additionally, temperature and rainfall were predicted to increase significantly in the future. The PET was projected to increase by a mean (range) of 9% (7–12%), 18% (9–30%) and 25% (8–49%), while the mean annual runoff was projected to change by a mean (range) of 1% (−33 to 40%), −9% (−47 to 27%) and −4% (−44 to 35%), in the 2030s, 2060s and 2090s, respectively. The AI was projected to decrease in the future, particularly for the RCP8.5. Overall, the results of this study indicate that climate change will most likely lead to lower water resource levels than are currently present in the Geumho River Basin.     

Forecasting impacts of climate change on Great Lakes surface water temperatures

Temperature influences the rates of many ecosystem processes. A number of recent studies have found evidence of systematic increases in Great Lakes surface water temperatures. Our study aims to construct empirical relationships between surface water temperatures and local air temperatures that can be used to estimate future water temperatures using future air temperatures generated by global climate models. Remotely sensed data were used to model lake-wide average surface water temperature patterns during the open-water period in Lakes Superior, Huron, Erie, and Ontario. Surface water temperatures typically exhibit linear warming through the spring, form a plateau in mid-summer and then exhibit linear cooling in fall. Lake-specific warming and cooling rates vary little from year to year while plateau values vary substantially across years. These findings were used to construct a set of lake-specific empirical models linking surface water temperatures to local air temperatures for the period 1995–2006. Hindcasted whole-lake water temperatures from these models compare favourably to independently collected offshore water temperatures for the period 1968–2002. Relationships linking offshore water temperatures to inshore water temperatures at specific sites are also described. Predictions of future climates generated by the Canadian Global Climate Model Version 2 (CGCM2) under two future greenhouse gas emission scenarios are used to scope future Great Lakes surface water temperatures: substantial increases are expected, along with increases in the duration of summer stratification.     

Impact of land use land cover change on a sand dune ecosystem in Northwest Beach,Point Pelee National Park,Canada

This paper analyses Land use land cover (LULC) change in the Northwest (NW) Beach, Point Pelee National Park (PPNP) to understand its effect on sediment transport dynamics for sand dune restoration. Due to development of infrastructure, beginning in the 1960s, sand dunes were completely removed from parts of NW beach. Spatial-temporal changes for LULC were assessed using aerial photos and images for 1959, 1977, 2006 and 2015. Based on the Ecological Land Classification System (Southern Ontario), object based image analysis and feature extraction methods were used to generate classified maps. The photos were the highest quality available in the Parks Canada, PPNP archive. LULC classes included Shoreline Vegetation, Deciduous Thicket, Sand Barren and Dune Type, and Infrastructure. Aerial photographs of LULC change for 1959–1977 and South Western Ontario Orthoimagery Project (SWOOP) images for 2006–2015 were analysed. A large gap exists between 1977 and 2006 as no images were available for that time period. Results indicated a significant increase in the Deciduous Thicket in 2015, acting as a barrier for sand movement to the parking lots. Decrease in the Shoreline Vegetation Type along with an increase in the lake level indicate a decrease in beach width and supply area for sediment transport. Based on the analysis, active management through the removal of cottonwood trees, and policy changes are recommended for dune restoration in Point Pelee. Accuracy assessment of the 2015 classification using an error matrix resulted in an overall accuracy for the LULC classification of 88%.     

塔里木河下游土地利用/覆被变化对生态输水的响应

以2000—2015年的遥感影像资料和生态输水数据为基础数据源,利用ENVI和GIS数据分析处理工具,基于时间轨迹分析方法研究塔里木河下游土地利用/覆被变化(LUCC)对生态输水的响应。结果表明:2000—2015年的16次、1 670 d间歇性生态输水,使林地和草地分别增加了823个和1 347个像元,耕地、湿地和人工用地分别减少了1 422个、736个和222个像元,其他用地增加了210个像元;植被面积总体上呈扩大趋势,2015年较2000年净增植被面积382.85 km²,人工表面增加356.10 km²;戈壁、裸土、沙漠等其他用地面积共计减少了738.95 km²;土地利用变化主要发生在塔里木河下游两岸的河水漫溢、滞留区,呈现出破碎化、不规则化和复杂化的趋势。     

泾河流域土地利用/覆被变化对径流情势的影响

通过建立泾河流域SWAT分布式水文模型,重点模拟分析了河流径流情势对土地利用/覆被变化的响应,对比了不同气候条件及人类活动综合影响下研究区水文过程的变化。结果表明:1996年以前土地利用/覆被变化是影响水文过程的主要人类活动影响源,径流量年际变化平稳,属有小幅增加的正偏;年内影响以枯水季节为主,年内分配更趋均匀,径流集中度降低,集中期略有滞后,且趋于平稳;土地利用/覆被变化导致流域蒸散发量、冠层和落叶层截留量减小,入渗量增加,河川基流量和地表径流量相应增大,并在时域上耦合形成了水文过程的新变化;1996年以后,气候条件驱动下泾河年径流量呈现明显的增大趋势,人类活动亦从以土地利用/覆被变化为主转变为以人类水事活动为主的综合影响模式,且人类水事活动超过气候变化和土地利用/覆被变化成为影响水文过程变化的主因。     

Spatio-temporal effect of climate and land-use change on water balance of the Ganga river basin

The assessment of climate and land-use transformations upon the hydrologic response is crucial for decision-makers to accomplish various adaptation strategies. The Regional Climate Models (RCMs) have been extensively employed to study the impact of climate change on various hydrologic components. However, these climate models are subjected to a large number of uncertainties, which demands a careful selection of an appropriate climate model. To rationalize such uncertainties and select suitable models, a multi-criteria ranking technique has been employed. Ranking of RCMs has been done on its capability to simulate hydrologic components, i.e., simulations of the surface runoff by employing Soil Water Assessment Tool (SWAT), exercising Entropy, and PROMETHEE-2 approach. The spatial extent of changes in the hydrologic components is examined over the Ganga river basin, using the top three ranked RCMs, for a period from January 2021-December 2100. For the monsoon months (June-September), the future annual mean surface runoff will decrease substantially (−50% to −10%), while the flows for post-monsoon months (October-December) are projected to increase (10–20%). Extremes are noted to increase during the non-monsoon months, while a substantial decrease in medium events is also highlighted. Snow-melt is projected to increase during the months of November-March (50% to 400%). Major loss of recharge is expected to occur in the central part of the basin. The investigation presents not only a reliable impact assessment but also the valuation of future alterations in individual hydrological components and will furnish the administrators with substantive information, a prerequisite to formulating ameliorative policies.     

基于SWAT分布式流域水文模型的下垫面变化和水利工程对径流影响分析

近年来随着人类活动的加剧,兴建了许多中、小型水利和水土保持工程,迅速改变着流域的自然面貌,因而改变了径流的原有规律。选取1960以前水利工程较少的时期作为人类活动不明显期来率定SWAT模型参数,对于1990以后人类活动稳定期的径流分别设置3个情景:应用原SWAT模型、应用只考虑下垫面变化的SWAT模型和应用考虑下垫面变化和水利工程影响的SWAT模型分别进行模拟。对于五道沟以上流域和流域内东丰、磐石、样子哨3个子流域模拟结果显示:考虑下垫面变化和水利工程影响后的径流模拟相关系数R2和纳什效率系数NSE分别从0.82、0.56提高到0.91、0.79,分别提高了11.0%和41.1%。其中模拟精度的提高量中91.3%是由于考虑水利工程作用所引起的,剩余部分是由考虑下垫面变化引起的。相比下垫面变化,水利工程运行对该流域径流变化占据主导作用。