湿地蒸散测算方法进展   总被引：3，自引：0，他引：3  

梁丽乔  闫敏华  邓伟 《湿地科学》2005,3(1):74-80

湿地是地球上三大生态系统之一 ,蒸散是湿地生态系统的重要水文特征 ,是能量和水分的主要消耗途径 ,因此研究湿地蒸散对分析湿地水量平衡、热量平衡以及水资源估算等都具有十分重要的意义。通过总结国内外湿地蒸散量的测算方法 ,如Thornthwaite公式、Penman Monteith模型、Prestley Taylor模型、三江平原沼泽湿地蒸散经验模型、涡度相关法和遥感方法等 ,提出在湿地特定的自然条件下 ,经验模型法在湿地蒸散中的应用要比在其它陆地生态系统蒸散研究中的应用更为准确。  相似文献   

典型岩溶断陷盆地农作物生态需水研究——以蒙自地区为例     

曾锐  张陶  蒲俊兵  李建鸿  王赛男 《中国岩溶》2020,39(6):873-882

从合理调控生态用水角度出发,探讨典型岩溶断陷盆地区农作物生态需水问题。根据蒙自断陷盆地的岩溶地貌特征,分别选取位于盆地、坡面和高原面的大洼子、朵古、牛耳坡3个观测点,利用Penman-Monteith公式、作物系数（FAO推荐）及同期有效降雨量,估算3个观测点2018年的参考蒸散量、生态需水量以及不同作物生长所需的人工灌溉水量。结果表明:（1）大洼子、朵古及牛耳坡的参考蒸散量分别为1 346.10 mm、1 200.00 mm、1 064.30 mm,远大于同期降水量,均呈现出蒸发旺盛的特点,加大了作物对于水分的需求;同时三者的参考蒸散量表现出较为明显的时空差异,使得3个观测点的农业种植条件存在差异;（2）大洼子种植的水稻、小麦、花生、油菜、大豆、马铃薯、葡萄等作物的生态需水定额均远大于大洼子同期的有效降水,在大洼子种植的作物均需要大量人工浇灌才能正常生长,而农作物的种植与其种植条件匹配度不高;（3）朵古及牛耳坡种植的玉米、万寿菊的生态需水定额与同期有效降水之间的差值较小甚至完全满足,表明玉米、万寿菊在高原山区的种植是与当地种植条件相匹配的;而种植在朵古及牛耳坡的苹果、烤烟的生态需水定额与同期有效降水之间的差值较大,表明在高原山区大量种植苹果及烤烟对于人工浇灌要求较高;（4）研究区大部分农作物在生长发育阶段内所需的水分主要依靠人工灌溉,与本地降水分布规律匹配度不高,区内农业结构与种植模式有待调整。在岩溶断陷盆地内要种植耗水较少,对热量要求较高的作物,山区则需要发展具有生态保护和经济效益的作物,但种植的重点区域仍是盆地区。   相似文献   

Potential Evapotranspiration Characteristic and Its Abrupt Change Across the Qinghai-Tibetan Plateau and Its Surrounding Areas in the Last 50 Years   总被引：1，自引：0，他引：1  

Tianci Yao  Hongwei Lu  Qing Yu  Wei Feng 《地球科学进展》2020,35(5):534-546

Daily routine observation data from 274 meteorological stations in the Qinghai-Tibetan Plateau and its surrounding areas from 1970 to 2017 were utilized to examine the spatial patterns and abrupt changes of potential evapotranspiration with the formula of FAO Penman-Monteith, in consideration of China’s eco-geographical divisions. The results showed that \mathrm{①} annual and seasonal average potential evapotranspiration, except for summer and winter, displayed a distinct spatial pattern in the Qinghai-Tibetan Plateau and its surrounding areas, with higher values in the north and south but lower values in the middle; the time when monthly potential evapotranspiration reached its maximum or minimum showed clearly zonal differences, namely earlier in the south and later in the north. \mathrm{②} The prevailing mean and trend abrupt changes of potential evapotranspiration were observed in the study area, while there were large differences in the abrupt change time in different regions and seasons. Specifically, the mean abrupt change was dominated by positive mutation, with generally the earliest abrupt change time occurring in spring and the latest appearing in winter; the trend abrupt change pattern was mainly described as the process shifting from a downward trend to an upward trend, the trend change points in year, spring, autumn and winter were postponed gradually from the northeast to the southwest with a delay of about 20, 10, 20 and 5 years, respectively. Comparatively, the abrupt change time of potential evapotranspiration trend in the whole plateau was later than that in the whole buffer zone, with a respective lag of 5, 1, 12, 5 and 4 years. \mathrm{③} Corresponding to the periodic change of potential evapotranspiration, significant evaporation paradox only scattered through the study area during the period before the trend change point (2007), but it was absent afterwards and would not appear in the future. The above findings will provide a scientific basis for further understanding the climate change and eco-hydrological process of the Qinghai-Tibetan Plateau and its surrounding areas in global warming.  相似文献   

基于多种机器学习模型的西北地区蒸散发模拟与趋势分析          下载免费PDF全文

季鹏  袁星 《大气科学学报》2023,46(1):69-81

基于机器学习方法和多源数据构建高精度蒸散发（Evapotranspiration,ET）产品对研究气候变化背景下干旱、半干旱地区陆地水循环变化具有重要意义。本文利用西北地区12个草地通量站点与卫星遥感产品,基于随机森林、极端梯度提升、支持向量回归和人工神经网络4种机器学习方法构建ET估算模型,制作5 km分辨率ET产品,并分析ET的长期变化趋势。交叉验证结果表明,4种模型的均方根误差都低于0.57 mm·d^-1,R²高达0.73～0.88。SHAP （SHapley Additive exPlanation）可解释性分析表明,4种模型均将净辐射、植被和土壤湿度作为ET估算的重要因子,也能刻画出土壤偏干时土壤水分对ET的限制作用,有较好的物理解释性。多模型集合的ET结果相比单一机器学习模型以及现有遥感产品误差分别降低7％～20％和45％～70％。趋势分析结果显示,西北地区非裸地下垫面在2001—2018年间整体呈现ET增加趋势,平均速率为19 mm/（10 a）。在河套平原和内蒙古中部和东北部地区,ET的增长速率超过降水,这可能会进一步加剧这些地区的干旱化。  相似文献   

基于CLM模型的月尺度中亚陆表蒸散和土壤水分模拟估算     

姜勃  田静  苏红波 《地理科学进展》2020,39(3):433-442

论文基于CLM 4.5模拟1980—2009年月尺度中亚陆表蒸散发和土壤水分,并和GLDAS、GLEAM数据产品进行对比,结果表明CLM 4.5模拟的蒸散和土壤水分区域平均值和其他产品具有较好的一致性。从CLM 4.5模拟的陆表蒸散结果分析可知：全年蒸散大部分集中于春夏2季,在5月达到一年的最大值,夏季中亚的蒸散高值区集中在哈萨克斯坦北部和东北部、东南部的山地区,对应主要的农田区和林地区,植被蒸腾占主导因素;春季东南部天山山脉和帕米尔高原是蒸散高值区,主要因为该地区春季降水量较大,且积雪开始融化,水量充足,地表蒸散发充分;蒸散低值区主要在西南的土库曼斯坦和乌兹别克斯坦,地表覆盖以荒漠为主,植被覆盖较少,降水也较少,导致地面蒸散量较低。模拟的表层土壤水分结果表明：冬季陆面蒸散低,降水大多储存在表层土壤内或者以积雪的形式覆盖在地面上,春季气温升高,积雪融化下渗到土壤中,土壤水分持续增加,4月份达到峰值;夏季蒸散增加,降水减少,土壤水分持续下降,9月份达到最低值;进入秋冬季后蒸散降低,土壤水分呈上升趋势。中亚土壤水分高值区集中在北部和东北部的林地、农田区,以及天山山脉和下游的阿姆河、锡尔河流域区,西南部的荒漠区依然是低值区。一年中,夏季降水较少,由于地面蒸发的作用,土壤水分持续较少,蒸散也随之降低。三者之间相关性很高;冬季降水和土壤之间的相关性较高,尤其是裸地区;在植被覆盖较大的情况下,春季降水和蒸散相关性较高,土壤水分和降水、蒸散之间相关性较低,会出现负相关情况。CLM 4.5模拟的结果为进一步中亚地区的水问题研究奠定基础。  相似文献   

Temporal and Spatial Distribution of Evapotranspiration and Its Influencing Factors on Qinghai-Tibet Plateau from 1982 to 2014     

CUI Mingyue  WANG Junbang  WANG Shaoqiang  YAN Hao  LI Yingnian 《资源与生态学报(英文版)》2019,10(2):213-224

Evapotranspiration is the key driving factor of the earth’s water cycle, and an important component of surface water and energy balances. Therefore, it also reflects the geothermal regulation function of ecohydrological process. The Qinghai-Tibet Plateau is the birthplace of important rivers such as the Yangtze River and the Yellow River. The regional water balance is of great significance to regional ecological security. In this study, ARTS, a dual- source remote sensing evapotranspiration model developed on a global scale, is used to evaluate the actual evapotranspiration (ET) in the Qinghai-Tibet Plateau from 1982 to 2014, using meteorological data interpolated from observations, as well as FPAR and LAI data obtained by satellite remote sensing. The characteristics of seasonal. interannual and dynamic changes of evapotranspiration were analyzed. The rates at which meteorological factors contribute to evapotranspiration are calculated by sensitivity analysis and multiple linear regression analysis, and the dominant factors affecting the change of evapotranspiration in the Qinghai-Tibet Plateau are discussed. The results show that: (1) The estimated values can explain more than 80% of the seasonal variation of the observed values (R² = 0.80, P < 0.001), which indicates that the model has a high accuracy. (2) The evapotranspiration in the whole year, spring, summer and autumn show significant increasing trends in the past 30 years, but have significant regional differences. Whether in the whole year or in summer, the southern Tibetan Valley shows a significant decreasing trend (more than 20 mm per 10 years), while the Ali, Lhasa Valley and Haibei areas show increasing trends (more than 10 mm per 10 years). (3) Sensitivity analysis and multiple linear regression analysis show that the main factor driving the interannual change trend is climate warming, followed by the non-significant increase of precipitation. However, vegetation change also has a considerable impact, and together with climate factors, it can explain 56% of the interannual variation of evapotranspiration (multiple linear regression equation R² = 0.56, P < 0.001). The mean annual evapotranspiration of low-cover grassland was 26.9% of high-cover grassland and 21.1% of medium-cover grassland, respectively. Considering significant warming and insignificant wetting in the Qinghai-Tibet Plateau, the increase of surface evapotranspiration will threaten the regional ecological security at the cost of glacial melting water. Effectively protecting the ecological security and maintaining the sustainable development of regional society are difficult and huge challenges.  相似文献   

中国东部南北样带森林生态系统蒸腾与蒸散比值(T/ET)时空变化   总被引：3，自引：1，他引：2  

任小丽  路倩倩  何洪林  张黎  牛忠恩 《地理学报》2019,74(1):63-75

植被蒸腾与蒸散的比值(transpiration/evapotranspiration, T/ET)表征了植被蒸腾对生态系统蒸散的贡献率,是准确量化生态系统水分利用效率的关键参数,对研究植被水分运移的生理生态机理以及碳水循环关系具有重要意义。基于站点数据验证PT-JPL模型(Priestly-Taylor JetPropulsion Laboratory Model)模拟精度,集成遥感数据和气象栅格数据模拟中国东部南北样带森林生态系统2001-2010年T/ET,并分析其时空变化及影响因子。结果表明:①PT-JPL模型适用于中国东部森林生态系统蒸散及其组分模拟,具有较高的稳定性和可靠性;②中国东部南北样带森林生态系统T/ET空间差异显著,整体呈南部低、北部高,主要由夏季T/ET空间格局主导;样带整体T/ET均值为0.69,2001-2010年呈显著缓慢上升趋势,增幅为0.007/yr(p <0.01);③T/ET季节和年际变异的主控因子不同:温度和EVI是影响T/ET季节变异的关键因子,两者均可解释T/ET季节变异的90%左右(p <0.01);而T/ET的年际变异则主要受EVI影响,解释率为53%(p <0.05)。  相似文献   

博斯腾湖流域潜在蒸散发时空演变及归因分析   总被引：1，自引：0，他引：1       下载免费PDF全文

钟巧  焦黎  李稚  焦伟  陈亚宁 《干旱区地理》2019,42(1):103-112

运用博斯腾湖流域1970—2014年的气象站点数据及Penman-Monteith公式计算潜在蒸散发(ET0),对比分析了流域山区和平原区ET0的时空变化及对主要气象因子的不同影响。结果表明:(1)在年际尺度上,山区ET0在1970—2000年整体呈波动下降的趋势(P <0. 01),2000年开始,ET0呈现略微上升的趋势;平原区ET0在1970—1993年间以-77 mm·(10 a)-1的速率呈减小的趋势(P <0. 01),1993年之后逆转为以83. 8 mm·(10 a)-1的速率呈上升趋势(P <0. 01),平原区的变化明显强于山区。(2)季节上呈现夏季为流域ET0最高的季节,是年变化的主要贡献者;而变化趋势则表现为平原区春季和夏季ET0大于山区,秋季和冬季略小于山区。(3) ET0变化对净辐射和风速最为敏感,同时,山区净辐射和风速对ET0变化的贡献率最大,平原区影响ET0变化的主导因素是风速,风速对ET0的贡献率均超过50%。  相似文献   

现代学徒制背景下的教学设计与实践——以工程变形测量课程为例     

吴欢  王炎  黄海虹 《北京测绘》2020,(1):135-139

随着工程测量技术专业的发展,校企基于现代学徒制的特点开始开展深度合作,重点在于培养更多无缝对接岗位需求的高素质技术技能人才。根据近些年的《工程变形测量》课程教学经验,从设计思路与原则、提炼教学目标、凝练教学内容、改进教学方法与手段、精准考核与评价等方面进行课程教学与探索,通过江西环境工程职业学院1个班级的教学探索,取得了预期的良好成效,为后期工程变形测量课程教学继续深入改革与探索做好铺垫。  相似文献   

印度洋偶极子预报技巧在多模式中的对比研究   总被引：1，自引：0，他引：1  

雷蕾  伍艳玲  唐佑民 《海洋学报》2020,42(7):51-63

本文采用北美多模式集合产品数据,分析了印度洋偶极子指数在不同模式中实际预报技巧和潜在可预报性的差异,并进一步探究其可能的原因。结果表明,印度洋偶极子的有效预报时效在不同模式中差别较大,从2个月到4个月不等。其中东极子海温异常在不同模式中预报技巧的差别较西极子海表面温度异常更明显,表明模式误差和初始误差对东极子海表面温度异常演变的影响更为显著。另外,印度洋偶极子的实际预报技巧和潜在预报技巧存在明显的线性关系,潜在预报技巧高的模式,其实际预报技巧也高。最后,本文诊断、分析了厄尔尼诺对印度洋偶极子预报技巧的影响,发现在厄尔尼诺和印度洋偶极子相关性较高的气候模式中,印度洋偶极子实际预报技巧也较高。  相似文献