基于改进的SEBS模型的作物需水量研究--测试文章

为了探讨以蒸散发为基础的作物需水量情况，便于为农业生产提供数据支持，利用风云三号、风云二号气象卫星数据，结合自动站气象数据，基于改进的SEBS模型对山西省进行作物需水量研究。结果表明：通过与实测数据对比验证发现模型结果精度较高。山西省2012年3—9月全省日均作物需水量最大值出现在春季的5月份，为1.27 mm，其中，以单季作物为代表的晋东北和中西部日均作物需水量最大值均出现在5月，分别为1.05 mm和1.38 mm；以双季作物为代表的晋东南日均作物需水量最大值出现在5月和7月，分别为1.28 mm和1.23 mm。可见山西省作物需水量普遍以春季最大，其中尤以中西部突出，晋东北则相对最低。     

基于SEBS方法的蒸散量计算及可靠度分析——以鄂尔多斯高原海流兔河为例

区域蒸散发量的分析计算,在水资源评价及分析研究中是至关重要的,其计算成果精度的高低对水资源的计算影响很大.但目前蒸散发还难以在大范围内进行直接测定,蒸散发量计算多采用间接估算的方法.表面能量平衡系统(SEBS)是近年来应用较为广泛的估算蒸散量的方法之一.该文将大范围的卫星遥感资料与地面和高空观测的气压、气温、相对湿度、...     

Remote sensing techniques for predicting evapotranspiration from mixed vegetated surfaces

Evapotranspiration (ET) is a key component of the hydrological cycle however it is also the most difficult factor to quantify. In recent decades, estimating ET has been improved by advances in remote sensing, particularly in agricultural studies. However, quantifying ET from mixed vegetation environs, particularly urban parklands, is still challenging due to the heterogeneity of plant species, canopy covers, microclimates, and because of costly methodological requirements. Several studies have recently been conducted in agriculture and forestry which may be useful for mixed landscape vegetation studies with some modifications. This review describes general remote sensing-based approaches to estimate ET and describes their advantages and disadvantages. Most of these approaches need extensive time investment, medium to high skill levels and are quite expensive. However, in addition to the reviewed methods, the authors recommend combining remotely sensed vegetation indices and ground-based techniques for ET estimation of mixed landscape vegetation such as urban parklands.     

Application of MIKE SHE modelling system to set up a detailed water balance computation

Estimation of total water balance is a substantial issue for watershed modelling in order to simulate the major components of the hydrological cycle to determine the stress of different anthropogenic activities on the available water resources within a catchment. In this context, the fully distributed physically based MIKE SHE modelling system was used to simulate the individual hydrological components of the total water balance for the Paya Indah Wetlands (PIW) watershed in the west of Peninsular Malaysia. Results reveal that the overall water balance is predominantly controlled by climate variables. Application of the model to the PIW watershed provides detailed estimation of the total water balance for a first‐order catchment in which actual evapotranspiration (ET) represents approximately 65 and 58%, while overland flow (OL) to the PIW lake system represents 12.38 and 12.3% of the total rainfall during the calibration and validation periods, respectively. The difference of the inflow and outflow was taken as storage in depth. Overall, the model gives a reasonable output of total error of less than 1% of the total rainfall, which in turn indicates that the interaction among components is satisfactorily sustained.     

基于小型蒸渗仪试验的潜在蒸散发估算方法评价

为了更直接地揭示潜在蒸散发估算方法与实际潜在蒸散发的差异,基于淮北平原五道沟水文水资源实验站2014年8月1日至2015年8月31日的水文气象观测资料,计算Penman系列方法、P-T法、H-S法、FAO24Radiation法及Turc法7种蒸散发估算方法的估算结果,对比相应时间蒸渗仪试验实测潜在蒸散量,评价各模型在该地区的适用性。结果表明,Penman系列估算方法是估算五道沟地区潜在蒸散发最佳的方法,但7种方法均存在较大误差。FAO56P-M方法估算结果与实测值有相对最好的线性关系,但存在10%的低估倾向,同时夏季(6～8月)绝对误差较春秋季有所增加。Turc法及P-T法更适用于缺资料地区长周期潜在蒸散发估算,H-S法及FAO24Radiation法相对不适用于五道沟地区。     

气候及土地利用变化对嘉陵江流域实际蒸散发量的影响

根据嘉陵江流域内12个气象站点1956~2012年的逐日气象资料,分别采用改进前后的平流干旱模型对嘉陵江三个子流域的实际蒸散发进行模拟,提出了一种基于气候变化和土地利用变化的实际蒸散发(Ea)贡献率计算方法。结果表明,与水量平衡法的估算结果相比,改进后模型对Ea的估算精度高于原始模型,且修正后模型参数α与土地利用类型具有相关性;三个子流域的年际实际蒸散发变化主要受下垫面因素变化的影响,是气候变化对其影响的2~5倍。此外,气候变化导致涪江流域的Ea在整个评估期内减少,另外两个子流域的Ea增加;下垫面变化导致涪江和嘉陵江子流域Ea减小,渠江Ea增加。     

垃圾填埋场灾变过程的温度–渗流–应力–化学耦合效应研究

 针对当前垃圾填埋场灾变过程预测与控制的迫切需求,结合垃圾填埋场及其周围复杂而特殊的环境地质条件,从温度–渗流–应力–化学(T-H-M-C)多场耦合角度深入分析垃圾填埋场灾变过程的演化机制与开展多场耦合研究的必要性。提出填埋气体运移的微生物降解–温度–渗流(B-T-H)耦合模型、考虑好氧和厌氧微生物降解作用的垃圾渗沥液污染物迁移转化渗流–微生物降解–化学(H-B-C)耦合模型、复合衬垫系统污染物运移渗流–化学(H-C)耦合模型以及考虑热量变化和水蒸气迁移过程对开裂过程影响的填埋场封场覆盖系统干燥开裂温度–渗流–应力(T-H-M)耦合模型,为垃圾填埋场灾变过程的预测和安全性评价提供有效的分析手段。提出一套多场耦合测试分析方法与试验技术,开发集监测、控制与数据采集于一体的填埋场中污染物传输的多场耦合测试分析系统。形成一套填埋场污染物多参数远程同步监测方法与技术,研制集实时监测与视频监督于一体的垃圾填埋场污染物远程在线监督系统。针对多场耦合作用下封场覆盖系统开裂问题,提出新型环保的垃圾填埋场封场覆盖生态污泥腾发覆盖技术(EST)。上述研究成果可为垃圾填埋场灾变过程的预防与控制提供科学手段和技术支持,同时对于丰富和拓宽多场多相耦合理论的发展具有重要的理论意义和应用价值。     

气候变化条件下黑龙江省作物生长季潜在蒸散发量时空变化特征及其敏感性分析

潜在蒸散发量(E_(ET0))是制定农业灌溉管理制度的重要参考指标,为分析黑龙江省1964~2013年作物生长季(5~10月)的E_(ET0),首先采用Penman-Monteith法计算E_(ET0);其次利用反距离加权(IDW)法计算E_(ET0)的空间变化特征,根据改进的Mann-Kendall(M-K)法分析E_(ET0)的时间变化特征;最后利用敏感系数法分析E_(ET0)对各气象因子的敏感性。结果表明,黑龙江省作物生长季的多年平均E_(ET0)在空间上大致呈西高东低和南高北低的特征,其值变化范围为437~694mm;时间上总蒸发量呈显著下降趋势,减少率为-7.2mm/10a,其中5月份减少幅度最大,减少率为-2.9 mm/10a;E_(ET0)对相对湿度的变化最为敏感,相对湿度的增加是导致E_(ET0)减少的直接原因。     

基于气象条件的巨菌草蒸散发动态研究

巨菌草是一种已经并将继续在中国干旱和半干旱地区广泛推广的草种,其蒸散发(ET)动态是目前关注较多但仍未解决的问题,制约了灌溉制度、节水途径和潜力、抗旱性能提升以及产量预测等相关主题的发展。基于盆栽控制试验,利用Si B2模型模拟和回归分析方法揭示了巨菌草蒸散发的主要过程及影响因素。结果表明:受气象因素的影响,巨菌草ET在0.5~6.9 mm/d的范围内波动。其中,ET季节动态与温度、日照时数和饱和水汽压差的关系呈先增后减的单峰关系;随相对湿度、短波辐射和净辐射的增大,ET分别线性降低、增大和增大;连续晴天和连续阴天条件下,ET日动态主要受短波辐射和净辐射的正相关影响。利用气象因素建立的多元回归关系,能够解释99%巨菌草ET的波动,总体误差为3.38±7.64 mm。     

Analysis of catchment evapotranspiration at different scales using bottom-up and top-down approaches

Physically-based hydrological models are used to predict catchment water balance through detailed simulation of hydrological processes at small temporal and spatial scales. However, annual catchment water balance can also be easily and simply predicted using lumped conceptual model. Comparison between physically-based hydrological models and lumped conceptual models can help us understand the dominant factors on catchment water balance at different scales. In this paper, a distributed physically-based hydrological model (i.e., bottom-up approach) and a simple water-energy balance model (i.e., top-down approach) are used to predict actual evapotranspiration in nine sub-catchments, and the whole basin of the Luan River in northern China. Both simulations give very close values of annual evapotranspiration and show the same complementary relationship between actual and potential evapotranspiration at annual time scale. From the analysis at different time scales through comparison of the top-down and the bottom-up methods, it is shown that the annual catchment evapotranspiration is controlled mainly by annual precipitation and potential evapotranspiration, and the variability of soil water and vegetation becomes more important at a smaller time scale in the study areas. It is also known that the relationship between potential and actual evapotranspiration shows a highly nonlinear relationship at the annual and catchment scale but can be simplified to a linear relationship at hourly temporal and hillslope scales, which is commonly used in the physically-based hydrological models.