题名干旱区绿洲农田蒸散量及其时空变化研究
作者马金龙
学位类别硕士
答辩日期2015
授予单位中国科学院大学
授予地点北京
导师李小玉
关键词蒸散发 涡度相关 SEBAL 绿洲农田 玛河流域
学位专业理学硕士
中文摘要水资源是干旱区农业发展最关键的限制因素,近年来随着节水灌溉技术的发展,对缓解水资源供需矛盾、扩大灌溉面积起到了重要作用,理解非充分灌溉条件下的农田蒸散发过程,对于揭示农田水分循环和指导节水实践均具有重要的科学意义。玛纳斯河流域是新疆最大的绿洲农耕区,流域膜下滴灌面积接近总灌溉面积的75%,创造了农田大面积应用滴灌规模的历史,玛纳斯河流域的水资源利用过程和农业节水模式在全疆乃至全国都具有极强的典型性。本文在利用遥感影像提取玛河流域主要作物种植结构信息的基础上,分别通过涡度相关系统以及SEBAL模型计算了流域主要作物的蒸散量,并对其时空变化以及主要影响因素进行了分析。本文得出的结论如下:(1)玛河流域种植面积最大的三大作物分别为棉花、玉米和小麦,分别占流域耕地面积的51.9%、6.3%、1.4%。三大作物种植结构具有明显的空间特征,棉花主要分布在光照充足、温度较高的中下游平原区,玉米主要分布在山区冲积平原和出山口前的冲积-洪积平原区,小麦零散分布山区冲积平原和中下游的冲积-洪积平原区。(2)膜下滴灌棉田阶段蒸散耗水量和日蒸散强度在花铃期最大,阶段蒸散耗水量为248.51mm,平均日蒸散强度为3.94mm·d-1;蕾期次之,阶段蒸散耗水量为98.34mm,平均日蒸散强度为3.78mm·d-1;播种-出苗期最小,阶段蒸散耗水量为10.70mm,平均日蒸散强度为1.07mm·d-1;不同生育期的蒸散量与蒸散强度基本保持一致。全生育期蒸散量为487.14mm,平均作物系数为0.42。在整个生长过程中,太阳净辐射是影响棉田蒸散的主控因素。在苗期和吐絮期,土壤温度变化对棉田的蒸散过程有较强的影响;蕾期和花铃期,气温和风速对其蒸散过程有较强的影响,气温升高和风速变大都会加剧棉田的蒸散强度。(3)利用SEBAL模型反演干旱区绿洲农田作物蒸散量具有现实可行性。模型反演的膜下滴灌棉田的日蒸散值为1.27 mm·d-1、2.25 mm·d-1、4.34 mm·d-1、4.52 mm·d-1、3.55 mm·d-1、3.66 mm·d-1、3.26 mm·d-1,地面观测的日蒸散量分别为1.23mm·d-1、2.35 mm·d-1、3.43 mm·d-1、5.17 mm·d-1、2.98 mm·d-1、3.59 mm·d-1、2.92 mm·d-1,二者的相对误差介于1.9%到26.6%之间;模型反演的蒸散量为508.30mm,地面观测的全生育期蒸散量为478.03mm,二者的相对误差仅为6.3%,说明模型反演精度较高,能够用于该区域的蒸散发值相关研究。由于试验数据观测站点等原因的限制,本文在膜下滴灌棉田蒸散量计算及分析时仅用了一年的涡度相关数据,未能进行更长时间序列的分析;SEBAL模型中一些地表参数的具体反演系数采用模型提供的系数,未对其进行重新计算,需通过地面实测数据加强验证分析,争取使模型反演结果更为准确和稳定。
英文摘要Water resources is a major constraint on agricultural development in arid areas. In recent years, with the development of water-saving irrigation technology, the non-balance condition between supply and demand of water resources was alleviated and the irrigation area was expanded. Understanding the evapotranspiration process of cropland under non-full irrigating has great scientific significance to reveal the water cycle process and guide water-saving practices. Manas river basin is the largest oasis agricultural area in Xinjiang, the area of mulched drip irrigation nearly 75% of the total drainage area of irrigated area, making history of large-scale application of Drip Irrigation in agricultural production. It has a strong typical in Xinjiang even if the whole country that water usage process and agricultural water-saving mode of the Manas river basin. By eddy covariance system and remote sensing retrieval model for evapotranspiration (SEBAL), this pater measures evapotranspiration of the regional main crops and analyzes the important spatial-temporal variation of regional evapotranspiration and major factors. Conclusions below are drawn from paper: (1) The top three dominant crops that with the largest planting area are cotton, corn and wheat, with planting areas accounting for 51.9%, 6.3%, and 1.4% of cultivate area in Manas river basin, respectively. Those three crops have distinctive characteristics on spatial distributions: cotton mainly distributed in the middle and lower reaches of plain where the illumination is adequate and temperature is high, and corn mainly distributed in mountainous alluvial plain and piedmont alluvial and diluvial plains, and wheat dispersed distributed in mountainous alluvial plain and the middle and lower reaches of diluvial plains. (2) Evapotranspiration and its rate of cotton field under mulched drip irrigation in oasis were reached peak in the flowering stage, the phasic evapotranspiration is 248.51 mm, average diurnal evapotranspiration rate is 3.94 mm·d-1; this was followed by the values in the budding stage, the phasic evapotranspiration is 98.34mm, average diurnal evapotranspiration rate is 3.18 mm·d-1; and the minimum values were occurred in the sowing and seeding stages, the phasic evapotranspiration is 10.70 mm, average diurnal evapotranspiration rate is 1.07 mm·d-1; they are basically in line at different growth stages. In summary, evapotranspiration is 487.14 mm during the whole growing period, and average crop coefficient is 0.42. Net solar radiation is the dominant influence factor of cotton evapotranspiration over the entire growth stages. Soil temperature changes have great influence on cotton evapotranspiration at seedling stage and boll-opening stage, and temperature and wind speed at bud stage and boll-forming stages. The increase of temperature and wind speed can result in the increase of cotton evapotranspiration. (3) Using SEBAL model retrieve crop evapotranspiration on oasis farmland in arid region is feasible. The model inversing evapotranspiration values are 1.27 mm·d-1, 2.25 mm·d-1, 4.34 mm·d-1, 4.52 mm·d-1, 3.55 mm·d-1, 3.66 mm·d-1, 3.26 mm·d-1, the ground monitoring evapotranspiration values are separately 1.23mm·d-1, 2.35 mm·d-1, 3.43 mm·d-1, 5.17 mm·d-1, 2.98 mm·d-1, 3.59 mm·d-1, 2.92 mm·d-1, relative error are between 1.9% to 26.6%; the evapotranspiration values of the whole growth period by the model inversing is 508.30 mm and the evapotranspiration values of the whole growth period by monitored is 478.03 mm, relative error is only 6.3%, which means that the SEBAL model has a higher retrieval accuracy and it can applicate in evapotranspiration relate study in this area. Due to the restrictions of measured data of observation stations and other reasons, we only had used one year data of eddy covariance to calculate and analysis the evapotranspiration of cotton field under mulched drip irrigation, failed to carry out analysis of longer sequences. The specific coefficient of surface retrieval parameters of SEBAL model is by SEBAL model itself provided rather than recalculated by measured data, which need to strengthen confirmatory analysis by more ground measured data and strive to make the model retrieval results more accurate and stable.
语种中文
学科主题地图学与地理信息系统
内容类型学位论文
源URL[http://ir.xjlas.org/handle/365004/14972]  
专题新疆生态与地理研究所_研究系统_荒漠环境研究室
作者单位中科院新疆生态与地理研究所
推荐引用方式
GB/T 7714
马金龙. 干旱区绿洲农田蒸散量及其时空变化研究[D]. 北京. 中国科学院大学. 2015.
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