【作者】 杨建莹；

【导师】 梅旭荣； 严昌荣；

【作者基本信息】 中国农业科学院 ， 农业水土工程， 2014， 博士

【摘要】 黄淮海平原作为我国北方重要的粮食生产基地，种植制度主要为冬小麦—夏玉米一年两熟，因地下水资源严重超采、降水量时空分布极不平衡、降水与作物需求不匹配等问题，成为我国水资源供需矛盾最突出的地区之一。如何提高农业用水效率，在保障高产前提下减少农业用水量，提高作物水分生产力，成为破解黄淮海平原农业用水短缺与粮食持续稳产高产矛盾的关键问题。本文以黄淮海平原2011～2012年MODIS影像为主要数据源，并辅以地面调查点，研究提取了冬小麦－夏玉米轮作信息，确定了冬小麦－夏玉米轮作系统在黄淮海平原的种植区域。在确定了SEBAL模型在黄淮海平原适用性的基础上，以2001～2002年、2006～2007年和2011～2012年MODIS多时相遥感影像、气象数据和作物生育期为基础，利用SEBAL模型，估算了冬小麦和夏玉米实际蒸散量（ETa）。通过MODIS NDVI光谱曲线特征及单产数据的耦合，将县域尺度作物单产“解集”到基于像元大小的产量栅格图，实现了冬小麦和夏玉米产量栅格化。在作物蒸散量模拟和产量栅格化的基础上，估算了黄淮海平原作物水分生产力（WP），并尝试找出冬小麦、夏玉米水分生产力的关键影响因素，研究区域作物水分生产力的提升途径。（1）估算了2001～2002、2006～2007和2011～2012三个时期冬小麦和夏玉米的作物实际蒸散量。2001～2002、2006～2007和2011～2012三个时期，夏玉米ETa平均值分别为448.9、440.4和354.8mm，高值区域主要位于河北、河南、北京、天津以及江苏地区，河南西部以及河北中部地区夏玉米ETa处于连续下降的态势。冬小麦ETa分别为630.7、550.8和538.4mm，高值区域位于河北、河南、苏北以及山东地区，北京、天津、河北以及山东中北部地区冬小麦ETa连续下降。两种作物ETa与地表温度呈显著负相关，与作物生长中后期的NDVI指数呈显著正相关。夏玉米ETa与经度显著负相关，而冬小麦ETa与纬度显著负相关。（2）实现了冬小麦和夏玉米产量栅格化。黄淮海地区粮食生产呈逐年增加的趋势。2001～2002、2006～2007和2011～2012三个时期，夏玉米单产平均值分别为383.4、408.5和439.6kg/亩，高产区域主要位于河北和山东地区，单产提高区域主要位于河北、江苏以及山东中北部地区。三个时期冬小麦单产区域平均值分别为332.0、380.9和420.8kg/亩，高产区域主要位于河北、河南和山东地区，单产提高区域主要位于河南、山东、江苏和安徽地区。（3）明确了冬小麦—夏玉米水分生产力时空分异特征。2001、2006和2011年夏玉米WP平均值分别为1.30、1.37和1.93kg·m-3，高值区主要位于山东地区，京津地区、河北、河南以及山东地区的，夏玉米WP一直处于提升的态势。2002、2007和2012年冬小麦WP平均值分别为0.81、1.09和1.21kg·m-3，高值区主要位于山东及河北地区。河北、山东中北部地区冬小麦WP表现出缓慢的提升。（4）探明了作物水分生产力与P-ETc（降水盈亏量）和ETa-ETc（需水盈亏量）的相关关系。结果表明，作物水分生产力与降水盈亏量成显著正向相关关系（P <0.05），与需水盈亏量成显著负相关（P <0.05）。夏玉米水分生产力提升潜力较大的区域位于黄淮海平原的西部地区，而冬小麦水分生产力提升潜力较大的区域主要位于黄淮海平原的中南部地区。针对黄淮海平原的农田水分收支的实际情况，提出的提高作物水分生产力的措施包括：第一，通过调节植物蒸腾、减少土面蒸发来减少作物实际蒸散量，第二，优化灌溉制度，减少水资源的不合理利用。作物产量形成和作物水分耗散是复杂的过程，不仅与气象要素相关，更多的是受到作物品种、人为管理等因素的影响。借助作物生长模型，对影响作物水分生产力的非气候要素以及影响机理进行研究，协同作物高产和高效用水提高作物水分生产力是未来发展的方向。更多还原

【Abstract】 The Huang-Huai-Hai plain (3H plain) is recognized as an important grain production area innorthern China, and where winter wheat-summer maize rotation is the main cropping systems.Currently,3H plain has become one of the most prominent contradiction areas between water supplyand demand due to over-exploited water resources, uneven spatial-temporal distribution of precipitation,and mismatch between precipitation and crop water requirements. How to develop the agricultural wateruse efficiency, reduce agricultural water use and improve crop water productivity has become a keyissue to resolve contradictions between agricultural water and continued high yield in3H plain. As theprimary data source, MODIS remote sensing, statistics, meteorological data, crop growth period dataand ground survey data in2001-2002,2006-2007, and2011-2012were used in crop informationextraction, crop yields rasterizing, actual evapotranspiration estimation and crop water productivity(CWP) calculation. Spatial and temporal variation of crop water productivity was investigated in orderto reveal the key factors of crop water productivity. In addition, the way to improve crop waterproductivity was discussed in3H plain. The results is expected to provide a basis information foragricultural water management, improvement of crop water productivity and choice of adaptivemechanism under climate change in3H plain. The main results are as follows:(1) The water consumption by actual evapotranspiration is estimated with Surface Energy BalanceAlgorithm for Land (SEBAL) model taking meteorological data and MODIS products as input. Theaverage instantaneous net radiation flux, soil heat flux, sensible heat flux and latent heat flux of3Hplain were558.92W·m-2,56.97W·m-2,56.97W·m-2and282.22W·m-2respectively in97(April7th)2011. Average daily evapotranspiration of3H plain was4.39mm and4.87mm in winter wheat andsummer maize rotation, after extracted by the crop dominant map. Results showed that SEBAL issuitable for estimating evapotranspiration in winter wheat and summer maize rotation in3H plain, basedon the comparation between evapotranspiration measured by Yucheng (in Shandong province) andevapotranspiration estimated by SEBAL. Actual evapotranspiration of winter wheat and summer maizewere calculated by space interpolation method, and spatial distribution of actual evapotranspiration inwinter wheat and summer maize growing season were mapped. Actual evapotranspiration in winterwheat growing season was found higher than that in summer maize growing season. Average value ofevapotranspiration in summer maize growing season were448.87mm,440.39mm and354.83mmrespectively in2001to2002,2006to2007and2011to2012, while630.70mm,550.76mm and538.41mm in winter wheat growing season. Crop evapotranspiration showed a decreasing tendency inthese three periods. Crop evapotranspiration was found more relative to NDVI in mid and late growingstages. Compared to NDVI, significant negative correlation was detected between evapotranspirationand surface temperature. Evapotranspiration in summer maize growing season showed significantcorrelation with longitude, which increase1degree will lead an reduce of13.71mm in summer maizeevapotranspiration. There is a significant correlation between evapotranspiration of winter wheat and latitude. Latitude, for each additional1degree, evapotranspiration of summer maize will reduce19.93mm.(2) The statistical cropped area and production data were synthesized to calculate district-level landproductivity, which is then further extrapolated to pixel-level values with1km×1km using MODISNDVI product based on crop dominance map. An increasing tendency was detected in crop productivityin3H plain. Yield of summer maize in2001was approximately350to450kg/mu with the average valueof383.4kg/mu and with higher value detected in Shijiazhuang-Jinan line, as well as the southern partof Jiangsu province. Yield of summer maize was400to500kg/mu in2006, and high yield area waslocated in Hebei, Henan and Shandong provices. Summer maize yield has increased to more than400kg/mu in2011, with high yield area located in Hebei, Shandong and Jiangsu provinces. Yield ofwinter wheat yield was250to400kg/mu in2002with the average value of332.0kg/mu, and high yieldarea was located in southern Hebei, northern Henan and Shandong provices. Winter wheat yield hasincreased to350to450kg/mu area in2007, with high yield area located in Hebei, Henan and Shandongprovinces. Yield of winter wheat yield in2012can reach to400kg/mu in most part of3H plain, withhigher value detected in Shandong and Henan provinces.(3) WP maps are then generated by dividing the rice productivity map with the actualevapotranspiration (ETa) maps. WP of summer maize (MWP) in most part of3H plain was less than1.4kg·m-3in2001, with regional average value1.37kg·m-3. High MWP area was found located inShandong province. MWP in most part of3H plain has increased to more than1.4kg·m-3in2006, withhigher MWP area located in Shandong province. Average MWP has increased to1.93kg·m-3in2011,and high-value WP area was located in Shandong and Jiangsu Provinces. MWP showed animprovement in Beijing and Tianjin, Hebei, Henan and southwestern region of Shandong during thesethree periods, while in eastern part of Shandong and Jiangsu province, MWP was detected with avolatility increase trend. WP of winter wheat (WWP) was less than0.9kg·m-3in2002, with regionalaverage value of0.81kg·m-3. High-value WP area was located in east part of Shandong and mid part ofHebei. WWP increased to1.09kg·m-3in2007, and detected with higher value in Shandong, Henan andHebei provinces. The regional average value is1.21kg·m-3in2012. In addition, WWP showed a greatvolatility except Anhui, entral and northern part of Hebei and parts of Shandong, where WWP improvedslowly and steady.(4) Significantly positive correlation and negative correlation were detected between CWP andP-ETa (precipitation deficit) and ETa-Etc (crop water demand deficit) respectively over3H plain. Thewestern part was identified as potential area for MWP, while central and southern areas for WWP. Twomeasures should be strengthened to improve crop water productivity in inference to the actual situationof farmland water budget of3H plain followed by reducing ETa through regulating crop transpirationluxury and soil surface evaporation and then cutting down the unreasonable use of water resourcesthrough optimization of irrigation system. Crop yield and water consumption are acknowledged as a complex process due to crop varieties,human management and so on together with meteorological variables. The non-climatic factors andinfluence mechanism is expected to investigate based on crop model with the purpose of improvingcrop water productivity.更多还原