Effects of urbanization on daily temperature extremes in North China简

The regional changes of daily temperature extremes in North China caused by ur- banization are studied further from observed facts and model estimates on the basis of ho- mogenized daily series of maximum and minimum temperature observations from 268 mete- orological stations, NCEP/DOE AMIP- Ⅱ reanalysis data （R-2）, and the data of simulations by regional climate model （RegCM3）. The observed facts of regional warming on long time scales are obtained by analyzing the indices of temperature extremes during two time periods of 1961-2010 and 1951-2010. For urbanization effect, the contributions to decreases in an- nual and winter diurnal temperature range （DTR） are 56.0% and 52.9%, respectively, and increases in the lowest minimum temperature （TNn） are 35.7% and 26.2% by comparison of urban and rural observations. Obtained by R-2 data with observations for contrast, on the other hand, increase in the number of annual warm nights （TN90p） contributed by urbaniza- tion is 60.9%. And observed facts of regional warming in daily temperature extremes are also reflected in the simulations, but what difference is urbanization progress at rural areas in North China would be prominent in the next few years relative to urban areas to some extent from model estimates.     

Human-driven topographic effects on the distribution of forest in a flat,lowland agricul-tural region简

Complex topography buffers forests against deforestation in mountainous regions. However, it is unknown if terrain also shapes forest distribution in lowlands where human impacts are likely to be less constrained by terrain. In such regions, if important at all, to- pographic effects will depend on cultural-historical factors and thus be human-driven （an- thropogenic） rather than natural, except in regions where the general climate or extreme soils limit the occurrence of forests. We used spatial regression modeling to assess the extent to which topographic factors explain forest distribution （presence-absence at a 48x48 m resolu- tion） in a lowland agricultural region （Denmark, 43,075 km2） at regional and landscape scales （whole study area and 10x10 km grid cells, respectively）, how landscape-scale for- est-topography relationships vary geographically, and which potential drivers （topographic heterogeneity, forest cover, clay content, coastal/inland location） determine this geographic heterogeneity. Given a moist temperate climate and non-extreme soils all landscapes in Denmark would naturally be largely forest covered, and any topographic relationships will be totally or primarily human-driven. At regional scale, topographic predictors explained only 5% of the distribution of forest. In contrast, the explanatory power of topography varied from 0%-61% at landscape scale, with clear geographic patterning. Explanatory power of topog- raphy at landscape scale was moderately dependent on the potential drivers, with topog- raphic control being strongest in areas with high topographic heterogeneity and little forest cover. However, these conditioning effects were themselves geographically variable. Our findings show that topography by shaping human land-use can affect forest distribution even in flat, lowland regions, but especially via localized, geographically variable effects.     

过去50年内蒙古极端气候事件时空格局特征简

为了掌握内蒙古极端气候事件的发生趋势与时空格局,本文运用内蒙古自治区境内46个国家级气象站点的日值记录数据,计算与植被生长的水热条件及寒旱灾害直接相关的极端气候事件指数,分析过去50年内蒙古温度和降水气候事件的时空演变特征。研究结果表明,研究区极端温度事件的发生频率与持续时间迅速变化发生于20世纪90年代以来,60年代至80年代末呈平稳态势。表征低温事件的霜日日数（FD0）、冷昼日数（TX10p）、冷夜日数（TN10p）、冷持续指数（CSDI）等指数均呈现下降趋势,同时表征高温事件的夏日指数（SU25）、作物生长期（GSL）、暖昼日数（TX90p）、暖夜日数（TN90p）、热持续指数（WSDI）则均呈上升趋势。与极端高温事件发生频率的加剧在90年代初开始凸显不同,表征强降水事件发生频率和强度的极端降水指标的显著变化发生在近10年。研究区极端温度指数过去50年的变化过程几乎没有明显的空间分异特征,但是在位于农牧交错区的部分站点的强降水事件呈现出与大多数站点不同的特征,最近10年的强降水事件高于前一时段,而其他多数站点最近10年的极端降水指数均低于前一时段。     

The GSC Regional Conferences held in 2013简

In order to provide better services to the members of Geographical Society of China （GSC） and geographers and engineers in China, and improve GSC＇s ability in hosting comprehensive aca- demic conferences, with the support of China Association for Science and Technology （CAST）, GSC established 7 regional divisions, representing different regions of China. In addition, GSC revised the annual conference organizing policies by hosting the comprehensive national aca- demic conference biannually. Instead of hosting annual national conferences, GSC organizes regional academic conferences. The new policy was initiated and executed in 2013. Up to now, 7 regional conferences have been successfully organized by the regional divisions in their areas. The 7 regional divisions are： Northern China Division, Northwest China Division, Northeast China Division, Southwest China Division, Central China Division, Southern China Division and Eastern China Division. The regional divisions promote the objectives of GSC through regional conferences and activities in their respective areas. The purpose is to build platforms extensively for academic exchange between geographers; collaborate with local geographical societies and integrate local resources; and unite all the regional academic organizations.     

Study on daily surface evapotranspiration with SEBS in Tibet Autonomous Region简

The estimation of surface evapotranspiration （ET） with satellite dataset is one of the main subjects in the understanding of climate change, disaster monitoring and the circulation of water vapor and energy in Tibet Autonomous Region （TAR）. This research selects satellite images on January 11, April 6, July 31 and October 19 in 2010 as the representative of winter, spring, summer and autumn respectively, estimates the distribution of daily surface ET based on the surface energy balance system （SEBS） along with potential evapotranspiration （PET） and ET derived from Penman-Monteith （P-M） method. The results are obtained as follows. （1） The seasonal distribution of ET and PET basically decreases from the southeast part to the northwest part of TAR. Although ET and PET have similar spatial distributions, there are still some differences to estimate the extreme values especially the maximum value in the middle and southeastern parts of TAR. No matter what kind of methods we adopted, the maximum value of ET and PET always appears in summer, followed by autumn or spring while that in winter is the smallest. （2） In order to better understand the accuracy of SEBS model in the estimation of ET, we compared the ET from SEBS and the ET obtained from P-M method. Results show that the ET from SEBS could estimates the variation trend of actual ET, but it slightly underestimates or overestimates the value of ET as a whole, especially for those areas with thick forest. （3） The spatial distribution of Normalized Difference Vegetation Index （NDVI） exhibits a decreasing trend from the southeast part to the northwest part of TAR which displays remarkable consistency of distributions between ET and vegetation index. ET is well positively related to NDVI, minimum, mean, maximum air temperature and sunshine duration in different seasons while negatively related to precipitation, relative humidity and wind speed in summer.     

The provincial pattern of the relationship between urbanization and economic develop-ment in China简

Understanding the relationship between China＇s urbanization and economic de- velopment on a provincial scale is of profound theoretical and practical significance. Based on data from 124 countries or regions throughout the world and 31 provinces or autonomous regions in China, applying improved methods using the quadrant map approach, this paper analyzed the spatial pattern of the relationship between China＇s urbanization and economic development level. The study identified the following results. （1） The 31 province-level re- gions fall into six categories： only one region is in the category of sharp over-urbanization, 3 regions are in medium over-urbanization, 11 slight over-urbanization, 8 basic coordination, one medium under-urbanization, and seven slight under-urbanization. （2） There are signifi- cant regional differences on a provincial scale in the relationships between urbanization and the level of economic development. （3） The provincial pattern of urbanization and economic development is significantly different between east and west. The eastern coastal areas are mainly over-urbanized, while the central and western regions are mainly under-urbanized. （4） The relationship between urbanization and the level of economic development is similar to the Matthew effect. Hence, two important insights are proposed. First, the phenomenon of over-urbanization in some developed regions should be viewed with some concern and vigi- lance. Second, urbanization needs to be speeded up moderately in the central and western regions.     

Impact of farmer households’ livelihood assets on their options of economic compensation patterns for cultivated land protection简

With rapid urbanization and the socio-economic transformation, cultivated land protection has gradually become a major concern in China. The economic compensation plays a crucial role in promoting cultivated land protection and improving the utilization ratio of cultivated land. Farmer household＇s satisfaction has a great influence on the effectiveness of compensation. Therefore, households＇ willingness to select the economic compensation pattern for cultivated land protection has been considered and re-examined. By employing Participatory Rural Appraisal method （PRA）, 3 villages and 392 households were investigated and sampled in mesa and hilly areas of Chongqing. Then a quantitative analysis framework of household livelihood hexagon has been developed to quantify the livelihood assets of differ- ent farmer households. Finally, the Gray Relation Model and Probit Regression Model have been employed to explore the coupling relationship between the household livelihood assets and their compensation pattern options. The results show that there are both qualitative and spatial heterogeneity in household livelihood assets. We found that the inequality of livelihood assets is evident for five household types. There is a spatial trend that the higher the eleva- tion, the less livelihood assets are. In addition, their options of economic compensation pat- tern vary from Chengdu Pattern to Foshan Pattern due to their difference in livelihood assets and difference in location. In detail, there is a coupling relationship between household live- lihood assets and their compensation pattern; negative correlation is observed between natural assets value and household pattern options, while the other livelihood assets have positive impacts on compensation pattern in varying degrees, which from the top are psy- chological assets, human assets, physical assets, financial assets, and social assets respec- tively. A conceptual compensation pattern system has been designed to meet the demands for farmer households mainly according to their shortage in livelihood assets. In addition, compensation method, compensation standard, the basis of compensation and the source of compensation funds have been proposed accordingly.     

气候变化对海河流域主要作物物候和产量影响简

基于海河流域30 个气象站点1960-2009年的实测资料,分析该流域1960年以来农业气象指标的变化趋势,并利用VIP模型模拟分析大气CO₂浓度增加、温度、降雨和日照时数变化对作物产量的影响。结果显示：冬季温度的显著上升使冬小麦种植北界在50年间向北移动大约70 km;在品种和灌溉条件不变的前提下,小麦产量平均每10年上升0.2%~3.4%,其中CO₂浓度增加、温度、降雨及日照时数变化对其产量的影响分别为11.0%、0.7%、-0.2%和-6.5%;大气CO₂浓度增加的产量正效应大于日照时数减少的负效应。气候变化使夏玉米产量呈下降趋势（0.6%~3.8%/10年）,其中大气CO₂浓度增加、温度、降雨及日照时数变化对其产量的影响分别为0.7%、-3.6%、-1.0%和-6.8%,温度上升和辐射下降是玉米产量下降的主要原因。研究结果可为气候变化影响的评估和适应性对策制定提供科学依据。     

Livestock-carrying capacity and overgrazing status of alpine grassland in the Three-RiverHeadwaters region,China简

The Three-River Headwaters region in China is an ecological barrier providing en- vironmental protection and regional sustainable development for the mid-stream and down- stream areas, which also plays an important role in animal husbandry in China. This study estimated the grassland yield in the Three-River Headwaters region based on MODIS NPP data, and calculated the proper livestock-carrying capacity of the grassland. We analyzed the overgrazing number and its spatial distribution characteristics through data comparison be- tween actual and proper livestock-carrying capacity. The results showed the following： （1） total grassland yield （hay） in the Three-River Headwaters region was 10.96 million tons in 2010 with an average grassland yield of 465.70 kg/hm2 （the spatial distribution presents a decreasing trend from the east and southeast to the west and northwest in turn）; （2） the proper livestock-carrying capacity in the Three-River Headwaters region is 12.19 million sheep units （hereafter described as ＂SU＂）, and the average stocking capacity is 51.27 SU [the proper carrying capacity is above 100 SU/km2 in the eastern counties, 60 SU/km2 in the cen- tral counties （except Madoi County）, and 30 SU/km2 in the western counties]; and （3） total overgrazing number was 6.52 million SU in the Three-River Headwaters region in 2010, with an average overgrazing ratio of 67.88% and an average overgrazing number of 27.43 SU/km2 A higher overgrazing ratio occurred in Tongde, Xinghai, Yushu, Henan and Z~kog. There was no overgrazing in Zhiduo, Tanggula Township and Darlag, Qumerleb and Madoi. The re- mainder of the counties had varying degrees of overgrazing.     

河北平原冬小麦播种面积收缩及由此节省的水资源量估算

以河北平原1998-2010 年11 地市的农业统计数据和22 个气象站点的逐日气温、降水量、水汽压、风速、日照时数和相对湿度等资料为基础,对该地区冬小麦播种面积的收缩情况及由此引发的耕作制度变化进行了分析;同时,结合作物系数法和逐旬有效降水量法,计算了不同耕作制度下的水分亏缺量,进而估算了该地区因耕作制度变化节省的水资源量。结果表明:① 该时段河北平原11 地市冬小麦的播种面积均呈收缩趋势,总面积下降了16.07%,约49.62×10⁴ hm²。京津唐城市群表现最为明显,下降了47.23%;② 冬小麦的降水满足率仅为20%~30%,而春玉米和夏玉米均为50%以上;冬小麦-夏玉米一年两熟制所需的灌溉水资源量为400~530 mm,而春玉米一年一熟制仅为160~210 mm;③ 该时段河北平原因冬小麦播种面积收缩而节省的灌溉水资源量约为15.96×10⁸ m³/a,相当于南水北调中线一期工程为京津冀三省市供水量的27.85%。     

河北平原冬小麦播种面积收缩对农业水资源消耗的影响(英文)

This study firstly analyzed the shrinkage of winter wheat and the changes of cropping systems in the Hebei Plain from 1998 to 2010 based on the agricultural statistic data of 11 cities and meteorological data, including daily temperature, precipitation, water vapor, wind speed and minimum relative humidity data from 22 meteorological stations, and then calculated the water deficit and irrigation water resources required by different cropping systems, as well as the irrigation water resources conserved as a result of cropping system changes, using crop coefficient method and every ten-day effective precipitation estimation method. The results are as follows. 1) The sown areas of winter wheat in the 11 cities in the Hebei Plain all shrunk during the study period. The shrinkage rate was 16.07% and the total shrinkage area amounted to 49.62×104ha. The shrinkage was most serious in the Beijing-Tianjin-Tangshan metropolitan agglomerate, with a shrinkage rate of 47.23%. 2) The precipitation fill rate of winter wheat was only 20%–30%, while those of spring maize and summer maize both exceeded 50%. The irrigation water resources demanded by the winter wheat-summer maize double cropping system ranged from 400 mm to 530 mm, while those demanded by the spring maize single cropping system ranged only from 160 mm to 210 mm. 3) The water resources conserved as a result of the winter wheat sown area shrinkage during the study period were about 15.96×108m3/a, accounting for 27.85% of those provided for Beijing, Tianjin and Hebei by the first phase of the Mid-Route of the South-to-North Water Diversion Project.     

Change of winter wheat planting area and its impacts on groundwater depletion in the North China Plain

Journal of Geographical Sciences - The North China Plain is one of the most water-stressed areas in China. Irrigation of winter wheat mainly utilizes groundwater resources, which has resulted in...     

冬季气候变暖对山西省冬小麦可种植区的影响

基于山西省境内较为均匀分布的70 个地面气象观测站1970-2012 年冬季逐日气温资料,采用线性倾向估计法分析了负积温、最冷月平均气温和年极端最低气温的变化特征,采用累积距平法确定其突变点,以突变点为界分为前后2 个时间段,依据前后时间段等值线的变化分析冬季气候变暖对山西省冬小麦可种植区的影响。结果表明：山西省负积温呈现显著减少趋势（通过了α=0.01 的显著检验）,最冷月平均气温和年极端最低气温呈现不显著升高趋势;突变后,负积温平均减少了103.4℃,最冷月平均气温和年极端最低气温分别升高了0.8℃和0.7℃;在3 个指标中,决定山西省冬小麦能否种植的关键因子是负积温和年极端最低气温,最冷月平均气温的影响较小;冬季气候变暖后,平均状况下,冬小麦可种植区域面积扩大了约2.9×10⁶ hm²,扩大52%,80%保证率下,冬小麦种植面积扩大了约2.3×10⁶ hm²,扩大79%。     

基于日尺度SPEI的黄淮海平原冬小麦生育阶段干旱特征分析

黄淮海平原地处燕山以南、淮河以北,包含黄河、淮河和海河冲积平原及部分丘陵山区,属于半干旱、半湿润地区,年降水量500~900 mm,是我国主要的冬小麦种植区。利用黄淮海平原49个农气站点1961—2017年日值气象数据,采用Penman-Monteith模型计算的日尺度SPEI指数,从气象干旱的角度分析了黄淮海平原近56 a冬小麦主要生育阶段干旱持续时间和干旱强度的变化,并采用R/S方法对干旱未来变化趋势进行预测。结果表明:(1)从空间分布上来看,冬小麦的营养生长期和并进期,北部干旱持续时间较短,干旱强度较小,南部干旱持续时间较长,干旱强度较大,而冬小麦生殖生长期与前两个生育期干旱分布相反。(2)从各站点变化趋势来看,在冬小麦整个生育期内干旱持续时间与干旱强度呈相反趋势。(3)从时间变化趋势上来看,1961—2017年干旱有明显减缓趋势,除个别站点外,在冬小麦的营养生长期和并进期,干旱持续时间和干旱强度自2003年起干旱有逐渐减缓趋势,在生殖生长期则从2007年起干旱有逐渐减缓趋势。(4)从未来变化趋势来看,营养生长期干旱持续时间将缩短,干旱强度将减小,并进期的干旱持续时间和干旱强度的变化将和过去56 a基本保持一致,生殖生长期干旱持续时间将有所增长,干旱强度将有所加重。本研究分析了黄淮海平原冬小麦生育阶段干旱特征,旨在认识分析和掌握冬小麦生育期干旱演变特征以及干旱发生规律,对保障粮食安全和防旱减灾提供了科学依据。     

西藏农牧区家庭生活用水特征及其影响因素

农村家庭用水结构调查与影响因素分析是分析农村用水情况,保障用水安全的基础。采用问卷调查和实测的方式获取西藏自治区9个县（市、区）的84个家庭的用水数据,对比分析不同家庭的用水量及用水结构,总结了西藏农村家庭用水的影响因素。研究表明：农村家庭人均生活用水量在33~38 L/d之间,家庭差异显著,主要集中在洗衣、洗菜、洗碗用水三项,家庭生活用水的主要用水项是卫生用水和厨房用水;生产方式与文化风俗习惯影响家庭用水水平,人口组成影响用水结构,常住人口数和家庭收入水平与家庭人均用水量呈现显著负相关。     

Impacts of climate change on winter wheat growth in Panzhuang Irrigation District, Shandong Province

Global climate change has significant impacts on agricultural production. Future climate change will bring important influences to the food security. The CERES-Wheat model was used to simulate the winter wheat growing process and production in Panzhuang Irrigation District (PID) during 2011–2040 under B2 climate scenario based on the Special Report on Emissions Scenarios (SRES) assumptions with the result of RCMs (Regional Climate Models) projections by PRECIS (Providing Regional Climates for Impacts Studies) system introduced to China from the Hadley Centre for Climate Prediction and Research. The CERES-Wheat model was calibrated and validated with independent field-measured growth data in 2002–2003 and 2007–2008 growing season under current climatic conditions at Yucheng Comprehensive Experimental Station (YCES), Chinese Academy of Sciences (CAS). The results show that a significant impact of climate change on crop growth and yield was noted in the PID study area. Average temperature at Yucheng Station rose by 0.86℃ for 1961–2008 in general. Under the B2 climate scenario, average temperature rose by 0.55℃ for 2011–2040 compared with the baseline period (1998–2008), which drastically shortened the growth period of winter-wheat. However, as the temperature keep increasing after 2030, the top-weight and yield of the winter wheat will turn to decrease. The simulated evapotranspiration shows an increasing trend, although it is not very significant, during 2011–2040. Water use efficiency will increase during 2011–2031, but decrease during 2031–2040. The results indicate that climate change enhances agricultural production in the short-term, whereas continuous increase in temperature limits crop production in the long-term.     

气候变化对山东省潘庄灌区冬小麦生长的影响(英文)

Global climate change has significant impacts on agricultural production.Future climate change will bring important influences to the food security.The CERES-Wheat model was used to simulate the winter wheat growing process and production in Panzhuang Irrigation District(PID) during 2011-2040 under B2 climate scenario based on the Special Report on Emissions Scenarios(SRES) assumptions with the result of RCMs(Regional Climate Models) projections by PRECIS(Providing Regional Climates for Impacts Studies) system introduced to China from the Hadley Centre for Climate Prediction and Research.The CERES-Wheat model was calibrated and validated with independent field-measured growth data in 2002-2003 and 2007-2008 growing season under current climatic conditions at Yucheng Comprehensive Experimental Station(YCES),Chinese Academy of Sciences(CAS).The results show that a significant impact of climate change on crop growth and yield was noted in the PID study area.Average temperature at Yucheng Station rose by 0.86℃ for 1961-2008 in general.Under the B2 climate scenario,average temperature rose by 0.55℃ for 2011-2040 compared with the baseline period(1998-2008),which drastically shortened the growth period of winter-wheat.However,as the temperature keep increasing after 2030,the top-weight and yield of the winter wheat will turn to decrease.The simulated evapotranspiration shows an increasing trend,although it is not very significant,during 2011-2040.Water use efficiency will increase during 2011-2031,but decrease during 2031-2040.The results indicate that climate change enhances agricultural production in the short-term,whereas continuous increase in temperature limits crop production in the long-term.     

黄淮海平原典型农区冬小麦干热风灾害的变化分析——以商丘为例

为探明黄淮海典型农区冬小麦干热风灾害发生规律,以商丘为例,利用1963-2012年历年冬小麦生长后期的气象资料,系统分析了近50年冬小麦干热风年平均发生日数分布特征及其对气候变化的响应,探讨了干热风发生次数与冬小麦单产的关系。结果表明:近50年商丘地区冬小麦轻度、重度干热风灾害总体表现为减少趋势,轻度、重度干热风灾害年际变化较大,20世纪60年代干热风危害最严重,20世纪80年代和最近10年干热风危害较轻。1972年干热风发生期日最高气温呈现递增突变(P0.05),14时风速在1984年前后出现了显著的减小突变(P0.05),14时相对湿度显著增加,在1981年出现了一次显著的递增突变(P0.05)。日最高气温、14时风速和14时相对湿度三个气候要素综合作用决定了商丘冬小麦干热风灾害整体上呈递减趋势,其中风速的显著减小对干热风灾害减弱起主要作用。商丘地区干热风的年均发生日数与冬小麦单产呈明显的负相关关系。     

土地利用对地下水位下降的影响--以河北平原为例

本文利用简化的水量平衡模型,模拟了河北平原1985-1995年多年平均降水入渗系数和含水层给水度,在此基础上计算出各用水部门和各种农作物平均每年引起的地下水位下降幅度。结果表明:农业用水是引起河北平原地下水位下降的主要因素,其次是工业用水和生活用水。小麦引起的地下水位下降幅度最大,谷子最小。生产单位产值的小麦消耗地下水量最大,引起的地下水位下降幅度也最大,生产单位产值的蔬菜消耗地下水量最小,引起的地下水位下降幅度也最小。实现河北平原地下水资源可持续利用,调整种植业结构当务之急。