基于MODIS遥感资料估算高原地表潜热通量

利用2014年夏季青藏高原9个观测站的实测资料,首先分析了夏季高原地区的湍流输送特征,并对MODIS(Moderate-Resolution Imaging Spectroradiometer)地表潜热产品在高原地区的适用性进行检验,进一步在潜热模型中引入MODIS昼夜地表温度来估算研究区的地表潜热,并将估算值与实测值进行对比。结果表明:下垫面以裸土/稀疏植被为主的阿里站能量输送以感热为主,其他观测站的湍流输送则以潜热输送为主;MODIS潜热产品在高原各地区的适用性存在差异,产品在高原东部偏东地区适用性较好,其他地区适用性较差,且高原西部的潜热有效数据大量缺失;而新提出的方法不仅可以弥补高原西部地表潜热的缺失,还可以提高地表潜热的估算精度,估算值与实测值之间相关系数达到0.77,均方根误差仅为29.8 W/m2,相对误差为35.59%;模型给出的高原地区地表潜热区域分布特征与高原的地表覆盖类型吻合较好,说明模型给出的高原地表潜热分布是合理的。     

基于MODIS和NOAA数据尺度转换的若尔盖植被变化研究

为获得若尔盖地区较长时间序列的遥感植被指数,采用重采样技术和一元线性回归方法实现了GIMMS NDVI和MODIS NDVI的空间尺度转换和时间尺度外推。结果表明:（1）不同重采样方法对MODIS NDVI数据的影响与空间尺度有关,对GIMMS NDVI数据的影响则与空间尺度关系不大;（2）空间分辨率2.5 km,对不同植被类型可建立GIMMS NDVI和MODIS NDVI数据的一元线性转换关系,利用GIMMS NDVI拟合的结果与MODIS数据的差值统计符合正态分布;（3）1982—2013年,以1998年为节点若尔盖地区的植被先退化后逐渐恢复,尽管近几年植被指数平均水平高于研究初期,但局部地区的植被退化形势仍然比较严峻。     

西藏农村远程教育与信息服务体系发展对策研究

西藏农村远程教育与信息服务体系是实现西藏农牧业跨越式和可持续发展、增加农牧民收入和促进农村经济、文化快速发展的重要平台。在基于西藏农牧业教育、农村信息化建设的现状的条件下,通过对农村远程教育与信息化服务所面临的主要问题的分析,提出了西藏农村远程教育与信息服务体系发展的对策。     

Finding a needle in the haystack: Regional analysis of suitable Eld’s deer (Cervus eldi) forest in Southeast Asia

For species whose decline preceded the modern era and whose distribution is in the developing world, it is difficult to map suitable habitat across its former range. Eld’s deer (Cervus eldi) is an endangered cervid whose range across Southeast Asia was reduced during the last century to disjoint populations in Myanmar and Cambodia. We used ecological data from the present populations to determine landscape and habitat parameters that would help us predict the occurrence of the species in forests not yet surveyed. The suitable-forest GIS model was created using four readily available datasets for elevation, forest type, canopy closure, and human density. Comparison of the GIS model with 24 verified sightings of Eld’s deer during recent large mammal surveys in Cambodia, found 22 sightings (92%) within predicted suitable forest. Use the suitable-forest GIS model to survey a province in southern Lao People’s Democratic Republic, located a single, previously unreported population from 9 patches surveyed. In a separate analysis, a logistic regression model to predict Eld’s deer habitat in Northern Cambodia found percent tree cover, presence of wetlands, and distance to villages as the best predictors of deer, similar to variables used in the GIS model, with the exception of the importance of wetlands. Using mean annual rainfall to rank suitable-forest patches identified in the GIS model indicated dry dipterocarp forests in Northeastern Cambodia and Northern Myanmar have the highest potential to conserve eld’s deer. Examination of the suitable-forest GIS map and current protected areas indicated only Cambodia, with 11% suitable forest protected, has placed sufficient dry dipterocarp forest under protected status. Other Southeast Asia countries have not recognized dry dipterocarp forest as a significant ecotype worthy of conservation status.     

黄土高原地区生态淤地坝效益分析探讨——以陕西延安地区为例

淤地坝工程是黄土高原区非常重要的水土保持措施之一,淤地坝的效益与一般水土保持建设工程的效益既有相同之处,又有不同之处。以陕西延安地区为例,对淤地坝的效益计算从生态安全、防洪减沙、淤积造地等几个方面进行了分析计算,为延安地区淤地的效益分析与评价提供理论和实践依据。     

The Optimization for Crop Planning and Some Advances for Water-Saving Crop Planning in the Semiarid Loess Plateau of China

The establishment of water-saving crop planning is an inevitable choice of the water-saving agriculture for the water-deficiency region in the arid and semiarid Loess Plateau of China and the world. The water-saving crop planning refers to the planting structure that centres the adjustment of the crop's adaptation to water, the optimization of temporal and spatial layout for crops, the local natural resources, marketing resources, human resources and financial input to enable region or basin with limited water resources to achieve the maximum economic, social and ecological benefits of planting industry under certain technology and economy. After the analysis on the research progress of optimization theory, optimization goals, optimization methods of water-saving cultivation structure and macro-control measures, it is pointed out that the main deficiencies of the current research of water-saving cultivation pattern optimization are lacking of a strong theoretical basis, and the immaturity of optimization technologies. The future crucial research direction will focus on five aspects such as the special optimization theory system, the division methods by studying the watershed unit and using 3S technology, optimization model based on multi-objective evolutionary algorithm, evaluation of rationality and macro-control measures on the basis of the public participation.     

黄土高原径流林业技术研究

以降水资源环境容量为基础控制林分密度,试验了不同集水技术对林地土壤水环境的改善作用,对林木生长的影响及集水技术的适用性.10年试验研究和大面积示范结果表明,在年降水量410mm左右地区造林,林地坡面经过不同的防渗处理,当每株树具有8m~2的集水面时,可使2m~2的植树带内收集到570～1270mm降水,造林成活率最高达到98%,林木生长量可提高40%～80%.     

黄土高原农业调水增产技术浅析

黄土高原地区水资源严重缺乏,大部分地区年降雨量为250～600mm,地表水平均径流量为136.91亿m3,人均484.58m3,仅为全国人均水平的1／3。阐述了黄土高原地区农业调水技术发展状况以及培肥地力以肥调水、轮作倒茬调水、抗旱育种调水、间隙休闲调水、径流农业调水、节水灌溉农业调水和化学技术调水增产技术的作用,为黄土高原发展节水型农业提供理论依据。     

黄土高原水土流失区森林资源价值核算

概述了目前常用的森林资源价值核算方法,较系统、全面地核算了黄土高原水土流失区森林资源环境价值(包括涵养水源价值、保育土壤价值、固碳制氧价值、景观游憩价值和净化环境污染价值)和实物价值(包括林地价值、林木和果品价值)的现值,并且分析了不同贴现率时森林资源价值的差异,指出基于可持续发展的需要,应取低贴现率进行森林资源价值核算。同时计算结果表明,森林资源环境价值是森林资源价值的主要部分,充分说明了森林环境价值的重要性,应该引起人们的高度重视。     

黄土高原植被恢复与建设的理论和技术问题

黄土高原地区植被恢复与建设是我国重大的生态工程,有巨大的战略意义。主要论述了植被恢复与建设中存在的科学理论和技术问题,以期在植被恢复与建设实践中,能用理论做科学指导,使技术得以充分持续地推广和应用,使植被恢复与建设产生明显的效果。