基于水资源生态足迹的浑河流域水资源利用评价

用水资源生态足迹模型计算浑河流域2005~2013年水资源生态足迹和水资源生态承载力,并基于各评价指标对浑河流域水资源利用情况进行评价。结果表明:2005~2013年浑河流域水资源生态足迹呈现不显著的下降趋势,水资源生态承载力呈现波动变化;流域一直处于水资源生态赤字状态,仅在2010年出现盈余;流域水资源生态足迹指数低于可持续发展足迹指数范围,但万元GDP水资源生态足迹持续下降。总体来看,流域水资源利用处于不可持续状态,但2010年后流域水资源利用效率明显提高,并向着可持续的方向发展。     

卤水镁矿产资源开发态势计量分析

从专利视角出发,对全球卤水镁矿产资源开发技术的发展现状与态势进行了分析,通过专利量的年度走势、区域分布、申请人分布、IPC分布、文本聚类、主题关联等信息,展示了百年卤水镁矿产资源开发的技术概况;为了解近期卤水镁资源开发的状况,分析了近5年全球卤水镁矿产资源开发技术的专利,通过对比分析,展现了卤水镁矿产资源研发的热点与态势。     

尺度重整分析中周期性成分的影响

目前，越来越多的研究者将尺度重整分析(R／S)引入古气候环境研究中。但在这些研究中很少提及周期性成分对尺度重整分析结果的影响。然而实际上，古气候环境演化往往显示出明显的周期性变化，而周期性成分的存在对尺度重整分析具有显著的影响。笔者列举了2个实例对此进行了说明。这些事实表明，在古气候环境研究中，没有考虑周期性成分影响的尺度重整分析的结果需要谨慎使用，有些可能需要做进一步修正。     

企鹅珍珠贝人工养殖及育珠的研究

在幼贝中间养成中采用柱形笼养殖法,母贝的养成中采用穿耳开放式养殖法,与全程采用锥形笼的传统式养殖方法相比较,进行企鹅珍珠贝人工养殖。结果表明:采用本技术养殖企鹅珍珠贝,在幼贝中间养成阶段,比传统养殖的壳高生长速率提高32·1%(P<0·05),壳长生长速率提高30·3%(P<0·01),成活率提高36%(P<0·01);母贝养成阶段,比传统养殖的壳高生长速率提高28·1%(P<0·05),壳长生长速率提高26·7%(P<0·01),成活率提高18·3%(P<0·01)。同时进行企鹅珍珠贝人工培育游离珠实验,植核贝在休养期和育珠期存活率分别为71·2%和54·3%,留核率分别为29·6·6%和21·0%,成珠率58·6%,优质珠比例为26·7%。     

SCISSORS DIFFERENCE AND ITS IMPACTS ON ECONOMIC VALUE OF CULTIVATED LAND IN CHINA

1IN T R O D U C T IO NAs we allknow,China isa countrywith vastpopulationand scarcelandpercapita(Y ANG and LI,2000)."T rea-suringlandverymuch,utilizinlgandrationallaynd pro-tectingthe cultivatedland conscientiously"is funda-mental statepolicyofChina.At the…     

半参数模型在平面坐标转换中的应用

坐标转换在测绘领域一直起着至关重要的作用,而模型的选取又直接制约着转换的精度,通常在坐标转换中采用相似变换（Hermert）的方法,在平面坐标转换过程中一般采用4参数模型。然而当系统误差不可忽略时,该模型处理得到的结果并不理想。本文将半参数模型应用到平面坐标转换中,分别采用4参数模型和半参数模型两种方法对实验数据进行了处理,并进行了对比与分析。实验结果表明：在处理带有系统误差的平面坐标数据时,半参数模型比传统的参数模型更加精确。     

《测绘法》适应性浅析

分析了新时期测绘发展面临的新形势,对《中华人民共和国测绘法》规定的有关概念内涵、管理体制、运行机制、准入制度等的适应性进行了探讨,对进一步修订《中华人民共和国测绘法》提出了建议。     

Winter season stratospheric circulation in the SAMIL/LASG general circulation model

In this paper, we examine the performance of the 26-level version of the SAMIL/LASG GCM (R42/L26) in simulating the seasonal cycle and perpetual winter mean stratospheric circulation as well as its variability by comparing them with the NCEP/NCAR reanalysis. The results show that the model is capable of reproducing many key features of the climatology and seasonal variation of the stratospheric circulation despite that the model’s mean polar vortex is stronger and more zonally symmetric compared to the obse...     

Comparison of AnnAGNPS and SWAT model simulation results in USDA‐CEAP agricultural watersheds in south‐central Kansas

This study was conducted under the USDA‐Conservation Effects Assessment Project (CEAP) in the Cheney Lake watershed in south‐central Kansas. The Cheney Lake watershed has been identified as ‘impaired waters’ under Section 303(d) of the Federal Clean Water Act for sediments and total phosphorus. The USDA‐CEAP seeks to quantify environmental benefits of conservation programmes on water quality by monitoring and modelling. Two of the most widely used USDA watershed‐scale models are Annualized AGricultural Non‐Point Source (AnnAGNPS) and Soil and Water Assessment Tool (SWAT). The objectives of this study were to compare hydrology, sediment, and total phosphorus simulation results from AnnAGNPS and SWAT in separate calibration and validation watersheds. Models were calibrated in Red Rock Creek watershed and validated in Goose Creek watershed, both sub‐watersheds of the Cheney Lake watershed. Forty‐five months (January 1997 to September 2000) of monthly measured flow and water quality data were used to evaluate the two models. Both models generally provided from fair to very good correlation and model efficiency for simulating surface runoff and sediment yield during calibration and validation (correlation coefficient; R², from 0·50 to 0·89, Nash Sutcliffe efficiency index, E, from 0·47 to 0·73, root mean square error, RMSE, from 0·25 to 0·45 m³ s^?1 for flow, from 158 to 312 Mg for sediment yield). Total phosphorus predictions from calibration and validation of SWAT indicated good correlation and model efficiency (R² from 0·60 to 0·70, E from 0·63 to 0·68) while total phosphorus predictions from validation of AnnAGNPS were from unsatisfactory to very good (R² from 0·60 to 0·77, E from ? 2·38 to 0·32). The root mean square error–observations standard deviation ratio (RSR) was estimated as excellent (from 0·08 to 0·25) for the all model simulated parameters during the calibration and validation study. The percentage bias (PBIAS) of the model simulated parameters varied from unsatisfactory to excellent (from 128 to 3). This study determined SWAT to be the most appropriate model for this watershed based on calibration and validation results. Copyright © 2008 John Wiley & Sons, Ltd.