中国土地适宜性评价研究进展

长期以来, 土地适宜性评价一直在土地规划利用中起着基础性作用。近十几年, 农业土地 适宜性评价持续深入开展, 城市用地、旅游用地、土地整理复垦以及其他用地的土地适宜性评价 日渐增多; 基于此, 土地适宜性评价的理论思想得到了进一步的丰富, 景观生态学被引入土地适 宜性评价, 可持续利用观深入人心; 土地适宜性评价在方法上也有新的发展, GIS 在土地适宜性 评价中得到广泛的应用, 这使得土地适宜性评价更为灵活、科学。     

太湖富营养化遥感评价研究

讨论利用Landsat/TM数据进行太湖富营养化评价的可行性,提出一种与常规湖泊富营养化评价方法(综合营养状态指数法)接轨的遥感评价新方法,建立了太湖富营养化遥感评价模型(中国湖泊营养状态指数模型TSIc),利用Landsat/TM数据定量反演出的太湖Chl - a浓度作为TSIc模型的输入变量,计算出太湖营养状态TSIc值,最后按照湖泊富营养化评价分级标准将太湖营养状态分为贫营养(TSIc＜30)、中营养(30≤TSIc≤50)、轻度富营养(50＜TSIc≤60)、中度富营养(60＜TSIc≤70)和重度富营养(＞70)5级.     

中国高技术产业投入产出有效性地区差异分析

运用DEA方法,从综合有效性、技术有效性和规模有效性3方面对全国30个省(市、区)(缺失西藏数据)的高技术产业投入产出有效性进行实证分析,根据技术有效性和规模有效性对其发展状态进行分类并提出相应对策。结果表明,我国高技术产业在现有的发展水平上存在投入产出效率不高、总体规模偏大等问题,各省市需针对自身特点制定相应发展策略。     

石家庄地面水回渗地下过程的氮行为影响试验研究

石家庄是我国北方地下水位下降较大的城市之一,利用其毗邻滹沱河宽阔河滩,地面水可直接入渗补给地下水的有利水文地质条件,实施地面水回渗地下工程,将具有现实意义.为探索地面水回渗后的水质变化,该文针对地面水在回渗过程中对水质起限制性影响的氮行为作用进行了模拟试验研究.结果显示,利用2 m厚的滹沱河细砂土及与粘土按一定比例的混合砂土层,可对间歇式实施地面水回渗中的铵氮组分形成一定容量的截留去除,并且该截留量又在随回渗次数的增加而缓慢下降,当采用人工增加环境碱度及湿度的办法后可消除这种下降.同时,还显示对回渗水中硝酸氮的去除率不高,但若采用人工添加乙醇碳源和接种优势脱氮微生物菌种方法,硝酸氮的去除率将会得到较大提高.     

巩乃斯避暑旅游气象指数分析与评价

根据巩乃斯、和静站2009—2018年6—8月的逐日平均气温、最高气温、相对湿度、风速等气象观测资料,采用对比分析、通径分析及模糊综合评价等方法对巩乃斯地区夏季避暑旅游气象资源优势进行分析和评价.结果表明:巩乃斯夏季气候凉爽、湿度适宜、风速不大,人体感觉凉爽、舒适,适合避暑旅行.人体舒适度与空气温度呈显著正相关,与相对...     

Assessing the potential of reservoir outflow management to reduce sedimentation using continuous turbidity monitoring and reservoir modelling

In‐stream sensors are increasingly deployed as part of ambient water quality‐monitoring networks. Temporally dense data from these networks can be used to better understand the transport of constituents through streams, lakes or reservoirs. Data from existing, continuously recording in‐stream flow and water quality monitoring stations were coupled with the two‐dimensional hydrodynamic CE‐QUAL‐W2 model to assess the potential of altered reservoir outflow management to reduce sediment trapping in John Redmond Reservoir, located in east‐central Kansas. Monitoring stations upstream and downstream from the reservoir were used to estimate 5.6 million metric tons of sediment transported to John Redmond Reservoir from 2007 through 2010, 88% of which was trapped within the reservoir. The two‐dimensional model was used to estimate the residence time of 55 equal‐volume releases from the reservoir; sediment trapping for these releases varied from 48% to 97%. Smaller trapping efficiencies were observed when the reservoir was maintained near the normal operating capacity (relative to higher flood pool levels) and when average residence times were relatively short. An idealized, alternative outflow management scenario was constructed, which minimized reservoir elevations and the length of time water was in the reservoir, while continuing to meet downstream flood control end points identified in the reservoir water control manual. The alternative scenario is projected to reduce sediment trapping in the reservoir by approximately 3%, preventing approximately 45 000 metric tons of sediment from being deposited within the reservoir annually. This article presents an approach to quantify the potential of reservoir management using existing in‐stream data; actual management decisions need to consider the effects on other reservoir benefits, such as downstream flood control and aquatic life. Copyright © 2012 John Wiley & Sons, Ltd.     

An integrated procedure to evaluate hydrological models

The growing concern for health‐related problems deriving from pollutants leaching is driving national and international administrations to support the development of tools for evaluating the effects of alternate management scenarios and identifying vulnerable areas. Cropping systems models are powerful tools for evaluating leachates under different environmental, social, and management conditions. As percolating water is the transport vehicle for pollutants transport in soil, a reliable evaluation of water balance models is a fundamental prerequisite for investigating pesticides and nitrate fate. As specific approaches for the evaluation of multi‐layer evolution of state variables are missing, we propose a fuzzy‐based, integrated indicator (I_SWC: 0, best; 1, worst) for a comprehensive evaluation of soil water content (SWC) simulations. We aggregated error metrics with others quantifying the homogeneity of errors across different soil layers, the capability of models to reproduce complex dynamics function of both time and soil depth, and model complexity. We tested I_SWC on a sample dataset where the models CropSyst and CERES‐Wheat were used to simulate SWC for winter wheat systems. I_SWC revealed that, in the explored conditions, the global assessment of the two models' performances allowed identification of CropSyst as the best (average I_SWC = 0·441, with a value of 0·537 obtained by CERES‐Wheat), although each model prevailed for some of the metrics. CropSyst presented the highest accuracy (average agreement module = 0·400), whereas CERES‐Wheat's accuracy was slightly worse, although achieved with a simplified modelling approach (average Akaike Information Criterion = − 230·44), thereby favouring large‐area applicability. The non‐univocal scores achieved by the models for the different metrics support the use of multi‐metric evaluation approaches for quantifying the different aspects of water balance model performances. Copyright © 2010 John Wiley & Sons, Ltd.     

场地地震效应及其预测的某些考虑

本文从场地地震危险性评价,地震危险性概率分析、场地地震工程地质单元划分、地震反应分析、活断层工程分类等五个方面、论述场地地震效应及其预测中基本原理和方法。根据工程地震危险性评价和分析、地震小区划等地震工程实践,对场地地震效应及其预测提供一些基本考虑和经验     

建议一个弥补震害资料不足的方法

本文用模糊贴近度原则作类比,提供了一种弥补震害预测时历史地震资料不足的方法,途径是将一个烈度之下的震害经验推广到其他烈度上去用。实践证明,用这种建立在近似推理基础之上的方法推导出来的结果,在总体趋势上和真实情况完全一致。     

The System Analysis and Reliability Evaluation of Rock Slopes

The principal of preferred plane analysis is a new research view and model of rock slope engineering geology. It advocates that the rock slope stability, boundary conditions and failure model are controlled by preferred planes. Therefore, the problem of slope stability evaluation can be converted into the search for preferred planes and determination of preferred separating bodies. The organic combination of the deterministic model and the indeterministic model can be realized by applying the systems engineering principle and the research model and method of reliability analysis in the quantitative evaluation and prediction of rock slope stability. Finally, the paper presents the case studies of slopes of the Yangtze Gorge Project and the Ma'anshan openpit mine.