辽宁省不同地区发展日光温室适宜性分析

温度和光照是影响日光温室环境的主要因素,结合辽宁省农业气候资源的地域特点,对辽宁省不同地区发展日光温室的适宜性进行简要评价,并提出了不同地区发展适宜性建议。     

北京市地下空间资源利用地质适宜性评价研究

城市地下空间资源开发利用受到多种地质条件的综合影响,在现有技术条件下进行开发、利用以及运营时不可避免产生一定风险,为规避风险,要对地下空间资源开发利用的适宜性开展评价。本文以地下空间资源利用地质适宜性为评价对象,在北京市地下空间资源调查评价研究成果的基础上,建立了基于基础条件和约束条件相结合的地下空间资源开发利用地质适宜性评价指标体系,确定了各因子指标量化取值标准,建立了综合评价模型,划分了3个评价等级,通过模糊数学法和层次分析法,对北京市某地区地下空间资源开发利用地质适宜性进行了综合评价,取得了高度符合地质条件的优良成果。     

基于高山生境特征的岩石园植物造景设计研究

以解决岩石园"如何设计""为何设计"的问题入手,通过分析国内外知名岩石园,从而得到当前岩石园规划设计依据的类型,确定以高山生境特征作为设计依据。但高山生境在城市中无法完全复制,因此仅以模仿其景观风貌特点作为设计依据。以中国高山生境为例,通过对生长的高山植被景观风貌进行提炼,得到高山植被外观风貌构建模式图;结合外观风貌特点,提取高山植被景观元素特点和设计要点,通过植物种类替换,构建出岩石园基于高山生境特征的植物造景设计模式。     

鲜湿米粉原料加工适应性及配米技术研究

针对我国米粉原料质量不稳定、标准化差、专用品种不明晰等问题,选取我国种植广泛的12种籼稻,研究鲜湿米粉原料加工适应性及配米技术。因子分析及聚类分析结果表明：天优华占、中嘉早1号、中早39号适合加工鲜湿米粉。淀粉含量、直链淀粉含量、支链淀粉含量、直支比、脂肪含量、衰减值、最终黏度值、回生值、白度与米粉综合品质显著相关,核心指标的适宜范围为：总淀粉含量78.5~85.5 g/100g、直链淀粉含量24.3~27.3 g/100g、支链淀粉含量53.5~58.5 g/100g、直支比0.44~0.48、衰减值400~800 cP、最终黏度值3500~3900 cP、回生值1600~1850 cP、白度大于76.4、脂肪含量0.72~1.14 g/100g。配米试验结果表明：把理化性质不同的稻米依据特定的标准进行精准化调配,制作的米线优于市售产品,该方法有利于保证原料的稳定性和产品的质量。     

GIS技术在土地利用环境适宜性评价中的应用

讨论了土地利用环境适宜性评价的模糊综合评价法,以模糊综合评价法的模型为基础,开发了一个基于MapObject的土地利用适宜性评价系统,以铜山县为例,对土地利用耕地水环境进行适宜性评价。     

Comparative analysis of glacial and nival streamflow regimes with implications for lotic habitat quantity and fish species richness

Growing interest in the differential responses of glacial and nival rivers to climatic forcing, and in ecological distinctions between the two streamflow regimes, suggests the need for a better comparative understanding of how the annual hydrologic cycle differs with presence or absence of catchment glacial cover. In this study, timing and magnitude characteristics of the average annual hydrographs of five glacierized and four nival catchments in the southwestern Canadian subarctic are empirically identified and compared. Likely effects upon fish habitat are qualitatively assessed, and net fisheries potential is tentatively investigated using taxa richness data. The chief hydrological conclusions at P < 0.05 using Kolmogorov–Smirnov and empirical orthogonal function analyses are: (1) catchment glacial cover results in freshets that are longer, larger, and peak later than those experienced by the nival regime; (2) the winter baseflows of glacial rivers are also much higher on a unit‐catchment‐area basis; and (3) basin scale and degree of catchment glacial cover are of comparable importance in determining the magnitude of the annual hydrologic cycle. These differences arise from the greater availability, both in volume and over time, of meltwater in glacial catchments, which in part reflects the consistently negative alpine glacial mass balances observed both in the present study area and globally under historical climatic warming. Such regime distinctions result in increased spawning season and winter aquatic habitat availability, which may in turn offset negative habitat characteristics previously identified for glacial river ecosystems. While previous studies have suggested that glacial influences tend to decrease macroinvertebrate diversity and increase salmon populations, preliminary analysis of available fish species presence/absence data from the current study area tentatively appears to suggest similar or, perhaps, slightly higher fish taxa richness relative to nival streams; in all three cases, however, catchment lake cover may play a key hydroecological modifying role. The results strongly confirm and extend existing understanding of glacial–nival regime differences with respect to both streamflow and fisheries ecology, and raise new questions for future research. Copyright © 2005 John Wiley & Sons, Ltd.     

Measuring the reach‐scale geomorphic diversity of streams: application to a stream disturbed by a sediment slug

There is increasing evidence that greater physical diversity in a stream leads to a greater diversity of habitats, and hence species. Human impact has reduced the physical diversity within many stream systems. This paper reviews a range of techniques used to measure the physical diversity of a stream reach and specifically examines variability measures of a stream's thalweg, cross‐section and sediment size at the scale of millimetres to metres. Each measure was evaluated against synthetic data with different levels of diversity. From the original thirteen, eight measures were considered appropriate for application to data measured in the field. Creightons Creek (Victoria, Australia) was selected as a test site as it contains areas that are in their original geomorphic condition, as well as sections that have been disturbed by increased bed‐load in the form of a sediment slug. All eight measures showed that the area impacted by the sediment slug was less diverse in terms of its geomorphic variability than the unimpacted reaches. This suggests that massive increases in sediment load to streams will reduce the geomorphic complexity of a stream, and in turn, the diversity of habitat for biological communities. Copyright © 2005 John Wiley & Sons, Ltd.     

河流健康评估的原则和方法

河流健康评估应包括物理-化学评估、生物栖息地质量评估、水文评估和生物群落的评估等内容.评估需要建立生境因子与生物因子的相关关系,需要建立基准点即参照系统,需要明确水文条件、水质条件和栖息地质量三个要素,需要因地制宜地为每一条河流建立健康评估体系及建立生物监测系统和网络.     

Application of a 2D hydrodynamic model to design of reach‐scale spawning gravel replenishment on the Mokelumne River,California

In‐stream chinook salmon (Oncorhynchus tschawytscha) spawning habitat in California's Central Valley has been degraded by minimal gravel recruitment due to river impoundment and historic gravel extraction. In a recent project marking a new direction for spawning habitat rehabilitation, 2450 m³ of gravel and several boulders were used to craft bars and chutes. To improve the design of future projects, a test was carried out in which a commercial modelling package was used to design and evaluate alternative gravel configurations in relation to the actual pre‐ and post‐project configurations. Tested scenarios included alternate bars, central braid, a combination of alternate bars and a braid, and a flat riffle with uniformly spaced boulders. All runs were compared for their spawning habitat value and for susceptibility to erosion. The flat riffle scenario produced the most total, high, and medium quality habitat, but would yield little habitat under flows deviating from the design discharge. Bar and braid scenarios were highly gravel efficient, with nearly 1 m² of habitat per 1 m³ of gravel added, and yielded large contiguous high quality habitat patches that were superior to the actual design. At near bankfull flow, negligible sediment entrainment was predicted for any scenario. Copyright © 2004 John Wiley & Sons, Ltd.     

Effects of channel morphology and sensor spatial resolution on image-derived depth estimates

The utility of remote sensing in the study of fluvial systems depends upon the extent to which image data can be used to derive quantitative information of sufficient accuracy and precision for specific applications. In this study, we evaluate the effects of channel morphology on depth retrieval by coupling a radiative transfer model to various morphologic scenarios. Upwelling radiance L_u spectra generated for a range of depths (2-150 cm) and benthic cover types (limestone, periphyton, and gravel) were linearly mixed to simulate sub-pixel bed topography and substrate heterogeneity. For sloping bottoms, solar-streambed geometry modified L_u relative to a level bottom, especially for beds sloping steeply away from the sun. Aggregate pixel scale L_u spectra were compared to a database of simulated spectra to determine the radiance-equivalent depth of a uniform bottom (REDUB). REDUB spectra for hypothetical stepped streambeds indicated underestimation of the actual area-weighted mean depth, but the ln (L_u,560/L_u,690) REDUB ratio consistently reproduced the pixel-scale mean for beta distributions of depths. Similarly, when both dark periphyton and bright limestone substrates occurred within a pixel, REDUB spectra produced large errors while the ratio proved robust. Along channel banks, pixels will inevitably be mixed, and our simulations indicated that although bank fractions estimated by spectral mixture analysis were highly accurate for vegetated cutbanks, gravel bars were sensitive to the selection of both aquatic and terrestrial end members and subject to relatively large fraction errors. These theoretical results were tested using a ratio-based relative depth map and two-end member mixture models derived from a hyperspectral image of the Lamar River in Yellowstone National Park, which also served to illustrate the importance and applicability of our simulations. The primary conclusions of this study are that 1) the ratio-based algorithm is well-suited to complex river channels; 2) channel morphology and sensor spatial resolution must be considered jointly during data collection and analysis; and 3) the accuracy and precision of depth estimates are influenced by channel morphology and thus vary spatially.