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891.
膨胀岩(土)病害是一种特殊的工程地质现象。文章通过对广西军体校膨胀岩山体滑坡的整治经验进行总结,探讨其成因机理,提出对整治设计的一些看法 相似文献
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Human settlement evaluation in mountain areas based on remote sensing, GIS and ecological niche modeling 总被引:3,自引:0,他引:3
The Qinghai-Tibet Plateau is the world’s highest and largest plateau. Due to increasing demands for environment exploration and tourism, a large transitional area is required for altitude adaptation. Hehuang valley, which locates in the transition zone between the Loess Plateau and the Qinghai-Tibet Plateau, has convenient transportation and relatively low elevation. Our question is whether the geographic conditions here are appropriate for adapted stay before going into the Qinghai-Tibet Plateau. Therefore, in this study, we examined the potential use of ecological niche modeling (ENM) for mapping current and potential distribution patterns of human settlements. We chose the Maximum Entropy Method (Maxent), an ENM which integrates climate, remote sensing and geographical data, to model distributions and assess land suitability for transition areas. After preprocessing and selection, the correlation between variables and spatial autocorrelation input data were removed and 106 occurrence points and 9 environmental layers were determined as the model inputs. The threshold-independent model performance was reasonable according to 10 times model running, with the area under the curve (AUC) values being 0.917 ± 0.01, and 0.923 ± 0.002 for test data. Cohen’s kappa coefficient of model performance was 0.848. Results showed that 82.22% of the study extent was not suitable for human settlement. Of the remaining areas, highly suitable areas accounted for 1.19%, moderately for 5.3% and marginally for 11.28%. These suitable areas totaled 418.79 km2, and 86.25% of the sample data was identified in the different gradient of suitable area. The decisive environmental factors were slope and two climate variables: mean diurnal temperature range and temperature seasonality. Our model showed a good performance in mapping and assessing human settlements. This study provides the first predicted potential habitat distribution map for human settlement in Ledu County, which could also help in land use management. 相似文献
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利用辽宁省59个国家气象站2008—2017年6—8月逐时地面观测资料,综合考虑夏季气候舒适度和高影响天气对避暑旅游的不利影响,确定辽宁避暑旅游气候适宜度评价方法,分析了辽宁避暑旅游适宜度时空分布,为公众及旅游相关部门了解当地避暑旅游气候资源提供参考。研究表明:(1)辽宁避暑旅游适宜度由西北到东南逐渐增强,59个地市(县)中,很适宜避暑的有14个,适宜避暑的有22个,较适宜避暑的有16个。(2)夏季辽宁大部避暑旅游气候舒适度较好,辽东和辽南气候舒适度优于辽宁中部和西部。辽宁东部的本溪和沿海的丹东、大连、葫芦岛和锦州南部气候舒适度等级最高,避暑气候条件更好。(3)辽宁夏季暴雨高风险区在东南部的宽甸、丹东和凤城一带。高温高风险区在朝阳大部和锦州西部。大风高风险区在铁岭北部、彰武、锦州、营口和长海。雷暴高风险区在铁岭、抚顺东部、朝阳西部和庄河一带。(4)6月、8月是辽宁适合避暑旅游的月份,尤其是6月,避暑旅游适宜度最高,适宜面积最大。8月份次之,7月避暑旅游适宜度较差。 相似文献
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Yuanhong Deng Shijie Wang Xiaoyong Bai Luhua Wu Yue Cao Huiwen Li Mingming Wang Chaojun Li Yujie Yang Zeyin Hu Shiqi Tian Qian Lu 《水文研究》2020,34(3):836-851
High-quality soil moisture (SM) datasets are in great demand for climate, hydrology, and other fields, but detailed evaluation of SM products from various sources is scarce. Thus, using 670 SM stations worldwide, we evaluated and compared SM products from microwave remote sensing [Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) (C- and X-bands) and European Space Agency's Climate Change Initiative (ESA CCI)], land surface model [Global Land Data Assimilation System (GLDAS)], and reanalysis data [ECMWF Re-Analysis-Interim (ERA-Interim) and National Centers for Environmental Prediction (NCEP)] under different time scales and various climates and land covers. We find that: (a) ESA CCI and GLDAS have the closest values to the in situ SM on the annual scale, whereas others overestimate the SM; ERA-Interim (averaged R = 0.58) and ESA CCI (averaged R = 0.54) correlate best with the in situ data, while GLDAS performs worst. (b) Overall, the deviations of each product vary in seasons. ESA CCI and ERA-Interim products are closer to the in situ SM at seasonal scales, and AMSR-E and NCEP perform worst in December–February and June–August, respectively. (c) Except for NCEP and ERA-Interim, others can well reflect the intermonthly variation of the in situ SM. (d) Under various climates and land covers, AMSR-E products are less effective in cold climates, whereas GLDAS and NCEP products perform poorly in arid or temperate and dry climates. Moreover, the Bias and R of each SM product differ obviously under different forest types, especially the AMSR-E products. In summary, SM from ESA CCI is the best, followed by ERA-Interim product, and precipitation is an important auxiliary data for selecting high-quality SM stations and improving the accuracy of SM from GLDAS. These results can provide a reference for improving the accuracy of the above SM products. 相似文献
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三个钻孔的岩心表明,南李庄泻湖沉积可分为5层,最大厚度15m左右。根据孢粉、微量元素以及岩相特点可将泻湖的演化分为5个阶段。资料表明,湖水变深时期是气候温湿时期,湖水变浅时期为气候凉干时期,指示泻湖的兴衰明显受气候控制。 相似文献