雲南雲縣那撒壩之褐炭田

雲縣褐炭係羅爲垣所發现,並测製鑛區圖,呈領探鑛欐。其後滇緬鉄路工程處亦注意及之。民國二十八年冬,西南聯合大學張印堂教授會一至其地。據前人之觀察,均認爲烟煤,且於煤田之價值,颇表樂觀,滇緬路線煙煤不豊,雲縣煤田,實     

华北平原禹城市耕地变化与驱动力分析(英文)

Taking Yucheng, a typical agricultural county in Shandong Province as a case, this study applied Logistic regression models to spatially identify factors affecting farmland changes. Using two phases of high resolution imageries in 2001 and 2009, the study obtained the land use and farmland change data in 2001-2009. It was found that the farmland was reduced by 5.14% in the period, mainly due to the farmland conversion to forest land and built-up land, although part of forest land and unused land was converted to farmland. The results of Logistic regressions indicated that location, population growth and farmer income were main factors affecting the farmland conversion, while soil types and pro-curvature were main natural factors controlling the distribution of farmland changes. Regional differences and temporal-spatial variables of farmland changes affected fitting capability of the Logistic re-gression models. The ROC fitting test indicated that the Logistic regression models gave a good explanation of the regional land-use changes. Logistic regression analysis is a good tool to identify major factors affecting land use change by quantifying the contribution of each factor.     

介绍玉屏水文站所作的长期預报

本文用对比分析和农諺所作的长期預报效果是值得重視的,在开展长期預报工作中,有显著的参考价值。其中所用的甲子、五行之說是否有科學理論根据,尚无定論,是否能用作預报依据,亦待進一步探討,本刊本着发揚敢想、敢說、敢作的精神,現将全文發表,希望大家討論、补充。     

华北平原降水的长期趋势分析(英文)

The North China Plain (NCP) is the most important food grain producing area in China and has suffered from serious water shortages. To capture variation water availability, it is necessary to have an analysis of changing trends in precipitation. This study, based on daily precipitation data from 47 representative stations in NCP records passed the homogeneity test, analyzed the trend and amplitude of variation in monthly, seasonal and annual precipitation, annual maximum continuous no-rain days, annual rain days, rainfall intensity, and rainfall extremes from 1960 to 2007, using the MannKendall (M-K) test and Sen’s slope estimator. It was found that monthly precipitation in winter had a significant increasing trend in most parts, while monthly precipitation in July to September showed a decreasing trend in some parts of NCP. No significant changing trend was found for the annual, dry and wet season precipitation and rainfall extremes in the majority of NCP.A significant decreasing trend was detected for the maximum no-rain duration and annual rain days in the major part of NCP. It was concluded that the changing trend of precipitation in NCP had an apparent seasonal and regional pattern, i.e., precipitation showed an obvious increasing trend in winter, but a decreasing trend in the rainy season (July to September), and the changing trend was more apparent in the northern part than in the southern and middle parts. This implies that with global warming, seasonal variation of precipitation in NCP tends to decline with an increasing of precipitation in winter season, and a decreasing in rainy season, particularly in the sub-humid northern part.     

GIS建库系统(GISID-B)设计

本文介绍了作者研制的可独立于商品化数据库管理系统的地理信息系统(GISID)的前端软件-建库系统的数字化输入、图式符号设计、图形编辑、属性编辑和制图输出等主要内容。然后说明了该系统的主要特点和关键技术,最后讨论了该系统的应用前景、存在的问题及今后的研究方向。     

EPIC模型及其应用

作物生长模型是定量评估作物生产潜力的重要工具。EPIC 模型自1985 年发表后, 以其强大的功能在全球范围内得到了广泛应用。本文简述了EPIC模型的主要结构和功能, 介绍了运行该模型所需的数据及数据库的构建方法, 总结了EPIC模型的主要应用领域以及在中国包括作物生产潜力评估、水分和气候变化对产量影响、养分循环和损失、土壤碳储量变化、土壤侵蚀预测等方面的应用情况, 最后提出了EPIC模型使用时的注意事项和研究展望。