鲁南海滨国家森林公园旅游开发的初步设想   总被引：1，自引：0，他引：1  

柴寿升  陈娟 《海岸工程》1999,18(2):109-113

依托滨海、森林优势,搞好旅游开发,这是鲁南海滨国家森林公园走出困境的必由之路。本文分析了共旅游开发的优势、不足,地开发指导思想与开发目标了探讨,并在此基础上就公园的功能分区规划提出了自己的见解。  相似文献   

Fire Weather in Israel — Synoptic Climatological Analysis     

Noam Levin  Hadas Saaroni 《GeoJournal》1999,47(4):523-538

The study examines the synoptic situations and weather conditions under which occurred Israel's largest forest fires between the years 1987–1995. Annual rainfall and maximum temperature were found to have a positive correlation with both the size of the burnt area and the frequency of fires. A negative correlation was found for the relative humidity at 12 UTC for the same parameters. The fire season in Israel starts in May and ends in November, the peak months being May, June and July. No large fires were observed during the rainy season, December–February, despite the relatively low precipitation characterizing the region. Atmospheric disturbances as well as quasi-stationary systems were found to be favorable for the development of forest fires in Israel: the North African (‘Sharav’) cyclone and the Red Sea trough, which are common during spring and autumn. These systems carry hot, dry air from the deserts and are responsible for 55% of the burnt area from major forest fires in Israel and up to 33% of the major forest fires. Sixty-five percent of the forest fires occurred during the summer all of them under the quasi-stationary system of the Persian Gulf trough. These fires did not spread as widely as those that occurred under the North African cyclone and the Red Sea trough systems. The role of weather in the propagation of fire is exemplified in the case study of the ‘Sha'ar ha Gai’ fire of July 1995 — the biggest forest fire in the history of Israel (1300 ha). This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

利用蓝晶石制作轻质莫来石耐火砖的研究   总被引：1，自引：0，他引：1  

倪文 《地质论评》1999,45(1):71-75

本文研究了利用蓝晶石制作轻质莫来石耐火砖的可行性,并探讨了轻质莫来石耐火砖的基本原理及在烧成过程中的物相变化。实验表明,利用中国丰富的蓝晶石原料可以生产出性能优良的莫来石轻质耐火砖。该制品具有隔热性能好,使用温度高,热容小等特点,是间歇式窑炉轻质耐火内衬的理想材料,可替代同类型的进口产品。  相似文献   

A STUDY ON PARTICIPATORY REFORESTATION PLANNING OF NANTING RIVER     

Lu Xing 《云南地理环境研究》1999,(Z1)

ＴｈｅｄｅｔｅｒｉｏｒａｔｉｏｎｏｆｅｃｏｌｏｇｉｃａｌｅｎｖｉｒｏｎｍｅｎｔｗｈｉｃｈｈａｐｐｅｎｅｄｉｎｔｈｅｍｉｄｓｔｒｅａｍｏｆＮａｎｔｉｎｇＲｉｖｅｒｈａｓｓｅｒｉｏｕｓｌｙａｆｆｅｃｔｅｄｔｈｅｐｅｏｐｌｅ＇ｓｌｉｖｉｎｇａｎｄｗｏｒｋｉｎｇｔｈｅｒｅ,ｓｏｒｅｓｔｏｒｉｎｇ,ｐｒｏｔｅｃｔｉｎｇｔｈｅｅｃｏｌｏｇｉｃａｌｅｎｖｉｒｏｎｍｅｎｔａｎｄｅｎｖｉｒｏｎｍｅｎｔｓｏｕｎｄｄｅｖｅｌｏｐｍｅｎｔａｎｄｅｑｕｉｔａｂｌｙｕｓｅｏｆｔｈｅｌｏｃａｌｒｅｓｏｕｒｃｅｓｏｆＮａｎｔｉ…  相似文献   

福建中亚热带天然阔叶林的主要类型与特征   总被引：13，自引：6，他引：7  

黄清麟  董乃钧 《山地学报》1999,17(4):368-374

按干扰形式和次生演替时间的不同将福建中亚热带天然阔叶林划为近原生阔叶林,早期阔叶林,择伐阔叶林,人促阔叶林及残次阔叶林五大类型,分别从群落结构,树种组成,物种多样性,林分生长,直戏结构,林分密度六方面说明各类型特征。  相似文献   

Exploring the potential of artificial intelligence techniques in prediction of the removal efficiency of vortex tube silt ejector     

Sanjeev Kumar  Chandra Shekhar Prasad Ojha  Nand Kumar Tiwari  Subodh Ranjan 《国际泥沙研究》2023,38(4):615-627

A vortex tube silt ejector is a curative hydraulic structure used to remove sediment deposits from canals and is recognized as one of the most efficient substitutes for physically removing canal sediment. The spatially varied flow in the channel and the rotational flow behavior in the tube make the silt removal process complex. It is even harder to accurately predict the silt removal efficiency by traditional models accurately. However, artificial intelligence(AI) and machine learning approaches...  相似文献   

Variation in canopy conductance of Cunninghamia lanceolata forest and its response to environmental factors after an extreme rainfall event     

Wanqiu Xing  You Cheng  Lilin Yang  Weiguang Wang 《水文研究》2024,38(3):e15121

Canopy conductance (g_c) is a crucial parameter in simulating evapotranspiration and modulating water exchange, but its variation mechanism has regional uncertainties and complex environmental co-controls. In addition, the effect of extreme rainfall on g_c cannot be ignored under the changing climate. Here, we investigated the variation and environmental controls on g_c and the effect of extreme rainfall events in a Cunninghamia lanceolata forest across the subtropical area of Southern China. In July 2020, an extreme rainstorm hit the source area of the Xin'an River, with the cumulative rainfall on July 7 and 8 reaching 216.6 mm. The thermal diffusion probe method was used to measure the density of sap flow, and the environmental factors such as air temperature (T_a), net solar radiation (R_n) and soil water content (SWC) were monitored during the growing seasons of 2020 and 2021. Ultimately, g_c obtained by the Penman-Monteith equation was adopted since the result from the Köstner equation was overestimated. g_c showed a unimodal curve on the diurnal scale, and this characteristic was more obvious after the extreme rainfall. Daily g_c appeared a fluctuating pattern with a maximum in summer. g_c was simultaneously affected by T_a, R_n, water vapour pressure difference (VPD), SWC, among which T_a was the most significant driving factor at both the diurnal and daily timescales. The regulation of T_a, VPD and SWC on g_c had obvious thresholds, and the most definite response mode was VPD (2020: 1.25 kPa; 2021: 0.95 kPa). SWC and T_a were the dominant factors after the rainfall period, and the promotion effect of VPD on post-rainy days turned to inhibition effect on typical sunny days. These findings will further reveal the water exchange mechanism between atmosphere and vegetation and impacts of environmental factors in subtropical coniferous forests, especially after the extreme rainfall events.  相似文献   

A physically based approach to model LAI from MODIS 250 m data in a tropical region     

Pavel Propastin  Stefan Erasmi 《International Journal of Applied Earth Observation and Geoinformation》2010

A time series of leaf area index (LAI) has been developed based on 16-day normalized difference vegetation index (NDVI) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) at 250 m resolution (MOD250_LAI). The MOD250_LAI product uses a physical radiative transfer model which establishes a relationship between LAI, fraction of vegetation cover (FVC) and given patterns of surface reflectance, view-illumination conditions and optical properties of vegetation. In situ measurements of LAI and FVC made at 166 plots using hemispherical photography served for calibration of model parameters and validation of modelling results. Optical properties of vegetation cover, summarized by the light extinction coefficient, were computed at the local (pixel) level based on empirical models between ground-measured tree crown architecture at 85 sampling plots and spectral values in Landsat ETM+ bands. Influence of view-illumination conditions on optical properties of canopy was simulated by a view angle geometry model incorporating the solar zenith angle and the sensor viewing angle. The results revealed high compatibility of the produced MOD250_LAI data set with ground truth information and the 30 m resolution Landsat ETM+ LAI estimated using the similar algorithm. The produced MOD250_LAI was also compared with the global MODIS 1000-m LAI product (MOD15A2 LAI). Results show good consistency of the spatial distribution and temporal dynamics between the two LAI products. However, the results also showed that the annual LAI amplitude by the MOD15A2 product is significantly higher than by the MOD250_LAI. This higher amplitude is caused by a considerable underestimation of the tropical rainforest LAI by the MOD15A2 during the seasonal phases of low leaf production.  相似文献   

西双版纳热带季节雨林细根周转的研究   总被引：4，自引：0，他引：4  

房秋兰  沙丽清 《山地学报》2005,23(4):488-494

研究了季节雨林0~20 cm土层中≤2 mm细根的生物量、分解量、死亡量、生长量和周转率,并比较了0~10 cm和10~20 cm土层细根生物量的差异。结果表明:0~10 cm的细根生物量明显多于10~20 cm的细根生物量;在0~20 cm土层中,季节雨林活细根和死细根生物量分别为5 418 kg.hm-2和707 kg.hm-2;细根生物量的季节变化显著,其中活细根生物量的最大值出现在5月,最小值出现在8月;年分解量、年死亡量、年生长量和年周转率分别为391 kg.hm-2,1 061 kg.hm-2,3 776 kg.hm-2和0.70 times.a-1。  相似文献   

基于"3S"的梵净山自然保护区植被分布探讨   总被引：5，自引：0，他引：5  

周忠发  秦青春  谢湛明  刘曼曼  彭晶晶 《测绘与空间地理信息》2006,29(3):4-6

利用“3S”技术对梵净山国家自然保护区森林植被类型的空间分布进行分析,并为森林植被的监测与管理提供依据,更好地对各个区域(核心区、缓冲区、影响区)危害因子进行监控,从而有效地对其森林植被进行有效的保护。  相似文献