共查询到20条相似文献,搜索用时 203 毫秒
1.
《内蒙古林业调查设计》2016,(1):131-132
研究基于Google Earth和Adobe Photoshop CS5软件的相互协作,以某一林区为例,通过Google Earth获取林区卫星地图,以林区卫星地图为底图,利用Photoshop进行林区平面地图的绘制。文章通过介绍林区平面地图的绘制,以期为相关平面地图的绘制,提供方法和经验借鉴。 相似文献
2.
我国北方的土地利用与沙漠化 总被引:2,自引:0,他引:2
沙漠化已成为我国北方地区一个重大的环境和经济问题。土地利用的方式和程度是沙漠化发展或逆转的主导因素。人类经济活动强度的增加和范围的扩大,造成北方地区农牧交错带的逐渐北移,大面积土地利用方式的改变和地表植被覆盖的减少,使得以风沙活动为主导外营力的沙漠化过程得以发展。我国北方地区近50年来的土地沙漠化面积不断扩展,已达近35万km2,其蔓延的速率呈加快的趋势。本文据历史资料分析、野外调查和遥感动态监测与评价,对典型沙漠化地区的土地利用与沙漠化过程的发展及其防治开展了深入的研究。 相似文献
3.
4.
土地沙漠化,是指干旱、半干旱地区由于人类不合理的开发经营活动,原有的脆弱生态平衡遭到破坏,致使原非沙漠地区出现了类似沙质荒漠的环境。沙漠化土地的扩展,严重威胁沙区经济社会的持续稳定发展。因此,防治土地沙漠化,改造并利用沙漠和沙漠化土地,已成为我国走向持续发展所必 相似文献
5.
本文以晋北、晋西北沙漠化地区不同植被覆盖率为主要评价参数,以沙漠化县(区)为评价单元,采用模糊数学的方法对该沙漠化区的生态环境质量现状进分析评价。 相似文献
6.
土地荒漠化已经成为当前我国生态问题中的一大分支,主要是由于全球气候变化异常以及不利的自然因素等共同导致,加上强劲频繁的起沙风为沙漠化的发生提供了强大的动力,对于地区的经济发展和人们的居住环境造成了严重的影响。当前,人们发现藓类结皮生长在荒漠化防治中能够起到一定的效果。藓类结皮生长其本身具有较强的适应能力,能够修复因荒漠化造成的植被破坏及沙漠化问题。基于此,本研究将结合古尔班通古特沙漠藓类结皮生长的特性及影响因素,分析其在荒漠化防治中应用,为我国沙漠化的防治工作提供一定帮助。 相似文献
7.
《河北林果研究》2020,(1)
为探究坝上地区沙化土地景观格局变化特征,选取研究区2009年和2014年的TM数据,在ENVI和ArcGIS软件的帮助下,借助景观指数分析法和马尔科夫转移矩阵模型对坝上沙化土地景观格局变化进行分析。研究结果表明,研究区主要景观类型为非沙漠化景观和轻度沙漠化景观;2009年到2014年研究区景观多样性指数和均匀度指数均减少;研究区整体被边界割裂的程度加深,中度沙漠化景观的边缘密度减少;非沙漠化景观和重度沙漠化景观斑块密度较大;极重度沙漠化景观稳定性最差,中度沙漠化景观形状分布最规则,稳定性最高;各景观要素转移趋势为中度、重度和极重度向轻度沙漠化的转移,重度向中度沙漠化的转移,以及极重度向非沙漠化和重度沙漠化的转移。研究区内非沙漠化土地面积增加,沙化程度减轻,土地沙漠化状况得到较大改善。 相似文献
8.
以辽西北地区沙漠化影响因素数据资料,对辽西北地区的气候特征和人文因素进行分析,并运用数量化理论Ⅰ对该区沙漠化主要驱动因子进行分析。结果表明:人口密度增大和不合理的人类活动是造成辽西北土地沙漠化发生、发展的主要原因,年均温、风速等对土地沙漠化的影响相对较小。因此,应加强对辽西北地区自然资源的保护,严格控制人口密度,合理利用土地资源,防止土地沙漠化的进一步蔓延。 相似文献
9.
青海省柴达木盆地沙漠化治理途径研究 总被引:1,自引:0,他引:1
党晓鹏 《内蒙古林业调查设计》2007,30(5):21-24
柴达木盆地现有沙漠化土地1659.9万hm2,是全省沙漠化最严重的地区之一。40年来,当地在治沙试验研究方面取得了一批科研成果,应用推广后,建立起香日德、诺木洪、格尔木、德令哈等一批绿洲,近10年来,随着治沙工程项目的实施,加快了治理速度,局部地区生态环境得到改善,但是整体在扩大。为更有效地防治沙漠化,根据沙漠化土地在柴达木盆地的分布现状,文章提出了以防治为主,防与治相结合的对策,及综合防治沙漠化的生物和工程技术措施。 相似文献
10.
建立沙漠化监测体系的探讨张胜邦(青海省林业勘察设计院,青海西宁810007)土地沙漠化是环境恶化的标志。为把我国防沙治沙的管理水平不断推向新阶段,改善农业生产和城乡环境条件,建立沙漠化监测体系,开展沙漠化监测工作,已经成为防沙治沙工作中不可缺少的组成... 相似文献
11.
12.
13.
Old growth forest has become a major and increasingly prevalent research topic over the past two decades. However, there is no generic definition that can be applied uncritically to all forest types. This is because a precise definition of old growth is ecologically meaningful only when it is applied to a specific vegetation type. This is demonstrated in this paper using the Mountain Ash (Eucalyptus regnans) forests of the Central Highlands of Victoria, south-eastern Australia as a case study. These forests have been the target of extensive and intensive research over the past 25 years. That work has shown that a number of attributes of stand structure and composition can be crudely used to distinguish old growth forest from other age cohorts of Mountain Ash forest. However, it is not unusual for some of these characteristics also to be recorded in regrowth stands. 相似文献
14.
当代世界林业科学技术发展特点 总被引:1,自引:0,他引:1
本文综述了当代世界林业科学技术发展的10大特点,简要介绍了森林培育学、生物工程、人工林、“接近自然的林业”、无性系林业、森林生态与环境、森林经理、森林病虫害防治、林业机械和林产工业等学科水平现状及发展趋势。 相似文献
15.
TWO-STORIED HIGH FOREST 总被引:1,自引:0,他引:1
The system has been adopted at Dartington with Japanese larch(Larix leptolepis), and it has been suggested that it worksthere because Japanese larch grows fast. It is argued in thispaper, however, that the system is best adapted to rather slowlygrowing trees, and the reason for its use with Japanese larchis that this species is characterized by a rapid height growthbut a small current annual increment, so that, unless the treesare isolated, they make extremely narrow annual rings. WithDouglas fir (Pseudotsuga taxifolia) and Sitka spruce (Piceasitcbensis) the annual rings might become too broad if thistreatment were applied, except at a rather advanced age. Nevertheless,the system has certain other advantages and, to attain these,it may be useful to adopt it more extensively, even if the annualrings become broader than we like. 相似文献
16.
Our comparative analysis of forest research networks indicates the emergence and strengthening of a new model of knowledge co-production involving knowledge producers and users, with the goal of fostering innovation and addressing challenges facing the forest sector. However, effective movement towards this model requires attention to design and to management, particularly in relation to the expectations of partners (both university and non-university) who are used to traditional models of knowledge production and linear processes of knowledge extension. Based on our survey and literature review, we argue that in the short-term, the objective of producing applied research requires that forest research networks prioritize diverse and tailored knowledge mobilization strategies, rather than emphasizing knowledge production. With regards to the longer-term objective of facilitating new avenues for innovation in the forest sector this requires a knowledge mobilization strategy that entails a level of engagement with partners that is creative and transformative rather than mainly informative. Building an organizational culture of innovation requires a different approach to producing applied research, although many of the same skills are required. Our analysis suggest that if networks are to be effective in both these short and long term objectives, they should foster openness by establishing transparent and responsive organizational processes. Although such policies may exist and be available to partners, we found relatively little information available on the processes of transparency, accountability and conflict resolution within the websites of the networks we compared. Establishing clear roles and consistent channels of communications is imperative to facilitate the efficient and effective management of the network and manage partners' expectations, regardless of the partnership model. 相似文献
17.
18.
19.