基于GIS的马莲河流域水系分维研究

指出了基于GIS软件的水文分析模块,以DEM为基础数据,提取马莲河流域河网水系,在此基础上采用网格法求取了马莲河流域水系分维数。结果表明:该流域分维数介于0.9999~1.0867之间,判断其处于地貌侵蚀发育阶段的幼年期,河流下切侵蚀较强,易导致水土流失。此研究有助于认识该流域地貌发育情况,并可为加强小流域水土流失治理提供一定参考。     

城市河流水质时空变化及富营养化评价:以深圳河及新洲河流域为例

以典型城市河流深圳河流域及新洲河流域为主要研究区域,分析了2017~2019年河流水质时空变化特征,借助对数型幂函数普适指数公式对流域的富营养化状态进行了综合评价。结果表明:深圳河及新洲河流域水体中COD_Cr、NH⁺₄-N和TP浓度在不同水期,即丰、平、枯之间无显著差异,但在年际间具有显著性差异,浓度呈现降低趋势。深圳河流域COD_Cr、NH⁺₄-N和TP浓度在丰水期空间变化幅度大,在平、枯水期空间变化幅度小。新洲河流域COD_Cr、NH⁺₄-N和TP浓度在不同水期空间分布基本保持一致,流域水质从上游到下游逐渐恶化。深圳河流域的富营养化程度高于新洲河流域,且富营养化程度有逐渐减弱的趋势。     

“三河流域国家元首及政府首脑峰会”在刚果召开

本刊讯＂亚马逊河-刚果河-湄公河三大热带森林流域国家元首及政府首脑峰会＂于2011年5月30日至6月3日在刚果（布）首都布拉柴维尔召开,旨在推进南南合作、南北合作对亚马逊河、刚果河和湄公河流域（以下简称＂三河流域＂）森林生态系统可持续管理,应对气候变化和促进三河流域国家经济发展。受中国外交部的委托,     

白鱼河流域生态经济型防护林体系建设及其效益评估

地处安康地区的白鱼河流域，经过十年的防护林体系建设，取得了很大的成绩，现总结如下。1流域自然条件与植被状况白鱼河流域属于亚热带季风气候区，气候温和，热量丰富，雨量充沛，年平均降雨量799．4mm，7、8、9三个月降水占全年44％，暴雨频繁，一日最大暴雨量可达172．8mm。地质构造为变质岩褶皱低山地貌，海拔高度为380～1157m，25°以上的山坡占流域面积的85％，地势陡峻。土壤以发育在片麻岩、片岩、千枚岩和板状页岩风化母质上的粗骨性黄褐土为主，酸性，土层薄，厚度多在25cm以下。流域原生森林植被为落叶阔叶树和针叶树组成的混交…     

茹河流域沙棘种植技术研究

茹河流域长期治理的实践中,运用科学的沙棘种植技术在茹河流域发展大片沙棘林,既能治理水土流失,改善生态环境,又增加了当地群众的收入,调动了群众的积极性,取得了明显的经济效益、生态效益和社会效益,实践证明,沙棘是茹河流域治理水土流失、发展经济的先锋树种.有耐贫瘠、耐干旱、耐盐碱、耐践踏,适应性强,成林速度快的特点,沙棘种植的关键技术及沙棘产生的效益,在同类流域治理中可推广应用.     

兴林草,搬去母亲河头上三柄“悬剑”

人类活动大多与长江大河密切相关 ,在古代 ,黄河流域孕育了中国的古代文明 ;尼罗河流域创造了古埃及文明的奇迹 ;幼发拉底和底格里斯两河流域产生了古巴比伦文明 ;同样 ,恒河流域也是古印度文明的摇篮。近代以来 ,人类开始了对沿海经济的大规模开发和扩张 ,但人类文明的发展仍主要以江河流域经济为基础和特征。密西西比河流域成为美国经济的重心区 ;伏尔加河和顿河流域是前苏联工农业最发达地区 ;多瑙河流域则为中欧最富庶的地区 ;德国的莱茵河、法国的塞纳河和英国的泰晤士河都连结着这些国家最著名的工商业城市。人类赖河流而生 ,文化因河…     

贵州赤水河流域生态保护策略探讨

本文从赤水河流域实际情况出发,描述了赤水河流域生态环境现状及保护的措施与成效,分析了赤水河流域存在的体制机制不健全、生态系统破碎、民众保护意识不强、生态补偿机制不合理、生态修复技术欠科学、工业项目和传统农业发展对环境威胁大等问题,提出赤水河流域应考虑资源整合保护,建立国家公园制度,并通过完善补偿机制,兼顾植被恢复与社会发展,鼓励发展生态经济促进生态保护的策略,严格控制影响生态的项目实施,减少污染,恢复生态,确保赤水河流域发挥最大的生态效益与社会效益。     

阿伦河流域水土保持林土壤抗蚀性研究

通过对阿伦河流域水土保持林内土壤抗蚀性能的试验 ,提出了阿伦河流域水土保持林不同林种、不同树种对土壤的物理性质、结构、有机质及抗蚀性都有不同程度的提高或增强 ,并总结出在阿伦河流域以落叶松、小黑杨、柳树为主体的水土保持林 ,对土壤抗蚀性能提高最大 ,为阿伦河流域水土保持林树种选择提供理论依据。     

古蔺河流域生态足迹分析

文章以流域为单元,在流域尺度上计算其生态足迹,对古蔺河流域的生态足迹和生态承载力进行了计算分析。选取折算后的具生产能力的耕地、草地、化石能源、建筑用地及水域6项指标,在收集了古蔺河流域生产性土地详细资料的基础上,进一步了解流域的生态足迹与生态承载力间的关系,寻找生态足迹较大的指标和导致生态赤字上升的因素,衡量古蔺河流域的可持续发展能力,为流域的可持续发展提供科学的指导依据。     

窟野河流域生境质量时空演变特征及其影响机制研究

窟野河地处黄河中游的“几”字湾,是黄河重要水源补给段,其生境质量的好坏关系到流域生态安全和人民福祉。基于GIS技术采用InVEST模型和线性回归分析,揭示窟野河流域2000—2020年土地利用和生境质量的时空演变特征,探究窟野河流域生境质量变化的主要影响因子。结果表明：1)2020年,窟野河流域草地面积较2000年下降了6.60%,林地面积较2000年增加了35.05%。2)2000—2020年,窟野河流域整体以中高等生境质量区为主。生境质量整体提升,部分区域出现生境质量下降。3)2000—2020年,第二产业总产值、工业总产值、年末总人口、景观分离度指数与生境质量指数呈现较为明显的负相关关系,可见窟野河流域产业发展及人类活动对研究区生境质量的下降具有十分显著的影响。     

Detecting forest stress and decline in response to increasing river flow in southwest Florida, USA

Forest stress and decline resulting from increased river levels were investigated in Myakka River State Park (MRSP), FL, USA. Since 1977, land-use changes around the upper Myakka River watershed have resulted in significant increases in water entering the river, which have caused extensive mortality in the upper watershed. The present study assessed whether similar forest stress and mortality was occurring downstream within the park. Our objectives were to (1) determine if tree die-off and/or stress resulting from increased river levels were present in MRSP and (2) determine the relationship between historical and present river levels regimes and growth of actively managed forested stands undergoing restoration located both above and below a dam. We used two methodological approaches. The first was recording indications of tree stress and decline (crown dieback, crown thinning, trunk rot, foliage discoloration, and parasitism) in Fraxinus caroliniana Miller dominated forested wetlands, Pinus elliottii Englem. var. densa Little & Dorman dominated mesic pine flatwoods, and Quercus laurifolia Michaux dominated oak palm hammocks. Our second approach was tree-ring analyses, which allows for more detailed analyses of growth in response to precipitation and river flow (a surrogate variable for water table depth) in the pine flatwoods stands.

Our results indicate significant stress and decline in some forested wetlands upstream of the dam, significant mortality in wet-mesic pine flatwoods sites close to the river, and significant amounts of stress in wet-mesic pine flatwoods sites upstream of the dam. F. caroliniana sites located upstream of the dam had more individuals with symptoms of stress than those downstream of the dam (67% versus 43%, P=0.031). In Q. laurifolia sites, 70–85% of the trees had evidence of flooding stress and mortality, which is comparable to distributions found in severely disturbed forest in the upper watershed. P. elliottii var. densa sites located <1000 m from the river had higher mortality than sites located >1050 m from the river (P<0.01), and the stressed trees in sites upstream of the dam had significantly lower growth rates in the 1990s versus the 1960s than those downstream. Although, the onset of stress and decline coincided with increasing river levels, we found that river levels were positively correlated with tree growth, both before and after flow increases in the system. Increasing river levels may play an indirect role through increased competition in the stress and decline in wet-mesic pine flatwoods, however, increased river levels seems to be the direct cause for stress and decline found in forested wetland stands.     

基于DEM的帽儿山实验林场水文分析

本文以帽儿山实验林场DEM数据为基础,利用ArcGIS10.0的水文分析功能,对帽儿山地区进行了水文分析,提取该地区水流长度、生成河网并对河网进行分级等。结果表明,用地理信息系统水文分析功能提取的河网与实际地形基本一致,可以作为一种工具,根据DEM数据来提取水文信息。     

DEM在低山丘陵区综合治理中的应用

随着低山丘陵区水土流失日益严重,基于多角度、新方法的综合治理迫在眉睫。DEM模型能准确快速地反映区域的地形地貌特征,在低丘的治理中有着多层次的应用。笔者提出了应用DEM模型进行低山丘陵区气温和降水的空间模拟方法,划分区域作物优生区、适宜区的操作流程以及土地利用分区的确定,并把理论应用到小流域的具体实践中,数字化地形图建立样区的DEM模型,根据DEM数据监测样区内各种土地利用类型的坡度等级分布,提取坡度>25°的耕地,为小流域进一步的退耕还林做数据支持。实验结果表明:应用DEM模型能形象地表达区域的地形因子及流域特征,在低山丘陵区的综合治理中有广泛的应用前景。     

基于ASTER GDEM的石漠化综合治理中的小流域提取研究——以广西石漠化综合治理应用为例

石漠化综合治理借鉴小流域综合治理的成功经验,以小流域作为基本治理单元.讨论了应用ArcGIS软件,基于ASTER DEM进行小流域提取的过程和方法,以及小流域提取结果在石漠化综合治理中的实际应用.对提取的小流域的精度及误差进行分析,结果表明:应用ASTER GDEM提取小流域的精度可达1:50 000的精度.利用ASTERGDEM自动划分小流域具有重要的研究意义和实际应用价值.     

基于集水区法的森林生态系统影响径流研究进展

森林生态系统结构复杂, 具有减少地表径流、调节河川流量、减小土壤侵蚀等一系列保护环境的功能。森林植被变化对森林水文过程的影响会改变水量平衡方程的各个变量, 从而影响森林流域的水分分配和河川径流量, 进而对陆地生态系统水分循环起到重要的调节作用。从森林结构、森林类型、森林覆盖率和森林经营4个方面总结了国内外基于集水区法研究森林生态系统影响径流的结论, 即小流域的研究结果认为森林的减少将增加河川径流量, 而大流域的研究结果认为森林的减少将减少河川径流量。最后指出, 在研究单位和研究项目合作研究的基础上, 结合各相关学科的新兴技术和研究设备, 通过整合相关学科的研究成果, 阐明森林生态系统水土保持过程与机理, 是今后森林生态系统水文服务功能研究的发展方向。     

Digital Terrain Analysis Based on DEM

The digital elevation model (DEM), an important source of information, is usually used to express a topographic surface in three dimensions and to imitate essential natural geography. DEM has been applied to physical geography, hydrology, ecology, and biology. This study analyzed digital elevation data sources and their structure, the arithmetic of terrain attribute extraction from DEM and its applications, and DEM’s error and uncertainty algorithm. The Hayachinesan mountain area (in northeastern Japan) was chosen as research site, and the focus was on terrain analysis and the impacts of DEM resolution on topographic attributes, analyzed using TNTmips GIS software (MicroImage, Inc., USA) and “Digital Map 25,000” (published by the Geographical Survey Institute of Japan in 1998). The results show that: (1) DEM is a very effective tool for terrain analysis: many terrain attributes (such as slope, aspect, slope type, watershed, and standard flow path) can be derived, and these attributes can be displayed with both image and attribute databases, with the help of GIS; (2) DEM resolution has a great influence on terrain attributes. The following details are shown: (a) DEM resolution has a significant effect on slope estimation: the average slope becomes smaller and the standard deviation becomes larger when DEM resolution changes from fine to coarse, and the different impacts of DEM resolution on different slope ranges can be classified into three gradient classes: 0–10° (underestimated slope), 10–35° (overestimated slope), and >35° (little impact on slope estimation); (b) DEM resolution has little effect on aspect estimation, but flat areas become larger when DEM resolution changes from fine to coarse; and (c) the quantity of hydrologic topography information declines as DEM resolution decreases. Translated from Journal of Beijing Forestry University, 2005, 27(2) (in Chinese)     

潮白河流域森林景观动态变化研究

在RS和GIS技术支持下,使用1972—2008年4期土地利用数据或遥感数据作为信息源,获取潮白河流域在此期间的景观格局特征数据,探讨潮白河流域森林景观类型变化特征,明确景观变化的主要类型和方向,旨在进一步揭示该流域土地利用时空变化规律。     

一种基于数字高程模型的流域边界提取修正方法

Boundary extraction of watershed is an important step in forest landscape research. The boundary of the upriver watershed of the Hunhe River in the sub-alpine Qingyuan County of eastern Liaoning Province, China was extracted by digital elevation modeling (DEM) data in Arclnfo8.1. Remote sensing image of the corresponding region was applied to help modify its copy according to Enhanced Thematic Mapper (ETM) image‘s profuse geomorphological structure information. Both the DEM-dependent boundary and modified copy were overlapped with county map and drainage network map to visually check the effects of result. Overlap of county map suggested a nice extraction of the boundary line since the two layers matched precisely,which indicated the DEM-dependent boundary by program was effective and precise. Further upload of drainage network showed discrepancies between the boundary and the drainage network. Altogether, there were three sections of the extraction result that needed to correct. Compared with this extraction boundary, the modified boundary had a better match to the drainage network as well as to the county map. Comprehensive analysis demonstrated that the program extraction has generally fine precision in position and excels the digitized result by hand. The errors of the DEM-dependant extraction are due to the fact that it is difficult for program to recognize sections of complex landform especially altered by human activities, but these errors are discernable and adjustable because the spatial resolution of ETM image is less than that of DEM. This study result proved that application of remote sensing information could help obtain better result when DEM method is used in extraction of watershed boundary.     

Effects of preferential flow on soil-water and surface runoff in a forested watershed in China

Preferential flow is a runoff mechanism intermediate between matrix flow and surface flow, transmitting water at high velocity through the subsurface zone. To assess the effect of preferential flow on soil-water flow and surface runoff in a forested watershed, precipitation and volumes of preferential flow, matrix flow and surface runoff were measured over a period of four years in a forested watershed in the Three Gorges area of southern China. Results show that preferential-flow hydrographs have gentler rises and steeper recessions than those for matrix flow and surface runoff. Preferential flow as a percentage of soil-water flow ranged from 2.40% to 8.72% and the maximum preferential-flow velocity exceeded as much as 5600 times that of matrix flow. This shows that preferential flow plays an important role in the movement of soil water. Preferential flow has a significant effect on peak surface runoff by increasing the surface runoff rate and accelerating the appearance of peak surface runoff. Preferential flow can also prolong the duration of surface runoff. Surface runoff was observed to be positively correlated with preferential flow. The greater the sum of rainfall amount and antecedent precipitation is, the greater the effect of preferential flow on surface runoff is.     

Impact of forest harvesting on river runoff in the Xiaoxing’an Mountains of China

Using the runoff experiment method in a large basin combined with the contrast experiment in a small watershed, and based on the runoff and forest resources data for the past 35 years, this paper studied the serial changes of river runoff in the Xiaoxing’an Mountains after forest harvesting. The results showed that the river flow increased in the initial ten years after forest harvesting, but decreased gradually with the growth and crown closure of the Larix gmelini plantations. The river flow tended to be the same or even lower than the level before harvesting. The river runoff had a close correlation with annual rainfall, the size of forest harvesting and regeneration. A significant positive correlation was observed between the annual flow and the size of forest harvesting, which resulted in the increase of river runoff after forest harvesting. Forest harvesting could also significantly increase the peak flood and snowmelt runoff. There was a negative correlation between the regenerated forest area and annual flow, and thus, forest regeneration would decrease annual flow. __________ Translated from Chinese Journal of Applied Ecology, 2005, 16(12): 2,259–2,262 [译自: 应用生态学报]