用好用足每一寸土地——永康市坚持节约集约用地保障科学发展的做法     

《浙江地质》2009,(10):14-15

浙江省永康市辖区土地总面积1049平方公里,其中山地丘陵面积占70％以上,土地资源十分稀缺。近年来,为缓解日益突出的用地矛盾,永康市认真贯彻节约集约用地政策,深入挖掘土地利用潜力,积极转变土地利用方式,努力寻求保护资源及保障发展之间的结合点,有力地促进了全市经济持续、稳定、健康发展。  相似文献   

Hydrochemistry and sediment characteristics of polar periglacial lacustrine environments on Fisher Island and Broknes Peninsula,East Antarctica     

Raj esh Asthana  Prakash Kumar Shrivastav  Hari Bahadur Srivastava  Mirza Javed Beg  Pradeep Kumar 《极地研究(英文版)》2013,(4):281-295

Fisher Island and Broknes Peninsula in the Larsemann Hills constitute part of a polar lowland periglacial environment between marine and glacial ecosystems. The landscape is characterized by gently rolling hills and broad valleys interspersed with lakes formed in glacially scoured basins. We analyzed the physieochemical parameters and the ionic constituents of water samples from 10 lakes in each of these two locations. Our results showed considerable differences between the two regions and demon- strated the influence of lithology and processes including weathering, evaporation, and atmospheric precipitation. All major cations and anions in the lake waters showed positive correlations indicating balanced ionic concentrations. Unconsolidated sediments were sparsely distributed and scattered over glacial deposits, valley fills, and occasional moraine ridges. The type and rate of sedi- mentation was mainly controlled by surface run-off and aeolian influx. The sediment samples from lake beds and the catchment area on Fisher Island were immature and poorly to very poorly sorted, consisting of gravelly sand with negligible silt and finer fractions. Sediments had a polymodal grain size distribution with the two major populations lying between -2 and 1 phi and be- tween 0 and 1.5 phi. The sediments were lithic arenite to arkosic in composition and the microtextures imprinted over quartz grains were dominated by mechanical textures resulting from several stages of glacial crushing and grinding. The presence of deep disso- lution cavities, cryptocrystalline precipitation, and euhedral crystal growth signified the effect of chemical activity after the deposition of grains in the lacustrine environment.  相似文献   

黄土高原面积-高程分析及其侵蚀地貌学意义   总被引：2，自引：0，他引：2  

信忠保  许炯心  马元旭 《山地学报》2008,26(3)

黄土高原是中国乃至世界最为著名的水土流失区之一,黄河的泥沙主要来源于此.面积-高程积分(Hypsometric integral,HI)分析常被用于侵蚀地貌区的地貌发育阶段判定.通过探讨HI与DEM分辨率、分析窗口之间的尺度效应,分析了黄土高原HI空间格局和发育阶段性,并在此基础上揭示了侵蚀产沙和地貌发育关系.研究表明:利用不同分辨率DEM计算的HI具有很好的稳定性,HI对DEM分辨率不具有依赖性;然而,利用不同分辨率的分析窗口所计算的黄土高原原HI值,表现出随着分析窗口的增大,HI表现出按照乘幂函数关系下降的趋势.黄土高原HI具有显著的空间分异特征,即汾渭谷地、宁夏内蒙沿黄冲积平原等地堑凹陷区是HI低值区,而黄土丘陵沟壑区是HI的高值区;黄土高原丘陵沟壑区地貌发育处于幼年期、壮年期和老年期的面积分别占总面积的7.9%、83.4%和8.7%,整体来看处于地貌发育壮年期;黄土高原丘陵沟壑区侵蚀产沙强度和地貌发育过程关系密切,HI与输沙模数存在显著的正相关.当前,黄土高原强烈的侵蚀产沙是其地貌发育处于壮年期的自然表现,这将是一个非常漫长的自然过程.  相似文献   

陕北黄土丘陵沟壑区农户气候变化的适应行为及影响因素分析   总被引：2，自引：0，他引：2  

王露  史兴民  孙立凡 《气候变化研究进展》2017,13(1):61-68

从农户个体微观视角,研究农业的活动主体--农户的气候变化适应行为。选择陕北黄土丘陵沟壑区,采用问卷调查和半结构式访谈相结合的方法研究农户气候变化感知与适应行为,运用二元逻辑回归模型分析影响该地区农户适应行为的因素。结果表明：农户对气候变化趋势感知比较一致,认为近5 年夏季和冬季气温升高,降水减少,但与实际观测存在一定偏差。农户应对气候变化采取适应行为的比重并不高,只有57.8% 的农户表示采取了相应的措施来应对气候变化。农户适应行为受气候变化感知的影响,此外,家庭社会经济属性对农户采取适应行为的概率影响显著,而性别、年龄、文化程度等人口属性因素与农户采取适应行为的概率关系不大。  相似文献   

浅谈低山丘陵地区1/5万地质灾害调查工作——以江西省定南县为例     

曾昭法  雷建 《地质灾害与环境保护》2017,28(1)

近年来,全国各省市陆续在开展1/5万地质灾害调查工作,不同地貌区地质灾害发育情况不同,调查方法与要求亦有区别。平原岗丘地区往往存在地质灾害点达不到观测点数量要求,需要增加地质环境点来满足精度;而西南高山区灾害点少但规模大,许多灾害点往往要通过大比例尺的测绘才能调查清楚。相比之下,低山丘陵地区地质灾害点具有点多面广的特点,规模多为小型,调查任务艰巨。本文以江西省定南县为例,阐述低山丘陵地区1/5万县(市)地质灾害调查的技术方法与认识,以期对类似地区的调查有所帮助。  相似文献   

黄土高原沟壑区干旱阳坡的地域分异特征   总被引：2，自引：0，他引：2  

赵荟  朱清科  秦伟  张英  安彦川  薛智德  刘中奇 《地理科学进展》2010,29(3):327-334

针对黄土高原沟壑区干旱阳坡这种典型的困难立地进行因地制宜的植被恢复建设。本文选取甘肃西峰、山西吉县、陕西安塞、宁夏固原为研究区,采用25 m分辨率的DEM为数据源,基于GIS提取相关地形信息研究其干旱阳坡的地域分异特征。结果表明：①不同类型沟壑区干旱阳坡面积比例占45%～54%,表现为高塬沟壑区＞过渡地带＞丘陵沟壑区。②不同类型沟壑区干旱阳坡面积比例随坡度的变化规律不同,高塬沟壑区呈左偏态分布,其他样区均基本呈近似正态分布,且丘五区和过渡地带呈双峰现象。③不同类型沟壑区梁峁坡面积比例关系为：高塬沟壑区>过渡地带>丘陵沟壑区;沟坡面积比例为：丘陵沟壑区>过渡地带>高塬沟壑区;川台地面积比例为：丘五区＞过渡地带＞丘二区＞高塬沟壑。④不同类型沟壑区各立地类型组所占的面积比例各不相同,除高塬沟壑区外基本呈阳向缓坡组＞阳向陡险坡组＞坡顶或沟底。研究成果可为黄土高原地区开展抗旱造林与植被重建提供理论依据。  相似文献   

黄土高原丘陵沟壑区单元流域次暴雨输沙模型     

崔普伟  蔡强国  方海燕  聂斌斌  陈小安 《地理科学进展》2010,29(4)

黄土高原尤其是黄土丘陵沟壑区土壤侵蚀异常严重,在该区开展单元流域产沙模拟对于流域侵蚀产沙及沟道系统泥沙输移比研究有着重要的意义。本文选取陕北岔巴沟单元流域团山沟为研究对象,利用1961-1969年间水文泥沙资料,构建了流域产沙模型:以流域输沙关系表达式Ms=CsH为理论框架,经分析发现洪峰流量、最大含沙量、平均流量与次洪含沙量相关性显著,近而以洪峰流量、平均流量、最大含沙量及径流深为模型变量,通过模拟误差分析,构建并选取了以径流深和洪峰流量、径流深和最大含沙量为变量的经验模型:Ms=H(109.2ln(Qz)+546.1);Ms=H(Cz-141.2)。与目前已有模型相比,以上模型具有很好的模拟效果,尤其是在模拟小产沙事件时模拟效果较好,模型在临近流域水旺沟上的应用效果也较好。另据研究发现,高含沙水流的存在,使得在不同产沙模数水平下产沙模拟响应机制不同,对产沙模数小于300 t/km2次暴雨事件,流量的对数函数拟合效果明显优于幂函数拟合;对产沙模数大于1000 t/km2次暴雨事件,流量的幂函数拟合效果好于对数函数拟合,但差异不大。  相似文献   

临朐县土地开发整理见实效     

周俊凤  王水清  吕廷蛟 《山东地质》2009,(6):54-55

临朐县土地总面积1834km^3,山地丘陵占全县土地总面积的87％。1999年国土资源部把临朐县设立为首批全国土地开发整理示范区之一,8年来,临朐县委县政府狠抓山区土地开发整理不放松,先后建设国家级土地开发整理项目2个,省级项目8个,市级项目20个,共开发整理土地2．33万hm^2,增加耕地0．47万hm^2,项目区农业、林果业生产能力提高1．2倍,农民人均纯收入翻了一番。  相似文献   

Soil erosion and its response to the changes of precipitation and vegetation cover on the Loess Plateau   总被引：8，自引：2，他引：6  

Wenyi?Sun  Quanqin?ShaoEmail author  Jiyuan?Liu 《地理学报(英文版)》2013,23(6):1091-1106

Soil erosion is a major threat to our terrestrial ecosystems and an important global environmental problem. The Loess Plateau in China is one of the regions that suffered more severe soil erosion and undergoing climate warming and drying in the past decades. The vegetation restoration named Grain-to-Green Program has now been operating for more than 10 years. It is necessary to assess the variation of soil erosion and the response of precipita- tion and vegetation restoration to soil erosion on the Loess Plateau. In the study, the Revised Universal Soil Loss Equation （RUSLE） was applied to evaluate annual soil loss caused by water erosion. The results showed as follows. The soil erosion on the Loess Plateau between 2000 and 2010 averaged for 15.2 t hm-2 a 1 and was characterized as light for the value less than 25 t hm-2 a-1. The severe soil erosion higher than 25 t hm-2 a-~ was mainly distributed in the gully and hilly regions in the central, southwestern, and some scattered areas of earth-rocky mountainous areas on the Loess Plateau. The soil erosion on the Loess Plateau showed a deceasing trend in recent decade and reduced more at rates more than 1 t hm 2 a 1 in the areas suffering severe soil loss. Benefited from the improved vegetation cover and ecological construction, the soil erosion on the Loess Plateau was significantly declined, es- pecially in the east of Yulin, most parts of Yah＇an prefectures in Shaanxi Province, and the west of Luliang and Linfen prefectures in Shanxi Province in the hilly and gully regions. The variation of vegetation cover responding to soil erosion in these areas showed the relatively higher contribution than the precipitation. However, most areas in Qingyang and Dingxi pre- fectures in Gansu Province and Guyuan in Ningxia Hui Autonomous Region were predomi- nantly related to precipitation.  相似文献   

彩色扫描地图中背景色的等高(等深)线矢量化研究   总被引：1，自引：0，他引：1  

陈换新  孙群  刘新贵  徐立 《武汉大学学报(信息科学版)》2013,38(5):622-625

在介绍矢量化方式的基础上,根据国外地图的特点,选择了基于全要素地图的矢量化方式。通过综合利用多义点及方向信息,对等高线矢量化的追踪过程控制,不仅避免了误追踪等特殊情况,且减少了人机交互,实现了有背景色区域等高(等深)线的半自动矢量化。  相似文献