Using land cover changes and demographic data to improve hydrological modeling in the Sahel          下载免费PDF全文

Jean Emmanuel Paturel  Gil Mahé  Pierre Diello  Bruno Barbier  Alain Dezetter  Claudine Dieulin  Harouna Karambiri  Hamma Yacouba  Amadou Maiga 《水文研究》2017,31(4):811-824

At the beginning of the drought in the Sahel in the 1970s and 1980s, rainfall decreased markedly, but runoff coefficients and in some cases, absolute runoff increased. This situation was due to the conversion of the land cover from natural vegetation with a low annual runoff coefficient, to cropland and bare soils, whose runoff coefficients are higher. Unless they are adapted, hydrological conceptual models, such as GR2M, are unable to reproduce this increase in runoff. Despite the varying environmental and climatic conditions of the West African Sahel, we show that it is possible to increase the performance of the GR2M model simulations by elaborating a time‐varying soil water holding capacity and to incorporate this value in the annual maximum amount of water to be stored in reservoir A of the model. We looked for interactions between climate, rural society, and the environment. These interactions drive land‐cover changes in the Sahel, which in turn drive the distribution of rainfall between infiltration, evaporation, and runoff and hence the water resources, which are vital in this region. We elaborated several time series of key indicators linked to these interactions. We then integrated these changes in the runoff conditions of the GR2M model through the maximum value of the reservoir capacity. We calculated annual values of water holding capacity using the annual values of four classes of land cover, natural vegetation, cultivated area, bare soil, and surface water. We then used the hydrological model with and without this time‐varying soil value of A and compared the performances of the model under the two scenarios. Whatever the calibration period used, the Nash–Sutcliffe index was always greater in the case of the time‐varying A time series.  相似文献   

Spatial and temporal variability of canopy and forest floor interception in a beech forest     

A. M. J. Gerrits  L. Pfister  H. H. G. Savenije 《水文研究》2010,24(21):3011-3025

Depending on season, rainfall characteristics and tree species, interception amounts to 15–50% of total precipitation in a forest under temperate climates. Many studies have investigated the importance of interception of different tree species in all kinds of different climates. Often authors merely determine interception storage capacity of that specific species and the considered event, and only sometimes a distinction is made between foliated and non‐foliated trees. However, interception is highly variable in time and space. First, since potential evaporation is higher in summer, but secondly because the storage capacity has a seasonal pattern. Besides weather characteristics, such as wind and rain intensity, snow causes large variations in the maximum storage capacity. In an experimental beech plot in Luxembourg, we found storage capacity of canopy interception to show a clear seasonal pattern varying from 0·1 mm in winter to 1·2 mm in summer. The capacity of the forest floor appears to be rather constant over time at 1·8 mm. Both have a standard deviation as high as ± 100%. However, the process is not sensitive to this variability resulting only in 11% variation of evaporation estimates. Hence, the number of raindays and the potential evaporation are stronger driving factors on interception. Furthermore, the spatial correlation of the throughfall and infiltration has been investigated with semi‐variograms and time stability plots. Within 6–7 m distance, throughfall and infiltration are correlated and the general persistence is rather weak. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

新疆沙产业状况与水资源承载力研究          下载免费PDF全文

刘洪霞  冯益明  管文轲 《干旱区地理》2020,43(5):1202-1209

采用 2000、2005、2010、2015 年 4 期土地利用/土地覆盖遥感解译数据以及新疆水资源公报 和统计年鉴资料，旨在评价新疆沙产业与水资源承载力状况。通过计算未利用土地转化成农地、 林地、草地的数量，分析 16 a 来新疆沙产业发展状况，结合水足迹模型和区域水资源承载力评价指 标，计算新疆 2000—2015 年水足迹，对区域水资源承载力进行评价。结果表明：（1）2000—2015 年 间，随着新疆人口增长和经济的发展，新疆沙产业发展迅速，部分沙地、戈壁等未利用土地和草地 被开发成耕地、林地、工矿和城镇及农村居民用地。（2）新疆水足迹整体呈上升趋势，水足迹以消费 农产品水足迹占主体，且消费农产品水足迹量快速增加，主要原因是新疆地区大力发展沙产业，利 用未利用土地、草地进行植物、沙生药材种植。（3）新疆人均水足迹、水资源压力指数、水足迹效益 指标呈现增加趋势，但数值明显低于我国人均水平。新疆社会经济发展总体趋势向好，但水资源 利用方式仍然比较粗放，水资源未得到合理开发。因此，新疆应采取优化产业结构、调整农作物种 植比例和用水结构，以增大水资源所支撑的沙产业发展规模，研究可为区域产业结构及消费模式 调整提供依据。  相似文献   

无人机摄影测量技术应用于垃圾填埋场形变监测及库容储量分析     

柏君  董秀军  陈立坚  张旭  谢梦阳  杨俊宇 《测绘通报》2020,(12):27

快速监测垃圾填埋场固体物质的体积空间变化及准确评估有效库容，可为城市管理者科学决策和合理安排社会资源提供重要依据。无人机摄影测量技术具有机动灵活、数据获取快捷且精度高等优点，在众多领域都有较为广泛的应用。本文以成都市长安垃圾填埋场为例，利用低空无人机摄影测量技术获取填埋库区连续一年的影像数据，并对多期模型数据进行差分处理，分析填埋库区各区域的体积变化量及形变特征；建立库容储量预测模型，研究库容量的变化值与入场物质量的关系，对填埋库区的实际可容纳入场固体物质量进行预测。  相似文献   

A Study of China’s Air Pollution Prevention and Control Policy Framework from a Policy Instrument Perspective     

QIN Qin  SUN Youhai 《资源与生态学报(英文版)》2020,11(2):182-190

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PT型袖珍贯入仪在海岸带地区工程地质调查中的应用          下载免费PDF全文

徐华  徐建国  张卓  张涛  纪汶龙 《山东国土资源》2018,34(4)

通过对莱州湾地区工程地质勘察中大量袖珍贯入试验与静力触探试验、标准贯入试验、土工试验数据的对比分析,采用数理统计方法,建立了PT型袖珍贯入阻力与静力触探试验指标、标准贯入试验击数、土的液性指数及压缩模量相关公式。为今后在海岸带地区工程地质勘察中,采用PT型袖珍贯入仪对岩心的现场贯入试验,及时准确地判定土的物理力学性质提供了依据。  相似文献   

“Caribou was the reason,and everything else happened after”: Effects of caribou declines on Inuit in Labrador,Canada     

《Global Environmental Change》2021

For many Indigenous Peoples in the Circumpolar North, cultural engagement and continuity across generations is directly related to relationships between and among people, animals, and landscapes. However, minimal research outlines the emotional responses and disruptions to culture and identity that are driven by ecological change, and the subsequent cultural dimensions of coping and adapting to this uncertainty. Through a case study that explores how caribou population declines and a caribou hunting ban are impacting Inuit in the Nunatsiavut and NunatuKavut regions of Labrador, Canada, this article examines the critical interplay between cultural continuity and adaptive capacity for responding to ecological uncertainty. More specifically, this study: 1) described the central role that caribou play for Inuit emotional wellness, identity, and cultural continuity; 2) explored how the rapid declines of caribou in Labrador are affecting Inuit emotional wellness, identity, and cultural continuity; and 3) characterized the ways in which Inuit are adapting to these emotio-social, cultural, and ecological changes. Drawing from an Inuit-led, multi-year, multi-media qualitative and visual media research program, data from video interviews (n = 84: Nunatsiavut region: n = 54; NunatuKavut region: n = 30) were analyzed using a video-based qualitative analysis, constant-comparative methods, and inductive qualitative approach. Results indicated that caribou are a foundational element for Inuit emotional wellness, identity, and cultural continuity. The changes in caribou populations are resulting in complex emotional responses, losses to cultural meaning and knowledge, and alterations to Inuit identities. The impacts on emotions, identity, and cultural continuity related to Inuit-caribou relations at an individual and collective level reflect the interconnections between cultural continuity and adaptive capacity that underlie the loss of this culturally important species. Though this research focuses on two Inuit groups and caribou in Labrador, the insights from these lived experiences highlight the ongoing cultural and identity consequences associated with species declines occurring globally.  相似文献   

多源时相遥感影像数据耦合的水库库容曲线重构     

王金鑫  桑学锋  常家轩  裴亮  赵天玮  宝康妮 《测绘通报》2021,(11):42-47

遥感技术为库容曲线的重构带来了新思路,但仍存在多源遥感影像数据难以直接应用、水库批量面积提取效率低等问题,难以形成一套系统化、流程化的方法进行广泛应用。基于此,本文提出了多源时相遥感影像数据耦合的库容曲线重构方法,并重构了深圳市径心水库的水位-库容关系曲线。试验证明,重构后的库容曲线常水位区间的库容曲线偏离率在4.23%~11.5%之间,能够为径心水库的调度管理提供参考,同时对全国库容曲线无法及时重构的水库具有参考意义。  相似文献   

Geographical imbalances and divides in the scientific production of climate change knowledge     

《Global Environmental Change》2015

Studies on scientific production of climate change knowledge show a geographical bias against the developing and more vulnerable regions of the world. If there is limited knowledge exchange between regions, this may deepen global knowledge divides and, thus, potentially hamper adaptive capacities. Consequently, there is a need to further understand this bias, and, particularly, link it with the exchange of knowledge across borders. We use a world-wide geographical distribution of author affiliations in >15,000 scientific climate change publications to show that (1) research production mainly takes place in richer, institutionally well-developed countries with cooler climates and high climate footprints, and (2) the network of author affiliations is structured into distinct modules of countries with strong common research interests, but with little knowledge exchange between modules. These modules are determined mainly by geographical proximity, common climates, and similar political and economic characteristics. This indicates that political-economic, social and educational-scientific initiatives targeted to enhance local research production and collaborations across geographical-climate module borders may help diminish global knowledge divides. We argue that this could strengthen adaptive capacity in the most vulnerable regions of the world.  相似文献   

基于HWSD的流域栅格土壤水分常数估算     

王斌  黄金柏  宫兴龙 《水文》2015,35(2):8-11

在科研及实践工作中往往需要大量的、空间分辨率较高的凋萎系数、田间持水量和饱和含水量数据,大规模布点测定这些土壤水分常数难度较大,需要探索估算这几种常用土壤水分常数的新方法。以黑龙江省呼兰河流域为例,采用DEM数据提取流域边界,应用提取后的流域DEM从世界土壤数据库(HWSD)中提取流域土壤的砂粒、粘粒百分含量及USDA土壤质地分类数据,再应用这三种土壤属性数据估算流域各栅格的凋萎系数、田间持水量和饱和含水量。研究结果表明:应用HWSD可以估算出呼兰河流域0~30cm和30~100cm两种土层的凋萎系数、田间持水量和饱和含水量,空间分辨率可达到30″,为获取较高分辨率及深土层的区域土壤水分常数提供了一种新方法。  相似文献