缺水地区城市河流健康评价研究—以太原市区九条河流为例

缺水地区城市河流有流域规模小、季节性断流、生态功能弱、景观效果差等特征和问题,使得其健康评价不同于其他地区城市河流健康评价。为了拓展针对缺水地区城市河流的健康评价方法、理论和实践,丰富缺水城市水系管理、河流生态修复的理论基础,本文以太原市九条城市河流为研究对象,从水文水质、河流形态、生物、社会经济等4方面选取13个指标构建适用于缺水城市的河流健康指标体系,采用层次分析法和集对分析法进行评价。结果表明：九条河流均在过去5年里经历过大规模改造,各河流健康状态较为接近,其中,北排洪渠处于健康状态,风峪沙河处于不健康状态,其余7条河流处于亚健康状态;各河社会经济方面均处于健康状态,生物状况、河流形态多处于亚健康状态,水文水质多处于亚健康和不健康状态。评价结果较好地符合现实情况,水文状况较差是目前的主要问题。当前在河道尺度上开展生态补水是改善河流健康状态的主要手段和可行措施,而实施水源涵养、水资源优化配置、河道近自然恢复、海绵城市建设等流域综合治理修复是维持河流生态健康的治本之策。     

关中地区再造山川秀美行动战略研究

关中地区存在着严重的生态环境问题.再造山川秀美的关中地区,应坚持系统性原则,分区分类原则,退耕还林还草与治理工业污染并举等原则.必须通过系统调查,建立生态环境数据库和指标体系;划分不同生态功能区并分别进行科学研究;集成、推广已有的与治理生态环境有关的科技成果;从行政手段、立法与执法、经济激励等方面提供保障.     

三江源地区天然牧草气候生产力评估

选用河南、甘德、同德、玉树、曲麻莱、五道梁和玛多7个气象台站的1971～2004年的气象资料,对三江源地区的气候条件进行了分析,应用综合数学模型建立了三江源地区的天然草场植物气候生产力评估模型。结果表明：三江源地区气候生产力总体上呈下降的趋势,气候生产潜力较大。在较小范围内,海拔高度和气候生产力呈反比关系,海拔每上升100m气候生产力约降低1200～1425kg/ha,同时水分也是三江源地区天然牧草气候生产力的制约因素之一。     

常熟地区河湖水体的氮污染源研究

利用GPS定位的方法在丰水期和枯水期对常熟地区境内12条河流和3个湖荡水体氮磷污染现状进行了调查研究,对常熟地区主要河湖地表水中不同形态氮浓度的季节性变化特征进行了初步探讨。根据地表水中不同形态氮的浓度及总磷、溶解磷的浓度,结合15N示踪法和大型原状土柱渗漏池试验进一步补充探明了对该地区河湖水体中的氮磷污染来源。研究发现,该地区河、湖水体氮磷污染已相当严重,现阶段氮磷污染源主要来自城镇生活污水、农村人畜排泄物,在此基础上提出了缓解该地区水体氮磷污染的相应对策。     

新疆塔里木盆地两河流域野生麻资源调查

麻具有药用、轻纺、保健、造纸、制作药烟、蜜源等多种经济价值.新疆塔里木盆地两河(叶尔羌河、塔里木河)流域是野生麻(大叶白麻Poacynum hendersonii、白麻P.pictum、罗布麻Apocynum venetum)的主要产区,其中大叶白麻分布广,面积大,储量多.按有关分类方法,将野生麻资源划分为6个群系12个群丛.野生麻分布面积23.56万hm2,有麻面积18.12万hm2,其中大叶白麻占99.51%;白麻占0.49%.鲜麻总产量59.35万t,折合干麻总产量24.41万t.为更好的利用野生麻资源,在对其种类、分布、面积、生物量调查的基础上,对麻的开发前景、野生麻田的保护管理及改良培育、人工麻田的建立、科技攻关5个方面提出了建议.     

Vegetation fractional coverage change in a typical oasis region in Tarim River Watershed based on remote sensing

Vegetation fractional coverage(VFC) is an important index to describe and evaluate the ecological system.The vegetation index is widely used to monitor vegetation coverage in the field of remote sensing(RS).In this paper,the author conducted a case study of the delta oasis of Weigan and Kuqa rivers,which is a typical saline area in the Tarim River Watershed.The current study was based on the TM/ETM+ images of 1989,2001,and 2006,and supported by Geographic Information System(GIS) spatial analysis,vegetation index,and dimidiate pixel model.In addition,VBSI(vegetation,bare soil and shadow indices) suitable for TM/ETM+ images,constructed with FCD(forest canopy density) model principle and put forward by ITTO(International Tropical Timber Organization),was used,and it was applied to estimate the VFC.The estimation accuracy was later proven to be up to 83.52%.Further,the study analyzed and appraised the changes in vegetation patterns and revealed a pattern of spatial change in the vegetation coverage of the study area by producing the map of VFC levels in the delta oasis.Forest,grassland,and farmland were the three main land-use types with high and extremely-high coverage,and they played an important role in maintaining the vegetation.The forest area determined the changes of the coverage area,whereas the other two land types affected the directions of change.Therefore,planting trees,protecting grasslands,reclaiming farmlands,and controlling unused lands should be included in a long-term program because of their importance in keeping regional vegetation coverage.Finally,the dynamic variation of VFC in the study area was evaluated according to the quantity and spatial distribution rendered by plant cover digital images to deeply analyze the reason behind the variation.     

Seasonal effects of macrophyte growth on rainbow trout habitat availability and selection in a low‐gradient,groundwater‐dominated river

Rainbow trout habitat use is often described in high‐gradient, runoff‐driven, heterotrophic streams where geomorphic features and overhanging riparian vegetation provide channel complexity and cover. However, many rainbow trout populations thrive in rivers with contrasting aquatic habitat. We describe rainbow trout habitat use in a low‐gradient, groundwater‐dominated tailwater river where river flow management and macrophyte growth and senescence largely govern available trout habitat. In the summers of 2013 and 2014, available aquatic habitat (depth, velocity, macrophyte cover, substrate size) was quantified, while individual trout location was determined by radio telemetry and linked to environmental variables. Detailed habitat surveys indicate that macrophyte cover increases throughout the summer and is a strong determinant of in‐stream habitat characteristics. Paired logistic regression shows that adult rainbow trout prefer greater depths. Water depth increases with macrophyte abundance at both reach and local scales as plants restrict flow, and available trout habitat is linked to this seasonal pattern. When macrophyte abundance is high, adult trout show secondary preference for localised areas of lower macrophyte cover but otherwise show no selectivity for macrophyte cover, velocity or substrate size. Results suggest that submerged aquatic plants increased the quantity and quality of rainbow trout habitat as a source of channel complexity and cover. Macrophytes may play a similar role in other low‐gradient streams and should not be overlooked by fisheries managers considering habitat suitability.     

山丘区河流滩地边缘内凹形态对溶质运移及水质恶化风险的影响

滩地是河流的重要组成部分,具有调蓄洪水、净化水质、供生物栖息等功能。以浙江龙游县灵山港为典型山丘区河流,在现场勘测的基础上,提出了弯曲度指数(I-e)以表征滩地边缘内凹形态。基于I-e,滩地内凹形态可划分为低弯(I-e<2)、中弯(2≤I-e<4)和高弯(I-e≥4)3个等级。根据对灵山港下游18个滩地4次现场监测数据,并应用Mike 21构建该河段的二维水动力-水质耦合模型,定量分析了近滩区溶质运移过程。现场监测与数值模拟均表明随着I-e升高,河流水质风险随之呈极显著升高(P<0.01)趋势。模拟结果进一步表明,适当降低高弯内凹形态可有效降低河流水质风险;而根据维持生境多样性的需求,不宜将内凹形态降至低弯。所获取的不同边缘形态下的溶质时空分布可为滩地保护及修复提供重要参考。     

山区河道综合开发利用研究

介绍山区河道综合治理的重要性，从水量、环境和效益的角度出发，分析河道综合开发利用的方法及其相关技术，探讨河道管理部门行政和经济相结合的管理手段，防止个别自然条件较好的河流出现项目拥堵，为河道的可持续发展保驾护航。     

FY-3a卫星数据在青海省三江源区土壤水分监测中的应用

中国新一代极轨气象卫星FY-3a,搭载的中分辨率光谱成像仪(MERSI)具有5个250m分辨率通道,进一步加强了对地表地物的反演能力。本研究利用FY-3a250m分辨率卫星资料,采用植被供水指数法,建立了青海省三江源区土壤水分监测模型,利用气象部门地面常规监测点土壤水分资料,验证了植被供水指数与土壤水分之间的关系,从验证结果看:当植被指数为0.3～0.5时,遥感反演出的土壤水分值与实测值较为接近。