改良式人工湿地处理乡镇河流污水工程应用

采用改良式潜流人工湿地工艺处理乡镇河流污水,结果表明,处理系统稳定,操作简单,维持技术要求低,投资低,运行费用低,处理效果好.对于治理乡镇生活及河流污水具有较大的推广应用价值.     

慢速渗滤土地处理设计参数的研究

由于慢速渗滤土地处理系统对污水中的有机污染物有较高的去除能力,且城市污水的有机污染物浓度远低于系统的处理负荷量,故系统的设计参数受污水中氮浓度控制.试验表明,BOD_5负荷率高达3.57g/m~2·d仍不会影响系统的工艺性能,但氮负荷率一般不应超过0.6—0.7g/m~2·d.由氮极限值确定的水力负荷率为3—6m/a.在规定的负荷率下,投配水深采用<7cm,4—5天投配一次污水的投配频率是适宜的.     

快速渗滤土地处理法去除污水中挥发卤代烃的效率研究

本文就不同周期和布水率对快速渗滤系统中挥发性有机物去除率的影响进行了探讨。通过该法与六种常用的污水处理技术对挥发性卤代烃去除率的比较,表明快速渗滤土地处理法更为行之有效。     

不同利用方式对江西省农田土壤碳氮磷生态化学计量特征的影响

根据江西省2013年采集的16582个农田耕层(0～20 cm)土壤样点数据,运用实地调查、经典统计学与地统计学等相结合方法,研究了江西省耕地土壤碳氮磷生态化学计量特征的空间变异性及不同农田利用方式对其的影响.研究结果表明:江西省耕地土壤有机碳(SOC)、全氮(TN)和全磷(TP)平均含量分别为17.90、1.58和0.52 g·kg~(-1),土壤碳氮比(C∶N)、碳磷比(C∶P)和氮磷比(N∶P)平均值分别为11.72、38.29和3.38,土壤C∶N∶P比平均值为34.44∶3.03∶1,说明P是江西省耕地土壤主要的限制因素.此外,由于碳、氮、磷三者之间并不存在显著的两两相关性,表明江西省耕地土壤中不存在稳定的"Redfield ratio";半方差函数表明,江西省土壤碳、氮、磷生态化学计量特征具有中等程度的空间变异性,其空间变异特征主要受到随机性因素的影响;经ANOVA检验显示,不同农田利用方式对土壤碳氮磷生态化学计量特征影响显著(p0.05),土壤SOC和TN平均含量依次表现为:两季水田水旱轮作一季水田一季旱地两季旱地,土壤TP平均含量依次表现为:两季旱地两季水田一季水田一季旱地水旱轮作,土壤C∶N依次表现为:两季水田两季旱地一季水田水旱轮作一季旱地,土壤C∶P平均值依次表现为:水旱轮作两季水田一季水田一季旱地两季旱地,土壤N∶P平均值依次表现为:水旱轮作一季旱地两季水田一季水田两季旱地.总体而言,土壤碳、氮、磷生态化学计量比的变化特征是农田利用方式和环境因子综合作用的结果,土壤C∶N∶P比对土壤碳、氮、磷储量及养分的限制性具有重要的指示作用.     

GIS ASSESSMENT OF THE VULNERABILITY OF THE ROSETTA AREA, EGYPT TO IMPACTS OF SEA RISE

A study of the area, including Rosetta city and the estuary of the river Nile (Rosetta branch), has been carried out for assessment of the impact of sea level rise (slr). A geographic information system (GIS) has been built including layers of land use, topography, archeological sites, land cover and population. Analysis of data has been carried out to assess vulnerability of various land use and land cover classes to the impact of sea level rise.Because the area under study has geomorphic relief profiles just over the sea level, inundation of total land could reach 26% of total study area due to only half a meter rise in sea level. This lost area includes 32% of urban clusters mainly used for human shelter and contains 52% of present monuments, 25% of valuable high quality dense palm trees cultivation, 75% of beaches and 19% of lands suitable, 25% of valuable high quality dense palm trees cultivation, 75% of beaches and 19% of lands suitable for agricultural reclamation (although suffering from salt water intrusion and soil salinization). This is expected to cause a significant impact on the present population, economic activities, total regional revenue, and also on tourism. At 1.1 m sea level rise, 72% to total study area could be inundated. This area contains all beaches, half of the palm cultivation, 43% of total urban clusters, which includes 81% of the monumental sites and historic buildings.Other environmental problems such as solid waste management, sanitary disposal network, deteriorating conditions of some monumental structures, in addition to the sea level rise act negatively on the environmental quality of the urban community. Future plans for urban expansion in the area must be studied carefully in order to preserve valuable palm lands and maintain and protect monuments and historic sites which help the promotion of tourism. An environmental management program is essential for upgrading tourism, promoting urban development and protecting coastal lands.     

黄土高原区煤矿排土场复垦及区域生态恢复示范工程

黄土高原资源开发后物生态恢复问题是该区域生态环境中亟待解决的重要问题,以内蒙古准格尔露天矿排土地复垦及区域环境生态恢复示范工程为实例,研究了在黄土高原资源开发区搞生态恢复工程的技术,方法和效果。研究结果表明,该生态恢复的技术关键是在必要的土地处理和工程措施基础上,选择适宜的植物种类,依不同的立半条件和功能划分,建立与之适应的生态结构模式。该研究中选出了６０余种适宜植物种和８种适宜生态结构类型,使其     

石墨矿废弃地生态复垦研究

通过现场试验和小区工程措施,研究了石墨矿废弃地的生态复垦问题并建立了复垦示范田。结果表明,通过一定的技术工程措施石墨矿废弃矿坑和尾渣堆的复垦土地的理化性质基本达到了当地农业耕地的水平。从技术、经济的角度分析,石墨矿废弃地复垦的关键是耕种层的熟土配比。经筛选后的矿渣或矿毛与熟土按1:1或1:2的比例混配都可达到生态复垦的目的,但是前者的保水、供水、供肥能力不及后者。     

Modeling future land cover and water quality change in Minneapolis,MN, USA to support drinking water source protection decisions

Continued alteration of the nitrogen cycle exposes receiving waters to elevated nitrogen concentrations and forces drinking water treatment services to plan for such increases in the future. We developed four 2011–2050 land cover change scenarios and modeled the impact of projected land cover change on influent water quality to support long-term planning for the Minneapolis Water Treatment Distribution Service (MWTDS) using Soil Water and Assessment Tool. Projected land cover changes based on relatively unconstrained economic growth led to substantial increases in total nitrogen (TN) loads and modest increases in total phosphorus (TP) loads in spring. Changes in sediment, TN, and TP under two “constrained” growth scenarios were near zero or declined modestly. Longitudinal analysis suggested that the extant vegetation along the Mississippi River corridor upstream of the MWTDS may be a sediment (and phosphorus) trap. Autoregressive analysis of current (2008–2017) chemical treatment application rates (mass per water volume processed) and extant (2001–2011) land cover change revealed that statistically significant increases in chemical treatment rates were temporally congruent with urbanization and conversion of pasture to cropland. Using the current trend in chemical treatment application rates and their inferred relationship to extant land cover change as a bellwether, the unconstrained growth scenarios suggest that future land cover may present challenges to the production of potable water for MWTDS.     

Achieving sustainable development goals through participatory forest management: Examples from South-Eastern Bangladesh

Forests managed through peoples' participation can help to achieve a number of sustainable development goals (SDGs). This paper, drawing data from four participatory forest management (PFM) projects in south-eastern Bangladesh, explored: (a) the factors that influenced the outcomes of PFM; and (b) contribution of PFM towards achieving selected SDGs. The research used observation, semi-structured household interviews, group discussions, vegetation survey and Ostromʼs design principles for data collection, Divergent forest conditions and factors in four PFM sites have had differential contribution to SDGs. Heterogeneity of user groups, insufficient coordination, absence of motivation, and land tenure conflicts had affected the attainment of SDGs. The PFM helped to achieve 9–11 SDGs comprising poverty reduction (Goal 1), improving food security (Goal 2), maintaining health and well-being (Goal 3), enhancing childrensʼ education (Goal 4), fair access to jobs and committees (Goals 5 and 10), sources of clean drinking water (Goal 6), affordable energy for cooking (Goal 7), increased household economy (Goal 8), climate change through carbon sequestration (Goal 13), forest conservation (Goal 15), and partnerships with relevant institutions (Goal 16). In order to achieve SDGs, PFM could be viewed as an integral part of government development strategies, which needs sectoral coordination and integration of relevant policies.     

Impact of Changing Climate and Land Cover on Flood Magnitudes in the Delaware River Basin,USA

Changing climate and land cover are expected to impact flood hydrology in the Delaware River Basin over the 21st Century. HEC‐HMS models (U.S. Army Corps of Engineers Hydrologic Engineering Center‐Hydrologic Modeling System) were developed for five case study watersheds selected to represent a range of scale, soil types, climate, and land cover. Model results indicate that climate change alone could affect peak flood discharges by ?6% to +58% a wide range that reflects regional variation in projected rainfall and snowmelt and local watershed conditions. Land cover changes could increase peak flood discharges up to 10% in four of the five watersheds. In those watersheds, the combination of climate and land cover change increase modeled peak flood discharges by up to 66% and runoff volumes by up to 44%. Precipitation projections are a key source of uncertainty, but there is a high likelihood of greater precipitation falling on a more urbanized landscape that produces larger floods. The influence of climate and land cover changes on flood hydrology for the modeled watersheds varies according to future time period, climate scenario, watershed land cover and soil conditions, and flood frequency. The impacts of climate change alone are typically greater than land cover change but there is substantial geographic variation, with urbanization the greater influence on some small, developing watersheds.