Huangpu River is about 114.5 km from upriver Dianfeng to downriver Wusong, near the estuary of the Yangtze River. It plays a key role in supplying water for production, life, shipment and irrigation. With the industrial development, the pollution of the Huangpu River has become serious recently. The biological oxygen demand (BOD), total nitrogen (TN), total phosphorus (TP), oil, phenol and suspended solids (SS) were lower in the upstream sites than in the downstream sites, indicating pollutants being input along its course.Water quality was the worst in the Yangpu site, near the center of Shanghai City. Dissolved oxygen (DO) content was less than 2mg/L in the site of Yangpu in July. Among relations between thirteen characteristics, relations between BOD, DO, TN, TP, NH4+-N,NO3--N and the count of total bacteria or Escherichia coli were significant and interdependent. Inner relationships between these main characteristics in the Huangpu River were studied. High nutrient concentration led to growth of microorganisms, including E. coli.Degradation of organic matters and respiration of bacteria made oxygen concentration decreased in the water body, and DO was a key factor for nitrification-denitrification process of nitrogen. In the Yangpu site, DO was decreased to less than 3.0 mg/L with BOD higher than 7.5 mg/L in May and July. Low DO concentration will decrease nitrification rate. Nitrification need at higher DO value than other organic substrate oxidation. Consequently, river water contains low NO3--N values with high amounts of TN and NH4+-N there. This will block the self-purification of surface water, by decreasing the rate of nitrification-denitrification transformation process in the water body....
Because of the human exploitation and utilization of water resources in the Tarim Basin,the water resources consumption has changed from mainly natural ecosystem to artificial oasisecosystem, and the environment has changed correspondingly. The basic changes are: desertifi-cation and oasis development coexist, both "the human being advance and the desert retreat" and"the desert advance and the human being retreat" coexist, but the latter is dominant. In the upperreaches, water volume drawing to irrigated agricultural areas has increased, artificial oases havebeen enlarging and moving from the deltas in the lower reaches of many rivers to the piedmontplains. In the middle and lower reaches of the Tarim River, the stream flow has decreased, old oa-ses have declined, natural vegetations have been degenerating, desertification has been enlarging,and the environment has deteriorated. The transition regions, which consist of forestlands, grass-lands and waters between the desert and the oases, have been decreasing continuously, theirshelter function to the oases has been weakened, and the desert is threatening the oases seri-ously....
Natural zeolite and coal cinder were layered as main packing medium of the ecological filter instead of traditional filling to remedy the static lake water in Northern China.The ecological filter was running in a combined upward and downward flow mode.Dynamic experiments were carried out to study the effects of retention time and ambient temperature on pollutants' removal efficiency of the hybrid ecological filter. The function of plant was also studied by contrast test.It is showed that the removal efficiencies of NH_4~+ -N and TP are increased when the retention time is changed from 1 h to 2 h and 4 h,but the removal efficieney of TN is decreased,the removal efficiency of NH_4~+ -N is increased from 91.5% to 98% and that of TP is increased from 31.8% to 52.5%. When the temperature declines, the temporal removal efficiency of NH_4~+ -N is reduced, but the removal efficiency of 24 h and 48 h is remained. The removal efficiency of TP after 24 h and 48 h is decreased when the temperature declines evidently. The retention time plays an important role in NH_4~+ -N and TP removal,and the ambient temperature is significant for TP removal.The plant favors for TP and organic matter removal but has little effect on TN removal....
The authors designed an ecological storm water system in a residential area to replace the conventional underground channels for the collection of storm water so as to reduce the nutrients and sediments discharged. This system contains natural sub-creeks as drainage channels discharging overflow to nearby creeks, an open green trench, a storage pond,and natural sub-creeks. The sub-creeks were designed to be integrated into community landscape, which not only increases the efficiency of water usage, but also improves the aesthetic qualities of the community residence area as required by Agenda 21. This research proved the feasibility of an open storm water collection and utilization system for the design of a community water system....
Temporal sequential analyses of the hydrological observational data in the Tarim Ba-sin over the last forty years revealed an annual increase of 2 × 107m3 in the water quantities at thethree headstreams of the upper courses and an annual decrease of 3 × 107m3 in the water flowfrom Alaer, which is on the upper main stream. A prediction of the trends indicates that there canbe severe situations under which intermittent water interceptions occur. By means of approximateestimations on vegetative water consumption through phreatic evaporation combined with a quotaassessment, the ecological water demands required to maintain the ecological environment in themainstream area over the three different targeted years of 2005, 2010 and 2030 are defined asstanding at 31.86× 108m3, 36.27× 108m3 and 41.04× 108m3 respectively. Ecological fragility in-dexes are established on the basis of the selection of environmental sensitivity factors. Rationalevaluations give proof that the lower reaches of the mainstream have already turned into zoneswhere their ecological environments are gravely damaged. Multi-objective optimization should beconducted and protective schemes be framed within the threshold limits of the bearing capacitiesof water resources and the environment....
In view of no generally accepted ecological compensation standards and methods at present,this paper discusses the introduction of the negotiation system to the process of ecological compensation for water source areas.That is,the government in water source areas and the downstream regions of river basins should confirm their respective rights and obligations and then establish their compensation standards through negotiations according to the different purposes of water use.The amount of compensation should be determined in the comprehensive consideration of the quality,quantity and compensation price of water.Through open and fair negotiations,an institutional arrangement will be set up,which can make the water source areas and the downstream regions of river basins fully express their true preferences and their independent choices on the ecological environment....
In recent decades,the control of floods is an efficient management practice for the rehabilitation of rangelands in most arid and semiarid areas.To evaluate the benefits,we used the Landscape Function Analysis (LFA) method to assess the function of patches and qualitative capability of a rangeland ecosystem in Gareh Bygone region,Fars province,southwestern Iran.Landscape functionality depends on soil,water and nutrient (collectively called "resources") conservation and use within a given ecosystem.Many landscapes are naturally heterogeneous in terms of resource control and possess patches,where resources tend to accumulate,and inter-patches.Assessing rangeland health and function of landscape patches in response to environment and management can give rise to correct management decisions for qualitative improvement of the ecosystem.Therefore,our study area was divided into two parts,i.e.water spreading and control parts,and sampling was done using LFA method in each part separately.Structural parameters,including the number,length and width of patches,and the mean length of inter-patches,were determined by the method to characterize the functional status of the monitoring sites.For each patch/inter-patch type identified in the transect organization log,we recorded its soil surface properties classified according to the Soil Surface Assessment Method.The density,canopy cover and composition of plants were then assessed.The results showed that the number of ecological patches and their dimensions were significantly increased in the water spreading site.Soil stability and the values of nutrient cycling indices were increased but the infiltration values were decreased in the water spreading site.It could be related to the effect of suspended materials transported by floods to the soils in the study area.The improvement of ecological patches and rangeland ecosystem was achieved where water spreading systems were practiced.Therefore it can be concluded that water spreading as a management plan plays an important role in arid land ecosystem functionality....
To investigate the ecosystem damage and environment pollution resulted from coal resources exploitation, based on remote sensing image, the landscape pattern was quantitatively analyzed with GIS and landscape pattern analysis software FRAGSTATS by utilizing multiform landscape pattern indexes, such as patch area,patch circumference, patch number, fractal dimension, fragmentation index, connectivity index and so on. Resuits indicate that the restored landscape type occupies the control status and accounts for the majority of the whole area, and needs to be further restored and adjusted because of its internal body with smaller patches,lower fractal dimension and better connectivity. The landscape type without restoration has destroyed the ecology and beauty of the whole landscape. In addition, some suggestive instructions for restoring various kinds of patches are put forward according to the quantitative analysis....
