The paper demonstrates why it is necessary to take the restoration of marine coastal ecosystem health as a new goal for integrated catchment management, in coastal area of the Tolo Harbour. The present goal of integra...The paper demonstrates why it is necessary to take the restoration of marine coastal ecosystem health as a new goal for integrated catchment management, in coastal area of the Tolo Harbour. The present goal of integrated catchment management (ICM) in the Tolo Harbour is to meet with Water Quality Objectives. The performance of an ICM plan, Tolo Harbour Action Plan (THAP), is evaluated by using marine coastal ecosystem health indicators including stress indicators and responses indicators. Since the implementation of THAP in 1988, some significant reduction in pollution loading has been observed - reduction of 83 % of BOD load and 82 % of TN between 1988 and 1999. There has been an improvement in the health state of Tolo Harbour marine coastal ecosystem as evidenced in the trends of the physical, chemical and biological indicators, although some reverse fluctuations in some periods exist. However, this can only be considered as the first sign of the ecosystem health restoration, since ecosystem health展开更多
Catchment floods are more challenging due to intensive urbanization and climate change.Enlightened by the Low Impact Development(LID),China initiated the Sponge City Program(SCP)to transform Urban Flood Management(UFM...Catchment floods are more challenging due to intensive urbanization and climate change.Enlightened by the Low Impact Development(LID),China initiated the Sponge City Program(SCP)to transform Urban Flood Management(UFM)to be more environmentally friendly in 2013.The China National Government(CNG)has subsidized municipal SCP facilities to enhance urban flood resilience while delivering multiple co‐benefits for urban ecosystems and social well‐being.Recent floods at Schleiden(Germany),Arizona State(USA),and Zhengzhou(China)in 2021 reflected the necessity of Catchment Flood Management(CFM)to cover the whole catchment scale.The SCP,designed to handle small‐scale urban pluvial floods,has brought concerns when facing larger‐scale fluvial floods after the Zhengzhou 2021 flood.Indeed,catchment‐scale Natural Flood Management(NFM)can manage fluvial floods while improving flood adaptations sustainably from upstream to downstream reaches.This research develops a new framework named the Sponge Catchment Management Plan(SCMP),including structural and Nonstructural elements.On the structural side,the SCMP framework integrates NFM with the SCP and Grey Engineering(GE)for reducing the fluvial flood discharge peaks in the whole‐catchment scale.On the nonstructural side,the SCMP encourages collaborative governance,revising technical standards,and improving“bottom‐up”participation.This research used Semi‐Structured Interviews(SSIs)and a Focus Group Approach(FGA)to explore 62 professional and Nonprofessional stakeholders’perspectives on the SCMP framework.Some professional respondents did not know much about the NFM and were worried about the effectiveness of this practice.But most interviewees supported the SCMP pilot work and shared the co‐benefits from the NFM.This case study at the SW China,Guiyang,could be a lesson to encourage other Chinese cities further implement SCP to improve catchment‐scale flood resilience.展开更多
Taking an example of Majiayu Catchment Area (14.15 ha) in Taoyuan County of HunanProvince, the soil and water resources dynamics, fertility evolution characteristics andland productivity changing situation were studie...Taking an example of Majiayu Catchment Area (14.15 ha) in Taoyuan County of HunanProvince, the soil and water resources dynamics, fertility evolution characteristics andland productivity changing situation were studied. Fixed observation results from 1993to 2002 showed that pools covering about 15% of total area could store up 10% of surfacerunoff, keep 78.1% of eroded soil and 65.4% of lost nutrients. The yearly ratio ofinterception and evapotranspiration in land, storage in pools and drainage was 7:2:1,which ensured the resources and nutrients equilibrium and a benign recycle in thecatchment area system, and benefited the aquatic culture and helped to resist seasonaldrought. Moreover, the results showed that soil erosion modulus decreased significantly,equal to or lower than soil loss tolerance (≤500 tkm-2) in reddish yellow soil regions.Soil organic matter, total and available N content in sloping land, dryland and paddyfield increased steadily (>10%); water storage enhanced by more than 20% in sloping landand dryland in drought season; crop production increased by more than 20%; and productionof trees, fruits, tea and fish as well as land productivity increased yearly.展开更多
Background:There is a substantial interest in the values that consumers place on drinking water quality and supply.Financial resources are crucial to improving the urban potable water supply in developing countries th...Background:There is a substantial interest in the values that consumers place on drinking water quality and supply.Financial resources are crucial to improving the urban potable water supply in developing countries that are characterized by low-cost recovery rates and a high and rapidly growing demand for more reliable services.This study examined households’willingness to pay(WTP)for the improvement of water services by identifying their water choice decisions and the mode of water supply that they prefer the water supply authority to use among several alternative water supply options.Stated-preference data were collected from 322 randomly selected households in Addis Ababa,who were presented with three sets of choices(three alternative bundle choices,including the reference scenario).The data were analyzed using the mixed logit WTP space model.Three approaches to modeling the distribution of WTP(fixed,uncorrelated,and correlated)using mixed logit WTP space models were compared.Results:Three-quarters of the households agreed to contribute money toward ecosystem-based water supply management(EBWSM)intervention programs on a monthly basis.The average contribution that the respondents were willing to pay was 150.5 Ethiopian Birr(ETB)as a one-off lump sum to kick off the EBWSM activities.Most of the respondents chose a bundle of water supply options that provides risk-free and high-quality water with no months of shortages than moderate water quality that is safe to drink and palatable with 1 month shortages annually.This implies that households would need to be supplied with risk-free,high-quality water without interruption at an appropriate flow pressure.The model with correlations fitted the data well with the highest simulated log-likelihoods at convergence and gave the best estimate of the households’WTP for water improvement.Nearly 46%of the sampled households were willing to pay more than 33 ETB per month,and 49%of the households were willing to pay between 21 ETB and 33 ETB per month for the monthly water bill.Overall,approximately 95%of the sampled households were willing to pay more than 21 ETB.Conclusion:Customers are willing to pay to avoid most types of water supply restrictions.Moreover,WTP is sensitive to the scope of service improvement,income,affixed price,and elicitation method.In summary,mixed logit WTP-space models can help accurately predict household-level WTP,which can be used to select improvements in drinking water access and services in the Legedadie-Dire catchments.展开更多
We used the interdisciplinary model network REGFLUD to predict the actual mean nitrate concentration in percolation water at the scale of the Weser river basin （Germany） using an area differentiated （100 m × 1...We used the interdisciplinary model network REGFLUD to predict the actual mean nitrate concentration in percolation water at the scale of the Weser river basin （Germany） using an area differentiated （100 m × 100 m） approach. REGFLUD combines the agro-economic model RAUMIS for estimating nitrogen surpluses and the hydrological models GROWA/DENUZ for assessing the nitrate leaching from the soil. For areas showing predicted nitrate concentrations in percolation water above the European Union （EU） groundwater quality standard of 50 mg NO3-N/L, effective agri-environmental reduction measures need to be derived and implemented to improve groundwater and surface water quality by 2015. The effects of already implemented agricultural policy are quantified by a baseline scenario projecting the N-surpluses from agricultural sector to 2015. The REGFLUD model is used to estimate the effects of this scenario concerning groundwater and surface water pollution by nitrate. From the results of the model analysis the needs for additional measures can be derived in terms of required additional N-surplus reduction and in terms of regional prioritization of measures. Research work will therefore directly support the implementation of the Water Framework Directive of the European Union in the Weser basin.展开更多
The alpine terrestrials of the Maloti-Drakensberg in southern Africa play crucial roles in ecosystem functions and livelihoods,yet they face escalating degradation from various factors including overgrazing and climat...The alpine terrestrials of the Maloti-Drakensberg in southern Africa play crucial roles in ecosystem functions and livelihoods,yet they face escalating degradation from various factors including overgrazing and climate change.This study employs advanced Digital Soil Mapping(DSM)techniques coupled with remote sensing to map and assess wetland coverage and degradation in the northern Maloti-Drakensberg.The model achieved high accuracies of 96%and 92%for training and validation data,respectively,with Kappa statistics of 0.91 and 0.83,marking a pioneering automated attempt at wetland mapping in this region.Terrain attributes such as terrain wetness index(TWI)and valley depth(VD)exhibit significant positive correlations with wetland coverage and erosion gully density,Channel Network Depth and slope were negative correlated.Gully density analysis revealed terrain attributes as dominant factors driving degradation,highlighting the need to consider catchment-specific susceptibility to erosion.This challenge traditional assumptions which mainly attribute wetland degradation to external forces such as livestock overgrazing,ice rate activity and climate change.The sensitivity map produced could serve as a basis for Integrated Catchment Management(ICM)projects,facilitating tailored conservation strategies.Future research should expand on this work to include other highland areas,explore additional covariates,and categorize wetlands based on hydroperiod and sensitivity to degradation.This comprehensive study underscores the potential of DSM and remote sensing in accurately assessing and managing wetland ecosystems,crucial for sustainable resource management in alpine regions.展开更多
We quantified morphological and hydrographical characteristics of two drainage basins（Chanioti and N. Skioni） on Cassandra peninsula of Chalkidiki（North Greece）, and evaluated the effectiveness of post-fire flood ...We quantified morphological and hydrographical characteristics of two drainage basins（Chanioti and N. Skioni） on Cassandra peninsula of Chalkidiki（North Greece）, and evaluated the effectiveness of post-fire flood and erosion control works. The drainage basins were chosen because of their severe damage by fire, post-fire potential for erosion and flood due to the steep relief, and the importance of the area for residential and tourism development. The first measures taken in the area after the fire were salvage cutting of burned trees, a total ban on grazing, and construction of three types of works, log erosion barriers（LEBs）, log check dams and contour branch barriers. Almost all necessary post-fire works were completed in both catchments but many construction failures were recorded. Approximately 75 % of the LEBs and45 % of the contour branch barriers functioned properly,while the remainder failed. Nearly 80 % of the log dams were sedimented to 0–20 % of the dam height, 14.3 %were 20–40 % filled and 5.9 % collapsed. Despite these failures, peak discharge declined by 10.5 % in Chanioti and 20.4 % in N. Skioni catchment. The main reasons for works failures were the rush of construction and the limited supervision of workers, which resulted in floods during the years that followed.展开更多
文摘The paper demonstrates why it is necessary to take the restoration of marine coastal ecosystem health as a new goal for integrated catchment management, in coastal area of the Tolo Harbour. The present goal of integrated catchment management (ICM) in the Tolo Harbour is to meet with Water Quality Objectives. The performance of an ICM plan, Tolo Harbour Action Plan (THAP), is evaluated by using marine coastal ecosystem health indicators including stress indicators and responses indicators. Since the implementation of THAP in 1988, some significant reduction in pollution loading has been observed - reduction of 83 % of BOD load and 82 % of TN between 1988 and 1999. There has been an improvement in the health state of Tolo Harbour marine coastal ecosystem as evidenced in the trends of the physical, chemical and biological indicators, although some reverse fluctuations in some periods exist. However, this can only be considered as the first sign of the ecosystem health restoration, since ecosystem health
基金National Natural Science Foundation of China(NSFC),Grant/Award Number:41850410497National Key R&D Program of China,Grant/Award Number:2019YFC1510400+5 种基金National Natural Science Foundation of China(NSFC)Youth Project,Grant/Award Number:51909126University of Nottingham(UNUK)Project,Grant/Award Number:E01200500006Institute of Asia Pacific Studies Research Funded for the Environmental Security and SustainabilityCultural and Creative Industries Research Priority AreasFaculty of Science and Engineering(FTSE)Postgraduate Research Scholarship of University of Nottingham Ningbo ChinaGuizhou Science and Technology Planning of Project,Grant/Award Number:20192879。
文摘Catchment floods are more challenging due to intensive urbanization and climate change.Enlightened by the Low Impact Development(LID),China initiated the Sponge City Program(SCP)to transform Urban Flood Management(UFM)to be more environmentally friendly in 2013.The China National Government(CNG)has subsidized municipal SCP facilities to enhance urban flood resilience while delivering multiple co‐benefits for urban ecosystems and social well‐being.Recent floods at Schleiden(Germany),Arizona State(USA),and Zhengzhou(China)in 2021 reflected the necessity of Catchment Flood Management(CFM)to cover the whole catchment scale.The SCP,designed to handle small‐scale urban pluvial floods,has brought concerns when facing larger‐scale fluvial floods after the Zhengzhou 2021 flood.Indeed,catchment‐scale Natural Flood Management(NFM)can manage fluvial floods while improving flood adaptations sustainably from upstream to downstream reaches.This research develops a new framework named the Sponge Catchment Management Plan(SCMP),including structural and Nonstructural elements.On the structural side,the SCMP framework integrates NFM with the SCP and Grey Engineering(GE)for reducing the fluvial flood discharge peaks in the whole‐catchment scale.On the nonstructural side,the SCMP encourages collaborative governance,revising technical standards,and improving“bottom‐up”participation.This research used Semi‐Structured Interviews(SSIs)and a Focus Group Approach(FGA)to explore 62 professional and Nonprofessional stakeholders’perspectives on the SCMP framework.Some professional respondents did not know much about the NFM and were worried about the effectiveness of this practice.But most interviewees supported the SCMP pilot work and shared the co‐benefits from the NFM.This case study at the SW China,Guiyang,could be a lesson to encourage other Chinese cities further implement SCP to improve catchment‐scale flood resilience.
基金funded by the Knowledge Innovation Program of Chinese Academy of Sciences(KZCX2-SW-415,KZCX3-SW-426).
文摘Taking an example of Majiayu Catchment Area (14.15 ha) in Taoyuan County of HunanProvince, the soil and water resources dynamics, fertility evolution characteristics andland productivity changing situation were studied. Fixed observation results from 1993to 2002 showed that pools covering about 15% of total area could store up 10% of surfacerunoff, keep 78.1% of eroded soil and 65.4% of lost nutrients. The yearly ratio ofinterception and evapotranspiration in land, storage in pools and drainage was 7:2:1,which ensured the resources and nutrients equilibrium and a benign recycle in thecatchment area system, and benefited the aquatic culture and helped to resist seasonaldrought. Moreover, the results showed that soil erosion modulus decreased significantly,equal to or lower than soil loss tolerance (≤500 tkm-2) in reddish yellow soil regions.Soil organic matter, total and available N content in sloping land, dryland and paddyfield increased steadily (>10%); water storage enhanced by more than 20% in sloping landand dryland in drought season; crop production increased by more than 20%; and productionof trees, fruits, tea and fish as well as land productivity increased yearly.
文摘Background:There is a substantial interest in the values that consumers place on drinking water quality and supply.Financial resources are crucial to improving the urban potable water supply in developing countries that are characterized by low-cost recovery rates and a high and rapidly growing demand for more reliable services.This study examined households’willingness to pay(WTP)for the improvement of water services by identifying their water choice decisions and the mode of water supply that they prefer the water supply authority to use among several alternative water supply options.Stated-preference data were collected from 322 randomly selected households in Addis Ababa,who were presented with three sets of choices(three alternative bundle choices,including the reference scenario).The data were analyzed using the mixed logit WTP space model.Three approaches to modeling the distribution of WTP(fixed,uncorrelated,and correlated)using mixed logit WTP space models were compared.Results:Three-quarters of the households agreed to contribute money toward ecosystem-based water supply management(EBWSM)intervention programs on a monthly basis.The average contribution that the respondents were willing to pay was 150.5 Ethiopian Birr(ETB)as a one-off lump sum to kick off the EBWSM activities.Most of the respondents chose a bundle of water supply options that provides risk-free and high-quality water with no months of shortages than moderate water quality that is safe to drink and palatable with 1 month shortages annually.This implies that households would need to be supplied with risk-free,high-quality water without interruption at an appropriate flow pressure.The model with correlations fitted the data well with the highest simulated log-likelihoods at convergence and gave the best estimate of the households’WTP for water improvement.Nearly 46%of the sampled households were willing to pay more than 33 ETB per month,and 49%of the households were willing to pay between 21 ETB and 33 ETB per month for the monthly water bill.Overall,approximately 95%of the sampled households were willing to pay more than 21 ETB.Conclusion:Customers are willing to pay to avoid most types of water supply restrictions.Moreover,WTP is sensitive to the scope of service improvement,income,affixed price,and elicitation method.In summary,mixed logit WTP-space models can help accurately predict household-level WTP,which can be used to select improvements in drinking water access and services in the Legedadie-Dire catchments.
基金The research work presented in this article is carried out in the framework of the AGRUM Weser project which was funded on behalf of the German Federal Ministry of Food,Agriculture and Consumer protection (BMELV) and the River Basin Commission Weser (FGG).
文摘We used the interdisciplinary model network REGFLUD to predict the actual mean nitrate concentration in percolation water at the scale of the Weser river basin （Germany） using an area differentiated （100 m × 100 m） approach. REGFLUD combines the agro-economic model RAUMIS for estimating nitrogen surpluses and the hydrological models GROWA/DENUZ for assessing the nitrate leaching from the soil. For areas showing predicted nitrate concentrations in percolation water above the European Union （EU） groundwater quality standard of 50 mg NO3-N/L, effective agri-environmental reduction measures need to be derived and implemented to improve groundwater and surface water quality by 2015. The effects of already implemented agricultural policy are quantified by a baseline scenario projecting the N-surpluses from agricultural sector to 2015. The REGFLUD model is used to estimate the effects of this scenario concerning groundwater and surface water pollution by nitrate. From the results of the model analysis the needs for additional measures can be derived in terms of required additional N-surplus reduction and in terms of regional prioritization of measures. Research work will therefore directly support the implementation of the Water Framework Directive of the European Union in the Weser basin.
基金The Afromontane Research Unit of the University of the Free State partially funded this project.
文摘The alpine terrestrials of the Maloti-Drakensberg in southern Africa play crucial roles in ecosystem functions and livelihoods,yet they face escalating degradation from various factors including overgrazing and climate change.This study employs advanced Digital Soil Mapping(DSM)techniques coupled with remote sensing to map and assess wetland coverage and degradation in the northern Maloti-Drakensberg.The model achieved high accuracies of 96%and 92%for training and validation data,respectively,with Kappa statistics of 0.91 and 0.83,marking a pioneering automated attempt at wetland mapping in this region.Terrain attributes such as terrain wetness index(TWI)and valley depth(VD)exhibit significant positive correlations with wetland coverage and erosion gully density,Channel Network Depth and slope were negative correlated.Gully density analysis revealed terrain attributes as dominant factors driving degradation,highlighting the need to consider catchment-specific susceptibility to erosion.This challenge traditional assumptions which mainly attribute wetland degradation to external forces such as livestock overgrazing,ice rate activity and climate change.The sensitivity map produced could serve as a basis for Integrated Catchment Management(ICM)projects,facilitating tailored conservation strategies.Future research should expand on this work to include other highland areas,explore additional covariates,and categorize wetlands based on hydroperiod and sensitivity to degradation.This comprehensive study underscores the potential of DSM and remote sensing in accurately assessing and managing wetland ecosystems,crucial for sustainable resource management in alpine regions.
文摘We quantified morphological and hydrographical characteristics of two drainage basins（Chanioti and N. Skioni） on Cassandra peninsula of Chalkidiki（North Greece）, and evaluated the effectiveness of post-fire flood and erosion control works. The drainage basins were chosen because of their severe damage by fire, post-fire potential for erosion and flood due to the steep relief, and the importance of the area for residential and tourism development. The first measures taken in the area after the fire were salvage cutting of burned trees, a total ban on grazing, and construction of three types of works, log erosion barriers（LEBs）, log check dams and contour branch barriers. Almost all necessary post-fire works were completed in both catchments but many construction failures were recorded. Approximately 75 % of the LEBs and45 % of the contour branch barriers functioned properly,while the remainder failed. Nearly 80 % of the log dams were sedimented to 0–20 % of the dam height, 14.3 %were 20–40 % filled and 5.9 % collapsed. Despite these failures, peak discharge declined by 10.5 % in Chanioti and 20.4 % in N. Skioni catchment. The main reasons for works failures were the rush of construction and the limited supervision of workers, which resulted in floods during the years that followed.
