: A statistical downscaling method based on regressing precipitation data is introduced and applied to 60-km resolution Atmospheric General Circulation Model (AGCM60km) output for daily precipitation. The method utilizes a regression domain with a 3×3 60-km grid, and the downscaling target is 3×3 20-km grids in the center of the regression domain. By shifting the regression domain one grid by one grid in 60-km resolution, the same form of regression model, but different regression coefficients for each 20-km grid, can be applied to all the downscaling target areas. Based on application tests for the Asian Monsoon region, the statistical downscaling algorithm shows extremely effective results with a certain pattern of regression error. The monthly based downscaled results from AGCM60km output shows a rather good match to the monthly mean precipitation amount of AGCM20km. The downscaled results also show a plausible mimic to the AGCM20km output in the frequency of daily precipitation amounts; however, the results showed noticeable limitations in simulating low rainfall amounts (e.g., less than 5 mm d –1 ), especially on land.
{"title":"Statistical Downscaling of AGCM60km Precipitation based on Spatial Correlation of AGCM20km Output","authors":"Sunmin Kim, Y. Tachikawa, E. Nakakita","doi":"10.3178/HRL.11.58","DOIUrl":"https://doi.org/10.3178/HRL.11.58","url":null,"abstract":": A statistical downscaling method based on regressing precipitation data is introduced and applied to 60-km resolution Atmospheric General Circulation Model (AGCM60km) output for daily precipitation. The method utilizes a regression domain with a 3×3 60-km grid, and the downscaling target is 3×3 20-km grids in the center of the regression domain. By shifting the regression domain one grid by one grid in 60-km resolution, the same form of regression model, but different regression coefficients for each 20-km grid, can be applied to all the downscaling target areas. Based on application tests for the Asian Monsoon region, the statistical downscaling algorithm shows extremely effective results with a certain pattern of regression error. The monthly based downscaled results from AGCM60km output shows a rather good match to the monthly mean precipitation amount of AGCM20km. The downscaled results also show a plausible mimic to the AGCM20km output in the frequency of daily precipitation amounts; however, the results showed noticeable limitations in simulating low rainfall amounts (e.g., less than 5 mm d –1 ), especially on land.","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":"11 1","pages":"58-64"},"PeriodicalIF":1.1,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3178/HRL.11.58","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69393666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Kotani, T. Hiyama, T. Ohta, Miho Hanamura, J. Kambatuku, S. Awala, M. Iijima
This paper aims to evaluate the effect of mixed-cropping of rice and upland crops on evapotranspiration (ET) in a small seasonal wetland in the north-central Namibia. Meteorological observations were conducted in the experimental sloped field, which simulated the cultivation of both rice in a wetland environment and upland crops in the surrounding rain-fed area, and included a reference wetland with natural vegetation. During cultivation, ET from the rice field was similar to that from the wetland. However, during the dry period ET was remarkably reduced in the post-harvest field, while continuous ET occurred in the natural wetland even after surface water had dried up. The response of surface conductance to meteorological variables was investigated by means of the Jarvis–Stewart conductance model. During cultivation, surface conductance of the rice field and the wetland had a distinct stress response compared with that of the rain–fed crop field. During the dry period, surface conductance of the wetland site, in which the surface water dried–up, still responded to the meteorological conditions in contrast to those of the post-harvest field with plowed bare soil.
{"title":"Impact of rice cultivation on evapotranspiration in small seasonal wetlands of north-central Namibia","authors":"A. Kotani, T. Hiyama, T. Ohta, Miho Hanamura, J. Kambatuku, S. Awala, M. Iijima","doi":"10.3178/HRL.11.134","DOIUrl":"https://doi.org/10.3178/HRL.11.134","url":null,"abstract":"This paper aims to evaluate the effect of mixed-cropping of rice and upland crops on evapotranspiration (ET) in a small seasonal wetland in the north-central Namibia. Meteorological observations were conducted in the experimental sloped field, which simulated the cultivation of both rice in a wetland environment and upland crops in the surrounding rain-fed area, and included a reference wetland with natural vegetation. During cultivation, ET from the rice field was similar to that from the wetland. However, during the dry period ET was remarkably reduced in the post-harvest field, while continuous ET occurred in the natural wetland even after surface water had dried up. The response of surface conductance to meteorological variables was investigated by means of the Jarvis–Stewart conductance model. During cultivation, surface conductance of the rice field and the wetland had a distinct stress response compared with that of the rain–fed crop field. During the dry period, surface conductance of the wetland site, in which the surface water dried–up, still responded to the meteorological conditions in contrast to those of the post-harvest field with plowed bare soil.","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":"11 1","pages":"134-140"},"PeriodicalIF":1.1,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3178/HRL.11.134","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69393525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Formulating countermeasures to flooding risks is important, especially in areas where data are scarce. Numerical modeling techniques may enable hydrologists to model flooding events and access flood risk. Many floodinginundation models have been developed and successfully applied to many areas. The rainfall-runoff-inundation (RRI) model is one such model that has been applied in various places to estimate river discharges and flooding-inundation depths. However, its applicability to flat river basins is in question. Here, we evaluate the applicability of RRI model to a flat river basin in a data-scarce region. Using the Bago River basin, Myanmar, as a case study, we analyzed past extreme flooding events and developed flooding-inundation maps. The model was calibrated with observed discharge data for a 2011 flooding event and validated for flooding events in 2014 and 2015. The model produced reasonable hydrographs (both peak and base flows). Although the simulated discharges showed good agreement with observed data, the simulated inundation extent showed some discrepancies due to lack of data. Our results indicate that the RRI model may be applicable to flat river basins (short-term analysis). However, for long-term flood simulation, the model may not be the ideal choice as it does not include any land-atmosphere interactions.
{"title":"Consideration of the rainfall-runoff-inundation (RRI) model for flood mapping in a deltaic area of myanmar","authors":"S. Bhagabati, A. Kawasaki","doi":"10.3178/HRL.11.155","DOIUrl":"https://doi.org/10.3178/HRL.11.155","url":null,"abstract":"Formulating countermeasures to flooding risks is important, especially in areas where data are scarce. Numerical modeling techniques may enable hydrologists to model flooding events and access flood risk. Many floodinginundation models have been developed and successfully applied to many areas. The rainfall-runoff-inundation (RRI) model is one such model that has been applied in various places to estimate river discharges and flooding-inundation depths. However, its applicability to flat river basins is in question. Here, we evaluate the applicability of RRI model to a flat river basin in a data-scarce region. Using the Bago River basin, Myanmar, as a case study, we analyzed past extreme flooding events and developed flooding-inundation maps. The model was calibrated with observed discharge data for a 2011 flooding event and validated for flooding events in 2014 and 2015. The model produced reasonable hydrographs (both peak and base flows). Although the simulated discharges showed good agreement with observed data, the simulated inundation extent showed some discrepancies due to lack of data. Our results indicate that the RRI model may be applicable to flat river basins (short-term analysis). However, for long-term flood simulation, the model may not be the ideal choice as it does not include any land-atmosphere interactions.","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":"11 1","pages":"155-160"},"PeriodicalIF":1.1,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3178/HRL.11.155","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69393631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. A. Belgaman, K. Ichiyanagi, Rusmawan Suwarman, M. Tanoue, E. Aldrian, Arika I.D. Utami, S. D. A. Kusumaningtyas
The few previous studies of precipitation isotopes (δ18O and δD) in Indonesia, based on low spatial resolution observation datasets, have found several types of patterns in their seasonal variabilities. This study conducted high spatial resolution rainfall sampling and investigated the temporal characteristics of precipitation isotope in Indonesia. Rainfall samples were collected weekly from 33 stations in Indonesia. Cluster analysis showed that Indonesia could be divided into four types based on the seasonal variability of the precipitation of δ18O. The majority of stations showed seasonal patterns in the variability of δ18O, characterized by high values in the dry season (July–October) as type 1. Type 2 also showed one peak of high δ18O but in the longer period (June– November) was similar to type 1 stations. A region of Northwest Indonesia, comprising North and Central Sumatra and western Borneo, was identified as type 3, having two peaks of high δ18O values in January–February and May–August. Another pattern of variability was the anti-monsoonal type, indicated by low δ18O in May–July found in east part of Indonesia. Asia-Australia monsoon regime was the main factor that controls seasonal δ18O variability. This research showed that stable isotope in precipitation could correspond to precipitation climatology in Indonesia.
{"title":"Characteristics of seasonal precipitation isotope variability in Indonesia","authors":"H. A. Belgaman, K. Ichiyanagi, Rusmawan Suwarman, M. Tanoue, E. Aldrian, Arika I.D. Utami, S. D. A. Kusumaningtyas","doi":"10.3178/HRL.11.92","DOIUrl":"https://doi.org/10.3178/HRL.11.92","url":null,"abstract":"The few previous studies of precipitation isotopes (δ18O and δD) in Indonesia, based on low spatial resolution observation datasets, have found several types of patterns in their seasonal variabilities. This study conducted high spatial resolution rainfall sampling and investigated the temporal characteristics of precipitation isotope in Indonesia. Rainfall samples were collected weekly from 33 stations in Indonesia. Cluster analysis showed that Indonesia could be divided into four types based on the seasonal variability of the precipitation of δ18O. The majority of stations showed seasonal patterns in the variability of δ18O, characterized by high values in the dry season (July–October) as type 1. Type 2 also showed one peak of high δ18O but in the longer period (June– November) was similar to type 1 stations. A region of Northwest Indonesia, comprising North and Central Sumatra and western Borneo, was identified as type 3, having two peaks of high δ18O values in January–February and May–August. Another pattern of variability was the anti-monsoonal type, indicated by low δ18O in May–July found in east part of Indonesia. Asia-Australia monsoon regime was the main factor that controls seasonal δ18O variability. This research showed that stable isotope in precipitation could correspond to precipitation climatology in Indonesia.","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":"11 1","pages":"92-98"},"PeriodicalIF":1.1,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3178/HRL.11.92","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69393313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
: Flood damage functions form the core of flood risk assess ment. This study proposes a method for establishing flood damage functions for agricultural crops in data-scarce regions. The method assumes that the flood damage ratio is a function of inundation depth only and utilizes inundation depth estimated from flood extent information and hydro dynamic simulations. The parameters of the damage functions are calibrated through the SCEUA method (Shuffled Complex Evolution method developed at The University of Arizona) so that the calculated flood damages match obser vations compiled in flood disaster statistics. The established three functions show good agreement with actual agricultural damages caused by a rainfall event in 2010 and are validated against another rainfall event in 2009. The results indicate that the established damage functions are capable of estimating flood damage at the district scale, while damage estimations at finer spatial resolution differ between the functions, suggesting that detailed statistical data need to be incorporated to reduce the estimation uncertainty at fine scales.
{"title":"Establishing flood damage functions for agricultural crops using estimated inundation depth and flood disaster statistics in data-scarce regions","authors":"Nhu Y Nguyen, Y. Ichikawa, H. Ishidaira","doi":"10.3178/HRL.11.12","DOIUrl":"https://doi.org/10.3178/HRL.11.12","url":null,"abstract":": Flood damage functions form the core of flood risk assess ment. This study proposes a method for establishing flood damage functions for agricultural crops in data-scarce regions. The method assumes that the flood damage ratio is a function of inundation depth only and utilizes inundation depth estimated from flood extent information and hydro dynamic simulations. The parameters of the damage functions are calibrated through the SCEUA method (Shuffled Complex Evolution method developed at The University of Arizona) so that the calculated flood damages match obser vations compiled in flood disaster statistics. The established three functions show good agreement with actual agricultural damages caused by a rainfall event in 2010 and are validated against another rainfall event in 2009. The results indicate that the established damage functions are capable of estimating flood damage at the district scale, while damage estimations at finer spatial resolution differ between the functions, suggesting that detailed statistical data need to be incorporated to reduce the estimation uncertainty at fine scales.","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":"11 1","pages":"12-18"},"PeriodicalIF":1.1,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3178/HRL.11.12","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69393467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Nainar, K. Bidin, R. Walsh, R. Ewers, G. Reynolds
Suspended sediment concentrations (SSC) and the duration of high SSC are important for river ecology and water resource conservation. Using annual and storm-event datasets, this paper explores the hypothesis that key suspended sediment variables increase along a land-use disturbance gradient in hilly terrain in Sabah (Malaysian Borneo). Five small (1.7–4.6 km2) catchments of increasing disturbance history – primary forest, old growth virgin jungle reserve, twice-logged forest, multiple-logged forest and mature oil palm – were instrumented from late 2011 with dataloggers and sensors to record river stage, turbidity and rainfall. The oil palm catchment had 4–12 times greater mean dischargeweighted SSC (587 mg L–1), annual sediment yield (1128 t km–2 y–1), median event peak SSC, and duration of SSC above 1000 mg L–1 than in the other catchments. The multiple-logged catchment (last logged around 2004) has SSC characteristics close to values for primary forest, possibly due to increased ground protection against erosion afforded by low understorey regrowth and/or depletion of erodible sediment by multiple logging episodes. Results demonstrate that in hilly terrain even heavily logged rainforest has high value in safeguarding water quality and reducing erosion, whereas oil palm requires careful land management, especially of road runoff and ground cover.
悬沙浓度及其高悬沙浓度持续时间对河流生态和水资源保护具有重要意义。利用年度和风暴事件数据集，本文探讨了沙巴(马来西亚婆罗洲)丘陵地形中关键悬浮泥沙变量沿土地利用扰动梯度增加的假设。从2011年底开始，用数据记录器和传感器对5个干扰历史增加的小集水区(1.7-4.6平方公里)——原始森林、原始丛林保护区、两次采伐森林、多次采伐森林和成熟油棕——进行了测量，记录了河段、浑浊度和降雨量。与其他流域相比，油棕流域的平均流量加权SSC (587 mg L-1)、年产沙量(1128 t km-2 y-1)、中位事件峰值SSC和超过1000 mg L-1的SSC持续时间高4-12倍。多次采伐的集水区(最后一次采伐是在2004年左右)的SSC特征接近原生林的值，这可能是由于多次采伐增加了对地面的保护，以防止下层植被的低再生和/或可侵蚀沉积物的枯竭。结果表明，在丘陵地形中，即使是被严重砍伐的雨林也具有很高的保护水质和减少侵蚀的价值，而油棕需要仔细的土地管理，特别是道路径流和地面覆盖。
{"title":"Effects of different land-use on suspended sediment dynamics in Sabah (Malaysian Borneo) – a view at the event and annual timescales","authors":"A. Nainar, K. Bidin, R. Walsh, R. Ewers, G. Reynolds","doi":"10.3178/HRL.11.79","DOIUrl":"https://doi.org/10.3178/HRL.11.79","url":null,"abstract":"Suspended sediment concentrations (SSC) and the duration of high SSC are important for river ecology and water resource conservation. Using annual and storm-event datasets, this paper explores the hypothesis that key suspended sediment variables increase along a land-use disturbance gradient in hilly terrain in Sabah (Malaysian Borneo). Five small (1.7–4.6 km2) catchments of increasing disturbance history – primary forest, old growth virgin jungle reserve, twice-logged forest, multiple-logged forest and mature oil palm – were instrumented from late 2011 with dataloggers and sensors to record river stage, turbidity and rainfall. The oil palm catchment had 4–12 times greater mean dischargeweighted SSC (587 mg L–1), annual sediment yield (1128 t km–2 y–1), median event peak SSC, and duration of SSC above 1000 mg L–1 than in the other catchments. The multiple-logged catchment (last logged around 2004) has SSC characteristics close to values for primary forest, possibly due to increased ground protection against erosion afforded by low understorey regrowth and/or depletion of erodible sediment by multiple logging episodes. Results demonstrate that in hilly terrain even heavily logged rainforest has high value in safeguarding water quality and reducing erosion, whereas oil palm requires careful land management, especially of road runoff and ground cover.","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":"11 1","pages":"79-84"},"PeriodicalIF":1.1,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3178/HRL.11.79","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69393768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Future wave climate projection is important for climate impact assessment of the coastal hazards and environment. In this study, monthly averaged wave heights are estimated by a linear multi-regression model using atmospheric data as explanatory variables. The present statistical model considers local atmospheric information (wind speed at 10 m height, sea level pressure) and large scale atmospheric information obtained from principal component analysis (PCA) of the global sea level pressure field. The representation of swell in the lower latitude is greatly improved by introducing the large scale atmospheric information from the PCA. The present statistical model was applied to the results of the Japan Meteorological Research Institute’s Atmospheric General/Global Circulation Model (MRI-AGCM) climate change projection. The future change of wave heights shows an increase in the northern North Pacific Ocean and a decrease in the North Atlantic Ocean, middle latitude and tropics of the Pacific Ocean.
{"title":"Statistical modeling of global mean wave height considering principal component analysis of sea level pressures and its application to future wave height projection","authors":"R. Kishimoto, T. Shimura, N. Mori, H. Mase","doi":"10.3178/HRL.11.51","DOIUrl":"https://doi.org/10.3178/HRL.11.51","url":null,"abstract":"Future wave climate projection is important for climate impact assessment of the coastal hazards and environment. In this study, monthly averaged wave heights are estimated by a linear multi-regression model using atmospheric data as explanatory variables. The present statistical model considers local atmospheric information (wind speed at 10 m height, sea level pressure) and large scale atmospheric information obtained from principal component analysis (PCA) of the global sea level pressure field. The representation of swell in the lower latitude is greatly improved by introducing the large scale atmospheric information from the PCA. The present statistical model was applied to the results of the Japan Meteorological Research Institute’s Atmospheric General/Global Circulation Model (MRI-AGCM) climate change projection. The future change of wave heights shows an increase in the northern North Pacific Ocean and a decrease in the North Atlantic Ocean, middle latitude and tropics of the Pacific Ocean.","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":"11 1","pages":"51-57"},"PeriodicalIF":1.1,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3178/HRL.11.51","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69393655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
: Simple explanations for changes in surface soil moisture in the late 21st century under global warming were explored, based on statistical significance and without consideration of complicated mechanisms. The results of a multi-model ensemble (MME) analysis showed significant increases in surface soil moisture in one northwestern inland area, and significant decreases were projected in two inland areas in southern and northern China. Among three water flux vari ables, precipitation ( P ), evaporation ( E ), and total runoff ( R ), significant changes in E explained only 10% of the total area showing significant changes in surface soil moisture. Among three combinations of two water flux variables, ( P – E ), ( E + R ), and ( P – R ), significant changes in ( P – E ) were dominant in coastal northeastern China, but this area did not overlap with areas with significant changes in surface soil moisture. Individual analyses revealed that significant increases in E , ( P – R ), and ( E + R ) explained 26%, 13%, and 9%, respec -tively, of the total area showing a significant decrease in the MME mean surface soil moisture. This result indicates that reliance on the MME mean may hinder understanding of the geophysical mechanism linking water flux variables with surface soil moisture.
{"title":"Statistical evaluation of future soil moisture changes in East Asia projected in a CMIP5 multi-model ensemble","authors":"T. Nakaegawa","doi":"10.3178/HRL.11.37","DOIUrl":"https://doi.org/10.3178/HRL.11.37","url":null,"abstract":": Simple explanations for changes in surface soil moisture in the late 21st century under global warming were explored, based on statistical significance and without consideration of complicated mechanisms. The results of a multi-model ensemble (MME) analysis showed significant increases in surface soil moisture in one northwestern inland area, and significant decreases were projected in two inland areas in southern and northern China. Among three water flux vari ables, precipitation ( P ), evaporation ( E ), and total runoff ( R ), significant changes in E explained only 10% of the total area showing significant changes in surface soil moisture. Among three combinations of two water flux variables, ( P – E ), ( E + R ), and ( P – R ), significant changes in ( P – E ) were dominant in coastal northeastern China, but this area did not overlap with areas with significant changes in surface soil moisture. Individual analyses revealed that significant increases in E , ( P – R ), and ( E + R ) explained 26%, 13%, and 9%, respec -tively, of the total area showing a significant decrease in the MME mean surface soil moisture. This result indicates that reliance on the MME mean may hinder understanding of the geophysical mechanism linking water flux variables with surface soil moisture.","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":"11 1","pages":"37-43"},"PeriodicalIF":1.1,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3178/HRL.11.37","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69393568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Land-use change poses a major threat over much of the La Plata River Basin in South America. Paraguay, with one of the highest deforestation rates in the region, has experienced rapid loss of its natural forests. Such landscape transformation implies changes in vegetation traits that affect exchange of momentum, heat, and moisture between the surface and atmosphere. To understand how the regional climate of Paraguay could be affected by the deforestation that occurred between 1990 and 2000, we ran 1-month long simulations for each November during the 2006–2012 period for a control scenario and a past vegetation scenario. Climate responses to land-cover change differed with location and vegetation. In eastern Paraguay, replacement of forest with farmland increased albedo, leading to an overall lower latent heat and both lower and higher sensible heat fluxes. In western Paraguay, replacement of grassland with farmland slightly increased albedo, reducing the sensible heat and increasing evapotranspiration owing to greater surface soil wetness. Effects of land-use change on precipitation are more likely to change local patterns of precipitation than they are the country’s total monthly precipitation.
{"title":"Impact of land-cover change between 1990 and 2000 on the regional climate of Paraguay: a first overview","authors":"Alicia Pavetti Infanzón, Kenji Tanaka, Shigenobu Tanaka","doi":"10.3178/HRL.11.187","DOIUrl":"https://doi.org/10.3178/HRL.11.187","url":null,"abstract":"Land-use change poses a major threat over much of the La Plata River Basin in South America. Paraguay, with one of the highest deforestation rates in the region, has experienced rapid loss of its natural forests. Such landscape transformation implies changes in vegetation traits that affect exchange of momentum, heat, and moisture between the surface and atmosphere. To understand how the regional climate of Paraguay could be affected by the deforestation that occurred between 1990 and 2000, we ran 1-month long simulations for each November during the 2006–2012 period for a control scenario and a past vegetation scenario. Climate responses to land-cover change differed with location and vegetation. In eastern Paraguay, replacement of forest with farmland increased albedo, leading to an overall lower latent heat and both lower and higher sensible heat fluxes. In western Paraguay, replacement of grassland with farmland slightly increased albedo, reducing the sensible heat and increasing evapotranspiration owing to greater surface soil wetness. Effects of land-use change on precipitation are more likely to change local patterns of precipitation than they are the country’s total monthly precipitation.","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":"11 1","pages":"187-193"},"PeriodicalIF":1.1,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3178/HRL.11.187","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69393369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Water Sustainability Act in British Columbia, Canada is a source of conflict among citizens, the provincial government, and industrial groundwater users. The water extraction fees stipulated in the act highlight the issue of water commodification and its potential legal consequences. Complementary approaches for conflict analysis are used to study this emerging conflict in order to gain valuable strategic insights. Analysis is performed using the Graph Model for Conflict Resolution, a flexible methodology for analyzing and modelling conflicts. In addition, generalized metarationalities and metarational trees, which account for the role and influence of policies in decisionmaking, are used to explore possible resolutions of the conflict. The analyses show that the current situation, where protesters lobby the government but the fees are not increased, is an equilibrium and thus unlikely to change.
{"title":"Water pricing conflict in British Columbia","authors":"Amanda Garcia, K. Hipel, Amer Obeidi","doi":"10.3178/HRL.11.194","DOIUrl":"https://doi.org/10.3178/HRL.11.194","url":null,"abstract":"The Water Sustainability Act in British Columbia, Canada is a source of conflict among citizens, the provincial government, and industrial groundwater users. The water extraction fees stipulated in the act highlight the issue of water commodification and its potential legal consequences. Complementary approaches for conflict analysis are used to study this emerging conflict in order to gain valuable strategic insights. Analysis is performed using the Graph Model for Conflict Resolution, a flexible methodology for analyzing and modelling conflicts. In addition, generalized metarationalities and metarational trees, which account for the role and influence of policies in decisionmaking, are used to explore possible resolutions of the conflict. The analyses show that the current situation, where protesters lobby the government but the fees are not increased, is an equilibrium and thus unlikely to change.","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":"11 1","pages":"194-200"},"PeriodicalIF":1.1,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3178/HRL.11.194","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69393435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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