M. Maki, Supranee Sritumboon, M. Srisutham, Koshi Yoshida, K. Homma, S. Sukchan
{"title":"Impact of changes in the relationship between salinity and soil moisture on remote sensing data usage in northeast Thailand","authors":"M. Maki, Supranee Sritumboon, M. Srisutham, Koshi Yoshida, K. Homma, S. Sukchan","doi":"10.3178/hrl.16.54","DOIUrl":"https://doi.org/10.3178/hrl.16.54","url":null,"abstract":"","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69394450","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}
Adisorn Champathong, N. Hanasaki, Masashi Kiguchi, T. Oki
{"title":"Importance of observational reliability for hydrological parameter optimization: a case study of the Upper Chao Phraya River in Thailand","authors":"Adisorn Champathong, N. Hanasaki, Masashi Kiguchi, T. Oki","doi":"10.3178/hrl.16.59","DOIUrl":"https://doi.org/10.3178/hrl.16.59","url":null,"abstract":"","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69394492","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}
{"title":"Characteristics of soil and hillslope responses in humid tropical forests in Sumatra, Indonesia","authors":"T. Sayama, R. Araki, Kodai Yamamoto, Apip","doi":"10.3178/HRL.15.23","DOIUrl":"https://doi.org/10.3178/HRL.15.23","url":null,"abstract":": Extensive deforestation in tropical regions may signifi‐ cantly influence the hydrological cycle. However, subsur‐ face runoff processes in thick soil layers in humid tropical forests are poorly understood; thus, the impact of land-use changes in such regions remains unclear. To understand runoff generation mechanisms in the humid tropics, we monitored groundwater and soil moisture dynamics in a forested hillslope in Sumatra, Indonesia. We also conducted field and laboratory experiments to determine soil hydraulic characteristics and used the results to simulate vertical infiltration and groundwater recharge. Although the soil is categorized as silty clay loam, the high infiltrability and high water retention capacity of the soil enabled infil‐ tration during storm events and recharge to groundwater. Within the 4–5 m thick soil layer at the foot of the hillslope, the shallow groundwater table quickly responded to rainfall and did not drop below a depth of 2–3 m, possibly due to continuous flow contributions from the upslope. Overall, this study demonstrates the importance of subsurface flow and vertical infiltration in thick soil layers in humid tropical regions.","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69394556","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}
Inna Syafarina, Arnida Lailatul Latifah, Yosuke Miura, T. Nitta, K. Yoshimura
{"title":"Correction of the surface water formation parameter used in a malaria transmission model and future malaria projections for Africa","authors":"Inna Syafarina, Arnida Lailatul Latifah, Yosuke Miura, T. Nitta, K. Yoshimura","doi":"10.3178/hrl.15.98","DOIUrl":"https://doi.org/10.3178/hrl.15.98","url":null,"abstract":"The surface water formation parameter (Kw) currently used in malaria transmission models can dramatically affect larval development calculations. However, the parameter is often unrealistic due to the unavailability of observational datasets. This research presents an adjusted Kw by reference to an entomological inoculation rate (EIR) over the period 1983–2006, tuning the parameter by minimizing root mean square deviation of the water fraction from model calcula‐ tions and satellite observations from 2014–2018. A scaling factor, topography factor, and inverse distance weighting were used to reduce the gap between macroand microscales and to derive the appropriate spatial distribu‐ tion of Kw for a projection period from 2020–2100. The average EIR over the projection period under Representa‐ tive Concentration Pathway (RCP) scenarios 2.6, 7.0, and 8.5 in West Africa decreased by –29%, –43% and –35%, respectively, from the historical period. By contrast, for central southern Africa, the respective values increased by 3%, 6%, and 29% from the historical period. The reduced EIRs under RCPs 7.0 and 8.5 in West Africa were mostly affected by temperature, while monthly mean precipitation triggered a decrease in EIRs under RCP 2.6. By contrast, consecutive wet days have the most influential role in increasing the EIR in central southern Africa under all RCP scenarios. This research will help policy-makers eradicate vulnerable malaria areas and improve related policy design.","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69394326","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}
{"title":"Evaluation of drought features in the Dakbla watershed, Central Highlands of Vietnam","authors":"Vo Ngoc Quynh Tram, H. Somura, T. Moroizumi","doi":"10.3178/hrl.15.77","DOIUrl":"https://doi.org/10.3178/hrl.15.77","url":null,"abstract":": The drought impacts in the Dakbla watershed were assessed based on a combination of hydrological modeling and drought indices. Three drought indices, the Standard‐ ized Precipitation Index ( SPI ), Standardized Soil Moisture Index ( SSI ), and Streamflow Drought Index ( SDI ) were uti‐ lized to evaluate the drought features of meteo-hydrology and agriculture. The results indicated that these indices are well adapted to the local conditions, especially the 12-month time scale. Evaluations of drought features on the watershed scale could provide more specific information regarding drought risk than regional-scale/district-level assessments, because a watershed is a hydrologically fun‐ damental unit to consider water resources management. Additionally, evaluations of drought impacts using the SSI showed longer and higher trends than those using the SPI and SDI in terms of drought duration and frequency. Con‐ sidering the spatial distribution of drought frequency, the areas predominated by agricultural land in the target water‐ shed had higher drought risk. Thus, assessment of agricul‐ tural droughts along with meteo-hydrological droughts is extremely important to support realistic local drought man‐ agement strategies by considering water availability, water balance, and soil characteristics, especially in specific agri‐ cultural areas.","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69394688","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}
Kenichiro Kobayashi, Y. Kono, T. Kimura, H. Tanakamaru
{"title":"Estimation of paddy field dam effect on flood mitigation focusing on Suse region of Hyogo, Japan","authors":"Kenichiro Kobayashi, Y. Kono, T. Kimura, H. Tanakamaru","doi":"10.3178/hrl.15.64","DOIUrl":"https://doi.org/10.3178/hrl.15.64","url":null,"abstract":": Recently, Hyogo Prefecture in Japan has expanded its paddy field dam activity within the prefecture using wood weir plates. A wood weir plate was placed at the drainage outlet of a paddy field to limit drainage from the field, thus enabling the paddy fields to store rainwater to a certain extent. As the effect on flood mitigation was not appropri‐ ately estimated, we carried out a field experiment using a wood weir plate to estimate the weir coefficient, which determines the drainage discharge from the paddy accord‐ ing to the water depth. Then, using the estimated weir co‐ efficient, we developed a 3,000 m 2 paddy field dam model. Thereafter, we applied the model to the Suse region (approximately 33 ha) considering the 2009 and 2011 rain‐ fall events. It was observed that the paddy field dam has a relatively large effect on reducing the peak discharge (approximately 25.2% for 2009 and 48.5% for 2011) within the proximal downstream areas of the paddy dam site. However, the simulation showed that when the rainfall is extreme, as was the case in 2009, the paddy dam activity may cause erosion of the paddy levee due to the increase in the paddy water depth.","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69394636","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}
{"title":"Global integrated modeling framework of riverine dissolved inorganic nitrogen with seasonal variation","authors":"Yizhou Huang, Daisuke Tokuda, Xudong Zhou, T. Oki","doi":"10.3178/hrl.15.50","DOIUrl":"https://doi.org/10.3178/hrl.15.50","url":null,"abstract":": Understanding patterns and seasonal variations of exces‐ sive nutrients in surface water from anthropogenic activi‐ ties is important for pollution control. In this study, we developed an integrated biogeochemical modeling frame‐ work for nitrogen exchanges among the atmosphere, terres‐ trial, and aquatic ecosystems. A land surface model, a ter‐ restrial nitrogen cycle model, and a riverine hydrodynamics model incorporated with a river temperature model were consolidated and driven by multiple nitrogen sources related to anthropogenic activities. We estimated the global nitrogen loading and transporting in global rivers, with con‐ sideration of seasonal variations, and the validation demon‐ strates the reliability of the proposed model. The total dis‐ solved inorganic nitrogen (DIN) flow rate is accumulated following rivers and it has high total DIN loads even in regions with low population density but large basin area, such as those at high latitudes. This study successfully improves estimation of nitrogen loading on global scale with consideration of seasonal variation. Our results show consistent trends with the observed data of DIN concentra‐ tions in global rivers, where all above variables are greatly affected by seasonal variations. The results also reflect the monthly-variant nitrogen inputs help produce closer DIN concentration estimates to observations, which will possi‐ bly stress the need for further study on seasonal variability of anthropogenic emissions.","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69394621","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}
I. Takayabu, N. Ishizaki, T. Nakaegawa, H. Sasaki, W. Wongseree
{"title":"Potential of representing the diurnal cycle of local-scale precipitation in northeastern Thailand using 5-km and 2-km grid regional climate models","authors":"I. Takayabu, N. Ishizaki, T. Nakaegawa, H. Sasaki, W. Wongseree","doi":"10.3178/HRL.15.1","DOIUrl":"https://doi.org/10.3178/HRL.15.1","url":null,"abstract":"The diurnal cycle of precipitation over northeast Thai‐ land during the Southeast Asian summer monsoon season was examined using non-hydrostatic (5-km grid) and convection-permitting (2-km grid) regional climate models. The results indicate that these fine grid models exhibit a better performance in terms of representing the diurnal cycle of precipitation due to the realistic orographic repre‐ sentation. The models successfully simulated the local cir‐ culation corresponding to the intensification of precipita‐ tion and were consistent with the satellite-based observed diurnal cycle of precipitation. The model simulation indi‐ cated that the convergence area over the mountain on the south of the Khorat Plateau occurred in the afternoon in association with the occurrence of precipitation. The con‐ vergence area migrated northward and contributed to the precipitation peak over the plateau during the nighttime. A bias in terms of the amount of precipitation in the 5-km grid model was partially removed through the convectionpermitting 2-km grid model.","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69394505","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}
Koshi Yoshida, Supranee Sritumboon, M. Srisutham, K. Homma, M. Maki, K. Oki
{"title":"Climate change impact on soil salt accumulation in Khon Kaen, Northeast Thailand","authors":"Koshi Yoshida, Supranee Sritumboon, M. Srisutham, K. Homma, M. Maki, K. Oki","doi":"10.3178/hrl.15.92","DOIUrl":"https://doi.org/10.3178/hrl.15.92","url":null,"abstract":"In northeast Thailand, 17% of the total agricultural land is classified as salt-affected. In the future, climate change may exacerbate salt-affected soil problems. Therefore, in this study, we conducted a field survey to evaluate seasonal changes in soil electrical conductivity (ECe) in salt-affected paddy areas of Ban Phai District, Khon Kaen Province, northeast Thailand. Fifteen soil samples were collected every 2 weeks from October 2016 to December 2018, and the ECe, soil water content, and soil textures were ana‐ lyzed. Then, the HYDRUS-1D model was applied to esti‐ mate seasonal changes in the salinity level, and the simu‐ lated results corresponded well with observed data. Using HYDRUS-1D and the global circulation model (MIROC5) outputs under the Representative Concentration Pathways 8.5 scenario, future ECe was predicted. Under a tempera‐ ture increase of 2.8°C from 2016 to 2100, annual potential evapotranspiration increased from 1,430 mm (2016–2025) to 1,584 mm (2081–2100). The average ECe in cultivation season increased from 2.63 dS/m (2016–2025) to 3.31 dS/m (2081–2100). As a countermeasure to mitigate soil salt accumulation, a 5 cm reduction in groundwater level offsets the negative impact of climate change, and a 10 cm reduction significantly improves the soil ECe rela‐ tive to the current soil salinity level.","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69394764","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}
{"title":"A methodology to examine a depth-discharge constitutive equation for rainfall-runoff modelling","authors":"Y. Ichikawa, H. An, Y. Tachikawa","doi":"10.3178/hrl.15.44","DOIUrl":"https://doi.org/10.3178/hrl.15.44","url":null,"abstract":"A number of rainfall-runoff models have been developed for hydraulic and hydrological engineering with an empha‐ sis on reproducing river discharge time series. Physicallybased rainfall-runoff models have recently reached a certain level of achievement following the advancement of com‐ puters and the development of various geographical and meteorological datasets. However, it has been pointed out that the current physically-based models do not properly reflect observed hillslope water dynamics. The present paper proposes a methodology to examine the capability of a depth-discharge constitutive equation for physicallybased rainfall-runoff modelling to simulate hillslope water dynamics. An application of the methodology suggested that 1) the targeted constitutive equation was capable of representing the depth-discharge relationship on hillslopes under the assumed conditions, 2) the runoff simulations with the constitutive equation described hillslope water flows, at least in the downward direction, and 3) there was a possibility that the parameters in the constitutive equation was determined from the internal structure of hillslope water dynamics.","PeriodicalId":13111,"journal":{"name":"Hydrological Research Letters","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69394616","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}