The historical habitat of swamps and a lake in the Hula Valley was modified during the early 1950’s. The Swamps and the old Hula Lake were drained and the land was converted to an agricultural development. As a result of inappropriate cultivation, it was necessary to once more implement management improvement. It was done within the Hula Project. Part of the Hula Project was a modified usage of 10% of the area previously used for agriculture for eco-tourism. Independently, thousands of migratory Cranes attracted by peanut crop leftover started wintering in the valley. These bird flocks significantly improved the management objective to ensure prevention of nutrient flux into Lake Kinneret. Consequently, the partnerships between Kinneret water quality protection, nature conservation and agricultural utilization of the peat land is presently operated. Migratory wintered Cranes is a factor of management stability accompanied by costly artificial feeding for bird in a dedicated land block to prevent damage to adjacent crops.
{"title":"Partnerships between the Managements of Cranes (Grus grus) and Kinneret Water Quality Protection in the Hula Valley, Israel","authors":"M. Gophen","doi":"10.4236/OJMH.2017.72011","DOIUrl":"https://doi.org/10.4236/OJMH.2017.72011","url":null,"abstract":"The historical habitat of swamps and a lake in the Hula Valley was modified during the early 1950’s. The Swamps and the old Hula Lake were drained and the land was converted to an agricultural development. As a result of inappropriate cultivation, it was necessary to once more implement management improvement. It was done within the Hula Project. Part of the Hula Project was a modified usage of 10% of the area previously used for agriculture for eco-tourism. Independently, thousands of migratory Cranes attracted by peanut crop leftover started wintering in the valley. These bird flocks significantly improved the management objective to ensure prevention of nutrient flux into Lake Kinneret. Consequently, the partnerships between Kinneret water quality protection, nature conservation and agricultural utilization of the peat land is presently operated. Migratory wintered Cranes is a factor of management stability accompanied by costly artificial feeding for bird in a dedicated land block to prevent damage to adjacent crops.","PeriodicalId":70695,"journal":{"name":"现代水文学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48308406","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}
Ten years of monthly dataset of cladoceran (Diaphanosoma sp., Bosmina spp., Ceriodaphnia spp.) density in Lake Kinneret (spatially scattered lake sampling stations), Israel, was studied with the aim of searching impact factors controlling their dynamics. Statistical regressions indicated that out of several environmental factors (among others, non-pyrrhophyte algal biomass, invertebrate predation) only temperature factor was relevant. Additional speculative assumptions of zooplanktivore fish predation suggest this factor as a significant impact on cladoceran dynamics.
{"title":"Search for Environmental Causation of the Cladoceran Dynamics in Lake Kinneret, Israel","authors":"M. Gophen","doi":"10.4236/OJMH.2017.72005","DOIUrl":"https://doi.org/10.4236/OJMH.2017.72005","url":null,"abstract":"Ten years of monthly dataset of cladoceran (Diaphanosoma sp., Bosmina spp., Ceriodaphnia spp.) density in Lake Kinneret (spatially scattered lake sampling stations), Israel, was studied with the aim of searching impact factors controlling their dynamics. Statistical regressions indicated that out of several environmental factors (among others, non-pyrrhophyte algal biomass, invertebrate predation) only temperature factor was relevant. Additional speculative assumptions of zooplanktivore fish predation suggest this factor as a significant impact on cladoceran dynamics.","PeriodicalId":70695,"journal":{"name":"现代水文学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42978345","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 study of the Kinneret Littoral ecosystem is presented. Environmental parameters were integrated, aimed at evaluation of the Littoral ecosystem functioning: Water Level Fluctuations Index (WLFI), commercial fish landings with respect to stock assessment, fingerling food sources and density distribution, the beach vegetation impact, spawning intensity of nest builder-mouth breeder tilapias. It is concluded that WLFI is not affecting reproduction whilst long-term low WL altitude reduces the intensity of nesting by Sarotherodon galilaeus and Tristramella simonis simonis. Low WL did not affect reproduction of Coptodon zillii (Syn. Tilapia zillii). Density of fingerlings was not correlated with Inundated Beach vegetation during WL decline. Nevertheless, submerged macrophytes and shadowing Tamarix trees were preferably utilized by fingerling shoals as documented in the north-eastern half open lagoons of the lake shallows (Beteicha).
{"title":"Ecological Dynamics in the Kinneret Littoral Ecosystem","authors":"M. Gophen","doi":"10.4236/OJMH.2017.72007","DOIUrl":"https://doi.org/10.4236/OJMH.2017.72007","url":null,"abstract":"A study of the Kinneret Littoral ecosystem is presented. Environmental parameters were integrated, aimed at evaluation of the Littoral ecosystem functioning: Water Level Fluctuations Index (WLFI), commercial fish landings with respect to stock assessment, fingerling food sources and density distribution, the beach vegetation impact, spawning intensity of nest builder-mouth breeder tilapias. It is concluded that WLFI is not affecting reproduction whilst long-term low WL altitude reduces the intensity of nesting by Sarotherodon galilaeus and Tristramella simonis simonis. Low WL did not affect reproduction of Coptodon zillii (Syn. Tilapia zillii). Density of fingerlings was not correlated with Inundated Beach vegetation during WL decline. Nevertheless, submerged macrophytes and shadowing Tamarix trees were preferably utilized by fingerling shoals as documented in the north-eastern half open lagoons of the lake shallows (Beteicha).","PeriodicalId":70695,"journal":{"name":"现代水文学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49119971","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 hydrology of the Little Ruaha River which is a major catchment of the Ihemi Cluster in the Southern Agricultural Growth Corridor of Tanzania (SA-GCOT) has been studied. The study focused on the hydrological assessment through analysis of the available data and developing a model that could be used for assessing impacts of environmental change. Pressures on land and water resources in the watershed are increasing mainly as a result of human activities, and understanding the hydrological regime is deemed necessary. In this study, modeling was conducted using the Soil and Water Assessment Tool (SWAT) in which meteorological and streamflow data were used in the simulation, calibration and evaluation. Calibration and evaluation was done at three gauging stations and the results were deemed plausible with NSE ranging between 0.64 and 0.80 for the two stages. The simulated flows were used for gap filling the missing data and generation of complete daily time series of streamflow at three gauging stations of Makalala, Ihimbu and Mawande. Results of statistical trends and flow duration curves, revealed decline in magnitudes of seasonal and annual flows indicating that streamflows are changing with time and may have implications on envisioned development and the water dependent ecosystems.
{"title":"Assessing the Hydrology of a Data-Scarce Tropical Watershed Using the Soil and Water Assessment Tool: Case of the Little Ruaha River Watershed in Iringa, Tanzania","authors":"W. Mbungu, J. Kashaigili","doi":"10.4236/OJMH.2017.72004","DOIUrl":"https://doi.org/10.4236/OJMH.2017.72004","url":null,"abstract":"The hydrology of the Little Ruaha River which is a major catchment of the Ihemi Cluster in the Southern Agricultural Growth Corridor of Tanzania (SA-GCOT) has been studied. The study focused on the hydrological assessment through analysis of the available data and developing a model that could be used for assessing impacts of environmental change. Pressures on land and water resources in the watershed are increasing mainly as a result of human activities, and understanding the hydrological regime is deemed necessary. In this study, modeling was conducted using the Soil and Water Assessment Tool (SWAT) in which meteorological and streamflow data were used in the simulation, calibration and evaluation. Calibration and evaluation was done at three gauging stations and the results were deemed plausible with NSE ranging between 0.64 and 0.80 for the two stages. The simulated flows were used for gap filling the missing data and generation of complete daily time series of streamflow at three gauging stations of Makalala, Ihimbu and Mawande. Results of statistical trends and flow duration curves, revealed decline in magnitudes of seasonal and annual flows indicating that streamflows are changing with time and may have implications on envisioned development and the water dependent ecosystems.","PeriodicalId":70695,"journal":{"name":"现代水文学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46663126","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 Great Cormorant (Phalcrocorax carbo sinensis) is a well-known fish predator and migratory bird. The bird is a wintering visitor in Israel from the end of October through March. During 1950-1990, the Cormorant used to stay mostly in northern Israel, in the Hula Valley, preying on fish in Lake Kinneret as well as fishponds and adjacent reservoirs. Flocks of Cormorants were deported from northern Israel to eastern and central country regions, causing severe damage to aquaculture. A second operative deportation was carried out and the birds migrated to Lake Kinneret. A survey of their feeding habits was done by The National Nature and Parks Conservation Authority. The outcome information was compiled with international data and assembled towards a conclusive summary of potential causative damage to Lake Kinneret Fishery and Ecosystem structure. Consequences are described and recommendations made.
{"title":"Tilapia Stock Suppression by the Great Cormorant (Phalacrocorax carbo) in Lake Kinneret, Israel","authors":"M. Gophen","doi":"10.4236/OJMH.2017.72009","DOIUrl":"https://doi.org/10.4236/OJMH.2017.72009","url":null,"abstract":"The Great Cormorant (Phalcrocorax carbo sinensis) is a well-known fish predator and migratory bird. The bird is a wintering visitor in Israel from the end of October through March. During 1950-1990, the Cormorant used to stay mostly in northern Israel, in the Hula Valley, preying on fish in Lake Kinneret as well as fishponds and adjacent reservoirs. Flocks of Cormorants were deported from northern Israel to eastern and central country regions, causing severe damage to aquaculture. A second operative deportation was carried out and the birds migrated to Lake Kinneret. A survey of their feeding habits was done by The National Nature and Parks Conservation Authority. The outcome information was compiled with international data and assembled towards a conclusive summary of potential causative damage to Lake Kinneret Fishery and Ecosystem structure. Consequences are described and recommendations made.","PeriodicalId":70695,"journal":{"name":"现代水文学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47669432","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}
This study was aimed to assess the impact of climate change on the water resource of Megech river catchment. In this study, large scale regional climate model (REMO) output was downscaled statistically to metrological variables at a daily resolution using SDSM model version 5.11. We noticed that statistical downscaling smooth out the bias between REMO output and observed data. According to the projected climate data, the maximum temperature is likely to have an increasing trend +0.57°C while the minimum temperature shows a decreasing trends ﹣0.61°C. There is no clear trend for precipitation, both increasing and decreasing trend observed in the catchment. The HBV-Light hydrological model was successfully calibrated (1991-1995) and validated (1998-2000) using current climatic inputs and observed river flows. The overall performances of the model was good at monthly time scale both on calibration (NSE = 0.91) and validation (NSE = 0.86). Future discharge (2015-2050) was simulated using statistically downscaled 20 ensembles climate scenario data for both A1B and B1 scenarios. HBV-Light model simulation results showed a reduction of the peak discharge in August and September.
{"title":"Assessment of Climate Change Impacts on the Water Resources of Megech River Catchment, Abbay Basin, Ethiopia","authors":"Endalkachew Abebe, A. Kebede","doi":"10.4236/OJMH.2017.72008","DOIUrl":"https://doi.org/10.4236/OJMH.2017.72008","url":null,"abstract":"This study was aimed to assess the impact of climate change on the water resource of Megech river catchment. In this study, large scale regional climate model (REMO) output was downscaled statistically to metrological variables at a daily resolution using SDSM model version 5.11. We noticed that statistical downscaling smooth out the bias between REMO output and observed data. According to the projected climate data, the maximum temperature is likely to have an increasing trend +0.57°C while the minimum temperature shows a decreasing trends ﹣0.61°C. There is no clear trend for precipitation, both increasing and decreasing trend observed in the catchment. The HBV-Light hydrological model was successfully calibrated (1991-1995) and validated (1998-2000) using current climatic inputs and observed river flows. The overall performances of the model was good at monthly time scale both on calibration (NSE = 0.91) and validation (NSE = 0.86). Future discharge (2015-2050) was simulated using statistically downscaled 20 ensembles climate scenario data for both A1B and B1 scenarios. HBV-Light model simulation results showed a reduction of the peak discharge in August and September.","PeriodicalId":70695,"journal":{"name":"现代水文学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47281970","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}
There is no word to describe the importance of evapotranspiration research for water resource utilization. We have already proposed a new method for the reciprocal estimation of the sensible (H) and latent heat fluxes (lE) by using a single height temperature (Tz) and humidity (rehz) based on the observed net radiation (Rn) and ground heat flux (G). This research is more advanced than the previous research because it uses a Ts observed by a radiometer and identifies the observed data satisfactorily heat balance relationship in every hour at nine sites. First, we confirmed that the estimated H and lE are very close reproductions of the identified H and lE. Second, by analyzing the relative ground surface temperature (Ts - T0) [Ts: ground surface temperature, T0: observed temperature near the soil surface], the hourly and seasonal changes of (Ts - T0) were clarified, resulting in a marked difference in the (Ts - T0) from previous research in arid and semi-arid regions. Next, the estimation accuracy of H, lE and rehs (the humidity of the soil surface) was determined by observing the slope of the estimated and observed relationship, resulting in the reasonable accuracy (0.85 - 1.15 times) of rehs at seven of the nine sites. Furthermore, the annual evapotranspiration was estimated by comparing the identified and estimated H and lE, resulting in a reasonable accuracy (0.85 - 1.15) at five of the nine sites in the case of the application of constraint b. Moreover, the effect of the lag-time between the net radiation Rn and both Tz and Ts for the estimation accuracy on H and lE was tested, and no remarkable difference was found because the effect was included already in the original data. The above results will contribute greatly to the advance of water resource planning and hydrometeorology. This research was conducted using FLUXNET data.
蒸散研究对水资源利用的重要性是无法用语言来形容的。我们已经提出了一种新的方法，通过使用基于观测到的净辐射（Rn）和地面热通量（G）的单高度温度（Tz）和湿度（rehz）来倒数估计显热通量（H）和潜热通量（lE）。这项研究比以前的研究更先进，因为它使用了辐射计观测到的Ts，并在九个地点的每小时内确定了令人满意的热平衡关系。首先，我们证实了估计的H和lE是已识别的H和l E的非常接近的复制品。其次，通过分析相对地表温度（Ts-T0）[Ts:ground surface temperature，T0:observed temperature near soil surface]，阐明了（Ts-TO）的小时和季节变化，导致（Ts-To）与以往干旱和半干旱地区的研究有显著差异。接下来，通过观察估计和观测关系的斜率来确定H、lE和rehs（土壤表面湿度）的估计精度，从而得出9个地点中7个地点rehs的合理精度（0.85-1.15倍）。此外，通过比较已识别和估计的H和lE来估计年蒸散量，在应用约束条件b的情况下，九个地点中的五个地点的蒸散量具有合理的精度（0.85-1.15）。此外，还测试了净辐射Rn与Tz和Ts之间的滞后时间对H和lE估计精度的影响，并且没有发现显著差异，因为该效应已经包括在原始数据中。以上研究结果将为水资源规划和水文气象的发展做出重要贡献。本研究使用FLUXNET数据进行。
{"title":"Estimation Accuracy for Reciprocal Analysis of Sensible and Latent Heat Flux Focusing on Radiometric Temperature and Lag-Time","authors":"T. Maruyama, M. Segawa","doi":"10.4236/OJMH.2017.72006","DOIUrl":"https://doi.org/10.4236/OJMH.2017.72006","url":null,"abstract":"There is no word to describe the importance of evapotranspiration research for water resource utilization. We have already proposed a new method for the reciprocal estimation of the sensible (H) and latent heat fluxes (lE) by using a single height temperature (Tz) and humidity (rehz) based on the observed net radiation (Rn) and ground heat flux (G). This research is more advanced than the previous research because it uses a Ts observed by a radiometer and identifies the observed data satisfactorily heat balance relationship in every hour at nine sites. First, we confirmed that the estimated H and lE are very close reproductions of the identified H and lE. Second, by analyzing the relative ground surface temperature (Ts - T0) [Ts: ground surface temperature, T0: observed temperature near the soil surface], the hourly and seasonal changes of (Ts - T0) were clarified, resulting in a marked difference in the (Ts - T0) from previous research in arid and semi-arid regions. Next, the estimation accuracy of H, lE and rehs (the humidity of the soil surface) was determined by observing the slope of the estimated and observed relationship, resulting in the reasonable accuracy (0.85 - 1.15 times) of rehs at seven of the nine sites. Furthermore, the annual evapotranspiration was estimated by comparing the identified and estimated H and lE, resulting in a reasonable accuracy (0.85 - 1.15) at five of the nine sites in the case of the application of constraint b. Moreover, the effect of the lag-time between the net radiation Rn and both Tz and Ts for the estimation accuracy on H and lE was tested, and no remarkable difference was found because the effect was included already in the original data. The above results will contribute greatly to the advance of water resource planning and hydrometeorology. This research was conducted using FLUXNET data.","PeriodicalId":70695,"journal":{"name":"现代水文学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49566041","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}
Due to global climatic changes, flash floods are followed as a yearly disaster with high magnitude of influence. During the years 1981, 1988, 2010, 2012 and in January 2013, Tabuk city, northwest of Saudi Arabia suffered huge flash floods. These are major factors affecting on the swelling behavior of expansive Tabuk shale. The examined geotechnical properties of the surface and subsurface lithology of the sedimentary deposits distinguished Tabuk city into three zones. The expansive zone is spread in the middle and the non-expansive zones are distributed in the east and west of the city. The Watershed Modeling System (WMS) and Hydrologic Engineering Center (HEC-1) models were used to delineate and identify the drainage system and basin morphometry, where flash floods and accumulation of water might take place. Integration between geotechnical distribution maps of the expansion soil and surface hydrological data in terms of runoff maps was done. It has been identified the whereabouts the soils which have expansion characteristics and areas prone to flooding and surface runoff. They are helpful in defining the hazard zones map. Based on this map, it can be avoided constructions on the risk neighborhoods such as Al Qadsiyah, Al Maseif, Arrwdah, Al Nakhil and Al Rajhi. Also, it can suggest that the western side of Tabuk city is suitable for future urban extension. These results will help planners and citizens to create alternative development scenarios and determine their impact on the future urbanization patterns. Moreover, the direction of surface runoff flow or storm water discharge should be away from the expansion soil areas. Therefore, constructing dams on the outlet of the high-risk basins, south of Tabuk city is an important solution to control flash flood events, as well as increase groundwater recharge.
{"title":"Integrating Geotechnical Investigation with Hydrological Modeling for Mitigation of Expansive Soil Hazards in Tabuk City, Saudi Arabia","authors":"A. Embaby, A. A. Halawa, M. Ramadan","doi":"10.4236/OJMH.2017.71002","DOIUrl":"https://doi.org/10.4236/OJMH.2017.71002","url":null,"abstract":"Due to global climatic changes, flash floods are followed as a yearly disaster with high magnitude of influence. During the years 1981, 1988, 2010, 2012 and in January 2013, Tabuk city, northwest of Saudi Arabia suffered huge flash floods. These are major factors affecting on the swelling behavior of expansive Tabuk shale. The examined geotechnical properties of the surface and subsurface lithology of the sedimentary deposits distinguished Tabuk city into three zones. The expansive zone is spread in the middle and the non-expansive zones are distributed in the east and west of the city. The Watershed Modeling System (WMS) and Hydrologic Engineering Center (HEC-1) models were used to delineate and identify the drainage system and basin morphometry, where flash floods and accumulation of water might take place. Integration between geotechnical distribution maps of the expansion soil and surface hydrological data in terms of runoff maps was done. It has been identified the whereabouts the soils which have expansion characteristics and areas prone to flooding and surface runoff. They are helpful in defining the hazard zones map. Based on this map, it can be avoided constructions on the risk neighborhoods such as Al Qadsiyah, Al Maseif, Arrwdah, Al Nakhil and Al Rajhi. Also, it can suggest that the western side of Tabuk city is suitable for future urban extension. These results will help planners and citizens to create alternative development scenarios and determine their impact on the future urbanization patterns. Moreover, the direction of surface runoff flow or storm water discharge should be away from the expansion soil areas. Therefore, constructing dams on the outlet of the high-risk basins, south of Tabuk city is an important solution to control flash flood events, as well as increase groundwater recharge.","PeriodicalId":70695,"journal":{"name":"现代水文学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45069686","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}
Sensible and latent heat flux at semi-arid and arid region, i.e., evapotranspiration, has been researched for long time because it serves an important role for water resource issues. However, the issues have not solved completely yet. Accordingly, by applying the Bowen ratio concept on the soil surface, the sensible and latent heat fluxes are reciprocally estimated using single height temperature (Tz) and humidity (rehz) with the net radiation (Rn) and heat flux into the ground (G). The procedure proposed by authors initially estimates the soil surface temperature (Ts) and the relative humidity (rehs) using optimization techniques. The method is remarkably effective to expand for estimating evapotranspiration at various regions. The validity of the method is confirmed by the latent heat flux (lE) and sensible heat flux (H) observed by the eddy covariance method. The hourly change of the lE, H, Ts and rehs on the soil surface, yearly change of lE and H and relationship of estimated lE and H versus observed are clarified. Yearly change of evapotranspiration is also estimated. The analysis is performed by general method (1), conventional method and general method (2). Above results are very useful for water resources issue and irrigation planning. The research is conducted using hourly data at eight globally dispersed sites using FLUXNET.
{"title":"Estimation of the Sensible and Latent Heat Fluxes by Reciprocal Analysis at an Arid and Semi-Arid Region","authors":"T. Maruyama, M. Segawa","doi":"10.4236/OJMH.2017.71003","DOIUrl":"https://doi.org/10.4236/OJMH.2017.71003","url":null,"abstract":"Sensible and latent heat flux at semi-arid and arid region, i.e., evapotranspiration, has been researched for long time because it serves an important role for water resource issues. However, the issues have not solved completely yet. Accordingly, by applying the Bowen ratio concept on the soil surface, the sensible and latent heat fluxes are reciprocally estimated using single height temperature (Tz) and humidity (rehz) with the net radiation (Rn) and heat flux into the ground (G). The procedure proposed by authors initially estimates the soil surface temperature (Ts) and the relative humidity (rehs) using optimization techniques. The method is remarkably effective to expand for estimating evapotranspiration at various regions. The validity of the method is confirmed by the latent heat flux (lE) and sensible heat flux (H) observed by the eddy covariance method. The hourly change of the lE, H, Ts and rehs on the soil surface, yearly change of lE and H and relationship of estimated lE and H versus observed are clarified. Yearly change of evapotranspiration is also estimated. The analysis is performed by general method (1), conventional method and general method (2). Above results are very useful for water resources issue and irrigation planning. The research is conducted using hourly data at eight globally dispersed sites using FLUXNET.","PeriodicalId":70695,"journal":{"name":"现代水文学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43355552","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 feeding habits of the cichlid Tilapia zillii (Gervais) in Lake Kinneret (Israel) were experimentally studied in indoor glass containers (2.5 hrs) and two trials in outdoor 5 m3 tanks (20 - 25 days). The trait of food particle collection by adult fishes was measured. A survey was carried out in the littoral (0 - 1.0 m deep) zone and fingerlings were sampled by electro-chocker. The gut content of the fingerlings was analyzed. The feeding habits of T. zillii were indicated as planktivorous filtration with more enhancements of small zooplankters (Nauplius, Brachionid rotifers) and fewer of Cladocerans suppressions.
{"title":"Experimental Study of the Feeding Habits of Tilapia zillii (Gervais) in Lake Kinneret","authors":"M. Gophen","doi":"10.4236/OJMH.2017.71001","DOIUrl":"https://doi.org/10.4236/OJMH.2017.71001","url":null,"abstract":"The feeding habits of the cichlid Tilapia zillii (Gervais) in Lake Kinneret (Israel) were experimentally studied in indoor glass containers (2.5 hrs) and two trials in outdoor 5 m3 tanks (20 - 25 days). The trait of food particle collection by adult fishes was measured. A survey was carried out in the littoral (0 - 1.0 m deep) zone and fingerlings were sampled by electro-chocker. The gut content of the fingerlings was analyzed. The feeding habits of T. zillii were indicated as planktivorous filtration with more enhancements of small zooplankters (Nauplius, Brachionid rotifers) and fewer of Cladocerans suppressions.","PeriodicalId":70695,"journal":{"name":"现代水文学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42968030","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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