Hydrology and Earth System Sciences最新文献

{"title":"Water cycle changes in Czechia: a multi-source water budget perspective","authors":"Mijael Rodrigo Vargas Godoy, Y. Markonis, O. Rakovec, Michal Jeníček, Riya Dutta, R. Pradhan, Zuzana Bešťáková, Jan Kyselý, Roman Juras, S. Papalexiou, M. Hanel","doi":"10.5194/hess-28-1-2024","DOIUrl":"https://doi.org/10.5194/hess-28-1-2024","url":null,"abstract":"Abstract. The water cycle in Czechia has been observed to be changing in recent years, with precipitation and evapotranspiration rates exhibiting a trend of acceleration. However, the spatial patterns of such changes remain poorly understood due to the heterogeneous network of ground observations. This study relied on multiple state-of-the-art reanalyses and hydrological modeling. Herein, we propose a novel method for benchmarking hydroclimatic data fusion based on water cycle budget closure. We ranked water cycle budget closure of 96 different combinations for precipitation, evapotranspiration, and runoff using CRU TS v4.06, E-OBS, ERA5-Land, mHM, NCEP/NCAR R1, PREC/L, and TerraClimate. Then, we used the best-ranked data to describe changes in the water cycle in Czechia over the last 60 years. We determined that Czechia is undergoing water cycle acceleration, evinced by increased atmospheric water fluxes. However, the increase in annual total precipitation is not as pronounced nor as consistent as evapotranspiration, resulting in an overall decrease in the runoff. Furthermore, non-parametric bootstrapping revealed that only evapotranspiration changes are statistically significant at the annual scale. At higher frequencies, we identified significant spatial heterogeneity when assessing the water cycle budget at a seasonal scale. Interestingly, the most significant temporal changes in Czechia occur during spring, while the spatial pattern of the change in median values stems from summer changes in the water cycle, which are the seasons within the months with statistically significant changes.\u0000","PeriodicalId":507846,"journal":{"name":"Hydrology and Earth System Sciences","volume":"82 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139452112","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":"Data-driven estimates of evapotranspiration and its controls in the Congo Basin","authors":"M. W. Burnett, G. Quetin, A. Konings","doi":"10.5194/hess-2020-186","DOIUrl":"https://doi.org/10.5194/hess-2020-186","url":null,"abstract":"Abstract. Evapotranspiration (ET) from tropical forests serves as a critical moisture\u0000source for regional and global climate cycles. However, the magnitude,\u0000seasonality, and interannual variability of ET in the Congo Basin remain\u0000poorly constrained due to a scarcity of direct observations, despite the\u0000Congo being the second-largest river basin in the world and containing a\u0000vast region of tropical forest. In this study, we applied a water balance\u0000model to an array of remotely sensed and in situ datasets to produce\u0000monthly, basin-wide ET estimates spanning April 2002 to November 2016. Data\u0000sources include water storage changes estimated from the Gravity Recovery\u0000and Climate Experiment (GRACE) satellites, in situ measurements of river\u0000discharge, and precipitation from several remotely sensed and gauge-based\u0000sources. An optimal precipitation dataset was determined as a weighted\u0000average of interpolated data by Nicholson et al. (2018), Climate Hazards\u0000InfraRed Precipitation with Station data version 2 (CHIRPS2) , and the\u0000Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks–Climate Data Record product (PERSIANN-CDR), with the relative weights based on the error magnitudes of each dataset as determined by triple collocation. The resulting water-balance-derived ET (ETwb) features a long-term average that is consistent with previous studies (117.2±3.5 cm yr−1) but displays greater seasonal and interannual variability than seven global ET products. The seasonal cycle of ETwb generally tracks that of precipitation over the basin, with the exception that ETwb is greater in March–April–May (MAM) than in the relatively wetter September–October–November (SON) periods. This pattern appears to be\u0000driven by seasonal variations in the diffuse photosynthetically active radiation (PAR) fraction, net radiation (Rn), and soil water availability. From 2002 to 2016, Rn, PAR, and vapor-pressure deficit (VPD) all increased significantly within the Congo Basin; however, no corresponding trend occurred in ETwb. We hypothesize that the stability of ETwb over the study period despite sunnier and less humid conditions may be due to increasing atmospheric CO2 concentrations that offset the impacts of rising VPD and irradiance on stomatal water use efficiency (WUE).\u0000","PeriodicalId":507846,"journal":{"name":"Hydrology and Earth System Sciences","volume":"43 25","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141206939","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}