•A novel data-driven regionalization modeling framework for PUB is proposed.•The DTW-KMeans technique is suitable for catchment classification.•Matching model complexity and number of training ...catchments can improve performance.•Catchment similarity plays a crucial role on regionalization modeling.
Streamflow prediction in ungauged catchments is a challenging task in hydrological studies. Recently, data-driven models have demonstrated their superiority over traditional hydrological models in predicting streamflow in ungauged catchments. However, previous studies have overlooked the similarities between the training and the target catchments. Therefore, this study explores the role of catchment similarity in regionalization modeling using the publicly available CAMELS dataset. We employed the dynamic time warping-based KMeans (DTW-KMeans) time-series clustering technique to cluster the streamflow data from gauged catchments. We utilized the long short-term memory (LSTM) neural network to construct regional models for different classes of gauged catchment. Additionally, the mapping relationship between gauged catchment classes and static attributes was established using the random forest (RF). By combining the trained RF model with the static attributes of an ungauged catchment, we determined its class and used the corresponding regional LSTM to predict streamflow. To evaluate the effectiveness of the framework, we applied the classification-based regionalization modeling (CRM) and non-classification-based regionalization modeling (NRM) approach for comparison. The results indicate that: (1) The DTW-KMeans-based catchment classification method is generally accurate and reasonable; (2) the complexity of the LSTM model and the number of training catchments should be appropriately matched to improve streamflow prediction; and (3) catchment similarity plays a crucial role in regionalization modeling, the proportion of training catchments with high similarity to ungauged catchments significantly affects prediction results.
This paper presents a high-resolution quantitative phytoclimatic map of Europe (PME). Ecological studies and landscape planning need quantitative and reproducible tools to assess the environment and ...to define land based ecological units characterized by spatial and temporal boundaries. At small scales, Phytoclimatic maps seem appropriate to fulfill such requisites because climate determines broad ecosystem type and distribution. PME is based on Defaut’s system of phytoclimatic stages (DSPS). DSPS relies on a combination of mean annual temperature, mean temperature of the warmest month, thermal continentality and the Qn2 aridity/humidity index. Boundaries of phytoclimatic stages are defined by zonal phytosociological syntaxa. PME was developed by GIS processing, by kriging interpolation of phytoclimatic temperature classes, aridity/moisture and thermal continentality of 1113 climatological stations. PME shows fifty different phytoclimatic stages. Distribution and coverage of such stages and their main plant formations are described and discussed. PME was compared to the Map of the Natural Vegetation of Europe (MNVE) by Kappa analysis. Good agreement was found between PME and MNVE, but as expected, PME and MNVE do not match perfectly. Major circumstances that could lead to discordance between the two maps are discussed. In conclusion, it is felt that PME, thanks to its reliability and relative simplicity could be a useful and robust tool in ecological analysis and environment assessment, as well as in climate change studies, and for educational purposes.
The article explores the scope of use and the level of terminological and conceptual maturity of “Central Europe” in the post-war Soviet academic discourse. While there is a current in the ...international debate examining the notion in substance, an investigation of its usage in distinct academic languages can help to render the discussion more practice-oriented. The present work is based on a review of authoritative sources of the period, such as encyclopediae and academic dictionaries as well as publications of prominent Soviet scholars in the disciplines where the notion found its application (geography, history, etc.). The influence of foreign publications and the tendency to employ “Central Europe” as a schematic mental placement for distinct phenomena are found pivotal for the term development. The article contributes to the attempts of delimiting the region, through evincing shared understandings of and around it, and looking into the continuity between the Soviet and the post-Soviet perspectives.
We provide a map and shapefile of the 57 biogeographic provinces of the Neotropical region. Recognition of these provinces is based on their endemic species, but their delimitation on the map is ...based on ecoregions combining climatic, geological, and biotic criteria. These provinces belong to the Antillean, Brazilian and Chacoan subregions, and the Mexican and South American transition zones. We provide a vector file of the biogeographical regionalization by converting the map into a polygon shapefile and a raster file with all provinces.
The requirements for hydrological models have increased considerably during the previous decades to cope with the resolution of extensive remotely sensed data sets and a number of demanding ...applications. Existing models exhibit deficiencies such as overparameterization, the lack of an effective technique to integrate the spatial heterogeneity of physiographic characteristics, and the nontransferability of parameters across scales and locations. A multiscale parameter regionalization (MPR) technique is proposed as a way to address these issues simultaneously. Using this technique, parameters at a coarser scale, in which the dominant hydrological processes are represented, are linked with their corresponding ones at a finer resolution in which input data sets are available. The linkage is done with upscaling operators such as the harmonic mean, among others. Parameters at the finer scale are regionalized through nonlinear transfer functions which link basin predictors with global parameters to be determined through calibration. MPR was compared with a standard regionalization (SR) method in which basin predictors instead of model parameters are first aggregated. Both methods were tested in a basin located in Germany using a distributed hydrologic model. Results indicate that MPR is superior to SR in many respects, especially if global parameters are transferred from coarser to finer scales. Furthermore, MPR, as opposed to SR, preserves the spatial variability of state variables and conserves the mass balance with respect to a control scale. Cross‐validation tests indicate that the transferability of the global parameters to ungauged locations is possible.
This paper analyses the observed spatiotemporal characteristics of drought phenomenon in Syria using the Standardised Precipitation Index (SPI) and the Standardised Precipitation Evapotranspiration ...Index (SPEI). Temporal variability of drought is calculated for various time scales (3, 6, 9, 12, and 24months) for 20 weather stations over the 1961–2012 period. The spatial patterns of drought were identified by applying a Principal Component Analysis (PCA) to the SPI and SPEI values at different time scales. The results revealed three heterogeneous and spatially well-defined regions with different temporal evolution of droughts: 1) Northeastern (inland desert); 2) Southern (mountainous landscape); 3) Northwestern (Mediterranean coast). The evolutionary characteristics of drought during 1961–2012 were analysed including spatial and temporal variability of SPI and SPEI, the frequency distribution, and the drought duration. The results of the non-parametric Mann–Kendall test applied to the SPI and SPEI series indicate prevailing significant negative trends (drought) at all stations. Both drought indices have been correlated both on spatial and temporal scales and they are highly comparable, especially, over a 12 and 24month accumulation period. We concluded that the temporal and spatial characteristics of the SPI and SPEI can be used for developing a drought intensity - areal extent - and frequency curve that assesses the variability of regional droughts in Syria. The analysis of both indices suggests that all three regions had a severe drought in the 1990s, which had never been observed before in the country. Furthermore, the 2007–2010 drought was the driest period in the instrumental record, happening just before the onset of the recent conflict in Syria.
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•Few studies have been performed about this topic in this area which is one of the most sensitive areas to climate change.•Standardised Precipitation Index (SPI) and Standardised Precipitation Evapotranspiration Index (SPEI) have been applied.•The area has been divided into three heterogeneous and spatially regions using the Principle Component Analysis (PCA).•The study explains the severe drought periods in Syria over last decades which contributed to the outbreak of civil war.
The area of influence of global conurbations and agglomerations goes far beyond administrative borders. This questions the governance needed to deal with the challenges raised at this scale. This ...article offers to focus on the example of the Paris region, where the division has stayed the same since 1956 and where interregional cooperations have failed. More precisely, our objective is to understand why a small Parisian region was created and why its boundaries have not been modified to adapt to the functional aspect of the region. This geo-historical approach, using many archives, identifies the role played by the ideas and strategies of several actors, from Jean-François Gravier to the Valls government. The analysis also shows that political actors have difficulty in understanding the megaregional influence of Paris, and that the problems of cooperation in the megaregion will be exacerbated by the reform of the regional map (2015), which merged territories belonging in part to the urban area of Paris (Oise and Aisne, for example) with areas affected by very different dynamics and issues.
On the grounds of the long discussion in the literature for the construction of regional input–output (I/O) tables, the present study endeavors to identify the best performing method among the most ...applied location quotient based non-survey techniques. The analysis uses actual data—in particular, the EU input–output tables for the years 2010 and 2014—and by employing three different statistics, it compares the tables created by the quotients FLQ, AFLQ, SLQ, CILQ and RLQ. Comparison is made in both the technical coefficient tables and the Leontief ones. The results indicate that the AFLQ and FLQ provide better results for values of
δ
from 0.1 to 0.3, whereas for values of
δ
from 0.4 to 0.9, the results of the two quotients are not satisfactory. At the same time, using another statistic, the SLQ–CILQ technique seemed to yield satisfactory results. Similar results are also presented for the Leontief tables. Finally, using a linear regression model, the imports do not appear to be related to the value of
δ
in the FLQ.
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