In 2020 UN Water, the entity coordinating the United Nations’ work on water and sanitation, identified capacity development as one of the five accelerators required to achieve the Sustainable ...Development Goal on Clean Water and Sanitation (SDG 6). In today’s practical application, capacity development is mostly financed to deliver a product specified in advance, not to arrange a longer time frame and process to structurally learn from various activities and discover sustainable development paths (Alaerts and Zevenbergen 2022). The inclusion of traditional knowledge and cultural heritage in our joint-learning efforts will help us enlarge capacity for a more sustainable culture of water.
Water managers face many urgent challenges. Sea levels are rising, floods and droughts are in- creasing in frequency and intensity, while population growth and socio-economic transitions in- crease ...water demand.
These challenges cannot be resolved by technological innovation alone. To adapt to the changing requirements of water systems, we need to not only rethink institutions, laws and policies, but also to reflect on past cultures and the often-overlooked relationship between humans, water and eco-systems. We need to include the larger public and elevate their awareness of the value of water, spark more interest and foster engagement. Water challenges are also socio-cultural challenges: they are anchored in local practices, cultures and traditions.
To tackle these complex challenges, we need a better understanding of the interconnections be- tween water, cultures and societies, over time and through space. Researchers and practitioners from multiple disciplines and approaches need to forge a shared approach that connects techno- logical innovation with historical, anthropological, political and economic aspects.
This new journal, Blue Papers, aims to contribute by bringing together different disciplinary ap- proaches and stakeholders around the theme of water, culture and heritage. It will shine light on local adaptations and global visions. It will demonstrate the value of traditional knowledge and of the involvement of marginalized groups to develop sustainable management of water.
In this way, Blue Papers aspires to foster cross-disciplinary connections that will help the world tackle the urgent water challenges we as humanity face today.
We upscaled FLUXNET observations of carbon dioxide, water, and energy fluxes to the global scale using the machine learning technique, model tree ensembles (MTE). We trained MTE to predict site‐level ...gross primary productivity (GPP), terrestrial ecosystem respiration (TER), net ecosystem exchange (NEE), latent energy (LE), and sensible heat (H) based on remote sensing indices, climate and meteorological data, and information on land use. We applied the trained MTEs to generate global flux fields at a 0.5° × 0.5° spatial resolution and a monthly temporal resolution from 1982 to 2008. Cross‐validation analyses revealed good performance of MTE in predicting among‐site flux variability with modeling efficiencies (MEf) between 0.64 and 0.84, except for NEE (MEf = 0.32). Performance was also good for predicting seasonal patterns (MEf between 0.84 and 0.89, except for NEE (0.64)). By comparison, predictions of monthly anomalies were not as strong (MEf between 0.29 and 0.52). Improved accounting of disturbance and lagged environmental effects, along with improved characterization of errors in the training data set, would contribute most to further reducing uncertainties. Our global estimates of LE (158 ± 7 J × 1018 yr−1), H (164 ± 15 J × 1018 yr−1), and GPP (119 ± 6 Pg C yr−1) were similar to independent estimates. Our global TER estimate (96 ± 6 Pg C yr−1) was likely underestimated by 5–10%. Hot spot regions of interannual variability in carbon fluxes occurred in semiarid to semihumid regions and were controlled by moisture supply. Overall, GPP was more important to interannual variability in NEE than TER. Our empirically derived fluxes may be used for calibration and evaluation of land surface process models and for exploratory and diagnostic assessments of the biosphere.
Scarcity of in-situ observations coupled with high orographic influences has prevented a comprehensive assessment of precipitation distribution in the high-altitude catchments of Indus basin. ...Available data are generally fragmented and scattered with different organizations and mostly cover the valleys. Here, we combine most of the available station data with the indirect precipitation estimates at the accumulation zones of major glaciers to analyse altitudinal dependency of precipitation in the high-altitude Indus basin. The available observations signified the importance of orography in each sub-hydrological basin but could not infer an accurate distribution of precipitation with altitude. We used Kriging with External Drift (KED) interpolation scheme with elevation as a predictor to appraise spatiotemporal distribution of mean monthly, seasonal and annual precipitation for the period of 1998–2012. The KED-based annual precipitation estimates are verified by the corresponding basin-wide observed specific runoffs, which show good agreement. In contrast to earlier studies, our estimates reveal substantially higher precipitation in most of the sub-basins indicating two distinct rainfall maxima; 1st along southern and lower most slopes of Chenab, Jhelum, Indus main and Swat basins, and 2nd around north-west corner of Shyok basin in the central Karakoram. The study demonstrated that the selected gridded precipitation products covering this region are prone to significant errors. In terms of quantitative estimates, ERA-Interim is relatively close to the observations followed by WFDEI and TRMM, while APHRODITE gives highly underestimated precipitation estimates in the study area. Basin-wide seasonal and annual correction factors introduced for each gridded dataset can be useful for lumped hydrological modelling studies, while the estimated precipitation distribution can serve as a basis for bias correction of any gridded precipitation products for the study area.
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•We developed an improved estimation of precipitation distribution over the upper Indus basin.•Results show clear non-linear increases in precipitation with altitude.•The estimated precipitation is much higher compared to previous studies and gridded products.•The gridded precipitation products are unsuitable to force hydrological models in upper Indus.•The basin-wide seasonal and annual correction factors can be used for hydrological models.
We use eddy covariance measurements of net ecosystem productivity (NEP) from 21 FLUXNET sites (153 site-years of data) to investigate relationships between phenology and productivity (in terms of ...both NEP and gross ecosystem photosynthesis, GEP) in temperate and boreal forests. Results are used to evaluate the plausibility of four different conceptual models. Phenological indicators were derived from the eddy covariance time series, and from remote sensing and models. We examine spatial patterns (across sites) and temporal patterns (across years); an important conclusion is that it is likely that neither of these accurately represents how productivity will respond to future phenological shifts resulting from ongoing climate change. In spring and autumn, increased GEP resulting from an ‘extra’ day tends to be offset by concurrent, but smaller, increases in ecosystem respiration, and thus the effect on NEP is still positive. Spring productivity anomalies appear to have carry-over effects that translate to productivity anomalies in the following autumn, but it is not clear that these result directly from phenological anomalies. Finally, the productivity of evergreen needleleaf forests is less sensitive to phenology than is productivity of deciduous broadleaf forests. This has implications for how climate change may drive shifts in competition within mixed-species stands.
Precipitation in the high‐altitude Indus basin governs its renewable water resources affecting water, energy and food securities. However, reliable estimates of precipitation climatology and ...associated hydrological implications are seriously constrained by the quality of observed data. As such, quantitative and spatio‐temporal distributions of precipitation estimated by previous studies in the study area are highly contrasting and uncertain. Generally, scarcity and biased distribution of observed data at the higher altitudes and measurement errors in precipitation observations are the primary causes of such uncertainties. In this study, we integrated precipitation data of 307 observatories with the net snow accumulations estimated through mass balance studies at 21 major glacier zones. Precipitation observations are adjusted for measurement errors using the guidelines and standard methods developed under the WMO's international precipitation measurement intercomparisons, while net snow accumulations are adjusted for ablation losses using standard ablation gradients. The results showed more significant increases in precipitation of individual stations located at higher altitudes during winter months, which are consistent with previous studies. Spatial interpolation of unadjusted precipitation observations and net snow accumulations at monthly scale indicated significant improvements in the quantitative and spatio‐temporal distribution of precipitation over the unadjusted case and previous studies. Adjustment of river flows revealed only a marginal contribution of net glacier mass balance to river flows. The adjusted precipitation estimates are more consistent with the corresponding adjusted river flows. The study recognized that the higher river flows than the corresponding precipitation estimates by the previous studies are mainly due to underestimated precipitation. The results can be useful for water balance studies and bias correction of gridded precipitation products for the study area.
This study integrated precipitation data of 307 observatories with the net snow accumulations at 21 glaciers and adjusted them for measurement errors and ablation losses. The adjustments revealed average precipitation increase of 21.3% at the basin level, which ranged from 6 to 77% at sub‐basin scale with highest increases at higher altitudes during winter months. The contribution of net glacier mass balance to river flows is only marginal. Data quality‐driven underestimated precipitation is well‐recognized. Figure shows estimated biases from precipitation gauges due to measurement errors and spatial distribution of error‐adjusted annual precipitation.
Estimates of carbon leaching losses from different land use systems are few and their contribution to the net ecosystem carbon balance is uncertain. We investigated leaching of dissolved organic ...carbon (DOC), dissolved inorganic carbon (DIC), and dissolved methane (CH₄), at forests, grasslands, and croplands across Europe. Biogenic contributions to DIC were estimated by means of its δ¹³C signature. Leaching of biogenic DIC was 8.3±4.9 g m⁻² yr⁻¹ for forests, 24.1±7.2 g m⁻² yr⁻¹ for grasslands, and 14.6±4.8 g m⁻² yr⁻¹ for croplands. DOC leaching equalled 3.5±1.3 g m⁻² yr⁻¹ for forests, 5.3±2.0 g m⁻² yr⁻¹ for grasslands, and 4.1±1.3 g m⁻² yr⁻¹ for croplands. The average flux of total biogenic carbon across land use systems was 19.4±4.0 g C m⁻² yr⁻¹. Production of DOC in topsoils was positively related to their C/N ratio and DOC retention in subsoils was inversely related to the ratio of organic carbon to iron plus aluminium (hydr)oxides. Partial pressures of CO₂ in soil air and soil pH determined DIC concentrations and fluxes, but soil solutions were often supersaturated with DIC relative to soil air CO₂. Leaching losses of biogenic carbon (DOC plus biogenic DIC) from grasslands equalled 5-98% (median: 22%) of net ecosystem exchange (NEE) plus carbon inputs with fertilization minus carbon removal with harvest. Carbon leaching increased the net losses from cropland soils by 24-105% (median: 25%). For the majority of forest sites, leaching hardly affected actual net ecosystem carbon balances because of the small solubility of CO₂ in acidic forest soil solutions and large NEE. Leaching of CH₄ proved to be insignificant compared with other fluxes of carbon. Overall, our results show that leaching losses are particularly important for the carbon balance of agricultural systems.
Surface albedo is a key parameter in the Earth's energy balance since it affects the amount of solar radiation directly absorbed at the planet surface. Its variability in time and space can be ...globally retrieved through the use of remote sensing products. To evaluate and improve the quality of satellite retrievals, careful intercomparisons with in situ measurements of surface albedo are crucial. For this purpose we compared MODIS albedo retrievals with surface measurements taken at 53 FLUXNET sites that met strict conditions of land cover homogeneity. A good agreement between mean yearly values of satellite retrievals and in situ measurements was found (r2=0.82). The mismatch is correlated with the spatial heterogeneity of surface albedo, stressing the relevance of land cover homogeneity when comparing point to pixel data. When the seasonal patterns of MODIS albedo are considered for different plant functional types, the match with surface observations is extremely good at all forest sites. On the contrary, satellite retrievals at non-forested sites (grasslands, savannas, croplands) underestimate in situ measurements across the seasonal cycle. The mismatch observed at grassland and cropland sites is likely due to the extreme fragmentation of these landscapes, as confirmed by geostatistical attributes derived from high resolution scenes.
► In situ and satellite albedo are in good agreement at 53 FLUXNET sites (r2 0.83). ► MODIS albedo is systematically lower than in situ measurements for non-forest PFTs. ► The mismatch increases with the spatial heterogeneity of albedo in a 7×7km area. ► The seasonal pattern of MODIS albedo matches extremely well for forest PFTs.
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