Adaptation of water resources systems to changing society and environment: a statement by the International Association of Hydrological Sciences

ABSTRACT

We explore how to address the challenges of adaptation of water resources systems under changing conditions by supporting flexible, resilient and low-regret solutions, coupled with on-going monitoring and evaluation. This will require improved understanding of the linkages between biophysical and social aspects in order to better anticipate the possible future co-evolution of water systems and society. We also present a call to enhance the dialogue and foster the actions of governments, the international scientific community, research funding agencies and additional stakeholders in order to develop effective solutions to support water resources systems adaptation. Finally, we call the scientific community to a renewed and unified effort to deliver an innovative message to stakeholders. Water science is essential to resolve the water crisis, but the effectiveness of solutions depends, inter alia, on the capability of scientists to deliver a new, coherent and technical vision for the future development of water systems.

EDITOR D. Koutsoyiannis; ASSOCIATE EDITOR not assigned     

An international turbulence comparison experiment (ITCE 1976)

Turbulence data for the International Turbulence Comparison Experiment (ITCE) held at Conargo, N.S.W. (35° 18′ S., 145° 10′ E.) during October, 1976 are analysed. The standard deviation % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaiikaiqado% hagaqbamaaCaaaleqabaGaaGOmaaaakiaacMcadaahaaWcbeqaaiaa% igdacaGGVaGaaGOmaaaaaaa!3B93!\[(s'^2 )^{1/2} \] and covariance % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaa0aaaeaace% WG3bGbauaaceWGZbGbauaaaaaaaa!3809!\[\overline {w's'} \] measured by a number of instruments and instrument arrays have been compared to assess their field performance and calibration accuracy. Satisfactory agreement, i.e. typically 5% for % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaiikamaana% aabaGabm4CayaafaWaaWbaaSqabeaacaaIYaaaaaaakiaacMcadaah% aaWcbeqaaiaaigdacaGGVaGaaGOmaaaaaaa!3BA4!\[(\overline {s'^2 } )^{1/2} \] (except in humidity) and of the order of 20% for % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaiikaiqado% hagaqbamaaCaaaleqabaGaaGOmaaaakiaacMcadaahaaWcbeqaaiaa% igdacaGGVaGaaGOmaaaaaaa!3B93!\[(s'^2 )^{1/2} \], was achieved, but only after consideration of:

1. Instrumental response at high frequencies.
2. Flow distortion induced by instruments and supporting structures.
3. Spatial separation of instruments used for covariance measurements.
4. Statistical errors associated with single point measurements over a finite averaging time, and with lateral separation of two sensor arrays being compared.

     

A review of flux-profile relationships

Flux-profile relationships in the constant flux layer are reviewed. The preferred relationships are found to be those of Dyer and Hicks (1970), namely, _H = _W =(1–16(z/L))^–1/2, _M =(1–16(z/L))^–1/4 for the unstable region, and _H = _W = _M = 1+5(z/L) for the stable region.The carefully determined results of Businger et al. (1971) remain a difficulty which calls for considerable clarification.     

Distinctive microbial structures and the pre-phanerozoic fossil record

The live and sedimentary components of the flat laminated microbial mat at Laguna Figueroa have been studied since the late sixties. This paper reports the observation and isolation of a variety of micro-organisms, both prokaryotes and eukaryotes. The microbes were taken from the flat laminated mats submerged under at least one meter of water due to the spring rains of 1979 and 1980. Both in situ and enrichment culture observations were made using light and electron microscopic techniques. New strains of the following microbes are reported here: Bacillus megaterium, Bacillus licheniformis, Arthrobacter simplex and Paratetramitus jugosus. Several pseudomonads were isolated, some of which form distinctive subsurface colonial structures. Regular distinctive colony morphologies and desiccation resistant cysts were often observed, several types of which grow to characteristically large sizes and resemble objects found in the pre-Phanerozoic fossil record.Some colonies of manganese oxidizing bacilli and other bacteria are reminiscent of microfossils of the 2 Ga-old Gunflint Iron formation such as Metallogenium, Eosphaera tyleri, Eoastrion and Huronispora. Some manganese oxidizing bacteria form colonial structures that might be mistaken for individual organisms in the tens to hundreds of microns size range. The diversity of microbial structures, including those with preservation potential, must be kept in mind when interpreting the microfossil record.     

Wave Propagation In A Vertical Transversely Isotropic Medium: Field Experiment and Model Study

Summary. The continent-ocean transition adjacent to Hatton Bank was studied using a dense grid of single-ship and two-ship multichannel seismic profiles. The interpretation of the explosive expanding spread profiles (ESPs) which were shot as part of this survey are discussed here in detail. Extensive seaward dipping reflectors are developed in the upper crust across the entire margin. These seaward dipping reflectors continue northwards on the Faeroes and Vøring margins, where they have been shown to be caused by basaltic lavas, as well as on the conjugate margin of East Greenland. The dipping reflectors are an important feature of the rifting history of the margin and show that extensive volcanism was associated with the extension. The ESPs show clear seismic arrivals out to ranges of 100 km. Wide-angle Moho reflections can be seen on all the lines as well as good mid and lower crustal arrivals. The determination of seismic velocity structure was constrained by ray tracing and by amplitude modelling using reflectivity synthetic seismograms. The results from the ESPs show that there is a thick region of lower crustal material beneath the margin with an unusually high crustal velocity of 7.3–7.4 km s⁻¹. This lower crustal material reaches a maximum thickness of 14 km beneath the central part of the margin and is terminated at depth by the Moho. The lower crustal lens of high-velocity material is interpreted as underplated or intruded igneous rocks associated with the large volumes of extrusive basaltic lavas, now seen as dipping reflectors on the margin.     

Simulating low flows over a heterogeneous landscape in southeastern Poland

This paper presents a scheme describing low flow formation processes in areas with different environmental conditions, including the impact of the selection and explanatory power of predictors for a probabilistic model based on the Logit model. The research was carried out using 29 daily streamflow gauges located in the Lublin region of southeastern Poland for the hydrological period 1976–2018. Analysis resulted in two distinct low flow schemes. In the lowland rivers, low flows occur during the warm season and are related to evaporation exceeding precipitation. In the upland rivers, hydrogeological factors related to water levels in the local Cretaceous aquifers determine the occurrence of low flows. This differentiation affects the quality of the predictive models. For lowland rivers, models based on the climatic water balance with a monthly shift have a better fit, while these models used for upland rivers are characterized by an approximately 10% decrease in accuracy. For upland rivers, the combined C_tH_t models without shifts produce the best model fit. The generalized precision of the Logit models is around 80%–90%.     

Effects of Korean littoral environment on acoustic propagation

Environmental acoustics experiments were recently conducted in shallow to intermediate water depths in the Sea of Japan, east of Korea, along the shelf and slope, covering frequencies from 25 to 800 Hz. These were operational experiments carried out in three different seasons. The primary objectives of the data reported here are: (1) to characterize the Korean coastal environment during May 1998, September 1998, and February 1999 and (2) to assess how complexities of the environment might impact acoustic propagation in May and February, as measured by its transmission loss. Propagation data were obtained from broadband explosive SUS sources and sonobuoy receivers. The tests were conducted over varying bottom depths and slopes, both approximately normal and parallel to the bathymetric contours. Two different source depths were included. Environmental and acoustic data are reviewed and discussed. While many aspects of the observed propagation remain ill understood, on the whole a consistent and useful picture has emerged of acoustic propagation in this region. Environmental impacts on propagation are associated mainly with bottom properties, somewhat less so with source depth in relationship to sound speed profiles, and almost not at all with range-dependent profiles of a water mass front     

The Astrometric Telescope Facility

Summary The Astrometric Telescope Facility (ATF) proposed for use on NASA's planned Space Station is similar in form and data output to ground-based long focus astrometric instruments. With a focal plane scale of 12.7 arc seconds/mm, the strawman design has a field size of 10 arc min square and a limiting visual magnitude fainter than 16. Output from an observation includes the X and Y coordinates of each star and its relative brightness. The targeted precision for the AFT is 0.00001 arc seconds.Portions of the observing program will be made available to members of the astronomical community.