Development of a site selection methodology for run-of-river hydroelectric power plants within the water-energy-ecosystem nexus.

Even though water-energy systems and ecosystems have complex relationships, regional energy policies seldom consider this connection. The current regional energy policies are developed primarily based on technical and socio-economical aspects and lack ecological considerations that may deteriorate the ecosystems and sustainability of these policies. Hence, considering the water-energy-ecosystem nexus in the development stage of the energy policies can aid decision-makers in initiating successful multi-dimensional energy policies. This study proposes a novel approach to develop an environmental index to support the regional energy policies that rely on Run-of-river (RoR) hydroelectric power plants (HEPPs) with a nexus approach. First, significant environmental impacts of RoR HEPPs are identified as environmental flows, impacts on ecologically valuable areas such as heritage sites, wetlands, national parks, river water quality degradation, modification of habitat, and impact on ecosystems and biodiversity loss. Then these impacts are represented through indicators and are aggregated into an overall environmental performance index through a fuzzy multi-criteria decision-making approach. The proposed approach allows the integration of ecological dimensions into the evaluation of RoR HEPPs through easy-to-measure indicators, among which environmental flow is a critical component.

A pollution fate and transport model application in a semi-arid region: Is some number better than no number?

Fate and transport models are powerful tools that aid authorities in making unbiased decisions for developing sustainable management strategies. Application of pollution fate and transport models in semi-arid regions has been challenging because of unique hydrological characteristics and limited data availability. Significant temporal and spatial variability in rainfall events, complex interactions between soil, vegetation and topography, and limited water quality and hydrological data due to insufficient monitoring network make it a difficult task to develop reliable models in semi-arid regions. The performances of these models govern the final use of the outcomes such as policy implementation, screening, economical analysis, etc. In this study, a deterministic distributed fate and transport model, SWAT, is applied in Lake Mogan Watershed, a semi-arid region dominated by dry agricultural practices, to estimate nutrient loads and to develop the water budget of the watershed. To minimize the discrepancy due to limited availability of historical water quality data extensive efforts were placed in collecting site-specific data for model inputs such as soil properties, agricultural practice information and land use. Moreover, calibration parameter ranges suggested in the literature are utilized during calibration in order to obtain more realistic representation of Lake Mogan Watershed in the model. Model performance is evaluated using comparisons of the measured data with 95%CI for the simulated data and comparison of unit pollution load estimations with those provided in the literature for similar catchments, in addition to commonly used evaluation criteria such as Nash-Sutcliffe simulation efficiency, coefficient of determination and percent bias. These evaluations demonstrated that even though the model prediction power is not high according to the commonly used model performance criteria, the calibrated model may provide useful information in the comparison of the effects of different management practices on diffuse pollution and water quality in Lake Mogan Watershed.

An integrated map correlation method and multiple-source sites drainage-area ratio method for estimating streamflows at ungauged catchments: A case study of the Western Black Sea Region, Turkey.

Stream gauges measure the temporal variation of water quantity; thus they are vital in managing water resources. The stream gauge network in Turkey includes a limited number of gauges and often streamflow estimates need to be generated at ungauged locations where reservoirs, small hydropower plants, weirs, etc. are planned. Prediction of streamflows at ungauged locations generally relies on donor gauges where flow is assumed to be similar to that at the ungauged location. Generally, donor stream gauges are selected based on geographical proximity. However, closer stream gauges are not always the most-correlated ones. The Map Correlation Method (MCM) enables development of a map that shows the spatial distribution of the correlation between a selected stream gauge and any other location within the study region. In this study, a new approach which combines MCM with the multiple-source site drainage-area ratio (DAR) method is used to estimate daily streamflows at ungauged catchments in the Western Black Sea Region. Daily streamflows predicted by the combined three-source sites DAR with MCM approach give higher Nash-Sutcliffe Efficiency (NSE) values than those predicted using the nearest stream gauge as the donor stream gauge, for most of the trial cases. Hydrographs and flow duration curves predicted using this approach are usually in better agreement with the observed hydrographs and flow duration curves than those predicted using the nearest catchment.

Challenges in development and implementation of health-risk-based soil quality guidelines: Turkey's experience.

Management of contaminated sites is a critical environmental issue around the world due to the human health risk involved for many sites and scarcity of funding. Moreover, clean-up costs of all contaminated sites to their background levels with existing engineering technologies may be financially infeasible and demand extended periods of operation time. Given these constraints, to achieve optimal utilization of available funds and prioritization of contaminated sites that need immediate attention, health-risk-based soil quality guidelines should be preferred over the traditional soil quality standards. For these reasons, traditional soil quality standards are being replaced by health-risk-based ones in many countries and in Turkey as well. The need for health-risk-based guidelines is clear, but developing these guidelines and implementation of them in contaminated site management is not a straightforward process. The goal of this study is to highlight the problems that are encountered at various stages of the development process of risk-based soil quality guidelines for Turkey and how they are dealt with. Utilization of different definitions and methodologies at different countries, existence of inconsistent risk assessment tools, difficulties in accessing relevant documents and reports, and lack of specific data required for Turkey are among these problems. We believe that Turkey's experience may help other countries that are planning to develop health-risk-based guidelines achieve their goals in a more efficient manner.