Sediments in urban drainage systems (UDS) significantly impact their operation, so effective strategies are required to reduce their negative effects. Monitoring sediment accumulation provides valuable insights into sediment characteristics, sediment transport dynamics, and system performance. However, the effectiveness of monitoring systems is limited due to cost constraints and installation challenges. This study describes the development and application of a new system based on temperature dynamics to measure sediment depths in sewer systems. The methodology involves the analysis of temperature time series under dry weather flow conditions to identify harmonic patterns between wastewater and sediment-bed temperatures. These patterns are increasingly attenuated by increasing sediment depth. This study combines a system called MONitoring Temperatures in SEdiments (MONTSE), which integrates a dual-probe heat-pulse (DPHP) method to characterize sediment thermal properties, and a surrogate model, which includes temperature pattern analysis, to estimate sediment depths. Likewise, laboratory-scale experiments were performed to validate the temperature monitoring system and the surrogate model performance. The maximum absolute errors in measured sediment depths were less than 22 mm, and the uncertainty of the system was estimated at ±7.3 mm. Groundbreaking measurements of thermal properties of UDS sediments were also reported. Reliable information on sediment depths and properties was provided, so the system could significantly optimize sewer system operation and cleaning strategies.

Commercial microwave links (CMLs) in telecommunication networks can provide relevant information for remote sensing of precipitation and other environmental variables, such as path-averaged drop size distribution, evaporation, or humidity. The CoMMon field experiment (COmmercial Microwave links for urban rainfall MONitoring) mainly focused on the rainfall observations by monitoring a 38ĝ€¯GHz dual-polarized CML of 1.85ĝ€¯km path length at a high temporal resolution (4ĝ€¯s), as well as a co-located array of five disdrometers and three rain gauges over 1 year. The dataset is complemented with observations from five nearby weather stations. Raw and pre-processed data, which can be explored with a custom static HTML viewer, are available at 10.5281/zenodo.4923125 . The data quality is generally satisfactory for further analysis, and potentially problematic measurements are flagged to help the analyst identify relevant periods for specific study purposes. Finally, we encourage potential applications and discuss open issues regarding future remote sensing with CMLs.

The International Workshop on Rainfall Measurement Based on Microwave (MW) links from Commercial Cellular Communication Networks (Rain Cell) was held in Ouagadougou, Burkina Faso, from 30 March to 2 April 2015. The workshop's main objective was to build awareness and provide training on a technique that can provide accurate rainfall mapping in areas with poor rain gauge or weather radar coverage. The workshop brought together 87 participants representing research centers and weather services from 18 countries. A subgroup of 30 workshop participants followed a 2-day technical training course that covered in detail the physics of microwave attenuation by rain, other sources of signal fluctuations such as wet antennas, signal processing techniques to detect wet and dry periods and quantify rain-induced attenuation, and quantitative rain-rate estimation from microwave attenuation.

In this article, we study the performance of international water management at Lake Titicaca in order to assess the empirical applicability of a new concept for measuring policy performance. This performance measurement concept (PER) is a function of three variables: optimum performance (OP), actual performance (AP), and counterfactual performance (CP). In examining the joint management of Lake Titicaca by Bolivia and Peru, we identify practical difficulties in applying PER and suggest extensions of the concept to assess uncertainty. We find that this measurement concept has several advantages: it takes into account counterfactual performance; the analysis can be performed in a structured, standardized, and transparent manner; and the formal framework allows for an assessment of uncertainty. Problems in applying the concept include: choice of attributes, identification of optimum performance, time-scale, and subjectivity of information. We conclude that, on balance, this approach is superior to other policy performance assessment measures developed to date.