ASSESSMENT OF THE QUALITY OF SIMULATION OF CHANGES OF THE DOWNWELLING SHORTWAVE RADIATION IN THE SEVASTOPOL REGION USING THE CMIP6 MODELS

Using the data of the Coupled Model Intercomparison Project 6 (CMIP6), the quality of the simulation of the observed climate changes of downwelling shortwave radiation in the Sevastopol region for the period 1983–2012 is assessed. It is shown that the average values of the considered characteristics of solar resources according to the data of climate models are, in general, higher than according to the ob-servational data, whereas the values of the standard deviation are lower. The analysis of linear trends of the downwelling shortwave radiation show that most climate models from the CMIP6 project correctly simulate the process up to the sign of the linear trend. Using a number of statistical characteristics, mod-els have been determined that best simulate the analyzed climatic characteristic and will be suitable for assessing future changes in the solar energy potential in the Sevastopol region.

Defining Climate Zone of Borneo based on Cluster Analysis

Although Borneo Island is one of the most vulnerable tropical regions to climate change, maps depicting the local climate conditions employing climate classification are still not well defined. The present study attempted regional climate classification to divide the Borneo region into several homogenous groups based on long-term average climate behavior. Daily gridded rainfall and temperature (Tavg, Tmax, and Tmin) data at 0.25o resolution spanning 56-years (1960−2016) was used. The classification was done using non-hierarchical k-mean and several hierarchical methods, namely, Single, Complete, McQuitty, Average, Centroid, Median, and two algorithms of Ward's method, wardD, and wardD2. The results showed that k-mean, wardD, and wardD2 were able to classify the climate of Borneo into four zones, namely 'Dry and hot' (DH), 'Wet and hot' (WH), 'Wet' (W), and 'Wet and cold' (WC) with a considerable difference at the boundaries. Spatial relevancy, stability, and variability of the clusters based on correlation and compromise programming showed that the wardD method was the most likely to yield acceptable results with optimum 4-cluster to partition the area into four principal climate zones. The constructed cluster plot, centroid plot, and probability distribution function (PDF) showed a distinct climatic characteristic between the climate zones in terms of rainfall, temperature, and seasonality. The proposed climate zonation for Borneo can help in better understanding climate regionality and climate-related development planning.

A GIS based application of Benfratello's method to estimate the irrigation deficit in a semiarid climate

<p>Benfratello's <em>Contribution to the study of the water balance of an agricultural soil</em> (<em>Contributo allo studio del bilancio idrologico del terreno agrario</em>) was firstly published sixty years ago, in 1961. The paper provides a practical conceptual and lumped method to determine the irrigation deficit in agricultural disctricts. Since then, it has been used in many areas in Southern Italy.</p><p>According to the method, percolation and capillary rise from the groundwater table are absent, and surface runoff happens only when the soil capability of storing water is exceeded. The method is therefore suitable for semiarid (and eventually arid) climates. Dry and wet seasons are defined on a climatic basis, as the season during which potential evapotranspiration is greater than precipitations (and the stored soil--water decreases), and that during which precipitations exceed potential evapotranspiration (and the stored soil--water inccreases).</p><p>With these hypotheses, Benfratello proposed to adopt a power--relationship (with power <em>m</em> greater or equal to 0) to assess the ratio between the actual and the potential soil--water loss, as a function of the ratio between the stored soil--water and the maximum available storage. The solution provides, in a simple closed form, the actual soil--water loss as a function of the potential loss (which is a climatic characteristic), and generalizes previous approaches, viz Thorthwaite (1948) and Thornthwaite and Mather (1955) ones, for which <em>m</em> = 0 and <em>m</em> = 1, respectively.</p><p>In this contribution we present a GIS based application of Benfratello's method to assess the soil water balance and the irrigation deficit of the semiarid Capitanata plane (4550 <em>km</em><sup>2</sup>, Southern Italy), one of the most important agricultural districts in Italy. A comparison between the method and previous results for the same region will be provided as well. Due to its simplicity and to the small number of needed parameters, Benfratello's method might be regarded to as an effective tool to assess the effects of climatic, landuse and anthropogenic change scenarios on the soil water balance and on the irrigation deficit.</p>

Influence of rainfall and design criteria on performance of rainwater harvesting systems placed in different Brazilian climatological conditions

ABSTRACT Using rainwater harvesting (RWH) system is influenced by socioeconomic, environmental and technical factors. This work presents as analysis of the influence of the rainfall time series characteristics and design criteria on RWH performance of five Brazilian capitals with different climatic characteristic: Goiânia, João Pessoa, Manaus, Porto Alegre and São Paulo. The analysis combined different rooftop areas, storage volumes and the indoor and outdoor demands. Rainfall temporal discretization and the types of demands were the most important characteristics when assessing RWH reliability. Daily rainfall data were suitable for sizing the RWH, the time series length influenced the sizing of larger storage volumes, and the RWH efficiency was not significantly affected by the first-flush. Toilet flushing and the irrigation demands had the greatest impact on RWH performance. The greatest potentials for the implementation of RWH were observed for Porto Alegre, because of well distributed rainfall throughout the year, and for Manaus owing to higher annual volumes of precipitation. These results highlight relevant aspects that must be observed during the conception and design of RWH, complementing the guidelines provided in the Brazilian technical standards.

Phenological patterns of defoliation and refoliation processes of rubber tree clones in the Colombian northwest

The knowledge of the defoliation-refoliation process in rubber cultivation allows the development of management strategies in the production system to improve rubber yield. The objective of this study was to determine the intensity and duration of defoliation-refoliation of rubber clones FX 3864, IAN 710 and IAN 873 in the municipality of Tarazá and the FX 3864 and IAN 873 clones in the municipality of Nechí (northwestern Colombia). From October 2015 to June 2016, the measurements of the necromass were carried out in each location for each clone. The light environment was quantified, employing the hemispheric photographs technique to estimate canopy openness percentage (CO) and leaf area index. The assessed weeks were grouped by Principal Component Analysis (PCA) based on the original phenology and climatic variables. The defoliation-refoliation process was analyzed descriptively using graphical representations of the trend for the phenological variables that best described this process. The relationship between climatic and phenological variables in the period evaluated was evidenced; the rainfall was the most critical climatic characteristic in the induction of the defoliation process. The leaf area index was reduced to a minimum value in February, with values of 0.52 for IAN 710 clone in Tarazá, and 0.64 for the IAN 873 clone in Nechí, which corresponded to the highest defoliation stage in both locations. The refoliation period was short (4 to 6 weeks) and occurred during the dry season for all the clones in both places.

Rainfall zoning of Bahia State, Brazil: an update proposal

The state of Bahia’s main climatic characteristic is the high spatial and chronological variability of precipitation. This heterogeneity may be used to determine of pluviometrically homogeneous areas that can define mesoregions in the state, since they allow better management of water resources and help in the elaboration of agricultural studies. The mesoregions already proposed by the scientific community for the state were based only on the annual precipitation in the proximity of the pluviometric stations. In this paper, besides these parameters, spatial and chronological rainfall distribution was considered, i.e., the Precipitation Concentration Degree (PCD) and Precipitation Concentration Period (PCP). The new zoning is based on an update of a study defined in 2000 that divided Bahia into eight mesoregions. Thus, 180 pluviometric stations were distributed throughout the state and grouped conforming to the division previously described. It was concluded that some stations of the same mesoregion had presented conflicting values for the analyzed parameters and, therefore, should not belong to the same area. Starting from an arrangement of the collection stations, considering their proximity, annual precipitation and statistical parameters, a new zoning for Bahia with 10 clusters was defined and validated through the statistical treatment of data.