Gunay Erpul

Assessing nature’s contributions to people

Recognizing culture, and diverse sources of knowledge, can improve assessments A major challenge today and into the future is to maintain or enhance beneficial contributions of nature to a good quality of life for all people. This is among the key motivations of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), a joint global effort by governments, academia, and civil society to assess and promote knowledge of Earths biodiversity and ecosystems and their contribution to human societies in order to inform policy formulation. One of the more recent key elements of the IPBES conceptual framework (1) is the notion of natures contributions to people (NCP), which builds on the ecosystem service concept popularized by the Millennium Ecosystem Assessment (MA) (2). But as we detail below, NCP as defined and put into practice in IPBES differs from earlier work in several important ways. First, the NCP approach recognizes the central and pervasive role that culture plays in defining all links between people and nature. Second, use of NCP elevates, emphasizes, and operationalizes the role of indigenous and local knowledge in understanding natures contribution to people.

Global rainfall erosivity assessment based on high-temporal resolution rainfall records

The exposure of the Earth’s surface to the energetic input of rainfall is one of the key factors controlling water erosion. While water erosion is identified as the most serious cause of soil degradation globally, global patterns of rainfall erosivity remain poorly quantified and estimates have large uncertainties. This hampers the implementation of effective soil degradation mitigation and restoration strategies. Quantifying rainfall erosivity is challenging as it requires high temporal resolution(<30 min) and high fidelity rainfall recordings. We present the results of an extensive global data collection effort whereby we estimated rainfall erosivity for 3,625 stations covering 63 countries. This first ever Global Rainfall Erosivity Database was used to develop a global erosivity map at 30 arc-seconds(~1 km) based on a Gaussian Process Regression(GPR). Globally, the mean rainfall erosivity was estimated to be 2,190 MJ mm ha−1 h−1 yr−1, with the highest values in South America and the Caribbean countries, Central east Africa and South east Asia. The lowest values are mainly found in Canada, the Russian Federation, Northern Europe, Northern Africa and the Middle East. The tropical climate zone has the highest mean rainfall erosivity followed by the temperate whereas the lowest mean was estimated in the cold climate zone.

THE EFFECT OF WIND ON RAINDROP IMPACT AND RAINSPLASH DETACHMENT

In wind–driven rains, variations in raindrop trajectory and frequency are expected due to the changes in the angle of raindrop incidence. This article presents experimental data on the effects of horizontal wind velocity on rainsplash detachment. In a wind tunnel facility equipped with a rainfall simulator, windless rains and rains driven by horizontal wind velocities of 6, 10, and 14 m s–1 were applied to three agricultural soils packed into 20 U 55 cm soil pans with both windward and leeward slopes of 7%, 15%, and 20%. Rain intensity was directly measured with inclined raingauges oriented with respect to the prevailing wind direction. These measurements showed that the actual amount of rainfall intercepted on the soil surface varied widely depending on the angle of rain incidence, which was a function of the rain inclination and slope gradient and aspect. A two–dimensional numerical model was used to estimate wind–driven raindrop trajectories. Rain energy was also measured by a kinetic energy sensor. Theory and measurement showed that an exponential relationship existed between the energy of simulated rainfall and the applied horizontal wind velocity. The experiments led to the conclusion that the wind not only increased the resultant raindrop impact velocity but also altered the angle of raindrop incidence, resulting in variable raindrop impact frequency and impact angle. Accordingly, differential rainsplash detachment occurred depending on the changes in raindrop trajectory and frequency with wind velocity and direction. There were significant differences in the detachment rates between the aspects, and the rates were as much as 44 times greater in the windward slopes than in the leeward slopes.

Raindrop and flow interactions for interrill erosion with wind-driven rain

Wind-driven rain (WDR) experiments were conducted to evaluate the interrill component of the Water Erosion Prediction Project model with a two-dimensional experimental set-up in a wind tunnel. Synchronized wind and rain simulations were applied to soil surfaces on windward and leeward slopes of 7, 15 and 20%. Since WDR fall trajectory varied with horizontal wind velocities of 6, 10, and 14 m s−1, magnitude of raindrop normal and lateral stresses on flow at the impact-flow boundary also changed and differentially directed lateral jets of raindrop splashes with respect to downward flows occurred. To account for interactions between raindrop impact and interrill shallow flow, a vector approach with kinetic energy fluxes of both raindrop splashes and flow were used and this resulted in greater correlations in predicting sediment delivery rates.

Assessing nature's contributions to people: recognizing culture, and diverse sources of knowledge, can improve assessments

Recognizing culture, and diverse sources of knowledge, can improve assessments A major challenge today and into the future is to maintain or enhance beneficial contributions of nature to a good quality of life for all people. This is among the key motivations of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), a joint global effort by governments, academia, and civil society to assess and promote knowledge of Earths biodiversity and ecosystems and their contribution to human societies in order to inform policy formulation. One of the more recent key elements of the IPBES conceptual framework (1) is the notion of natures contributions to people (NCP), which builds on the ecosystem service concept popularized by the Millennium Ecosystem Assessment (MA) (2). But as we detail below, NCP as defined and put into practice in IPBES differs from earlier work in several important ways. First, the NCP approach recognizes the central and pervasive role that culture plays in defining all links between people and nature. Second, use of NCP elevates, emphasizes, and operationalizes the role of indigenous and local knowledge in understanding natures contribution to people.

Process-based soil erodibility estimation for empirical water erosion models

ABSTRACT Functional relationships between soil erodibility equations of empirically-based revised universal soil loss equation and process-based water erosion prediction project models were investigated using new datasets from rainfall simulation experiments to overcome conceptual differences of models in estimating soil erodibility. Erodibility potentials of two different soils were quantified for three different initial soil moisture conditions, and relations between the process-based erodibility, partitioned as interrill erodibility, rill erodibility and critical shear stress, and empirically-based erodibility were examined. A process-based soil erodibility assessment within the universal soil loss equation was attempted. Statistically significant differences are found when considering the effects of surface hydrologic conditions on soil erodibility. Process-based soil erodibility estimates under dry conditions were found to be comparable with original water erosion prediction project datasets. The results showed that procedure could be useful for tapping into the large number of datasets available and building the next generation of process-based erosion models.

Spatial distribution of wind-driven sediment transport rate in a fallow plot in Central Anatolia, Turkey

ABSTRACT Wind erosion is a serious land degradation phenomenon in semi-arid parts of Turkey. It is even becoming more critical problem considering the current effects of global warming and climate change in the region. The objectives of this study are to model spatial variation of aeolian sediment transport and to map Sediment Transport Rate (STR) by geostatistics in a fallow plot in the Central Anatolia. STRs for four consecutive wind cases with different vegetation cover rates were determined using the cyclone BEST sediment traps. Plant cover ratio and height changed between 8 and 25% and 3–12 cm throughout the research period, respectively, and soil moistures ranged between 10.9 and 12.7%. The windstorms lasted for 400, 835, 1240, and 50 minutes with the mean wind velocities of 8.6, 7.7, 7.7, and 6.3 m s−1, respectively, for cases 1, 2, 3, and 4. The calculated STRs varied between 0.0248 ± 0.0170 kg m−1 h−1 and 0.190 ± 0.084 kg m−1 h−1. Spatial analysis revealed that the spatial correlations were between 19 and 48 m and different spatial patterns occurred from one case to another. The study results indicated that the amount of transported sediment and its spatial variation were mostly related to velocity and duration of erosive wind in the fallow area of the arid region.

Potential Use of BEST® Sediment Trap in Splash - Saltation Transport Process by Simultaneous Wind and Rain Tests

The research on wind-driven rain (WDR) transport process of the splash-saltation has increased over the last twenty years as wind tunnel experimental studies provide new insights into the mechanisms of simultaneous wind and rain (WDR) transport. The present study was conducted to investigate the efficiency of the BEST® sediment traps in catching the sand particles transported through the splash-saltation process under WDR conditions. Experiments were conducted in a wind tunnel rainfall simulator facility with water sprayed through sprinkler nozzles and free-flowing wind at different velocities to simulate the WDR conditions. Not only for vertical sediment distribution, but a series of experimental tests for horizontal distribution of sediments was also performed using BEST® collectors to obtain the actual total sediment mass flow by the splash-saltation in the center of the wind tunnel test section. Total mass transport (kg m-2) were estimated by analytically integrating the exponential functional relationship using the measured sediment amounts at the set trap heights for every run. Results revealed the integrated efficiency of the BEST® traps at 6, 9, 12 and 15 m s-1 wind velocities under 55.8, 50.5, 55.0 and 50.5 mm h-1 rain intensities were, respectively, 83, 106, 105, and 102%. Results as well showed that the efficiencies of BEST® did not change much as compared with those under rainless wind condition.

KIRŞEHİR ÇİÇEKDAĞ TARIM İŞLETMESİ TOPRAKLARININ KALİTE DURUMLARININ BELİRLENMESİ

Bu calismanin amaci Kirsehir- Cicekdag Tarim Isletmesi topraklarinin Parametrik Yontem kullanilarak kalite durumlarinin belirlenmesidir. Parametrik Yontemde topraklarin bunye, tuzluluk, alkalilik, toprak pH’si, toprak yapisi, kirec icerigi, katyon degisim kapasitesi, verimlilik gibi bazi fiziksel ve kimyasal ozellikleri ile haritalama birimlerinin egim, derinlik, taslilik, cakillilik, kayalilik, erozyon, drenaj ve yagis gibi cevresel ozellikleri kullanilmistir. Kullanilan parametreler, isletme topraklarinin 1/5000 olcekli detayli toprak etut haritalama calismalarindan hazirlanan sayisal toprak veri tabani ve sayisal yukselti modelinden elde edilmistir. Elde edilen verilere gore, calisma alaninin % 75,26’si (1262,921 ha) tarimsal yonden ve kalite ozellikleri bakimindan cok iyi ve iyi (S1 ve S2) sinifina dâhil edilmistir. Calisma alani topraklarinin % 23,45’i (393,62 ha) orta (S3) sinifina dâhil edilirken, % 1,28’i (21,50 ha) tarimsal kullanima uygun olmadigi bulunmustur. Bu arastirmada parametrik yontem arazi degerlendirme calismasinda basariyla kullanilmistir