Spatial variability of soil erodibility and its correlation with soil properties in semi-arid mountainous watershed,Saudi Arabia

Soil erodibility values are best estimated from long-term direct measurements on runoff-plots; however, in lack of field tests, these values can be estimated using relationships based on physico-chemical soil properties. The study objective was to assess the erodibility and its correlation with soil properties. The average erodibility value was estimated 0.043 t ha h ha^?1 MJ^?1 mm^?1. The areas with heavy textured soil and low organic matter content had the lowest values of erodibility. The erodibility decreases as the sand content increases, whereas silt showed a positive correlation. The erodibility factors and its relation to soil properties were evaluated using multiple regression analysis. Results revealed that sand and organic matter content of soil combinedly explained 78% of variation. Altitudinal increases also seem to affect the soil texture. This study has demonstrated that soil properties and erodibility values can be used as assistance for soil conservation practices and modelling of landscape processes.     

Study of discontinuities in hydrological data using catastrophe theory

Abstract

Modelling and prediction of hydrological processes (e.g. rainfall–runoff) can be influenced by discontinuities in observed data, and one particular case may arise when the time scale (i.e. resolution) is coarse (e.g. monthly). This study investigates the application of catastrophe theory to examine its suitability to identify possible discontinuities in the rainfall–runoff process. A stochastic cusp catastrophe model is used to study possible discontinuities in the monthly rainfall–runoff process at the Aji River basin in Azerbaijan, Iran. Monthly-averaged rainfall and flow data observed over a period of 20 years (1981–2000) are analysed using the Cuspfit program. In this model, rainfall serves as a control variable and runoff as a behavioural variable. The performance of this model is evaluated using four measures: correlation coefficient, log-likelihood, Akaike information criterion (AIC) and Bayesian information criterion (BIC). The results indicate the presence of discontinuities in the rainfall–runoff process, with a significant sudden jump in flow (cusp signal) when rainfall reaches a threshold value. The performance of the model is also found to be better than that of linear and logistic models. The present results, though preliminary, are promising in the sense that catastrophe theory can play a possible role in the study of hydrological systems and processes, especially when the data are noisy.

Citation Ghorbani, M. A., Khatibi, R., Sivakumar, B. & Cobb, L. (2010) Study of discontinuities in hydrological data using catastrophe theory. Hydrol. Sci. J. 55(7), 1137–1151.     

Spatiotemporal meteorological drought assessment: a case study in south-east Australia

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Simultaneous monitoring of soil 222Rn in the Eastern Himalayas and the geothermal region of eastern India: an earthquake precursor

Natural Hazards - Activity of 222Rn gas in soil has been recorded continuously at three monitoring centres, namely Ravangla and Diphu in the Eastern Himalayan region and Tantloi in the geothermal...     

Homogeneity and trend analysis of rainfall and droughts over Southeast Australia

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Geological and soil engineering properties of shallow landslides occurring in the Kutupalong Rohingya Camp in Cox’s Bazar,Bangladesh

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New insights into the occurrence of the catastrophic Zhaiban slope debris flow that occurred in a dry valley in the Hengduan Mountains in southwest China

Landslides - In 2019, the catastrophic Zhaiban slope debris flow (ZSDF) crushed an open road tunnel in Ganluo County, Sichuan Province, China, causing seven deaths and interrupting traffic flow for...     

Modelling undrained behaviour of sand with fines and fabric anisotropy

Acta Geotechnica - Fabric anisotropy and fines content (fc) in sands modify significantly their mechanical behaviour, particularly as related to static liquefaction under undrained conditions. The...