Evidence for variable precipitation and discharge from Upper Cretaceous–Paleogene fluvial deposits of the Raton Basin, Colorado–New Mexico, U.S.A.

ABSTRACT The Raton Basin of Colorado–New Mexico, USA, is the southeasternmost basin of the Laramide intraforeland province of North America. It hosts a thick succession (4.5 km or 15,000 ft) of Upper Cretaceous to Paleogene marine and continental strata that were deposited in response to the final regression of the Western Interior Seaway and the onset of Laramide intraforeland deformation. The Upper Cretaceous–Paleogene Raton and Poison Canyon formations were previously described as meandering river and braided river deposits that represented distal and proximal members of rivers that drained the basin-bounding Sangre de Cristo–Culebra uplift. We present new observations of fluvial-channel architecture that show that both formations contain the deposits of sinuous fluvial channels. However, fluvial channels of the Raton Formation formed in ever-wet environments and were affected by steady discharge, whereas channels of the overlying Poison Canyon Formation formed in drier environments and were affected by variable discharge. The apparent transition in fluvial discharge characteristics was coeval with the progradation of fluvial fans across the Raton Basin during the Paleocene, emanating from the ancestral Sangre de Cristo–Culebra uplift. The construction of fluvial fans, coupled with the sedimentary features observed within, highlights the dual control of Laramide deformation and early Cenozoic climatic patterns on the sedimentary evolution of the Raton Basin.

The 4.2 ka event and the end of the ‘Temple Period’ in Malta

<p>The compact size of the semi-isolated Maltese archipelago and its relatively challenging environmental conditions, with limited soil cover and variable precipitation averaging around 600 mm a year, mean that the area offers an important case study of human-environment interactions. Following an initial phase of Neolithic settlement, the ‘Temple Period’ in Malta began from around 5.8 ka and within a few hundred years the spectacular ‘temples’ which characterize the period and are among the oldest buildings in the world began to be constructed. After over a thousand years this long-lived culture came to a seemingly abrupt end at ca. 4.4 to 4.2 ka, and was followed by Bronze Age societies with radically different material culture, funerary behaviour, and architecture. Various ideas concerning the reasons for the end of the Temple Period have been expressed. These range from climate change, to invasion, to social conflict resulting from the development of a powerful ‘priesthood’. Here, the idea that the end of the Temple Period was caused by aridity induced by the 4.2 ka event is tested. The 4.2 ka event is a classic example of an abrupt climate episode, and while it has been linked with several examples of significant societal change, such as the end of the Old Kingdom in Egypt, its details and relevance have been debated. To evaluate the Maltese example, archaeological data is fused with an understanding of the geology and palaeoenvironment of Malta, as well as consideration of the wider regional situation at this time in terms of demography and material culture, as well as the possible role of factors such as disease epidemics. The Maltese example forms a fascinating case study for understanding issues such as chronological uncertainty, disentangling cause and effect when several different processes are involved, and the role of abrupt environmental change in impacting human societies. Ultimately, it is suggested that the 4.2 ka event played a significant role in the end of the Temple Period, but this has to be understood within the specific geological and societal circumstances of the Maltese islands.</p>

Changing Pattern of Agricultural Mechanization in Nalanda District of Bihar

In agricultural production, farm mechanisation is a very necessary input. The number of tractors has increased rapidly, and in recent years, the population of draught animals has decreased in Bihar. A study was conducted in Nalanda District of Bihar, to classify the trend of tractor use and their economics. Mechanization is one of the most striking and pervasive phenomena of our times. Unfortunately, its study has been neglected by the social sciences, which have not sufficiently recognized that while technology itself belongs to the field of the natural sciences, its far-reaching effects on social life make it a vital subject for study by the social sciences. Insufficient and high variable precipitation and low fertility are major constraints to agricultural productivity. This brings the role of irrigation facilities and use of fertilizers. India is witnessing growth in irrigation facilities. Wells, canals and dams are constructed to cater needs of farmers. However, there is a lot to be achived in this regard. Applaying fertlizes are increasing day by day. It increases production as well as productivity of the field. At the same time, there is rampat mechanization of agriculture. Thus, it reduces human efforts and increases production of the field.

Spatially Variable Precipitation and Its Influence on Water Balance in a Headwater Alpine Basin, Nepal

The current knowledge of the spatial variability of precipitation in High Mountain Asia is based on the remotely-sensed estimates (coarse spatial and temporal resolution) or data from sparsely-distributed rain gauges. However, as precipitation is strongly affected by topography in mountainous terrain, the spatially varying precipitation and the resulting water balances are currently poorly understood. To fill this gap in knowledge, we studied the spatial variation of the precipitation and its impact on water balance in a small headwater basin located in the foothills of the Himalaya, Nepal. We deployed ten rain gauges and climate stations, spanning the whole elevation range 700–4500 m above sea level (masl) for a period of four years. Our results show a quadratic polynomial relationship between annual precipitation and station elevation, which are used to produce annual precipitation maps. The performance of the elevation-based precipitation estimates is adequate in closing the water balance while the performances of average precipitation and Thiessen polygon method are poor and inconsistent in closing the water balance. We also demonstrate that precipitation estimates from one or two gauges at the lowest basin elevation substantially underestimate the water balance. However, the precipitation from one or two rain gauges at 2000–3000 masl provide a significantly better estimate of the water balance of a small headwater basin.

Statistical descriptive analysis of three climate variables; Precipitation, temperature and relative humidity. Study cases (Innaouene watershed; Morocco)

Hydrological data are mandatory for the elaboration of studies related to water management. Statistical analysis is a crucial step for the grasping of the distribution of data range. The presented study consists on applying statistical descriptive analysis on three climate variable; precipitation, temperature and relative humidity. Two gages stations were used; Bab Marzouka and Idriss First in Innaouène watershed. The obtained results underlines that the temporal variation exposes an overall rising trend in the temperature and a decreasing trend in the rainfall and relative humidity over the fours studied decades, it also uncovers the intra-seasonal fluctuation, humid and rainy in the winter and sec and dry in the summer, the autumn and the spring are considered as transition season where the temperature is moderated. The spatial variation is marked by a slight decreasing in precipitation and increasing of temperature moving from the middle part of the watershed to the downstream, which could be explained by the topographic variation and its impact on the climate. High altitude are generally marked by high precipitation and lower temperature comparing to lowlands areas.