无证驾驶闯大祸:3死、29伤,惨!

１９９９年５月１４日，对于新晃县步头降乡腿溪村农民李家根来说是一个黑暗的日子。这天，由于所请的为自己开车的司机回家有事，李家根为了不放过今天赶集接客的大好机会，吃过早饭后，凭着自己平时学来的一点技术，就高高兴兴地驾驶着自家的号牌为湖南Ｎ／００１６４的...     

Tank performance and multiple uses in Tamil Nadu,South India–comparison of 2 time periods (1996–97 and 2009–10)

Irrigation tanks in India are common property resources. Tanks provide not only for irrigation, but also forestry, fishing, domestic water supply, livestock, and other uses. Using empirical results from a study of tank performance from 80 tanks in Tamil Nadu, South India in two time period: 1996-97 and 2009-10, this paper evaluates tank irrigation system performance in terms of economic output and revenue generation forirrigation and other uses. The results indicate that irrigation and other productive uses put together raised the total value of output at tank level by 12 % in 1996-97 and just 6 % in 2009-10. This may suggest that tank multiple use values are small and getting smaller, and therefore not worth consideration. However, it was also found that, while declining in absolute terms, non-irrigation uses provided the majority of tax revenues and still more than cover government's operation and maintenance expenditure (O&M) budget. This finding provides another reason to consider multiple use values and their linkage with overall system viability.     

Replacing saline–sodic irrigation water with treated wastewater: effects on saturated hydraulic conductivity,slaking, and swelling

Irrigation with saline–sodic water imposes sodic conditions on the soil and reduces the soil’s productivity. We hypothesized that replacing saline–sodic irrigation water with lesser saline–sodic treated waste water (TWW), albeit with higher loads of organic matter and suspended solids, might help sodic soils regain their structure and hydraulic conductivity. We studied hydraulic conductivity (HC), aggregate stability and clay swelling of a soil from the Bet She’an Valley, Israel using samples taken from a non-cultivated field (control), and plots irrigated with TWW, saline–sodic Jordan River (JR) water, and moderately saline–sodic spring (SP) water. Soil samples were taken at the end of the irrigation season (autumn 2005) and at the end of the subsequent rainy season (spring 2006). In the HC and the aggregate stability determinations, for both sampling seasons, the TWW-irrigated samples gave significantly higher values than the SP- and JR-irrigated samples, but lower than the samples from the control plot. The autumn samples exhibited, generally, higher HC and lower swelling levels compared with the spring samples. Conversely, aggregate stability of the spring samples was higher than that of the autumn samples. These seasonal changes in the results of the three tests were associated with seasonal changes in the salinity and sodicity of the soils. Contributions from the Agricultural Research Organization, The Volcani Center, Bet-Dagan 50250, Israel. No. 601/2007 series.     

策马自沙漠,长驱登塞垣——斯巴鲁“31座森林星之旅”第二季呼和浩特站

库布齐沙漠神泉景区横跨黄河两岸,奔腾不息的黄河水将一弯绿洲留在了河北对岸。南岸的漫天黄沙之中,斯巴鲁“31座森林星之旅”的环保小伙伴们,将一组组防沙固沙的麦草方格留在了大漠之滨,为荒漠化防治尽自己的一份力。     

Determining water–yield relationship,water use efficiency,crop and pan coefficients for silage maize in a semiarid region

A field study was conducted to determine effects of seasonal deficit irrigation on plant cob, leaf, stem and total fresh yield, plant height and water use efficiency (WUE) of silage maize for a 2-year period in the semiarid region. In addition, the crop and pan coefficients k _c and k _p of silage maize were determined in full irrigation conditions. Irrigations were applied when approximately 50% of the usable soil moisture was consumed in the effective rooting depth at the full irrigation treatment. In deficit irrigation treatments, irrigations were applied at the rates of 80, 60, 40, 20 and 0% of full irrigation treatment on the same day. Irrigation water was applied by hose-drawn traveler with a line of sprinklers. Increasing water deficits resulted in a relatively lower cob, leaf, stem and total fresh yields. The linear relationship between evapotranspiration and total fresh yield were obtained. Similarly, WUE was the highest in full irrigation conditions and the lowest in continuous stress conditions. According to the averaged values of 2 years, yield response factor (k _y) was 1.51 for silage maize. When combined values of 2 years, seasonal pan coefficient (k _p) and seasonal crop coefficient (k _c) were determined as 0.84 and as 1.01 for silage maize, respectively.