Prioritization of potential regions that are severely threatened by soil erosion is a prerequisite for formulating and implementing conservation measures and management practices, particularly in fragile semiarid regions. The present study prioritized eight delineated Nagmati sub-watersheds located in the Kutch District of Gujarat State, India, based on three approaches, namely principal component analysis (PCA), integrated PCA with weighted sum (I-PCWS), and analytical hierarchy process (AHP), and on 10 morphometric erosion risk parameters (ERPs). Sub-watersheds were categorized into three priority classes, namely high, medium, and low. PCA retrieved the three most significant ERPs (i.e., length of overland flow, Lo; drainage texture, Dt; and compactness coefficient, Cc) explaining 86.876% of the variance and exhibiting the highest correlation, i.e., r?=?0.961, 0.986, and 0.934 for the first three principal components. Sub-watersheds SW2 and SW7 were rated high priority, SW1 was rated low priority, and the rest were rated medium priority. The I-PCWS approach revealed that sub-watersheds SW2, SW6, and SW7 were in high-priority zone, followed by SW3, SW4, and SW8 in medium-priority zone and SW1 and SW5 in the low-priority zone. The AHP assigned the highest and lowest ranks to “Lo” and “Cc,” respectively, with consistency ratio of 8.1% and principal eigenvalue of 11.075. Results from AHP revealed sub-watershed SW2 to be the highest priority and sub-watersheds SW1 and SW5 to be the lowest priority. Out of eight prioritized sub-watersheds from three approaches, five were found to be the common priority classes, with SW2, SW6, and SW7 demanding urgent implementation of efficient soil conservation measures to prevent further degradation of the identified regions. Results from I-PCWS approach closely complied with the existing landforms within the study area, and this approach was considered more reliable and robust than the other two approaches. The methodology adopted in this study can be applied to different vulnerable, data-scarce regions to sustainably manage and conserve soil erosion through efficiently framed strategies.
The paper tries to estimate the rate of waste generation per head/per day, to identify suitable sites for waste disposal,
to find out optimal route for collection vehicles and to analyze the financial aspects of solid waste management in Moradabad
City, India.The study is based on sample of 2,500 households and secondary data. The City generates about 318 tones of solid
waste with an average per capita rate of 460 gram per day. Collection and disposal efficiency is nearly 64%. Sensitivity analysis
of the present disposal site as per the norms of Central Pollution Control Board indicates that it is moderately suitable.
Subsequently two new disposal sites were identified. Redefined routes and related issues were evaluated in financial terms.
It is estimated that by adopting the proposed plan, the expenditure on waste management will increase by about 52%, but at
the same time about 90% of city area and 95% of city population will be served. 相似文献
The phase-averaged characteristics of the turbulent velocity fields beneath steep short wind waves are investigated. A scheme
was developed to compute the phase of individual wind waves using spatial surface displacement data. This information was
used to analyze the two-dimensional velocity data acquired using particle image velocimetry (PIV) in a wind-wave tank. The
experiments were conducted at a fetch of 5.5m and at wind speeds that ranged from 4 to 10ms−1. Under these conditions previous studies have shown that a significant percentage of the waves are microscale breaking waves.
An analysis of the phase-averaged results suggests under these conditions (short fetches and moderate wind speeds) a wind-driven
water surface can be divided into three regions based on the intensity of the turbulence. These are the crests of microscale
breaking waves, the crests of non-breaking waves and the troughs of all waves. The turbulence is most intense beneath the
crests of microscale breaking waves. In the crest region of microscale breaking waves coherent structures were observed that
were stronger and occurred more frequently than beneath the crests of non-breaking waves. Beneath the crests of non-breaking
waves the turbulence is a factor of two to three times weaker and beneath the wave troughs it is a factor of six weaker. These
findings provide additional support for the hypothesis that approximately two-thirds of the gas and heat fluxes occur across
the turbulent wakes produced by microscale breaking waves. 相似文献
We report on an experimental study conducted to investigate the influence of small-scale wind waves on the airflow structure
in the immediate vicinity of the air–water interface. PIV technique was used to measure the two-dimensional velocity fields
at wind speeds of 3.7 and 4.4 m s−1 and at a fetch of 2.1 m. The flow structure was analyzed as a function of wave phase. In the near-surface region, significant
variations were observed in the flow structure over the waveform. The phase-averaged profiles of velocity, vorticity, and
Reynolds stress showed different behavior on the windward and leeward sides of the wave in the near-surface region. The influence
of wave-induced velocity was restricted within a distance of three significant wave heights from the surface, which also showed
opposite trends on the windward and leeward sides of the crest. The results also show that the turbulent Reynolds stress mainly
supports downward momentum transfer whereas the wave-induced Reynolds stress is responsible for the upward momentum transfer
from wave to wind. In the immediate vicinity of the air–water interface, the momentum is transferred from waves to wind along
the windward side, whereas, the momentum transfer is from wind to waves along the leeward side. 相似文献