Watershed ecosystem monitoring and evaluation indicators need to factor in land cover/use change rationally and adaptively. Vegetation canopy greenness can be utilized to seek an accurate solution to various land cover/use change issues, for example, by applying the Normalized Difference Vegetation Index (NDVI) algorithm. This research set out to analyze the relationship between the spatial pattern of canopy greenness and small island watersheds’ hydrological characteristics. It used NDVI algorithm extraction and BFLOW+ 3.0 filter in the HydroOffice 12.0 program and then examined the two resulting datasets using correlation analysis. The results showed that the spatial pattern of canopy greenness derived from NDVI changed significantly near the river mouth. The densely populated settlements in the coastal stretch continued to sprawl towards mountainous regions, which naturally function as recharge zones. Meanwhile, the hydrological characteristics displayed a fluctuating trend during the observation period (2015-2019). Based on the correlation analysis, canopy greenness patterns and hydrological features form a positive and relatively strong relationship (38.8%). For this reason, ecological shifts in small island watersheds require climate change mitigation and adaptation measures.
Flood Frequency Analysis (FFA) method was introduced by Fuller in 1914 to understand the magnitude and frequency of floods. The present study is carried out using the two most widely accepted probability distributions for FFA in the world namely, Gumbel Extreme Value type I (GEVI) and Log Pearson type III (LP-III). The Kolmogorov-Smirnov (KS) and Anderson-Darling (AD) methods were used to select the most suitable probability distribution at sites in the Damanganga Basin. Moreover, discharges were estimated for various return periods using GEVI and LP-III. The recurrence interval of the largest peak flood on record (Qmax) is 107 years (at Nanipalsan) and 146 years (at Ozarkhed) as per LP-III. Flood Frequency Curves (FFC) specifies that LP-III is the best-fitted probability distribution for FFA of the Damanganga Basin. Therefore, estimated discharges and return periods by LP-III probability distribution are more reliable and can be used for designing hydraulic structures.
This paper points to changes of the coastline using two ways, calculating the annual rate of erosion using 1) radioactive materials and 2) GIS and DSAS extension. Finally, both results were verified. Radioactivity results indicate both erosion and accretion zones, the annual scavenging rate in Promontory area shows that it is presented main accretion area, unlike the results of the DSAS extension, which showed that the Promontory is erosion area. The Burullus area annual scavenging rate results showing erosion, despite results of DSAS, it shows that it is an accretion area, but this was clarified by calculating the average distance between the shoreline of 2017 and 2018, and the 2018 shoreline retreat with an average distance 41.4 cm, which makes the Burullus region suffer from erosion. Two methods showed similarity in results in the Edco area, which shows that the Edco area suffers from erosion.
In the last decades, Adama city has experienced drastic changes in its shape, not just in its vast geographical expansion, but also by internal transformations. Subsequently, understanding and evaluating the spatiotemporal variability of urban land use and land cover (LULC) shifts, and it is important to bring forth the right strategies and processes to track population development in decision-making. The goal of this analysis was therefore to examine LULC changes that have taken place over 37 years, forecast the long-term urban development in Adama City using geospatial techniques. To attain this, satellite data of Landsat 1973, 2000 and 2010 was downloaded from USGS Earth Explorer and processed using Arc GIS 10.5, Erdas 9.2, and Idrisi 32. A supervised classification technique has been used to prepare the base maps with six land cover classes that are accustomed to generate LULC maps. The maps are cross-tabulated to measure LULC changes, to look at land-use transfers between the land cover classes, to spot increases and declines in built-up areas in comparison to other land cover classes, and to determine the spatial changes in built-up areas. Finally, Markov Chain and CA-Markov techniques were used to model the LULC changes in the Adama district and to forecast possible changes in urban land use. The model was verified by the Kappa statistics and also by the application of other validation techniques. The growth of built-up areas in the last 37 years has risen from 2% in 1973, 10% in 2000 and 23% in 2010 and estimated about 60% over the next 30 years (2040).
Monitoring and measurement of urban growth pattern with the help of urban-rural gradient and spatial metrics are gaining significant importance in recent times. Rapid and unplanned urban growth has a great impact on natural resources, local ecology, forestry and infrastructure. Temporal satellite data, gradient analysis and landscape metrics of urban landscapes will help to evolve appropriate strategies for integrated planning and sustainable management of natural resources. This communication focuses on spatiotemporal patterns of land use dynamics of Howrah Municipal Corporation (HMC), India and its surroundings with six buffer zones of 2kms. Analysis has been carried out on HMC using temporal remote sensing data. HMC has been used to identify the changes in the gradient of urban to peri-urban and rural regions. Further, the entire study area has been divided into eight zones radiated from city center based on directions. Different landscape metrics have been computed for each zone which helps to understand the spatiotemporal patterns and associated dynamics of the landscape at local levels.