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Comprehensive use of multi-source remote sensing data, the method of combining object-oriented image analysis and visual interpretation was used to interpret the land use or cover of Huainan mining area in 2007, 2010, 2013, 2016 and 2019. Through the calculation of statistics, dynamic degree, diversity index, utilization degree index and transfer matrix for each land use or cover type area and its proportion, the spatial and temporal change characteristics of land use or cover in Huainan mining area between 2007 and 2019 were analyzed. The results show as follows. The area and proportion of cultivated land in Huainan mining area has been declining continuously, a large number of cultivated land were destroyed, resulting in soil erosion, followed by urban and industrial land, and occupied by solid waste. The order of dynamic degree of all land use or cover types was waterlogging subsidence area > lake reservoir > solid waste > industrial and mining land > forest land > bare land > urban land > road > cultivated land > rural residential land, indicating that coal mining activities have a great impact on land use in mining areas. All mine land use or cover types were disturbed by human activities, and the land use diversity index and land use degree index increased. [ABSTRACT FROM AUTHOR]

This paper presents a methodological alternative to analyze land use trajectories. It takes as a case study and prototype an analysis of changes in land use at a general level in Argentina (the Pampas region, the Northwest, the Northeast, and Cuyo, excluding the Patagonia). The objective is to obtain a map with the highest possible resolution that allows to detect the following situations: 1) areas of recent agrarian frontier expansion; 2) areas of “consolidated” agriculture, and 3) areas of recent urban expansion. This paper focuses especially on the development of the applied methodology and a first attempt to validate it. Based on data from the European Space Agency (ESA) linked to the "Climate Change Initiative-Land" (ESA-CCI-LC) for the 1992-2020 period, a clustering of land use trajectories from distances is generated by means of editing distances (used for sequence analysis). There were 29 types of pixel-level trajectories obtained, validated by visual analysis, with an acceptable performance for detection of different trajectories. [ABSTRACT FROM AUTHOR]

Due to their frequency and magnitude, urban floods affect different regions of the world. For this reason, several methodologies integrate information on hazard (H) and vulnerability (V) using a «Classic» Risk (R) model for risk analysis. However, this combination of variables generally overestimates the risk in places where the frequency of flooding is low. In this work we propose a model that we call «Adjusted Risk» (AR) that integrates values of urban proximity (p) to bodies of water, as a tool to assess the risk of floods. The comparison between the R and AR models showed a higher efficiency of AR to reproduce the frequency of floods for 210 cities in Veracruz, while R overestimated the level of risk in cities with low frequency of floods. The correlation values associated with the frequency of flood events for a period of 45 years (1970-2015), allow to establish the utility of the AR model to evaluate the risk of urban floods when using different scales of analysis. [ABSTRACT FROM AUTHOR]

The cultivation of watermelons has been a fast growing agriculture industry in the arid, desert regions of Morocco, relying on groundwater pumping and transformation of rangelands to farms due to growing demand for the fruit in national and international markets. This study aims to measure the impact of watermelon expansion on groundwater resources in the Feija Basin, which is one of the largest watermelon cultivation areas in Southern Morocco. Field measurements, statistics, Kriging interpolation, and regression methods were used to measure the temporal variations in the groundwater level (GL) and salinity between 2013 and 2018 to determine the correlation between different parameters. Remote sensing data was also used to monitor the watermelon cultivation expansion. Results show a rapid expansion of agricultural areas from just 185.11 ha in 2007 to 2560.1 ha in 2018. The groundwater level declined rapidly by about 10 m below ground level during the 5 years of the study period. Additionally, the decline was accompanied by a significant increase in electrical conductivity (salinity) values over the same time interval from 1077.55 to 1211.9 µS/cm. As a consequence of the continuous overexploitation and unsustainable management, a lot of wells have run dry and there have been drinking water shortages in the city of Zagora, the closest city nearby. Results can help target efforts to improve the implementation of conservation strategies to ensure the sustainability of water use and food production in this region of Morocco. [ABSTRACT FROM AUTHOR]

Lamu archipelago is endowed with rich biodiversity including Kenya's largest continuous acreage of mangroves (approx. 33,000 ha) among other ecosystems making it a hotspot for management and conservation efforts. Yet, the involvement of the local community in management in this area is still in its infancy, with threats from large-scale developments, population growth, and climate change on the rise. Here, the structural status of the mangroves around Pate Island and Kiunga Marine National Reserve (KMNR) was assessed and information applied to guide and promote community-based conservation, as well as the development of the national mangrove management plan. Stratified and random spot sampling was used to collect vegetation data and mapping undertaken to estimate the mangrove cover change between 1995 and 2014. There was a loss in mangrove cover of up to 22.6% over 19years. A substantial loss was associated with illegal selective harvesting outside the KMNR, some clear-cutting to pave way for large-scale development and natural mortality of overgrown mature trees within the KMNR. In particular, natural mortality was found to hinder natural regeneration within the KMNR. The results however showed a generally stable system with potentially sustainable levels of natural regeneration and recoveries in isolated patches. These results reveal two management actions: raising awareness of mangrove ecosystems' ecological value and controlling old-growth harvesting in the KMNR to facilitate natural regeneration and development of young vigorous forest through gap creation. This information provides a strong foundation for conservation planning including future mangrove restoration and conservation activities. A comprehensive coordinated conservation strategy that links conservation to communities, livelihoods, and governance frameworks is recommended. • Loss in mangrove cover of up to 22.6% reported over a period of 19 years. • Natural regeneration potentially sufficient to sustain the forest but selective harvesting led to structural imbalance. • Natural mortality of mainly overgrown mature trees noted within the Reserve. • Need for a well-coordinated strategy linking conservation to communities, livelihoods and governance framework. [ABSTRACT FROM AUTHOR]

The ecological environment and water resources of the Han River Basin (HRB) are incredibly susceptible to global warming. Naturally, the analysis of future runoff in HRB is believed to offer a theoretical basis for water resources management and ecological protection in HRB. The purpose of this study is to investigate and forecast the effects of climate change and land use change on runoff in the HRB. This study uses CMIP6 data to simulate three future climate change scenarios (SSP126, SSP245 and SSP585) for changes in precipitation and temperature, a CA-Markov model to simulate future land use change scenarios, and the Budyko framework to predict future runoff changes. The results show that: (1) Between 1974 and 2014, annual runoff ( R ) and annual precipitation ( P ) in the HRB decline not so significantly with a rate of 1.3673 mm/a and 1.2709 mm/a, while maximum temperature ( Tmax ) and minimum temperature ( Tmin ) and potential evapotranspiration ( E 0 ) show a non-significantly increasing trend with 0.0296 °C/a, 0.0204 °C/a and 1.3313 mm/a, respectively. Precipitation is considered as main contributor to the decline in Han River runoff, accounting for 54.1%. (2) In the HRB, overall precipitation and temperature are estimated to rise in the coming years, with all other hydrological variables. The comparison of precipitation rise under each scenario is as follows: SSP126 scenario > SSP585 scenario > SSP245 scenario. The comparison of the temperature increase under each scenario is as follows: SSP585 scenario > SSP245 scenario > SSP126 scenario. (3) In the HRB, farmland and grassland land will continue to decline in the future. The amount of forest acreage is projected to decline but not so significantly. (4) The future runoff of the HRB shows an increasing trend, and the future runoff varies in different scenarios and periods. Under the land use scenarios of maintaining LUCC1992-2014 and LUCC2040 and LUCC2060, the R change rates in 2015-2040 are 8.27-25.47% and -8.04-19.35%, respectively, and the R in 2040-2060 are 2.09-13.66% and 19.35-31.52%. At the same time, it is very likely to overestimate the future runoff of the HRB without considering the changes in the land use data of the underlying surface in the future.